Method for Operating a Machine Tool with a Gentle Start-Up

Abstract

A method for operating a machine tool with a gentle start-up, preferably a jigsaw wherein at least one physical characteristic of the machine tool, in particular a motor and/or battery current, is detected by a detection unit, in particular a control or regulating unit of the machine tool, in an idle operating state of the machine tool with a throttled movement. A threshold of the physical characteristic, in particular a scraping threshold, is ascertained by an analysis unit, in particular the control or regulating unit of the machine tool, on the basis of the detected physical characteristic, and in further operation of the machine tool, a drive unit of the machine tool is set to an operating state under load, with a movement speed which is increased relative to the idle operating state with a throttled movement, when it is detected that the ascertained threshold has been overshot or undershot.

Claims

1. A method for operating a a hand-held machine tool with an oscillating or stroke-shaped output movement comprising: detecting at least one physical characteristic of the machine tool during an idle operating state of the machine tool with a throttled movement, by a control or regulating unit of the machine tool wherein the at least one physical characteristic comprises a motor and/or battery current detected by an analysis unit comprising a control or regulating unit of the machine tool; ascertaining a scraping threshold of the at least one physical characteristic on the basis of the detected physical characteristic; and setting at least one drive unit of the machine tool to an operating state under load with an increased movement speed relative to the idle operating state with a throttled movement in a the further operation of the machine tool in response to detecting an overshoot or undershoot of the ascertained threshold.

2. The method according to claim 1, wherein the scraping threshold is ascertained by using the analysis unit to ascertain a base value from the detected at least one physical characteristic wherein the base value is a base average value, and, as a function of the ascertained base value, the scraping threshold deviating therefrom is calculated as a percentage or absolute value.

3. The method according to claim 2, wherein, when ascertaining the scraping threshold or the base value, a switch-on period of the machine tool is not taken into account, in particular a period of 1-1000 ms, advantageously 100-500 ms, in particular around 300 ms from a switch-on time of the machine tool.

4. The method according to claim 2, wherein, when ascertaining the scraping threshold or the base value, a detection period of the at least one physical characteristic of 10-1000 ms is taken into account immediately after an end of a switch-on period starting after 100-500 ms from the time of a switch-on of the machine tool.

5. The method according to claim 1, wherein: the idle operating state of the machine tool with a throttled movement corresponds to a setpoint rotational speed of the at least one drive unit of 2000 to 10000 rpm or to an oscillation or stroke rate of an output unit of 250 to 1000 oscillations or strokes/min; and/or the operating state of the machine tool under load corresponds to a setpoint rotational speed of the at least one drive unit of 6000-30000 rpm or a stroke rate of the output unit of 800 to 3800 strokes/min; the setpoint is a presettable setpoint; and the setpoint is one of 2-10 operating levels.

6. The method according to claim 1, wherein in response to detecting a typical change of an idling of the machine tool in the operating state under load, the typical change being a reduction of the motor and/or battery current with workpiece engagement by the tool, over a settable minimum detection period, the machine tool is set to an operating state with a throttled movement wherein the idle operating state with a throttled movement is reset.

7. The method according to claim 2, wherein when the scraping threshold is overshot and/or during the detection and/or ascertaining of the base value and/or scraping threshold, a signal in the form of an acoustic, optical and/or haptic signal, is output on an output field of the machine tool, on a functional interface and/or on an external unit.

8. The method according to claim 1, wherein, after the machine tool has been switched off and switched on again within a minimum rest period, the machine tool is immediately set to a load mode movement state wherein the machine tool is accelerated to a variably settable load mode movement state without previously being set to the idle operating state with a throttled movement.

9. A hand-held machine tool in the form of a jigsaw, reciprocating saw, or oscillating multifunction tool configured to carry out the method according to claim 1.

10. a system comprising: a hand-held machine tool in the form of a jigsaw, reciprocating saw, or oscillating multifunction tool; and a function interface and/or an external unit, in the form of a mobile terminal device such as a smartphone, with an application program set up to carry out the method according to claim 1.

11. The method according to claim 4 wherein: when ascertaining the scraping threshold or the base value the detection period of the at least one physical characteristic is 250-750 ms.

12. The method according to claim 11 wherein: when ascertaining the scraping threshold or the base value the detection period is around 500 ms; and the detection period starts after around 300 ms from the time of the switch-on of the machine tool.

Description

DRAWINGS

[0098] FIG. 1 shows a machine tool 10 in a perspective view. FIG. 2 shows the machine tool 10 according to FIG. 1 in a sectional view. The machine tool 10 is a hand-held machine tool 12. It is a reciprocating saw 16. It is a jigsaw 18. The jigsaw 18 is designed as a bar-shaped jigsaw 48. It therefore differs from a bow-shaped jigsaw (not shown here), which typically has a handle bow. A manual throttle switch is typically located on the handlebar of bow-shaped jigsaws, which can be used to manually control the drive or tool speed, sometimes rendering an automatic gentle start-up obsolete. But even machine tools with manual accelerator switches could in principle have an automatic gentle start-up.

