Attachment spindle device for use in machine tools

Abstract

The present invention relates to an attachment spindle arrangement for use on a machine tool, comprising a fixed connection part 12 for fixing the attachment spindle arrangement to a working spindle of the machine tool, an attachment spindle part 14 with a spindle 14a for driving a drilling tool fixed to the spindle 14a, a drive part 15 for applying a force to the attachment spindle part 14, and an electromagnetic actuator 16 for applying a force to the attachment spindle part 14 that is opposite and balances the force of the drive part 15.

Description

[Technical field]

[0001] The present invention relates to an anterior spindle device (Vorsatzspindelvorrichtung) for use in a machine tool, a system including an attachment spindle device, a method for controlling an attachment spindle device, and a computer program product for performing the method for controlling an attachment spindle device. [Background technology]

[0002] In the prior art, attachment spindle devices are used in machine tools, particularly when the spindle of the attachment spindle device in the machine tool is rotated by the machine part. To be floated It is known for use in drilling. The machine part includes a mechanical spring that exerts a spring force on the spindle when a weight plate is placed on it, and the spindle is adjusted by adjusting the spring force with an adjustment screw. Floating position When the indicator is turned with the dial gauge's adjustment screw until the dial gauge reaches zero, it determines the maximum distance that corresponds to a given force. When this value is reached, the machine tool spindle is released so that the machine tool can perform its drilling operation.

[0003] In the case of the attachment spindle arrangement as described above, it has been found that having to manually apply a weight to the attachment spindle arrangement is not practical, since the application of the weight repeatedly interrupts the drilling process. Moreover, the structure of the attachment spindle arrangement is unnecessarily enlarged by the mechanical parts, thereby limiting the working space of the working spindle of the machine tool. By manually applying the weight, control of the attachment spindle arrangement cannot be performed by the attachment spindle arrangement. Summary of the Invention [Problem to be solved by the invention]

[0004] Starting from the attachment spindle arrangements in the prior art, the object of the present invention is to optimise the structure of an attachment spindle arrangement for use in a machine tool.

[0005] In order to solve the above problem, an attachment spindle arrangement is proposed according to claim 1. The dependent claims relate to preferred exemplary embodiments of the invention.

[0006] According to the invention an attachment spindle arrangement is proposed for use in a machine tool, said attachment spindle arrangement comprising a fixed connection part for fixing said attachment spindle arrangement to a working spindle of the machine tool, an attachment spindle part with said spindle for driving a drilling tool fixed to the spindle, a drive part for applying a force to said attachment spindle part, and an electromagnetic actuator for applying a balancing force to said attachment spindle part counter to the force of the drive part.

[0007] This has the advantage that the structure of the attachment spindle arrangement is kept compact due to the electromagnetic actuator, while the functionality of the counterforce to the drive force is still maintained. This results in drilling with a form that ensures that the drilling can be performed with a constant force by the attachment spindle arrangement and that small holes can be produced particularly well.

[0008] In an advantageous exemplary embodiment, the electromagnetic actuator is adapted to move the attachment spindle arrangement to the workpiece with the spindle axis vertical and the drilling tool pointing downwards. The attachment spindle portion is configured to apply a counterbalancing force corresponding to the weight of the attachment spindle portion when secured to the work spindle of a machine tool.

[0009] In an advantageous exemplary embodiment, the electromagnetic actuator is adapted to rotate the attachment spindle part when the attachment spindle arrangement is fixed to the work spindle of the machine tool with the spindle axis vertical and the drilling tool pointing downwards. Floating position The attachment spindle is configured to apply a counterbalancing force corresponding to the weight of the attachment spindle such that

[0010] This has the advantage that the drilling process can be carried out particularly steadily and the attachment spindle part can drill precisely, so that small holes can be drilled particularly accurately.

[0011] In an advantageous exemplary embodiment, the attachment spindle arrangement includes a housing in which the attachment spindle part is mounted so as to be movable parallel to the spindle axis of the spindle.

[0012] The configuration of the attachment spindle device is kept particularly stable by the housing, so that the drilling process can be performed precisely by the attachment spindle device.

[0013] In an advantageous exemplary embodiment, the attachment spindle part is movably mounted on a guide extending parallel to a spindle axis of the spindle.

[0014] In an advantageous exemplary embodiment, the spindle includes an openly accessible tool receiving portion on one side of the housing for receiving a drilling tool.

[0015] In an advantageous exemplary embodiment, the fixed connection is arranged on a face of the housing facing away from the tool receiving portion of the spindle.

[0016] In an advantageous exemplary embodiment, the drive portion functions to apply a force to the attachment spindle portion in a direction parallel to the spindle axis of the spindle, in particular in a direction away from the fixed connection portion and / or towards the tool receiving portion of the spindle.

[0017] In an advantageous exemplary embodiment, the electromagnetic actuator functions to apply a balancing force to the attachment spindle part in a direction parallel to the spindle axis of the spindle, in particular towards the fixed connection part and / or away from the tool receiving part of the spindle.

[0018] In an advantageous exemplary embodiment, the fixed connection part is arranged in such a way that, when the fixed connection part is fixed on the working spindle of the machine tool, the spindle axis of the spindle is oriented parallel to, in particular coaxially with, the spindle axis of the working spindle of the machine tool.

[0019] In an advantageous exemplary embodiment, said drive comprises a linear motor.

[0020] In an advantageous exemplary embodiment, the linear motor is configured to move the attachment spindle portion to apply a force.

