Measuring device for a machine tool

Abstract

Measuring device (1) for a machine tool (18), wherein the measuring device (1) comprises a detection device (2) and at least two measuring probes (3, 4), and wherein the detection device (2) and the measuring probes (3, 4) are designed for wireless signal transmission from at least each of the measuring probes (3, 4) to the detection device (2), characterized in that reception parameters are specified on the detection device (2), wherein the reception parameters are provided for specifying a sequence of non-overlapping time periods (31, 32, 35, 36, 37) in which exactly one of the measuring probes (3, 4) is assigned to each time period (31, 32, 35, 36, 37) such that a signal received in one of the time periods (31, 32, 35, 36, 37) is assigned to the measuring probe (3, 4) of the respective time period (31, 32, 35, 36, 37). 32, 35, 36, 37) is assigned, and that each of the measuring probes (3, 4) is equipped with an electronic unit (6) in which transmission parameters are predefined or adjustable,with which the electronic unit (6) permits the transmission of measured values ​​only in such time intervals (31, 32, 35, 36, 37) that are assigned to a subsequence of the sequence of time intervals (31, 32, 35, 36, 37) whose time intervals (31, 32, 35, 36, 37) are assigned to the respective measuring probe (3, 4), wherein the electronic units (6) of the measuring probes (3, 4) are configured to detect a synchronization signal with which, in each electronic unit (6), the subsequence of time intervals (31, 32, 36) in which the respective measuring probe (3, 4) transmits is synchronized with the sequence of time intervals (31, 32, 36) in which the detection device (2) receives.

Description

[0001] The invention relates to a measuring device for a machine tool according to the preamble of claim 1. State of the art

[0002] Some machine tools are designed to machine two or more workpieces simultaneously. Besides a higher production rate, this can also result in higher achievable manufacturing accuracy. For example, identical or complementary shapes can be produced with tools that are guided along the same spatial axes by shared spindles and shafts.

[0003] In contrast to machining, however, the measuring processes often cannot be carried out simultaneously but only one after the other, individually on each workpiece, which increases the machining times accordingly.

[0004] The state of the art is cited in EP 2 508 839 A1, which relates to a measuring device with a transmitting circuit for the wireless transmission of a measurement signal.

[0005] The invention presents an improved measuring device for machine tools. Purpose and advantages of the invention

[0006] The object of the present invention is to provide a measuring device with which the total dwell time of workpieces in machine tools can be reduced.

[0007] The problem according to the invention is solved by a measuring device for a machine tool with the features of claim 1.

[0008] Preferred and advantageous embodiments of the invention are specified in the dependent claims.

[0009] The invention relates to a measuring device for a machine tool, wherein the measuring device comprises a detection unit and at least two measuring probes. The detection unit and the measuring probes are designed for wireless signal transmission from at least each of the measuring probes to the detection unit.

[0010] The core of the invention consists in the fact that reception parameters are specified at the detection device, wherein the reception parameters are provided for specifying a sequence of non-overlapping time periods in which exactly one of the measuring probes is assigned to each time period such that a signal received in one of the time periods is assigned to the measuring probe of the respective time period, and that each of the measuring probes is equipped with an electronic unit in which transmission parameters are specified or adjustable, with which the electronic unit permits the transmission of measured values ​​only in such time periods that are assigned to a subsequence of the sequence of time periods whose time periods are assigned to the respective measuring probe, wherein the respective electronic units of the measuring probes are designed to detect a synchronization signal with which the subsequence of time periods is determined in each electronic unit.in which the respective measuring probe transmits is coordinated with the sequence of time periods in which the detection device receives.

[0011] The time intervals can follow each other directly in a sequence. A time interval can be provided between time intervals, for example, between each pair of consecutive time intervals. This advantageously compensates for temporal inaccuracies between the detection device and the measuring probes.

[0012] Within such a time interval, for example, transmission from each of the measuring probes to the acquisition unit can be prevented. This time interval can be intended, for instance, to allow signal transmission from the acquisition device to one or more measuring probes, including status information and, in particular, additional synchronization information.