[0099] The illustrated machine tool 10 has an on/off switch 50. In addition, the machine tool 10 has a device 52 for selecting different setpoint operating parameters, in particular operating levels or rotational speed levels. This allows different operating levels of a drive unit 40 of the machine tool 10 or stroke rate levels of an output 36 of the machine tool to be selected. The machine tool 10 has a power supply device 58. Here a battery pack 60 or an exchangeable battery packin simple terms a replaceable battery. It is therefore a battery-powered or battery-operated electric machine tool. In principle, however, the machine tool could also be mains-powered. The machine tool 10 has the drive unit 40. It has a control or regulating unit 20. This controls or regulates at least the drive unit 40 and/or the energy withdrawal from the battery pack or the provision of load for the drive unit, in particular by controlling or regulating the current or voltage provided. Furthermore, the machine tool 10 has a communication module 62. This is intended to exchange data with an external unit or to be connected to it. In particular, settings, operating parameters, data and other information can be exchanged with an external unit. The communication module is advantageously set up to send and/or receive data, for example via Bluetooth or another network protocol. The machine tool 10 drives a tool holder 64. The drive movement is transmitted by a drive train 38. The drive train 38 converts the rotating drive movement of the drive unit 40 into an oscillating output movement 14 of the output 36 or the tool holder 64, in particular by means of a gearbox (as shown, for example, in FIG. 2). The gear ratio is ideally 5-10, in this case 7.5. Correspondingly here: 7.5 motor revolutions result in one stroke movement. The drive unit 40 is designed as an electric motor, in particular as an EC motor. A tool 66, in this case a replaceable saw blade 68 or jigsaw blade, is inserted into a tool holder 64 of the machine tool. The saw blade 68 can optionally be operated with a pendulum stroke, in particular with a pendulum stroke that can be set. Saw blades 68 with different inertias, weights, geometries and/or other properties can be inserted into the tool holder 64. The drive train 38 of the machine tool can have different internal resistances. Be it because of its running-in and/or lubrication state, because of tolerances between different machine tools of the same type and/or because of other conditions. The battery or battery pack 60 can also have different internal resistances depending on the operating temperature.

[0100] Furthermore, the jigsaw 18 has a settable lateral guide 70 for the saw blade 68. This pincer-like guide can be adjusted using a setting mechanism 72. This can lead to increased sliding resistance for the saw blade 68, for example, if a narrow gripper guide is used to prevent the saw blade 68 from running or to increase the cutting precision, or similar. This sliding resistance for the saw blade 68 can also be assigned to the internal resistances of the jigsaw 18, as it can also act when the jigsaw 18 is idling.

[0101] FIG. 3 shows a method for operating a machine tool or the machine tool 10 with, in particular, adaptive gentle start-up, in particular for operating a hand-held machine tool 12, advantageously with an oscillating output movement 14, for example a reciprocating saw 16, preferably a jigsaw 18, a reciprocating saw or an oscillating multifunction tool 19. In principle, the method could also be used to operate machine tools, in particular hand-held machine tools, with rotating, oscillating or other input or output movements. It is advantageously designed for machine tools 10 without a manual accelerator switch. In particular, it is intended for machine tools 10 with an on/off switch 50. Advantageously for machine tools 10 with on/off switch 50 and a device 52 for selecting different setpoint operating parameters of the machine tool, in particular setpoint rotational speeds or operating levels, in particular for different operating states under load. The method is particularly preferred for operating machine tools with adaptive, configurable or settable gentle start-up and/or for operation with a functional interface, in particular for setting a gentle start-up. In the following, the method for operating the machine tool 10 or the jigsaw 18 according to FIGS. 1 and 2 is explained by way of example.

[0102] In a step 100, the machine tool 10 is switched on according to FIG. 3, for example via an on/off switch 50. See also the time t.sub.0 in FIG. 4.

[0103] In a step 110, a control or regulating unit 20 of the machine tool 10 checks a setting value, in this case a setpoint rotational speed value for a load mode movement state 184 of the drive unit 40 or the output 36. In this example, it is 3800 strokes/min or 7.5 times the number of revolutions per minute of the drive unit. Alternatively, other values would also be conceivable for a jigsaw 18, here for example stroke rates between 800 and 3800 strokes/min or corresponding rotational speeds of the drive unit 40.

[0104] Advantageously, for example, four, six or eight advantageously preconfigured or configurable operating levels 310 can be selected on the machine tool. The respectively set or selected operating level 310 can be displayed, for example, via a display 368 of a function interface 358 of the machine tool 10 (see FIG. 8). A button 370 can be used to select or set different operating levels 310 advantageously corresponding to different operating states under load or operating speeds or rotational speeds of the machine tool 10. The function interface 358 on the machine tool 10 can also provide further selection or display options. For example, a working light of the machine tool 10 can be switched on and off via a button 372. Activation (display fields 374) or deactivation (display fields 376) of the working light can be indicated via display fields 374, 376. Further setting options or information can be output via the display fields 378, 380e.g. further information is available in an application program of an external device connected to the machine tool (display fields 378) and/or it can be displayed whether a gentle start-up is active or inactive (display fields 380). For example, an output field 382 can signal that a base value and/or threshold ascertaining is currently taking placeas will be explained lateror the like.