[0021] In an advantageous exemplary embodiment, the drive is adapted to determine the position of the drive and / or the drive The position measuring means is adapted to determine a change in distance (Wegänderung) of the moving part.

[0022] In an advantageous exemplary embodiment, the attachment spindle device includes a transmitter for transmitting a signal to a controller of the machine tool, the transmitter being configured to control a feed movement of the working spindle of the machine tool in the direction of a spindle axis of the working spindle.

[0023] This has the advantage that the drilling process is controllable and can be performed automatically using the attachment spindle arrangement, which optimizes the drilling process and allows the machining of a large number of accurately machined holes in a shorter time.

[0024] In an advantageous exemplary embodiment, the transmitter is configured to transmit a control signal to the controller of the machine tool, the control signal being indicative of all forces acting on the attachment spindle part and / or position or distance changes of the attachment spindle part and / or the drive part.

[0025] In an advantageous exemplary embodiment, the transmitting unit is configured to receive a setting signal, in particular a setting signal indicating a target value, from the controller of the machine tool, and the drive unit is configured to apply a force to the attachment spindle unit that is set based on the setting signal.

[0026] This has the advantage that the amount of force can be defined in the drilling program and can also be adjusted during processing, allowing control for precise drilling where multiple holes can be drilled in an optimized manner.

[0027] In an advantageous exemplary embodiment, the spindle comprises an ultrasonic generator configured to generate ultrasonic vibrations of the spindle, in particular parallel to a spindle axis of the spindle.

[0028] In an advantageous exemplary embodiment, said spindle comprises an internal coolant supply line, in particular in the form of a hole, for guiding a coolant.

[0029] This has the advantage that the attachment spindle arrangement can be cooled during machining and the drilling process can be carried out smoothly, therefore defects due to heating are reduced or completely avoided.

[0030] In an advantageous exemplary embodiment, the fixed connection comprises a hollow shank taper interface.

[0031] In an advantageous exemplary embodiment, the attachment spindle apparatus includes a housing having a first housing half and a second housing half, the attachment spindle portion and the electromagnetic actuator being disposed within the first housing half.

[0032] In an advantageous exemplary embodiment, the attachment spindle arrangement includes a first end and a second end, an intermediate plate is disposed between the first half of the housing and the second half of the housing, and a guide rod is disposed within the first half of the housing from the intermediate plate to the second end for guiding the attachment spindle portion within the first half of the housing.

[0033] In an advantageous exemplary embodiment, the attachment spindle part comprises a first plate and a second plate. the attachment spindle portion further includes at least one hollow cylinder disposed between the first plate and the second plate for connecting two plates, the spindle being fixed to the first plate, and the at least one hollow cylinder being radially symmetrically disposed around the spindle.

[0034] In an advantageous exemplary embodiment, the drive part is arranged in the second half of the housing and includes a rotor for moving the spindle parallel to the spindle axis of the spindle, the rotor of the drive part being fixed to the second plate of the attachment spindle part.

[0035] In an advantageous exemplary embodiment, the electromagnetic actuator includes a stator and a rotor, the stator of the electromagnetic actuator being arranged on the attachment spindle portion and the rotor of the electromagnetic actuator being arranged on the housing and the intermediate plate.

[0036] This has the advantage that the structure of the attachment spindle arrangement is kept particularly compact, the drilling process is carried out steadily and the holes are drilled with high precision.

[0037] According to the invention, a system is proposed, said system comprising a numerically controlled machine tool with a working spindle and an attachment spindle device according to one of the above mentioned advantageous exemplary embodiments received in said working spindle.

[0038] In an advantageous exemplary embodiment, the machine tool includes a controller configured to control a feed movement of the work spindle of the machine tool in the direction of a spindle axis of the work spindle, and the attachment spindle device includes a transmitting unit for transmitting a signal to the controller of the machine tool.

[0039] In an advantageous exemplary embodiment, the transmitter is configured to transmit a control signal to the controller of the machine tool, the control signal being indicative of all forces acting on the attachment spindle part and / or position or distance changes of the attachment spindle part and / or the drive part.

[0040] In an advantageous exemplary embodiment, the controller of the machine tool is configured to control or adjust the feed rate of the work spindle based on a control signal received from the transmitter of the attachment spindle device.

[0041] In an advantageous exemplary embodiment, the controller of the machine tool is configured to transmit a setting signal indicative of a desired force, in particular a setting signal indicative of a target value, to the transmitter of the attachment spindle device, the transmitter being configured to receive the setting signal from the controller of the machine tool, and the drive being configured to apply the set force to the attachment spindle part based on the setting signal.

[0042] According to the invention, a method for controlling a drilling process performed on a machine tool with a working spindle using an attachment spindle device according to one of the above-mentioned exemplary embodiments is proposed, said method comprising the steps of: activating the electromagnetic actuator of the attachment spindle device in order to apply a balanced force to the attachment spindle part of the attachment spindle device when the attachment spindle device is fixed to the working spindle of the machine tool with the spindle axis vertical and a drilling tool pointing downwards; driving the drive of the drilling tool fixed to the spindle of the attachment spindle device; moving the working spindle to a workpiece; and performing a hole drilling operation on the workpiece using a hole drilling tool driven by the spindle of the attachment spindle device, wherein performing a hole drilling operation on the workpiece includes controlling a feed motion of the working spindle in a hole drilling direction when the electromagnetic actuator of the attachment spindle device is driven and when a force opposite to the balancing force of the electromagnetic actuator is applied by the drive unit of the attachment spindle device.