[0013] The acquisition unit can, for example, specify the duration of the time intervals and the number of measuring probes as receiving parameters. If the time intervals for the individual measuring probes follow each other immediately after the synchronization signal, a processing unit, with which the acquisition device may be equipped, can calculate a delay time relatively easily from the duration and number of each individual time interval. This results in a sequence of time intervals to which received measurement signals can be assigned in such a way that the measurement signals can ultimately be assigned to the respective measuring probes 3 and 4 by, for example, the acquisition device 2.

[0014] The measuring probes can be configured to have a transmission parameter for a rank in a predefined sequence, as well as a time interval duration. This allows the electronic unit of each probe to calculate, based on the respective time rank and duration, the time interval in which transmitted measurement data is assigned to that probe, and to allow transmission within that time interval after a synchronization signal. This process can be repeated by means of a re-provided, e.g., periodically occurring, synchronization signal.

[0015] Furthermore, a sequence of time intervals can be predefined such that signals from each probe can be received multiple times, particularly cyclically, after a synchronization signal. Another reception parameter can therefore be, for example, a number of time intervals corresponding to a predefined sequence of probes for cyclic repetitions. This allows multiple time intervals for signal transmission to be permitted for each probe after the synchronization signal. The synchronization signal is provided to trigger reception and transmission; its detection allows a common start time to be determined for the sequence of time intervals in the acquisition device and the subsequences of time intervals in the probes.

[0016] The reception parameters of the sequence of time intervals, as defined in the acquisition device, and the assignment of these time intervals to individual probes, result in multiple subsequences from a single set of time intervals. Each subsequence comprises only the time intervals of its assigned probe. By specifying or adjusting the transmission parameters of each probe to match the values ​​of the reception parameters of the corresponding subsequence on the acquisition device, each probe can be synchronized with the acquisition device. This allows each probe to transmit one or more measurement events precisely within the time interval(s) in which the acquisition device expects a transmission from its assigned probe after receiving the synchronization signal.

[0017] The synchronization signal can, for example, be received from outside the measuring device according to the invention and be provided, for example, by a machine tool. In a preferred embodiment of the invention, the detection device is configured to provide the synchronization signal. This allows the detection device to also transmit transmission parameters to the measuring probes when signaling the synchronization signal.

[0018] Preferably, the measuring probes and, if applicable, the detection device are each equipped with their own power supply, in particular with their own energy storage device such as a battery or accumulator, so that their power supply is also advantageously not restricted in terms of movable mounting and reliability by electrical cable connections and contacts.

[0019] With a measuring device according to the invention, several probes can be operated simultaneously for checking geometric dimensions. Mutual interference between the probes during wireless transmission of measurement data is advantageously avoided because the adjustable transmit and receive parameters allow each probe to be assigned an exclusively usable time period during which, with suitable settings, none of the other probes can transmit and thus cause interference. The measurement process at each probe can be decoupled from the transmission of the measurement event, making it advantageous to use several probes operating independently of each other simultaneously on a machine tool.

[0020] By enabling the transmission of the measuring probes and the reception of the acquisition device, and with appropriate adjustment of the transmission and reception parameters, it can be ensured that no time delay occurs between two or more measuring probes when transmitting measurement signals to the acquisition device. This prevents overlapping time periods of different measuring probes during a measurement operation, in which two or more probes could transmit simultaneously and interfere with each other. A further advantage is that the receiving elements of the acquisition device can be of a comparatively simple design.

[0021] The transmitter parameters of the electronic unit can be adjusted electronically or mechanically at the probes. For manual adjustment by a user, one or more of the probes can have mechanical adjustment elements such as a rotary switch or DIP switches. To prevent accidental adjustments, one or more adjustment elements can be designed so that they are only accessible or adjustable with the aid of a tool, such as a screwdriver. For electronic adjustability, the probes can be designed, for example, to accommodate an electronic memory card, whereby the transmitter parameter values ​​can be defined using an electronic computer system, such as a personal computer or a notebook computer, and saved to the memory card.