[0105] Setting values for the operating levels 358 can advantageously be made by a user via an external function interface 300 or an external unit 30. Pre-settable or configurable setting values are advantageously setpoints for the load mode movement state 184 of the machine tool 10in particular setpoints for a stroke rate of the output drive 36 or the tool 66 or saw blade 68 or a rotational speed of the drive unit 40. Alternatively or additionally, an operating level could also be selected by a user or automatically, for which the corresponding setpoint rotational speed or setpoint stroke rate values are stored in the control or regulating unit 20. These settings can advantageously be made on a function interface 358 of the machine tool 10 and/or the external function interface 300, or the external unit 30. The external function interface 300 or the external unit 30 is advantageously connectable/connected to the machine tool 10 via a communication module 62. The external functional interface 300 or unit 30 is designed in particular as a mobile end device, advantageously as a smartphone see FIG. 5 or tablet. It comprises a corresponding application program or appi.e. a computer program comprising instructions which, when the program is executed by a computer, cause the computer to enable the aforementioned and subsequent functionality of the external unit. As an alternative to the stroke or rotational speed value, another characteristic physical typical for the machine tool, e.g. a torque, a load, a current, a movement of a drive train component, a stroke rate and/or a drive, output and/or tool speed or the like, can also serve as a setting value.

[0106] In a step 120, it is checked, in particular by the control unit 20, whether a gentle start-up is activated, in particular for the predetermined load mode movement state or the selected operating level, in this case the 3800 strokes/min of the output 36 or the corresponding setpoint load rotational speed of the drive unit 40.

[0107] If the gentle start-up is activated, in a step 130 the stroke rate 132 of the output or the rotational speed of the drive unit 40transmission ratio between drive unit 40 and output 36 is 7.5in FIG. 4 the stroke rate 132 is plottedof the machine tool 10 is accelerated to an idle operating state or idle mode movement state 144 with a throttled movement (see FIG. 4). The machine tool 10 is therefore set to this statein this case around 800 strokes/min corresponding to 6000 rpm of the drive unit 40. See also FIG. 4, which shows the acceleration period t.sub.0 to t.sub.1 and the period t.sub.1 to t.sub.4 during which the machine tool is operated with a throttled movement. Stroke rates of 250 to 1000 strokes/min, advantageously 500, 700, 800 or 1000 strokes/min, would also be typical for jigsaw 18 for the idle operating state or idle mode movement state 144 with a throttled movement. Deviating stroke rates or rotational speeds for the idle operating state or idle mode movement state 144 with a throttled movement could, for example, be called up or loaded in a step 125 by the control or regulating unit 20, advantageously entered via the function interface 300. In the idle operating state 144 with a throttled movement, the stroke rate 132 is kept as constant as possible (as can also be seen in FIG. 4). If the gentle start-up were not activated, in a step 200 the stroke rate 132 is accelerated directly or sometimes after a delay that can be set and/or further settable parameters to the setpoint load stroke rate or the operating state 184 under load, in this case of 3800 strokes/min corresponding to 38500 rpm of the drive unit 40.

[0108] In a step 140, at least one physical characteristic 142 of the machine tool 10, for example the voltage 146 and/or the motor current 24 and/or the battery current, is detected by means of a detection unit 22, in particular the control or regulating unit 20 of the machine tool 10, at least during the idle mode or idle mode movement state 144 of the machine tool 10 with a throttled movement. Here, the motor current 24 is specifically detected by the control or regulating unit. In principle, the detection unit 22 could also be a sensor unit. Comprising at least one sensor or a sensor element; possibly also comprising filters and/or further electronic components, in particular for pre-processing and/or analysis of a sensor signal. The detection unit 22 could also be an external sensor or an external sensor unit, for example at least comprising a microphone, a vibration meter, an optical sensor and/or the like, which is connected to the control or regulating unit 20 of the machine tool 10 and/or an analysis unit at least in wireless or wired connection, at least in order to detect a physical characteristic and to make the measured and/or pre-analyzed data available to a control or regulating unit, in particular the control or regulating unit 20 of the machine tool 10. A microphone could, for example, distinguish typical workpiece scratching noises from noises of idle mode and/or the complete engagement mode of the tool in the workpiece, in particular by, for example, information stored in the analysis unit on reference noises for the different states or the like. In principle, the external sensor unit could even issue control or regulation instructions to the machine tool 10. The external sensor unit could in particular be the function interface 300, in particular comprising an application program intended for data exchange with the machine tool. A sensor could, for example, also be a resistance sensor for a sensor circuit energized by the control or regulating unit 20 or the like, which supplies, for example, a sensor signal representative of the physical characteristic 142 to be detected. In this example, the motor current 24 of the machine tool 10 is used as a typical physical characteristic. As shown in FIG. 4, it is detected by the control or regulating unit 20 of the machine tool 10 during the idle operating state or idle mode movement state 144 of the machine tool 10 with a throttled movement, which also controls or regulates the drive unit 40, in this case the electric motor.