[0043] According to the invention a computer program product is proposed, said computer program product comprising instructions which, when said program is executed by a computer connected to a numerically controlled machine tool or by a controller of the numerically controlled machine tool, cause said computer or said controller to execute a method for controlling a drilling process performed on a machine tool with a working spindle by means of an attachment spindle device according to one of the abovementioned exemplary embodiments. [Brief description of the drawings]

[0044] [Figure 1a] FIG. 1a shows an exemplary projection view of a first exemplary embodiment of an attachment spindle arrangement for use in a machine tool according to the present invention. [Figure 1b] FIG. 1b shows a further exemplary projection view of the first exemplary embodiment of an attachment spindle arrangement for use in a machine tool according to the invention. [Figure 2a] FIG. 2a shows an exemplary projection view of a second exemplary embodiment of an attachment spindle arrangement for use in a machine tool according to the present invention. [Figure 2b] FIG. 2b shows a further exemplary projection view of a second exemplary embodiment of an attachment spindle arrangement for use in a machine tool according to the present invention. [Figure 2c] FIG. 2c shows a further exemplary projection view of a second exemplary embodiment of an attachment spindle arrangement for use in a machine tool according to the present invention. [Diagram 3] FIG. 3 shows a further exemplary projection of the attachment spindle arrangement to illustrate the forces exerted by the attachment spindle arrangement according to the invention. [Figure 4] FIG. 4 shows an exemplary projection view of a system including a machine tool and an attachment spindle arrangement according to FIGS. 1a and 1b or 2a-2c. [Diagram 5] FIG. 5 shows a flow chart for explaining a method for controlling a drilling process carried out by a machine tool having a work spindle using an attachment spindle arrangement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] Examples or embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which the same or similar elements are designated with the same reference numerals, but sometimes with different reference numerals, in which:

[0046] It should be emphasized that the present invention is in no way restricted or limited to the exemplary embodiments and their implementation features described below, but instead further includes variations of the exemplary embodiments, in particular those that are included within the scope of the independent claims by variations of the features of the described examples or by one or more combinations of the features of the described examples.

[0047] 1a shows a projection view of an exemplary construction of an attachment spindle device 10, which includes a fixed connection part 12 for fixing a working spindle of a machine tool at a first end face 12a and a tool receiving part 21 for fixing a tool at a second end face 12b arranged opposite to the first end face 12a. The fixed connection part 12 for fixing a working spindle of a machine tool is configured, for example, as a hollow shank taper tool connection part.

[0048] The attachment spindle device 10 includes a first housing half 13a and a second housing half 13b. and a housing 13 divided into a first half 13a and a second half 13b of the housing, an intermediate plate 13a1 being disposed between the first half 13a and the second half 13b of the housing, a second end 12b having a tool receiving portion being disposed in the first half 13a of the housing, and a first end 12a having a fixed connection portion 12 disposed in the second half of the housing.

[0049] The attachment spindle unit 14 of the attachment spindle device 10 is arranged in the housing 13 and configured to be movable. The attachment spindle unit 14 includes a spindle 14a, which includes, for example, an ultrasonic generator for generating ultrasonic vibrations generated parallel to the spindle axis of the spindle 14a. Thus, the spindle 14a is configured as an ultrasonic spindle.

[0050] The attachment spindle device 10 further comprises a drive 15, which is arranged, for example, in the second housing half 13b. The drive 15 may be configured, for example, as a linear motor, but also as any other conceivable type of drive. The drive 15 is configured to apply a predetermined force to the attachment spindle part 14.

[0051] The attachment spindle device 10 further includes an electromagnetic actuator 16, which is arranged, for example, in the first half 13a of the housing. The electromagnetic actuator 16 is arranged to rotate the attachment spindle part 10 in response to a force applied by the drive part. The electromagnetic actuator 16 is configured to apply a counterbalancing force to the attachment spindle portion 14. The electromagnetic actuator 16 may be configured, for example, as a magnetic spring that rotates the attachment spindle portion 14 by the applied counterbalancing force. Floating position While the drive unit 15 applies a force to the attachment spindle unit 14, the electromagnetic actuator 16 rotates the attachment spindle unit 14 with a counterbalancing force applied. Floating position The electromagnetic actuator 16 may be configured, for example, as a permanent magnet with a steel core. The electromagnetic actuator 16 may be configured, for example, as a coil that applies a magnetic force to the attachment spindle portion 14 by induced current. The electromagnetic actuator is not limited to this embodiment and may be configured in any form so that a magnetic or electromagnetic force is applied to the attachment spindle portion 14.

[0052] A tool receiving part 21 configured for fastening a tool is arranged on the second end face 12b of the attachment spindle device 10. For example, a hollow drill 18a with an ejector unit 18 can be fastened to the tool receiving part 21 for performing drilling operations. The ejector unit 18 is configured in such a way that drill cores collected in the hollow drill 18a during the drilling operation and formed during the drilling operation are ejected by an ejection force applied by the ejector unit 18, so that the hollow drill 18a is freed from the resulting drill cores. The ejection force applied by the ejector unit 18 can be applied, for example, by electromagnetic force.

[0053] Figure 1b shows the attachment spindle arrangement 10 shown in Figure 1a in cross section, with the cross section being taken at the central axis of the attachment spindle arrangement 10. The components of the attachment spindle arrangement 10 already described in Figure 1 are similarly arranged in Figure 1b.