[0022] The receiving parameters of the acquisition device are preset at the factory, which simplifies commissioning of the measuring device. Due to its comparatively low susceptibility to interference, it is preferred that the measuring probes and the acquisition unit are designed for wireless signal transmission using infrared light. However, for a wireless connection, the measuring probes and the acquisition unit can also be designed for signal transmission using radio waves.

[0023] Preferably, the signals used by the probes to transmit measurement events are digitally coded signal waveforms. This enables a comparatively reliable transmission of measurement data. A measurement event detectable by one of the probes can be associated with several different data points, which together form a data set. Therefore, it is preferred that the duration of time intervals and the transmission rate for transmit and receive operations can be coordinated at the probes and the acquisition device such that at least one data set can be completely transmitted within a given time interval. Optionally, the amount of data in a data set can also be adjusted at the probe.

[0024] Furthermore, it is preferred that the transmit parameters of the probes and the receive parameters of the sensing device are adaptable to control parameters of a motion controller of a machine tool. An example of such a control parameter is the cycle time of a control cycle of a motion controller. Currently, cycle time values ​​for machine tools are often in the range between 10 milliseconds and 100 microseconds. For the reliable operation of a machine tool, it is preferred that only a relatively small number of control cycles elapse between a probe event and its availability in a motion controller. For this purpose, time intervals in the sensing device and in the electronic units of the probes can be limited, for example, to a maximum of one millisecond.

[0025] Preferably, the measuring probes and the sensing unit are designed for wireless signal transmission from the sensing unit to the measuring probes. For example, transceivers for bidirectional, especially digital, infrared transmission can be integrated into the measuring probes and the sensing unit. This allows the transmission path to be used in both directions and eliminates the need for an additional transmission path.

[0026] Such a design is particularly advantageous when the sensing unit is configured to generate the synchronization signal. For this purpose, the sensing device can be equipped with a reference timer with a predetermined temporal accuracy. Accordingly, the probes are preferably designed for wireless reception of the synchronization signal from the sensing device. This allows the probes to be equipped with comparatively simpler timers. By adjusting the frequency of transmission of the synchronization signal from the sensing device, the accuracy of the synchronization between the probes and the sensing device can be adapted to the specific application of the measuring device. Furthermore, the entire measuring device according to the invention, with a reference timer in the sensing device, can be synchronized with a machine tool more easily.

[0027] To assign touch events to other operating events, particularly to sensor readings on a machine tool, the probes are each equipped with a timer. Upon a touch event, the electronic unit of the respective probe is configured to read the timer and send the value to the acquisition unit. This allows the touch events to be assigned, for example, position data from one or more axes of motion of a machine tool using the time information, thus enabling verification of the conformity between actual and target values ​​of a geometry, e.g., of a tool or a workpiece.

[0028] The acquisition device is preferably designed such that a measured value received within a given time period can be transmitted to a machine tool according to its respective assignment to a measuring probe. For this purpose, the acquisition device can have several signal outputs, with each signal output being assignable to a measuring probe within the acquisition device. Such an assignment can be predefined, for example, for fast transmission. If necessary, the assignment of signal outputs can also be configured. This allows the measuring device according to the invention to be used even in manufacturing areas where flexibility is important.

[0029] Furthermore, it is preferred that the acquisition device has a communication interface, particularly a digital one, designed for data exchange with a machine tool. The communication interface can be, for example, an industrial fieldbus interface or a LAN connection, especially for Ethernet networks. This advantageously facilitates the integration of the measuring device according to the invention, particularly into a machine tool.

[0030] The invention is explained below using an exemplary embodiment with the aid of drawings, and further advantages are listed.

[0031] They show: Fig. 1 A schematic, perspective view of a measuring system according to the invention with two measuring probes and a receiver, Fig. 2a a schematic side view of a vertical sectional view of a detection device according to the invention, Fig. 2b a schematic side view of a measuring probe according to the invention, Fig. 2c a schematic top view of an electronic unit of a measuring probe, Fig. 3 a schematic, perspective view of a machine tool with a measuring system according to the invention, Fig. 4 a diagram for the schematic representation of a signal transmission operation of a measuring system according to the invention, Fig. 5 a diagram for the schematic representation of a signal transmission operation of a measuring system according to the invention.

