Method for monitoring an electric hand-held power tool and electric hand-held power tool

Abstract

A method (20) for monitoring an electric hand tool (1), in particular an impact wrench (1), comprises the following method steps (21, 22). The operating time of the electric hand tool (1) is determined. If the operating time is greater than or equal to a predefinable threshold, a notification is issued indicating that maintenance of the electric hand tool (1) is required.

Description

[0001] The present invention relates to a method for monitoring an electric hand-held power tool and an electric hand-held power tool.

[0002] In production lines, impact wrenches are used frequently to tighten screws and / or nuts. If one of these tools malfunctions during an assembly process, it causes disruptions throughout the entire assembly line and reduces production efficiency.

[0003] Typically, the user of an impact wrench decides when maintenance or repair is necessary. This often leads to premature maintenance, resulting in a reduced overall service life. Conversely, an impact wrench may fail due to a lack of timely maintenance.

[0004] An object of the present invention is to provide an improved method for monitoring an electric hand-held power tool and to provide an improved electric hand-held power tool. This object is achieved by a method for monitoring an electric hand-held power tool and an electric hand-held power tool with the features of the respective independent claims. Furthermore, a computer program for carrying out the method and a machine-readable storage medium containing the computer program are claimed. Advantageous embodiments are specified in the respective dependent claims.

[0005] A method for monitoring an electric hand tool, in particular an impact wrench, comprises the following steps. The operating time of the electric hand tool is determined. If the operating time is greater than or equal to a predefined threshold, a notification is issued indicating that maintenance of the electric hand tool is required.

[0006] The method is based on the concept of intelligent maintenance for electric power tools. The operating time of the electric power tool is monitored, and a notification is displayed to the user indicating that maintenance or repair should be carried out when the operating time reaches a predefined threshold. This advantageously prevents the electric power tool from being unnecessarily out of service or used for extended periods without maintenance. This can, for example, improve the efficiency of an assembly line or production line.

[0007] In one embodiment, the effective operating times of the electric hand tool are taken into account when determining the operating duration. In one embodiment, the effective operating times are determined by weighting the operating times and summing the weighted operating times.

[0008] The electric power tool may be used frequently, for example, if it is a rotary impact wrench and a large number of screw connections need to be made and / or loosened. Making and loosening a screw connection takes place within a certain operating time. The operating time is the sum of all operating times, for example, the sum of all times required to make and loosen screw connections. The operating time can also be referred to as the total operating time.

[0009] Furthermore, the electric power tool may be used for various tasks. For example, if the electric power tool is designed as an impact wrench, it may be used to create and / or loosen a variety of screw connections, but not every connection requires impact operation. Since impact operation demands more power and puts more strain on the impact wrench, weighting the operating times can be beneficial. For instance, all operating times in impact mode can be weighted so that they contribute more to the overall operating time than operating times in freewheel mode, where no impacts are generated. Generally, weighting can be based on factors such as power consumption, regardless of the operating mode.

[0010] The effective operating times can be determined alternatively or additionally to weighting, for example, based on auxiliary usage times and / or idle times of the electric hand tool, by subtracting these times from the operating times. An auxiliary usage time can, for example, include the time required to start up or shut down the electric hand tool. An idle time is a period during which the electric hand tool is operating, but no work is being performed.

[0011] In one embodiment, the determined operating time is stored in a memory and reset after maintenance of the electric hand tool. The determined operating time can, for example, be stored in the memory of the electric hand tool's control unit. Alternatively or additionally, the determined operating time can be sent via a communication module of the electric hand tool to a mobile device and stored in the mobile device's memory and / or a cloud connected to the mobile device.

[0012] In one embodiment, the threshold is adjusted if maintenance of the electric hand tool is performed by a predefinable further threshold value before or after the threshold has been exceeded. Advantageously, the threshold can thus be adapted to an individual hand tool that requires earlier or later maintenance compared to the threshold value. For example, earlier maintenance can be particularly beneficial if the electric hand tool is subjected to special stress.

[0013] In another embodiment, it can be checked at regular intervals whether an update of the threshold is necessary, for example every six months.