[0054] The attachment spindle part 14 comprises a first annular plate 19a, a second annular plate 19b and at least one hollow cylinder 11 arranged in the first housing half 13a. The attachment spindle part 14 shown in FIG. 1b comprises, for example, three hollow cylinders 11. The first annular plate 19a is arranged parallel to the second annular plate 19a in the first housing half 13a, and the first annular plate 19a is connected to the two annular plates 19a, 19b by a hollow cylinder 19c arranged perpendicularly. The guide rods 22 pass through the hollow cylinders 11. The spherical guide is arranged in the hollow cylinder 11 and extends from the intermediate plate 13a1 to the second end face 12b of the attachment spindle device 10. The spherical guide is arranged in the hollow cylinder 11 such that the attachment spindle part 14 can be guided on the guide rod 33. In the first half 13a of the housing, the attachment spindle part 14 is guided in the axial direction of the spindle axis of the spindle 14a. The attachment spindle part 14 is therefore arranged to move freely in the axial direction of the spindle 14a in the first half 13a of the housing. The guide rod 33 extends inside the hollow cylinder 11 and is arranged parallel to the hollow cylinder 11.

[0055] The spindle 14a is disposed in a first annular plate 19a of the attachment spindle part 14. The spindle 14a is arranged to be disposed in two annular plates 19a, 19b parallel to the hollow cylinder 11, and the two annular plates 19a, 19b are disposed perpendicular to the spindle 14a. The hollow cylinder 11 and the guide rod 33 extending through the hollow cylinder 11 are disposed radially symmetrically about the spindle 14a.

[0056] The electromagnetic actuator 16 includes a rotor 16a and a stator 16b. The stator 16b of the electromagnetic actuator 16 is disposed on the second annular plate 19b of the attachment spindle section 14. The rotor 16a is fastened to the intermediate plate 13a1 and the second end face 12b of the attachment spindle device 10, and the rotor 16a of the electromagnetic actuator 16 extends inside the stator 16b of the electromagnetic actuator 16. The rotor 16a of the electromagnetic actuator 16 is fixedly disposed on the intermediate plate 13a1 and the second end face 12b of the attachment spindle device 10, while the stator 16b of the electromagnetic actuator 16 is disposed on the attachment spindle section 14, which is freely movable in the axial direction of the spindle shaft of the spindle 14a.

[0057] The drive unit 15 includes a rotor 15a, which is movable in one direction. The drive unit 15 may be configured, for example, as a linear motor, but may also be configured as any other conceivable type of drive unit. The drive unit 15 is arranged in the second half 13b of the housing, and the rotor 15a of the drive unit 15 is fastened to the second annular plate 19b of the attachment spindle unit 14. In the drilling process, the rotor 15a of the drive unit 15 fastened to the second annular plate 19b applies a predetermined force to the attachment spindle unit 14 in the drive unit 15, so that a predetermined force is applied to the attachment spindle unit 14. While the drive unit 15 applies the predetermined force to the attachment spindle unit 14, the electromagnetic actuator 16 applies a counterbalancing force to the attachment spindle unit 14, so that the attachment spindle unit 14 moves in the direction of the axis ... Floating position It becomes.

[0058] The hollow drill 18a fixed on the tool receiving part 21 includes an ejection part 18 configured to eject a drill core. The ejection part 18 includes, for example, a first coil, a second coil, a circuit board, an electromagnetic switch, a voltage source, a magnet, and an ejector. The ejector is arranged on, for example, a rod-shaped or spherical magnet of neodymium.

[0059] By supplying a current to the first coil, the first coil is excited and an ejector attached to the magnet is moved to a first position. The second coil is driven by supplying a current to the second coil. The ejector is moved to a second position by stopping the current supply to the first coil and driving the second coil. If the first position is defined as the start position, this position clearly indicates a state in which the hole drilling process is being performed. After the hole drilling process is completed, the current supply to the first coil is stopped and the second coil is driven, so that the ejector is moved from the first position to the second position. The drill core generated during the hole drilling process is ejected by moving the ejector from the first position to the second position. After the drill core is ejected, the current supply to the second coil is stopped and the first coil is driven. Thus, the ejector is moved to the first position.

[0060] The ejection unit 18 can be controlled by the control unit. When the ejection unit 18 is driven, the duration and frequency of the ejector can be controlled and / or adjusted. In the drilling process with a hollow drill, the drill core generated in the drilling process causes interruptions in the machining process, since the hollow drill can become clogged or reach the machining area of ​​the machine tool. The above-mentioned ejection unit 18 has the advantage that the drill core is ejected in a controlled manner. The clogging of the hollow drill is reduced or avoided by the ejection unit 18. The ejection unit 18 prevents the drill core from being ejected into the machining area of ​​the machine tool by ejecting it far enough and in a controlled manner. By controlling the ejection of the drill core, the drilling process is optimized, since interruptions are avoided. By the control, the drilling process can be further automated and the drilling process can be performed steadily. When manufacturing many small holes, the production is further optimized and the machine tool is less prone to malfunction.

[0061] The spindle 14a of the attachment spindle part 14 includes an internal coolant supply line 17 configured to introduce a coolant. The internal coolant line is configured, for example, as a hole. The coolant is, for example, supplied to the attachment spindle device 10 from the outside and passes through a connection with the internal coolant supply line. The supply of the coolant can, for example, be controlled from the outside.