[0032] The Fig. 1, Fig. 2a, Fig. 2b and Fig. Figure 2c shows an embodiment of a measuring system 1 according to the invention in a configuration with a sensing device 2 and two probes 2 and 3. The sensing device 2 is designed to acquire signals from the probes 3 and 4, and is configured to provide data, in particular measurement data, from the probes 3 and 4 to machine tools. The sensing device 2 can advantageously also be operated in configurations with, for example, only one probe and, for example, with three or more probes.

[0033] The measuring probe 3 is according to Fig. 2b is provided with a mounting cone 5 for clamping the measuring probe 3 in a tool holder 18 of a machine tool 11, as described in Fig. 3 is shown, is intended

[0034] The probe 3 is equipped with an electronic unit 6. A setting element 34 on the housing of the probe 3 allows for adjustment of transmission parameters in the electronic unit 6. The electronic unit 6 is designed to detect touch events, such as when a stylus 15 of the probe 3 is deflected by a probe element 16 with a predefined geometry, e.g., a sphere, touches a surface (not shown). For this purpose, the probe has a sensor 14, which the stylus 15 acts upon when deflected. The sensor 14 can be, for example, a switch (not shown), in particular a circuit breaker (not shown). The sensor 14 is connected to the electronic unit 6 and is designed to transmit a signal to the electronic unit 6 each time the stylus 15 is deflected.

[0035] Electronic unit 6 comprises, as shown in Fig. Figure 2c shows a timer 12, designed such that, at least in one state of an activatable measurement operation, a time value can be retrieved from the timer 12 each time a signal is received from the sensor 14. The time value can be the only value provided as a measured value for signaling a measurement event from the measuring probe 3 to the acquisition device 2. The electronic unit 6 is configured to wait for the beginning of, for example, the next assigned time interval 28 in order to transmit the signal from the sensor 14 together with the time value from the timer 12 to the acquisition device 2 during this time interval 28.

[0036] For the provision of communication and measurement functions such as those mentioned above, the electronic unit 6 is preferably equipped with one or more electronic processing units (not shown), e.g., a microprocessor, a digital signal processor, or a programmable logic element such as an FPGA. The comparatively high integration density of such processing units enables a space-saving and energy-efficient design of the electronic unit 6 within the measuring probe 3.

[0037] Preferably, the measuring probe 4 is designed exactly the same as the measuring probe 3, making the measuring system 1 particularly suitable for monitoring the simultaneous production of identical components on a machine tool 18, such as those used, for example, in Fig. 3 is shown.

[0038] The measuring system 1 is designed for signal transmission using infrared light. For receiving IR signals, the detection device 2 is equipped with an infrared-sensitive receiver 8, which can be, for example, a photodiode or a phototransistor. The measuring probes 3 and 4 each have an infrared-emitting transmitter 7, for example, an infrared-emitting light-emitting diode (IR-LED). Signal transmission using infrared light offers the advantage of comparatively low susceptibility to interference, provided that the light path between the transmitting and receiving elements involved, such as a direct line of sight, is uninterrupted. Preferably, the detection device 2 and the measuring probes 3 and 4 are designed for signal transmission according to a digital data protocol, which further reduces susceptibility to interference.

[0039] Furthermore, the recording device 2 can have a transmitting element 10 and each measuring probe 3, 4 can have a receiving element 11, which advantageously enables bidirectional communication between the measuring probes 3, 4 and the recording device 2.

[0040] A communication sequence with a series of time periods 31 and 32 is in Fig. Figure 1 schematically depicts the time as a horizontal bar. Time is assumed to progress to the right, while the arrow-like left end of the bar describes the transmission direction for measurement signals from the measuring probes 3 and 4 to the acquisition device 2.

[0041] Measuring probes 3 and 4 are each assigned time intervals 31 and 32, respectively. For example, measuring probe 3 may be assigned the subsequence of time interval 31, and measuring probe 4 the subsequence of time interval 32, during which measuring probes 3 and 4 are each authorized to send signals to the acquisition device 2. Time intervals 31 and 32 can alternate, e.g., immediately following one another. Such an assignment of time intervals can be preset in the acquisition device, e.g., at the factory. The time intervals can have a fixed duration, e.g., one millisecond. However, one or more durations of time intervals 31 and 32 can also be adjustable or configurable on the acquisition device 2 and on measuring probes 3 and 4.