[0109] In a step 150, a base value 154 is ascertained from the detected physical characteristic 142 by means of an analysis unit 152, which in this case is also the control or regulating unit 20in this case by means of a moving average over a defined detection period 160. Potentially also repetitive during the period 182 until the first time a threshold 172 determined and updated for each repeat ascertaining is overshot (here time t.sub.3). When ascertaining the base value 154 of the physical characteristic, a switch-on period 156 of the machine tool 10 (for example between t.sub.0 and t.sub.1 see FIG. 4) is advantageously not taken into account. The switch-on period 156 is advantageously 100-500 ms from the switch-on time t.sub.0 of the machine tool 10. However, it could also be variablee.g. settable in one step 155 by a user or automatically adapted and set by the control or regulating unit 20. Advantageously detected and/or adapted variablye.g. using typical measured variables and/or sensor signal curves during acceleration of the machine tool 10, e.g. based on detected inertias of the tool, or delays during initial acceleration of the drive unit 40 or the output 36 or the like. The switch-on period 156 could also be automatically adapted as a function of a set idling rotational speed with a throttled movement, in particular so that at least the drive train of the machine tool is set to a largely uniform and/or constant movement state depending on the idling rotational speed to be achieved. The switch-on period 156 could possibly also be determined and defined based on a self-learning algorithm or the like, in particular in order to keep or select a switch-on period as short as possible, but as long as necessary, in particular so that a base or threshold that is as accurate or unadulterated as possible (i.e. without outlier measurements)i.e. without disturbance variablescan be ascertained. Here, the switch-on period 156 is around 300 ms from a switch-on time 158 of the machine tool 10. To ascertain the base value 154 or threshold 172, in particular to form a base average value, a detection period 160 of the physical characteristic 142 of advantageously 250-750 ms, here in particular around 500 ms, is taken into account. In the present case, the period t.sub.1 to t.sub.2 is defined, but could also be variably settable, e.g. in a step 165e.g. settable by a user or advantageously automatically recognized and/or adapted by the control unit 20e.g. by typical measurement or sensor signal curves, possibly also by a self-learning algorithm or the like, in particular in order to select the detection period as short as possible, but as long as necessary (so that a precise or reliable base value can be ascertained). Various averaging methods are conceivable for forming the base value 154, in particular common onese.g. moving average, weighted average or the like. Here, the arithmetic mean value of the motor current 24 over the detection period 160, in this case 500 ms, is formed as the average value. This is particularly the case immediately after the end of the switch-on period 156, in this case starting after around 300 ms (at time t.sub.1) after the switch-on time t.sub.0 or after the time t.sub.0 of a switch-on 158 of the machine tool 10. As a result, current peaks 162, in particular inrush current peaks of the electric motor current, and/or discontinuities of the physical characteristic 142 during the switch-on period 156 can be disregarded. The accuracy of the base value 154 is increased. By ascertaining the exact base value or threshold, the gentle start-up can ultimately be operated or terminated more sensitively, precisely and/or accurately, or the machine tool 10 can be transferred from the operating state with a throttled movement to the operating state under load more sensitively, precisely and/or accurately.

[0110] In a step 170, depending on the ascertained base value 154, a threshold 172 deviating therefrom, in particular a threshold 172 of the physical characteristic 142 deviating as a percentage or absolute value, is ascertainedhere in particular ascertained by the control or regulating unit 20. This is defined as threshold 172, in particular stored or saved accordingly in a memory of the control unit 20. A deviation 174 of the threshold 172 from the base value 154 can advantageously be set by a user. The deviation 174 can, for example, be defined via a sensitivity 176. The deviation 174 can advantageously be set as a relative value, percentage or absolute value, in particular as a so-called sensitivity 176, that can advantageously be set for a plurality of presettable setpoint operating states under load, in particular by means of or via a function interface 300, advantageously of a mobile terminal device. See also FIG. 5-7.

[0111] In this case, the ascertained threshold 172 for the motor current 24 is above the ascertained base value 154. The degree of deviation of the threshold 172 from the ascertained base value 154 can advantageously be set as so-called sensitivity 176, as will be explained later. When using, for example, a speed or stroke rate signal as a physical characteristic 142, a rotational speed threshold 172 lower than the base value would also be conceivable as a threshold, in particular when specifying a throttled idling motor current to be kept constant, but when operating the machine tool with a variable speed or stroke rate. In this case, it could be assumed that with a constant motor current but increased resistance on the tool due to the scratching of a workpiece, the rotational speed or movement speed of the drive unit drops during scratching. Therefore, a threshold for the physical characteristic can in principle also be overshot or undershot. When detecting vibrations or noises as a typical physical characteristic 142, a vibration or noise threshold above a base value 154 could be defined. This is only intended to show a few examples of the use of various physical characteristics, but is not an exhaustive list.