[0062] Figure 2a shows a second exemplary embodiment of the attachment spindle apparatus 10. Identical or corresponding features or parts of the attachment spindle apparatus 10 are provided with the same reference numerals as in Figures 1a and 1b. The following description will particularly address further features, and identical or similar features will not be described again.

[0063] The attachment spindle device 10 includes, for example, a coupling portion 10a configured to couple the attachment spindle device 10 to a machine tool. The coupling portion 10a includes, for example, a number of connection portions 10a1 that interact with corresponding contacts or connections of the machine tool when the attachment spindle device 10 is connected to the machine tool.

[0064] The attachment spindle arrangement 10 may be coupled to a machine tool or a work spindle of a machine tool by a coupling 10a, so that, for example, the attachment spindle arrangement 10 can be controlled via the machine tool or its machine control.

[0065] For this purpose, the connection part 10a1 includes, for example, electrical contacts for power supply and for the transmission of control signals (e.g. for drives, motors and / or other electrical or electromagnetic or piezoelectric actuators) or possibly also for the backtransmission (backtransmission) of any detection signals to a machine controller.

[0066] The connection portion 10a1 may further include, for example, electrical, pneumatic and / or hydraulic connections for the attachment spindle device 10.

[0067] The attachment spindle arrangement 10, the attachment spindle section 14, the spindle 14a, and the exhaust section 18 may be supplied by a coupling section 10a. For example, the coupling section 10a may be configured such that a coolant is supplied to the attachment spindle arrangement via the coupling section 10a.

[0068] The ejector 18 is connected to the first half 13a of the housing of the attachment spindle device 10, for example, via a support 18c. The ejector 18 may be held via the support 18c and may be supplied or controlled, as required, for example, by means of electrical current and control signals. This is also fine.

[0069] Figure 2b shows the attachment spindle arrangement 10 of the second exemplary embodiment from a different perspective than in Figure 2a. The attachment spindle arrangement 10 comprises a coupling part 10a with a connection part 10a1 as already explained in Figure 2a.

[0070] The coupling part 10a is, for example, arranged laterally in the second housing half 13b of the attachment spindle device 10. The coupling part 10a is, for example, connected at a right angle to the second housing half, the coupling part 10a being, for example, L-shaped, so that the connection part 10a1 is, for example, arranged parallel to the spindle 14a.

[0071] Fig. 2c shows the attachment spindle arrangement 10 of Fig. 2a and Fig. 2b in cross section. The attachment spindle arrangement comprises an attachment spindle part 14 with a spindle 14. The spindle 14 comprises an actuator 14b configured, for example, to generate ultrasonic movement or ultrasonic vibrations of the spindle 14. The actuator 14b is configured, for example, such that the spindle 14a is configured as an ultrasonic spindle. The actuator 14b may comprise, for example, a piezoelectric actuator.

[0072] For example, the attachment spindle arrangement is configured such that the guide rod 33 is fastened to the intermediate plate 13a1 and to the support part 18c. The discharge part 18 is advantageously stabilized by the connection of the support part 18c to the guide rod 33.

[0073] FIG. 3 shows an attachment spindle arrangement 10 according to one of the exemplary embodiments of FIGS. 1a, 1b, 2a, 2b and 2c, fixed, by way of example, to a work spindle 103 of a machine tool. The work spindle 103 with the fixed attachment spindle arrangement 10 is arranged vertically, for example in drilling. The attachment spindle part 14 is freely movable within the attachment spindle arrangement 10, and a weight force (Gewichtskraft) F_GK acts on the attachment spindle part 14. An electromagnetic actuator 16 of the attachment spindle arrangement 10 exerts a counterbalancing force F_EMA on the attachment spindle part 14 to counteract the weight force F_GK. The magnitude of the counterbalancing force F_EMA of the electromagnetic actuator 16 depends on the amount of force that the attachment spindle part 14 moves. Floating position This is the value that cancels out the gravity F_GK to the extent that

[0074] In drilling (e.g., see FIG. 5 , especially step S6), a work spindle 103 equipped with an attachment spindle device 10 to which a tool, e.g. a hollow drill 18a, is fixed is moved by the work spindle 103 in the direction of a workpiece 107 fixed on a workpiece table 105.

[0075] When the machine tool moves to the workpiece and contacts it for drilling, a drilling force F_BK acts on the attachment spindle device 10. The drive unit 15 of the attachment spindle device 10 applies a force F_A to the attachment spindle unit 14 to counteract the drilling force F_BK. The force applied by the drive unit 15 can be predetermined such that the drive unit 15 counteracts the drilling force F_BK, and the hole can be drilled by the force F_A of the drive unit 15. The force F_A is adjustable and can therefore be adapted to a wide variety of workpieces.

[0076] 4 shows a numerically controlled machine tool 100 with a working spindle 103, in which the attachment spindle arrangement 10 is received. The attachment spindle arrangement 10 can be, for example, as shown in FIGS. 1a, 1b or 2a, 2b, 2c. , and one of the attachment spindle arrangements 10 shown in Figures 1a, 1b or 2a, 2b, 2c, and 3. Components of the attachment spindle arrangement 10 that are identical to components of the attachment spindle arrangement 10 of Figures 1a, 1b or 2a, 2b, 2c, and 3 have the same reference numerals.