[0042] The electronic unit 6 of the measuring probes 3, 4 is designed to enable the respective measuring probe 3, 4 to signal only during the assigned time periods 31 or 32 and to block signal transmission outside of such time periods 31 or 32.

[0043] The measuring system can, for example, be designed such that the acquisition device 2 can only communicate with a number of measuring probes that corresponds to a predetermined maximum number, e.g., six measuring probes. Accordingly, the number of measuring probes actually used, e.g., two measuring probes, can be set on the acquisition device 2 using an adjustment element 33, e.g., a rotary selector switch. This allows the acquisition device to be configured so that successive time intervals of a predetermined duration are alternately assigned to one of, for example, the two measuring probes 3 or 4. Fig. Figure 1 shows a corresponding signal transmission sequence in which time periods 31 and 32 are cyclically alternately assigned to the measuring probes 3 and 4 for transmission to the recording device 2.

[0044] The effect of the previously described setting on the acquisition device 2 can be limited to the fact that, during reception, the acquisition device 2 distinguishes, for example, between time periods 31 and 32 in such a way that signals received in the respective subsequences of, for example, time periods 31 or 32 are treated differently. For the assignment of, for example, measuring probes 3 and 4, the setting element 34 can be provided on each probe, with which one of the subsequences of, for example, time periods 31 or 32 can be selected. However, such a setting of measuring probes 3 and 4 can also be factory-configured and fixed for an end user.

[0045] If, contrary to the example, more than two measuring probes (not shown) are set on the recording device, an assignment can be made sequentially from one of the specified measuring probes to the next, until each measuring probe has been assigned a time period and a new assignment for subsequent time periods can start again, e.g., with the first measuring probe.

[0046] To initiate communication using the transmit and receive parameters, which can be set, for example, with the setting elements 34 and 33, the devices—the receiver 2 and the probes 3 and 4—must be synchronized to a common start time and a common time measure. The time measure can be, for example, a uniform duration of time intervals 31 and 32, or, for example, fractions of such a duration, which can be predefined in the timers 12 of both the probes 3 and 4 and the acquisition device 2. Optionally, the probes 3 and 4 and the acquisition device can each include, for example, an additional setting element (not shown) with which a time measure can be set as a transmit or receive parameter.

[0047] For example, a timer 12 of a communication unit 7 of the acquisition device 6 can be provided as a reference timer with which a transmission of a synchronization signal from a transmitting element 10 of the acquisition device 2 can be triggered. The start of a signal transmission is in Fig. 4 for the in Fig. The time sequence shown in 1 is represented, with the lower bar pointing to the left corresponding to that of the Fig. 1 corresponds. The upper bar additionally shows a time synchronization section, during which the recording device sends out a synchronization signal that can be received simultaneously by all correspondingly set measuring probes 3 and 4.

[0048] The timer 12 is preferably also used in the communication unit for monitoring the receiving operation according to a sequence of time intervals 31, 32, in particular for controlling the assignment and further processing of received signals.

[0049] The communication unit 7 of the acquisition device 2 is in particular equipped with an interface 17, with which signals, in particular digital data signals, can preferably be transmitted to a machine tool. The interface 17 can have several separate channels, in particular several separate signal connections (not shown), each of which can be assigned to one of the measuring probes 3, 4, in order to provide signals from the respective assigned measuring probe 3, 4 separately for comparatively fast processing.

[0050] The Fig. Figure 3 shows an example of a machine tool 18 in which a measuring system 1 according to the invention, e.g., the one described above, is used. The machine tool 18 is designed for the simultaneous machining of two workpieces, in particular identical ones (not shown), which can be clamped at two machining stations 20a and 20b. For simultaneous machining, the machine tool 18 is also equipped with two tool spindles 24.