[0112] In a step 180, the control or regulating unit 20, advantageously also as a detection unit 22 of the physical characteristic 142, monitors the movement state with a throttled movement, in this case the motor current 24 in the idle operating state or idle mode movement state 144 of the drive unit 40, in this case at least during the period 182 (cf. t.sub.2 to t.sub.4 of FIG. 4), during further operation of the machine tool 10. It advantageously compares the currently detected and/or averaged physical characteristic 142 with the threshold 172 for the physical characteristic 142. Provided that the threshold 172 is not overshot or undershot, the idle operating state or idle mode movement state 144 is continued. The comparison of the currently detected physical characteristic 142 with the threshold 172 is continuously continued or repeated. Optionally, a step 185 may also be possible, according to which the steps 140, 150, 170, 180 are repeated, for example if the idle operating state or idle mode movement state 144 with a throttled movement lasts for a longer period of time, for example for 20, 30 or 60 seconds or another period of time. Advantageously, this could be signaled to a user during the period of initial and/or renewed base value 154 and threshold 172 ascertaining or definition, for example visually via the output field 382, haptically/tactilely, audibly and/or the like. This signaling function, e.g. via an output or the output field 382, could therefore also take place without multiple ascertaining.

[0113] In a step 190, an overshoot or undershoot of the defined threshold 172 is detected by the physical characteristic 142 if, for example, the tool 66 of the machine tool 10 scratches a workpiece. Cf. time period t.sub.3 to t.sub.4 in FIG. 4, wherein the motor current 24 overshoots the threshold 172. Overshooting the defined threshold 172 is specifically detected here. This can be, for example, a first overshoot, an overshoot in a number of measurements, an overshoot e.g. for a certain period of time (see t.sub.3 to t.sub.4 in FIG. 4) and/or an overshoot of an average value of the measurement e.g. of 10-100 ms. Another physical characteristic, e.g. a drop in voltage 146, could also be used to advantageously detect an undershoot of the threshold. By detecting several physical characteristics at the same time, the reliability with which a threshold is detected as being overshot or undershot could be improved or implemented redundantly. The machine tool and an external unit could also each detect a physical characteristic. If both units simultaneously detect an overshoot or undershoot of a threshold, the reliability could also be increased. Depending on the situation or environmental conditions, one or more physical characteristics could also be detected and used individually or together for adaptive gentle start-up control of the machine tool in particular.

[0114] In step 200, the drive unit 40 of the machine tool 10, in this case the electric motor, is then accelerated to the load mode movement state 184. A stroke rate 132 of the machine tool 10 or a motor rotational speed of the drive unit 40 is accelerated to the working setpoint, in this case 3800 strokes/min or 38500 rpm, or the machine tool is set to the operating state under load or load mode movement state 184. Alternatively, a motor current, a load, a stroke rate and/or an input, output and/or tool speed or the like could also be specified as a target variable for the load mode movement state.

The acceleration to the load mode movement state 184 can advantageously also take place with a delay, in particular with a delay that can be set, e.g. after a delay period that can be set, e.g. of 0-2 seccf. t.sub.3 to t.sub.4 of FIG. 4, in particular after the threshold 172 has been overshot for the first time by the detected physical characteristic. The delay setting can advantageously be made on a function interface 300 for all or the respective preset load mode movement state.

[0115] The acceleration function 332 (see FIG. 10) could also potentially be settable, e.g. having a linear 202, exponential 204, as a root function 206 or as a function with a saddle point 208 (see FIG. 10). This setting could be made in a step 195, for example in which the control or regulating unit checks whether corresponding delay settings and/or acceleration function settings have been defined by the user, wherein these would then be taken into account in the control or regulation of the machine tool 10.

[0116] In a step 210, upon detection of idling 186 (cf. between t.sub.6 and t.sub.7, FIG. 4) of the machine tool 10 in the load mode movement state 184, for example by a typical change in the detected physical characteristic 142, in particular reduction of the motor or battery current 24, in particular over a minimum detection period (not shown here in more detail), which can advantageously be set, the machine tool 10 could be set to a movement state with a throttled movement, advantageously the idle operating state or movement state 144 with a throttled movement could be reset. This would allow the machine tool 10 to be returned to the state of step 130 and steps 140 to 200 to be advantageously repeated.

[0117] FIG. 4 illustrates physical characteristics 142 detected during the implementation of the aforementioned method. Accordingly, this could also apply to other operating levels and/or settings for gentle start-up, in particular a configured and/or adaptive gentle start-up. The physical characteristics 142 correspond to the values detected in a test with a machine tool 10 designed as a jigsaw 18, which are shown in relative terms. The time is plotted on the abscissa and the values for the measured voltage 146, the motor current 24 and the stroke rate 132 are shown on the ordinate in relative size. In particular, the voltage signal is shown for a limited range of values for better visibilityi.e. it is displayed in an exaggerated form.

[0118] As this is an experimental setup, the measurement begins before the machine tool is switched on to and does not end when the machine tool 10 is switched off t7. In the period before t.sub.0, the rotational speed is 0, the voltage is constant according to the pole voltage of the battery pack, and the current is close to 0 due to the measurement and fluctuates slightly. The machine tool 10 is switched on at time t.sub.0. The motor current 24 is increased, the stroke rate 132 is raised to the idle mode with a throttled movement and the voltage 146 drops slightly. The current signal 142 and the voltage signal 146 indicate an inrush current peak 162 and a voltage peak 164. In addition to what has already been explained above in the description of the method, a few further aspects are highlighted below. The scratching of the workpiece from time t3 is visible in both the current signal 142 and the voltage signal 146. The control or regulating unit 20 keeps the rotational speed or the stroke rate 132 of the machine tool 10 constant. Due to the increased resistance on the workpiece from time t.sub.3, the control unit 20 must increase the motor current 24 in order to keep the rotational speed or stroke rate 132 constant, thereby overshooting the threshold 172. The more precisely (e.g. through fewer outliers, a more constant signal or a narrower signal spread, etc.) the base value 154 can be determined, the less (without causing false triggers) the threshold 172 can deviate from the base value 154, the more sensitively an over- or under-threshold of the physical characteristic 142 can be detected. This is useful, for example, for detecting scratching in balsa wood or another low-resistance workpiece.