[0077] The machine tool 100 comprises a machine base 102 and a machine bed 101 arranged on the machine base 102. The machine bed 101 may, for example, be arranged on the machine base 102 so as to be movable in one or more directions. A work spindle transport 104 carrying a work spindle 103 is arranged on the machine base 101. The work spindle transport 104 may, for example, be movable in one or more directions. The work spindle 103 is driven by a drive 103a. The machine tool 100 further comprises a workpiece bed 105, which is arranged on the machine base 102 with a workpiece fastening means 106 to which a workpiece 107 is fastened. The workpiece bed 105 may, for example, be configured as a rotating bed or as a swivel-rotating bed. The workpiece bed 105 may be arranged on the machine base 102 so as to be movable in one or more directions.

[0078] The machine tool 100 includes a controller 91 configured to make the working spindle 103 perform an axial feed movement. The controller 91 controls a drive 103a of the working spindle 103. The working spindle 103 is, for example, installed vertically, so that the attachment spindle arrangement 10 fixed to the working spindle 103 is arranged vertically. The working spindle 103 and the attachment spindle arrangement 10 are arranged parallel to each other. The controller 91 controls that the working spindle 103 is movable in the direction of the spindle axis of the working spindle 103.

[0079] The attachment spindle device 10 includes a transmitter 93 that transmits a signal to a controller 91 of the machine tool 100. When a force is applied to the attachment spindle part 14 of the attachment spindle device 10 by the drive part 15, the force is detected, for example, by a displacement and / or distance change of the attachment spindle part 14, and the transmitter 93 transmits a control signal to the controller 91 of the machine tool 100. The controller 91 receives this control signal of the transmitter 93 of the attachment spindle device 10 and controls the working spindle 103 of the machine tool 100 to respond to the displacement and / or distance change such that the displacement and / or distance change is compensated.

[0080] In drilling, for example, the attachment spindle unit 14 of the attachment spindle device 10 is driven by an electromagnetic actuator 16. Floating position Next Steps In the drawing, the working spindle 103 of the machine tool 100 moves toward the workpiece 107 arranged on the workpiece table 105 and starts drilling. When the hollow drill 18a is positioned on the workpiece, a predetermined force is applied to the workpiece 107 by the drive unit 15 of the attachment spindle device 10 to drill a hole. The predetermined force is transmitted from the controller 91 of the machine tool 100 to the transmitter 93 of the attachment spindle device 10 by a setting signal, in particular a setting value indicating a target value, and the drive unit 15 is configured to apply the predetermined force based on the setting signal. During the drilling process of the hollow drill 18a, for example, if a reaction force applied by the workpiece 107 itself exceeds the predetermined force by the drive unit 15 of the attachment spindle device 10, the transmitter 93 transmits a control signal to the controller 91 of the machine tool 100, and the controller 91 controls the drive unit 103a of the work spindle 103 to reduce the feed motion.

[0081] The attachment spindle part 14 is driven by an electromagnetic actuator 16. Floating positionThe drilling is performed after the controller 91 transmits a predetermined force to be applied by the drive unit 15 of the attachment spindle device 10 to the transmitter 93 of the attachment spindle device 10. Through the control by the controller 91 of the machine tool 100 and the transmitter 93 of the attachment spindle device 10, the drilling by the attachment spindle device 10 can be controlled and drilling defects can be avoided. For example, a change in distance in the drive unit 15 of the attachment spindle device 10 can be used to measure the amount of force, which can be transmitted by the transmitter 93 of the attachment spindle device 10 to the controller 91 of the machine tool 100, and the drive unit 103a of the work spindle 103 of the machine tool 100 can be controlled to respond to the change in distance.

[0082] Fig. 5 shows an exemplary flow diagram for illustrating a method for controlling a drilling process performed by means of the attachment spindle arrangement 10 on a machine tool 100 with a working spindle 103. The machine tool may be, for example, the machine tool 100 of Fig. 4, but also any controllable machine tool having the attachment spindle arrangement 10 fixed to the working spindle.

[0083] As an example, the drilling process is started in step S1. The drilling process includes step S2 of mounting the attachment spindle device 10, for example with a vertically oriented spindle axis, on the working spindle of the machine tool with the drilling tool pointing downwards. Here, the attachment spindle device 10 is, for example, arranged vertically. The spindle axis of the attachment spindle device 10 is, for example, vertically oriented, so that the hollow drill 18a fixed to the attachment spindle device 10 on the working spindle 103 of the machine tool 100 points downwards.

[0084] In a further step S3, the electromagnetic actuator 16 of the attachment spindle arrangement 10 is activated. In this case, a magnetic field, for example induced by applying a voltage, is generated so that the attachment spindle part 14 of the attachment spindle arrangement 10 Floating position Since the attachment spindle assembly 10 is oriented vertically, the attachment spindle section 14 is pulled down by gravity. The magnetic field generated by the electromagnetic actuator 16 exerts a balancing force upward on the attachment spindle section 14 to compensate for the weight, so that the attachment spindle section 14 Floating position become.

[0085] In a further step S4, a drilling tool (eg hollow drill 18a in FIG. 1b) fixed to the spindle 14a of the attachment spindle device 10 is driven.

[0086] In a further step S5, the working spindle 103 of the machine tool, in which the attachment spindle arrangement 10 with the drilling tool is received, is moved, for example vertically downwards, towards the workpiece 107.

[0087] In a further step S6, a drilling operation is performed in the workpiece by means of a drilling tool driven by the spindle 14a of the attachment spindle device 10.