[0051] The machining stations 20a and 20b are located on the upper side of a rotary table 21, with which the machining stations are jointly arranged to pivot about a horizontal axis. The machining stations 20a and 20b can be driven individually for rotation, and the rotary movements of the two machining stations 20a and 20b can preferably be synchronized.

[0052] The rotary table 21 is pivotally mounted on two columns 22a and 22b and connected via the columns 22a and 22b to a base frame 19 of the machine tool 18. The columns 22a and 22b are vertically displaceable on the base frame 19 and are driven by motors, in particular synchronously, which allows the height of the machining stations 20a and 20b to be changed as a further common axis of movement.

[0053] On the table-like base frame 19, a transport bridge 24 and a carriage 23 are movable in a horizontal plane by means of several drives (not shown). The transport bridge 24 is guided on the base frame 19 in a direction in which the distance of the transport bridge 24 to the processing stations 20a, 20b can be varied. The carriage 23 is slidably guided on the transport bridge 24. The carriage 23 can be moved along the transport bridge 24 at right angles to the direction of travel of the transport bridge 24 in the horizontal plane of the base frame 19.

[0054] The two tool spindles 25a and 25b are mounted on the carriage 23. Therefore, the guided directions of movement of the carriage 24 and the carriage 23 form coupled common axes of movement for machining workpieces at the machining stations 20a and 20b. However, the tool spindles 25a and 25b are guided and driven separately on the carriage, with the guide directions of the tool spindles 25a and 25b on the carriage being aligned parallel to the travel movements of the carriage 24. This allows each of the tool spindles 25a and 25b to be moved independently of the other to a respective machining station 20a or 20b, for example, to perform subsequent machining operations independently, such as correcting a workpiece shape.

[0055] The Fig. Figure 3 shows the machine tool 18 in operation with the measuring probes 3 and 4, which are mounted in tool holders 26 of the tool spindles 25a and 25b. The detection device 2 is mounted above the machining stations 20a and 20b by means of a linkage 30 such that signal transmission from the measuring probes 3 and 4 to the detection device 2 is possible via the shortest possible optical paths. The interface 17 ( Fig. 2a) The communication interface is designed to forward signals acquired by probes 3 and 4 to a control unit (not shown) of the machine tool 18. Signals from probes 3 and 4 are used in the control unit, preferably for monitoring, and in particular limiting, the drive of the motion axes of the machine tool 18. Furthermore, the timing of probe events from probes 3 and 4 allows them to be correlated with sensor data from the motion control system of the machine tool 18, from which measured position data can be derived. Such position data can be compared, for example, as actual values ​​with target values, which may be specified by a CAD model, thus enabling verification of compliance with manufacturing tolerances of a workpiece and, in particular, the conformity of two identical workpieces.

[0056] In Fig.Figure 5 shows another signal transmission sequence for which the measuring system 1 can be configured. The sequence of time intervals 31, 32, and 36 corresponds to a configuration with measuring probes 3 and 4, as well as a third measuring probe not shown. The receiving device is designed to trigger each sequence of time intervals 31, 32, 36, in which each measuring probe is authorized to transmit once, by sending a synchronization signal in a synchronization interval 35. This allows the timers 12, particularly those of the measuring probes, to be regularly synchronized to prevent overlapping time intervals during extended measurement operation. Another way to avoid overlapping time intervals is to insert pause intervals 37 between time intervals 31, 32, and 36. These measures also allow for the use of favorable timers 12 in the measuring probes, e.g.,Quartz crystal oscillators, usable without affecting the quality of signal transmission or measured values.