With regard to the measured variables in the period t.sub.4 to t.sub.5, where the rotation or stroke rate 132 is increased from operating state with a throttled movement to a load mode, it becomes clear that the motor current signal 24 and the voltage signal 146 have corresponding current or voltage peaks that are caused by the acceleration of the drive unit 40 to load mode. The workpiece is processed in the period t.sub.5 to t.sub.6. The rotational speed or stroke rate 132 is kept constant by the control or regulating unit 20, the current 24 fluctuates according to the working conditions, material conditions (cutting conditions), the selected feed rate by the user of the machine tools and sometimes many other boundary conditions such as stroke reversal in the jigsaw, etc. The voltage 146 drops over time in this period t.sub.4 to t.sub.5 due to the energy consumption of the battery (exaggerated as only shown as a section of a value range)this effect would probably not be visible in this way with mains devices. From time t.sub.6, workpiece processing or cutting is complete. The machine tool 10 is still in the operating state under load and moves at an increased or constant rotation or stroke rate 132 or operating speed. However, the machine tool 10 is now idling. The motor current 24 drops to a value between the idle mode with a throttled movement and the load mode processing the workpiece. The voltage 146 regenerates somewhat. If this idle operating state persists at the setpoint rotational speed or in principle load mode for a predetermined period of time, for example, the control or regulating unit 20 could also return the machine tool 10 to an idle operating state 144, in particular the idle operating state 144 with a throttled movement. For example, at time t.sub.1 or t.sub.2, depending on whether the base value or threshold formation is to be repeated, or whether a new gentle start-up is to be repeated with the previously ascertained base value or threshold until the next scratching is detectedin accordance with the method described above. At time t.sub.7, the machine tool is switched off, the rotational speed or stroke rate 132 drops to 0 with a slight delay due to the inertia of the drive train 38, the motor current 24 drops immediately, especially if no current braking is used by the drive unit 40, and the voltage 146 regenerates following the switch-off.

[0119] FIGS. 5 through 7 illustrate that a gentle start-up can be configured by a user of the machine tool 10, in particular in conjunction with a function interface 300, which is exemplified here as an external unit that can be connected to the machine tool 10, in this case wirelessly to the communication module 62. Alternatively, however, it could also be a functional interface formed on the machine tool 10, in particular one that exceeds the functionality of the functional interface 358 shown on the machine tool 10. The gentle start-up is to be understood here, in particular more generally than with the adaptive gentle start-up, as a control or regulating unit setting a drive unit of the machine tool to an operating state under load when a threshold or scraping threshold, in particular a typical physical characteristic, is overshot or undershot. How this threshold or scraping threshold is formed is irrelevant for the time being. Method steps or features of this so-called configurable gentle start-up can, however, be advantageously combined with the features of the aforementioned adaptive gentle start-up. An adaptive gentle start-up is to be understood as at least one method for operating a machine tool comprising the following steps: [0120] detectionin particular by means of a control or regulating unit 20 of the machine tool 10of at least one physical characteristic 142 of the machine tool, in particular a motor current 24 of the machine tool 10, during an idle operating state 144 of the machine tool 10 with a throttled movement, [0121] ascertaining of a scraping threshold 172, in particular a motor current scraping threshold, based on the detected physical characteristic 142, in particular by means of the control or regulating unit 20, [0122] The system is used to set a drive unit of the machine tool to an operating state under load when an overshoot or undershoot of the ascertained scraping threshold is detected.

[0123] Both the adaptive and the configurable gentle start-up are particularly advantageous for machine tools 10 without a manual accelerator switch, especially with an on/off switch 50. The method is designed for operating a machine tool 10 with gentle start-up, in particular a hand-held machine tool 12, advantageously with an oscillating output movement 14, for example a reciprocating saw 16, preferably a jigsaw 18, reciprocating saw or an oscillating multifunction tool 19, wherein the machine tool 10 in at least one method step is in a movement state or operating state with a throttled movement, advantageously idle operating state or idle mode movement state 144, and in a further method step, a drive unit 40 of the machine tool 10 is automatically accelerated to an operating state 184 under load or load mode movement state when an overshoot or undershoot of a scraping threshold 172 is detected, in particular by a control or regulating unit 20 of the machine tool 10. The gentle start-up can be configured by a user of the machine tool 10, for example by making settings for the gentle start-up via a function interface 300, advantageously an HMI, in particular a function interface 300 arranged on the machine tool and/or on an external device 301. The function interface 300 can be in wired or advantageously wireless connection 318 with the machine tool 10, in particular in connection 318 with the control or regulating unit 20 of the machine tool 10. In particular, the gentle start-up can be configured via an app on a smartphone 303 or tablet.