[0088] In step S6, the feed movement of the work spindle 103 of the machine tool 100 is controlled so that the drilling tool is first moved towards the workpiece 107 (drilling) and then, if necessary, moved away from the workpiece 107 again.

[0089] During the feeding operation, the electromagnetic actuator 16 is actuated, so that the attachment spindle part 14 Floating position The electromagnetic actuator 16 applies a counterbalancing force to the attachment spindle portion 14 to compensate for the forces acting on the attachment spindle portion 14. During the drilling process, a predetermined force is applied by the control portion 91 to the attachment spindle portion 14. The force is applied by the drive part 15 of the dollar device 10, and thus a hole is drilled in the workpiece 107.

[0090] The steps of the methods described above do not have to be performed in the order described, but may be performed in many variations and multiple times.

[0091] The method may be performed by a computer program product including instructions for controlling the drilling process when the program is executed by a numerically controlled machine tool 100 or a computer connected to a controller 91 of the numerically controlled machine tool 100, the drilling process being performed using an attachment spindle arrangement 10 of the machine tool 100 with a working spindle 103 for performing the method.

[0092] The above-mentioned embodiments and examples of the present invention and their advantages have been described in detail with reference to the attached drawings. It should be emphasized again that the present invention is in no way limited or restricted to the above-mentioned exemplary embodiments and their implementation features, but instead further includes variations of the exemplary embodiments, in particular those that are included within the scope of the independent claims by variations of the features of the described embodiments or by one or more combinations of the features of the described embodiments.

Claims

1. 1. An attachment spindle apparatus for use on a machine tool (100), comprising: a fixed connection (12) for fixing the attachment spindle arrangement to a working spindle (103) of the machine tool (100); an attachment spindle portion (14) having a spindle (14a) for driving a drilling tool fixed to the spindle (14a); a drive unit (15) for applying a force to the attachment spindle unit (14); an electromagnetic actuator (16) for applying a force to the attachment spindle portion (14) that is balanced against the force of the drive portion (15); Attachment spindle device comprising:

2. 2. The attachment spindle arrangement of claim 1, wherein the electromagnetic actuator (16) is configured to apply a counterbalancing force corresponding to gravity on the attachment spindle part (14) when the attachment spindle arrangement is fixed to the work spindle (103) of the machine tool (100) with the spindle axis vertical and a drilling tool pointing downwards.

3. 3. The attachment spindle arrangement according to claim 1 or 2, characterized in that the electromagnetic actuator (16) is configured to apply a counterbalancing force corresponding to the gravitational force of the attachment spindle part (14) such that the attachment spindle part (14) is in a floating position when the attachment spindle arrangement is fixed to the work spindle (103) of the machine tool (100) with its spindle axis vertical and a drilling tool pointing downwards.

4. 4. An attachment spindle arrangement according to claim 1, wherein the attachment spindle part (14) is characterised by a housing (13) which is mounted so as to be movable parallel to a spindle axis of the spindle (14a).

5. 5. An attachment spindle arrangement according to claim 4, characterized in that the attachment spindle part (14) is movably mounted on a guide extending parallel to a spindle axis of the spindle (14a).

6. 6. An attachment spindle arrangement according to claim 4 or 5, wherein the spindle (14a) includes an openly accessible tool receiving portion (21) on one side of the housing (13) for accommodating a drilling tool.

7. 7. The attachment spindle device according to claim 6, wherein the fixed connection portion (12) is arranged on a surface of the housing (13) opposite the tool receiving portion (21) of the spindle (14a).

8. 8. An attachment spindle arrangement according to claim 7, characterized in that the drive part (15) functions to apply a force to the attachment spindle part (14) in a direction parallel to a spindle axis of the spindle (14a), in particular in a direction away from the fixed connection part (12) and / or towards the tool receiving part (21) of the spindle (14a).

9. 9. An attachment spindle arrangement according to claim 7 or 8, characterized in that the electromagnetic actuator (16) functions to apply a balancing force to the attachment spindle part (14) in a direction parallel to a spindle axis of the spindle (14a), in particular towards the fixed connection part (12) and / or away from the tool receiving part (21) of the spindle (14a).

10. 10. An attachment spindle device according to claim 1, characterized in that the fixed connection part (12) is arranged such that, when the fixed connection part (12) is fixed to the working spindle (103) of the machine tool (100), the spindle axis of the spindle (14a) is oriented parallel to, in particular coaxially with, the spindle axis of the working spindle (103) of the machine tool (100).

11. Attachment spindle device according to any one of the preceding claims, characterized in that the drive (15) comprises a linear motor.

12. 12. The attachment spindle arrangement of claim 11, wherein the linear motor is configured to move the attachment spindle part (14) to apply a force.

13. 13. An attachment spindle device according to any one of claims 1 to 12, characterized in that the drive (15) comprises position measuring means arranged to determine the position of the drive (15) and / or a change in distance of the drive (15).

14. 14. The attachment spindle device according to claim 1, further comprising a transmitter (93) for transmitting a signal to a controller (91) of the machine tool (100), the transmitter being configured to control a feed movement of the working spindle (103) of the machine tool (100) in the direction of a spindle axis of the working spindle (103).

15. 15. The method according to claim 14, characterized in that the transmitting part (93) is configured to transmit a control signal to the controller (91) of the machine tool (100), the control signal being indicative of all forces acting on the attachment spindle part (14) and / or of position or distance changes of the attachment spindle part (14) and / or of the drive part (15). Attachment spindle device.