[0057] In an embodiment of the invention not shown, a measuring probe comprises a storage element with which transmission parameters can be set. Preferably, the measuring probe is designed for repeatable removal of the storage element, which can be, for example, a persistent memory card. For instance, the measuring probe can be screwed open for repeatable removal, thus advantageously allowing the measuring probe to be designed to be tightly sealed against environmental influences. Corresponding transmission parameters for each of the measuring probes used can be stored on the memory card and, for example, coordinated with each other and with an associated acquisition device using a computer program for a given set of measuring probes.Because a relatively large amount of data can be stored on a memory card, a greater number of transmission and reception parameters can be set, which allows the signal transmission to be advantageously adapted to environmental influences. Reference symbol list: 1 measuring system 2 recording devices 3 measuring probes 4 measuring probes 5 receiving cones 6 Electronic unit 7 Communication unit 8 Transmitter element 9 Receiving element 10 transmitting element 11 Receiving element 12 timers 13 Battery 14 Sensor 15 stylus 16 styluses 17 Interface 18 machine tool 19 Tool table 20a Processing station 20b Processing station 21 swivel frames 22a Lifting column 22b Lifting column 23 sleds 24 Bridge 25a Tool spindle 25b Tool spindle 26 Tool holder 27 Tool magazine 28 tool changers 29 grippers 30 poles 31 Time period 32 Time period 33 Adjustment element 34 Adjustment element 35 Synchronization section 36 Time period 37 Break

Claims

[1] Measuring device (1) for a machine tool (18), wherein the measuring device (1) comprises a detection device (2) and at least two probes (3, 4), and wherein the detection device (2) and the probes (3, 4) are designed for wireless signal transmission at least from each of the probes (3, 4) to the detection device (2), characterized by, that reception parameters are specified at the acquisition device (2), wherein the reception parameters are provided for specifying a sequence of non-overlapping time periods (31, 32, 35, 36, 37) in which exactly one of the measuring probes (3, 4) is assigned to each time period (31, 32, 35, 36, 37) such that a signal received in one of the time periods (31, 32, 35, 36, 37) is assigned to the measuring probe (3, 4) of the respective time period (31, 32, 35, 36, 37), and that each of the measuring probes (3, 4) is equipped with an electronic unit (6) in which transmission parameters are specified or adjustable, with which the electronic unit (6) allows the transmission of measured values ​​only in such time periods (31, 32, 35, 36, 37) that a Subsequence of the sequence of time intervals (31, 32, 35, 36, 37) are assigned, whose time intervals (31, 32, 35, 36, 37) are assigned to the respective measuring probe (3, 4), wherein the electronic units (6) of the measuring probes (3,4) are designed to detect a synchronization signal with which, in each electronic unit (6), the partial sequence of time intervals (31, 32, 36) in which the respective measuring probe (3, 4) transmits is synchronized with the sequence of time intervals (31, 32, 36) in which the detection device (2) receives. [2] Measuring device (1) according to claim 1, characterized by , that the measuring probes (3, 4) and the detection device (2) are designed for wireless signal transmission using infrared light. [3] Measuring device (1) according to one of the preceding claims, characterized by , that the measuring probes (3, 4) and the detection device (2) are designed for wireless signal transmission using radio waves. [4] Measuring device (1) according to one of the preceding claims, characterized by , that the time intervals (31, 32, 35, 36, 37) are limited to a maximum duration of one millisecond. [5] Measuring device (1) according to one of the preceding claims, characterized by , that a measured value received in a time period (31, 32, 35, 36, 37) can be transferred to a machine tool (18) according to the respective assignment to a measuring probe (3, 4). [6] Measuring device (1) according to one of the preceding claims, characterized by , that the measuring probes (3, 4) and the detection device (2) are designed for wireless signal transmission from the detection device (2) to the measuring probes (3, 4). [7] Measuring device (1) according to one of the preceding claims, characterized by , that the detection device (2) is designed to generate the synchronization signal. [8] Measuring device (1) according to one of the preceding claims, characterized by , that the measuring probes (3, 4) are designed for wireless reception of the synchronization signal from the detection device (2). [9] Measuring device (1) according to one of the preceding claims, characterized by , that the measuring probes (3, 4) are equipped with a timer (12), wherein, in the event of a touch event, the electronic unit (6) of the respective measuring probe (3, 4) is designed to read the timer (12) and send the value to the detection device (2). [10] Measuring device (1) according to one of the preceding claims, characterized by that the recording device (2) has a communication interface (17) which is designed for data exchange with a machine tool (18). [11] Measuring device (1) according to one of the preceding claims, characterized by , that the detection device (2) has several signal outputs, wherein in the detection device (2) each of the signal outputs can be assigned one of the measuring probes (3, 4).

Images