[0124] FIG. 5 shows a functional interface 300, in particular an HMI 302. This is an external unit 30, in this case a smartphone 303 with a corresponding application program (app). The function interface 300 is set up to enable a configurable, advantageously adaptive, gentle start-up of a machine tool 10 by a user. It is advantageous to configure the aforementioned adaptive gentle start-up or a gentle start-up of a machine tool in general by a user. The machine tool 10 is advantageously a hand-held machine tool 12, in particular a reciprocating saw 16, preferably a jigsaw 18, a reciprocating saw or an oscillating multifunction tool 19. The function interface 300 comprising means for setting 304, 306 and/or switching on or off 308 the gentle start-up, in particular for different operating levels 310, working setpoints 312 and/or operating states 314 under load, advantageously different working setpoints 312 of a drive rotational speed, stroke rate and/or drive, output and/or tool speed of the machine tool, advantageously for setting 304, 306 and/or switching on or off the gentle start-up jointly for several or optionally individually for each operating level 310, working setpoint 312 and/or operating state under load. The functional interface 300, 358 is advantageously provided by an external unit 30 and/or arranged on the machine tool 10, advantageously at least partially redundantly on both. In particular, the functional interface 300 can be a smartphone 303 or tablet with an application program that enables the configurable gentle start-up, for example via a user interface 316. The external unit 30, in particular the smartphone 303 or tablet, is at least indirectly connected 318 to the machine tool 10, in particular to a control or regulating unit 20 of the machine tool 10, in particular for data exchange, advantageously of input and/or output data. The function interface 300 can be connected 318 to the machine tool 10 wirelessly in principle, but also by wire, in particular via WLAN, Bluetooth, Zigbee or other networks.

[0125] The means for setting 304, 306 and/or enabling or disabling 308 the gentle start-up may comprise switching or operating elements, advantageously comprising graphical input and output elements for interaction with a user, in particular shown on the user interface 316 or a display 320 and at least partly provided by an application or control program executed on the functional interface and/or the external device 301. This enables intuitive configuration of the gentle start-up. The application program or functions thereof can also be executed at least partially on a control unit 20 of the machine tool 10. The function interface 300 is advantageously provided for data processing, in particular comprising means for executing a method for enabling the configurable gentle start-up. Also proposed is a computer program comprising instructions which, when the program is executed by a computer, cause the computer to execute the method for enabling the configurable gentle start-up.

[0126] A number of operating levels 310, working setpoints 312 and/or operating states 314 under load can be selected, for example in the input and/or output window 322. A working setpoint 312 can be set or selected between a predetermined maximum and minimum value 323, 325 for the respective working setpoint 312. This allows individual settings to be made for the gentle start-up for different operating levels or working setpoints 312 of the machine tool 10. Time can be saved for setting the gentle start-up when switching operating levels 310, in particular via the function interface 358in particular the switching of operating levels 310 directly on the machine tool 10, in particular via the device 52, as these are already preconfigured with regard to the setting of the gentle start-up via the function interface 300.

[0127] An acceleration period 326 can be set, e.g. between t.sub.4 and t.sub.5 according to FIG. 4, and/or a delay period 328, e.g. between t.sub.3 and t.sub.4 according to FIG. 4, for setting the machine tool to an operating state 184 under load from detection of an overshoot or undershoot of a scraping threshold 172, here for example at time t.sub.3, in particular as a relative value within a certain range, e.g. between short and long, or can be set as a percentage or as an absolute value, advantageously settable between 0 and 2 sec. For this purpose, as shown in FIG. 7, the function interface 300 in the gentle start-up settings (ASC settings 346) has the option of selecting a setting between short and long in the area labeled Delay 324. Acceleration period 326 is to be understood as a period of time for acceleration from an, in particular idle, operating state 144 with a throttled movement to a working setpoint and/or operating state 184 under load. A delay period 328 is to be understood as the period of time of a start of an acceleration of the drive unit 40 to a working setpoint 312 and/or load mode movement state 184, from detection of an overshoot or undershoot of a scraping threshold 172. In particular, the acceleration and/or delay period 328 can be set continuously or in stepsfor example of 0.1 sec or 5% or 0.3 sec or 20% or the like. The setting is advantageously made jointly for several working setpoints 312 and/or load mode movement states 184, as shown in FIG. 7, or optionally individually for each working setpoint 312 and/or load mode movement state 314. The gentle start-up can be switched on or off, e.g. via the selection means 308 in FIG. 6. An individual setting for each working setpoint 312 could be configurable by means of a setting symbol for each working setpoint 312, which leads to a submenu when pressedfor example, analogous to that of FIG. 7. This would make it possible to individually set the gentle start-up and positively influence a tear-out behavior for different working setpoints 312. Time could be saved for the user when defining or configuring the gentle start-up for each operating level.

[0128] A progression of the acceleration 330, in particular an acceleration function 332, could be set or selected as shown in FIG. 10, for example in a further submenu or the one according to FIG. 7 supplemented by this function, in particular having a linear 202, exponential 204, as a root function 206 or as a function with a saddle point 208, advantageously settable or selectable together for several or optionally individually for each operating level 310, working setpoint 312 and/or load mode movement state 314.