16. the transmitting unit (93) is configured to receive a setting signal, in particular a setting signal indicative of a target value, from the controller (91) of the machine tool (100); 16. The attachment spindle device according to claim 14 or 15, characterized in that the drive unit (15) is configured to apply a set force to the attachment spindle unit (14) based on a set signal.

17. 17. An attachment spindle arrangement according to any one of claims 1 to 16, characterized in that the spindle (14a) comprises an ultrasonic generator configured to generate ultrasonic vibrations of the spindle (14a), in particular parallel to a spindle axis of the spindle (14a).

18. Attachment spindle arrangement according to any one of the preceding claims, characterized in that the spindle (14a) comprises an internal coolant supply line (17), in particular in the form of a hole, for introducing a coolant.

19. Attachment spindle arrangement according to any one of the preceding claims, characterized in that the fixed connection (12) comprises a hollow barrel tapered tool connection portion.

20. 20. An attachment spindle arrangement as claimed in any one of claims 1 to 19, characterized in that the attachment spindle arrangement has a housing (13) with a first housing half (13a) and a second housing half (13b), the attachment spindle part (14) and the electromagnetic actuator (16) being arranged in the first housing half (13a).

21. the attachment spindle arrangement includes a first end (12a) and a second end (12b); an intermediate plate (13a1) is disposed between the first half (13a) of the housing and the second half (13b) of the housing; 21. An attachment spindle arrangement according to claim 20, characterized in that a guide rod (33) is arranged in the first housing half (13a) from the intermediate plate (13a1) to the second end (12b) for guiding the attachment spindle part (14) in the first housing half (13a).

22. The attachment spindle portion (14) includes a first plate (19a) and a second plate (19b), the attachment spindle portion (14) further comprises at least one hollow cylinder (11) arranged between the first plate (19a) and the second plate (19b) for connecting the two plates (19a, 19b); Attachment spindle arrangement according to claim 20 or 21, characterized in that the spindle (14a) is fixed to the first plate (19a) and the at least one hollow cylinder (11) is arranged radially symmetrically around the spindle (14a).

23. the drive (15) is disposed in the second half (13b) of the housing and includes a rotor (15a) for moving the spindle (14a) parallel to a spindle axis of the spindle (14a); 23. The attachment according to claim 22, characterized in that the rotor (15a) of the drive part (15) is fixed to the second plate (19b) of the attachment spindle part (14). Attachment spindle device.

24. The electromagnetic actuator (16) includes a stator (16b) and a rotor (16a), 22. The attachment spindle device according to claim 21, characterized in that the stator (16b) of the electromagnetic actuator (16) is arranged in the attachment spindle portion (14), and the rotor (16a) of the electromagnetic actuator (16) is arranged in the housing (13) and the intermediate plate (13a1).

25. 1. A system comprising: A numerically controlled machine tool (100) with a working spindle (103), an attachment spindle arrangement according to any one of claims 1 to 24 received on the work spindle (103); Including, the system.

26. The machine tool (100) comprises a controller (91) configured to control a feed movement of the work spindle (103) of the machine tool (100) in the direction of a spindle axis of the work spindle (103), 26. The system according to claim 25, characterized in that the attachment spindle device includes a transmitter (93) for transmitting a signal to the controller (91) of the machine tool (100).

27. 27. The system according to claim 26, characterized in that the transmitting unit (93) is configured to transmit control signals to the controller (91) of the machine tool (100), the control signals being indicative of all forces acting on the attachment spindle unit (14) and / or position or distance changes of the attachment spindle unit (14) and / or the drive unit (15).

28. 28. The system according to claim 27, characterized in that the controller (91) of the machine tool (100) is configured to control or adjust a feed rate of the work spindle (103) based on a control signal received from the transmitter (93) of the attachment spindle device.

29. the controller (91) of the machine tool (100) is adapted to transmit a setting signal indicative of a desired force, in particular a set value, to the transmitter (92) of the attachment spindle device, 29. The system according to at least one of claims 26 to 28, characterized in that the transmitting unit (93) is configured to receive the setting signal from the controller (91) of the machine tool (100), and the driving unit (15) is configured to apply a set force to the attachment spindle unit (14) based on the setting signal.

30. 25. A method for controlling a drilling process carried out on a machine tool (100) with a working spindle (103) using an attachment spindle device according to any one of claims 1 to 24, comprising the steps of: activating the electromagnetic actuator (16) of the attachment spindle arrangement to apply a balancing force to the attachment spindle portion (14) of the attachment spindle arrangement when the attachment spindle arrangement is fixed to the work spindle (103) of the machine tool (100) with a spindle axis vertical and a drilling tool pointing downwards; A hole punch fixed to the spindle (14a) of the attachment spindle device Driving the drive of the tool; moving said work spindle (103) to a workpiece (107); Drilling a hole in the workpiece (107) using a drilling tool driven by the spindle (14a) of the attachment spindle device; Including, Drilling the workpiece (107) includes controlling the feed movement of the working spindle (103) in the drilling direction when the electromagnetic actuator (16) of the attachment spindle device is driven and when a force opposite to the balancing force of the electromagnetic actuator (16) is applied by the drive part (15) of the attachment spindle device.

31. 1. A computer program product comprising:

31. A computer program product comprising instructions that, when the program is executed by a computer connected to a numerically controlled machine tool (100) or a controller (91) of the numerically controlled machine tool (100), cause the computer or the controller to perform the method according to claim 30.

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