[0129] It is proposed that a sensitivity 176, 334 of the gentle start-up can be set, in particular in the form of a duration of an overshoot or undershoot of a scraping threshold and/or a specification of a relative sensitivity of the gentle start-up. In FIG. 7, a user can set the sensitivity 334 (Sensitivity), for example, between low and high. In particular by relocating a slide 336. A user could also specify a relative value, percentage or absolute value of deviation of a scraping threshold 172 from a base value 154 of a physical characteristic 142, in particular base value 154 of a physical characteristic 142 of the machine tool 10 in the operating state with a throttled movement, in particular idle operating state 144 with a throttled movement. This base value would advantageously be a detected and ascertained base value 154 of the physical characteristic 142 of the machine tool 10, in particular according to the aforementioned method for operating a machine tool with adaptive gentle start-up.

[0130] Not shown further here, a sensitivity for detection or analysis of a physical characteristic 142 typical for the gentle start-up can also be set, for example by specifying an ascertaining method for forming a threshold, in particular by selecting, for example, the averaging method, e.g. formation of the moving average, a period for averaging the detected values of the physical characteristic, or the like.

[0131] The function interface 300 advantageously comprises at least one, advantageously several, of the following further display, selection and/or setting options: [0132] a connection state 338, designated here as connected, of an external device 301 providing the functional interface 300, here smartphones 303 with the machine tool 10 and/or an activation or deactivation of a connection with the machine tool 10; [0133] a name 340, a property and/or a state 342 of the machine tool 10; [0134] a selection option 344 for a number of operating levels 310 and/or working setpoint rotational speeds 312 available on the function interface and/or a function interface of the machine tool, in particular wherein a changeability of these available operating levels 310 and/or setpoint rotational speed 312 can be blocked; [0135] a display 350 and/or setting options 346 of a setpoint rotational speed 312 for each operating level 310; an activation or deactivation or enabling or disabling 308 the gentle start-up at least for one, in particular several, advantageously all operating levels 310 and/or setpoint rotational speeds 312; a sensitivity 334 and/or a delay 324 or a delay period 328 of the gentle start-up, in particular jointly for all operating levels 310 and/or setpoint rotational speeds 312, alternatively also optionally individually for each setpoint rotational speed and/or operating level; [0136] a kickback or drop shutdown 352 for the machine tool 10; [0137] a machine light setting option 354, in particular for switching on and off, setting the brightness and/or activating/deactivating a stroboscope mode; [0138] a property 356, in particular a brightness or button assignment of a function interface 358 directly on the machine tool 10, in particular an HMI on the machine tool 10; [0139] a level indicator 360 of the battery or battery pack of the machine tool 10.

[0140] It is proposed that the function interface 300 comprises at least one, advantageously a plurality of optical setting sliders 362, 364, 366, which are designed to be displaceable between a minimum and a maximum setpoint, in particular for defining a drive rotational speed, the sensitivity 334 of the gentle start-up and/or a delay period 328 for accelerating the machine tool to load mode after detection of an overshoot or undershoot of a scraping threshold 172.

[0141] When a gentle start-up is activated at the function interface 300, an icon for setting further properties of the gentle start-up may appear, in particular for setting further properties of the gentle start-up in a submenu of the application program, advantageously with respect to a setting of the sensitivity 334 and/or the delay period 328 or a delay 324, as shown for example in FIG. 7.

[0142] The output of a signal when the (scraping) threshold 172 is overshot and/or during the detection or ascertaining of the base value and/or threshold, in particular an acoustic, optical and/or haptic signal, can be performed, for example, by the or at the functional interface 358 of the machine tool 10 or by the or at the functional interface 300 or the external unit. For example, by output 382 on the machine tool.

[0143] It is proposed that after the machine tool 10 has been switched off and switched on again within a minimum rest period, for example 30 seconds, the machine tool 10 is immediately set to a movement state, in particular the load mode movement state 184 that can advantageously be set. On the other hand, once the minimum rest period of e.g. 30 seconds has been overshot, the machine tool 10 is initially operated again with gentle start-up, i.e. with a throttled movement until a scraping threshold 172 is overshot. The times given are merely examples.

[0144] FIG. 9 shows an alternative machine tool 10. It is a hand tool 12, advantageously an oscillating multifunction tool 19. It is set up to carry out one of the aforementioned methods or comprises an adaptive and/or configurable gentle start-up function. The oscillating multifunction tool 19 comprises a drive unit 40 and a control or regulating unit 20 at least for controlling or regulating the drive unit 40. It also has a tool holder 64 and advantageously a drive train 38 between drive unit 40 and tool holder 64. The machine tool 10 is battery-powered. Advantageously, the machine tool 10 has a detection unit 22 for time-dependent detection of a physical characteristic of the machine tool 10, preferably for time-dependent detection of a motor current and/or a motor rotational speed of the drive unit 40 designed as a drive motor.

[0145] The oscillating multifunction tool 19 can also be operated as a system with the function interface 300 or other external unit to enable a configurable and/or adaptive gentle start-up. At least other identical parts in principle are provided with corresponding reference signs.