[0014] A computer program product comprises instructions that, when executed on a computer, cause it to perform a procedure according to one of the described embodiments. The computer program product is stored on a machine-readable storage medium. This storage medium can, for example, be part of the control system of an electric power tool.

[0015] An electric power tool, in particular an impact wrench, has a control unit and a maintenance indicator connected to the control unit. The control unit is designed to determine the operating time of the electric power tool. The maintenance indicator is designed to display a message indicating that maintenance of the electric power tool is required when the operating time is greater than or equal to a predefined threshold.

[0016] The predefined threshold value can be determined experimentally for the electric hand tool, for example, during the development of the electric hand tool. The threshold value can be stored in the electric hand tool's memory before its initial commissioning.

[0017] In one embodiment, the electric handheld power tool has a communication module connected to the control unit for exchanging data with a mobile device. Advantageously, a user can set the predefined threshold value via the mobile device and monitor the operating time. Furthermore, the operating times can be stored and monitored on the mobile device and / or in a cloud.

[0018] In one embodiment, the control system is configured to adjust the threshold value when maintenance of the electric hand tool is performed at a predefined further threshold value before or after the threshold value has been exceeded. Alternatively, this threshold update can be performed via the mobile device and / or the cloud.

[0019] The procedure for operating an electric hand-held power tool is explained in detail below with the aid of schematic drawings. These show: Fig. 1 : Components of an exemplary electric hand-held power tool; Fig. 2 : Process steps of the procedure for operating the electric hand-held power tool; Fig. 3 : further procedural steps that can be carried out within the framework of the procedure.

[0020] Fig. 1 Figure 1 schematically shows components of an electric hand tool 1, which is exemplified as an impact wrench 1. However, the electric hand tool 1 could alternatively be configured, for example, as a cordless screwdriver, a drill, an angle grinder, or a saw, such as a jigsaw.

[0021] The impact wrench 1 has a drive motor 2, which is designed as an electric motor. For example, the drive motor 2 can be an electronically commutated motor (EC motor). The drive motor 2 is connected to a gearbox 3. The impact wrench 1 has a rotary hammer mechanism with a rotary hammer 4, which is connected to the gearbox 3. The impact wrench 1 is designed to accommodate a tool holder 6. The tool holder 6 is connected to an anvil 5, which can be coupled to the rotary hammer 4 and, together with the rotary hammer 4, forms the rotary hammer mechanism of the impact wrench 1.

[0022] The tool holder 6 is designed to hold a tool, for example, a screwdriver bit or a socket. The tool holder 6 is rotatable due to its connection to the drive motor 2 via the gearbox 3 and the rotary impact hammer mechanism. In other words, the tool holder 6 can be driven by the drive motor 2. Furthermore, the rotary impact hammer mechanism is designed to deliver impacts to the tool holder 6. This allows a torque to be generated and built up gradually and in pulses. This impact operation of the rotary impact wrench 1 can be used, for example, to tighten or loosen screw connections.

[0023] In general, the electric hand tool 1 includes at least the drive motor 2. If the electric hand tool 1 is not designed as an impact wrench 1, the rotary impact hammer mechanism, for example, is omitted. Furthermore, the tool holder 6 may be an integral part of the electric hand tool 1. In this case, the electric hand tool 1 includes at least the tool holder 6 and the drive motor 2 for driving the tool holder 6.

[0024] The electric hand tool 1 further comprises a control unit 7 connected to the drive motor 2, a battery 8 connected to the control unit 7 for supplying electrical energy to the electric hand tool 1, or to the control unit 7 and the drive motor 2, and a trip switch 9 connected to the control unit 7. The electric hand tool 1 also has a user interface 10 (human-machine interface, or HMI) connected to the control unit 7. The torque to be generated can be adjusted via the HMI 10. Furthermore, various operating modes can be selected via the HMI 10, such as operating modes for screw connections of varying hardness. The HMI 10 can, for example, be designed as or include a touch-sensitive display device. Alternatively, the HMI 10 can have a display device and separate operating elements.

[0025] The electric hand tool 1 also includes a speed sensor 11 and a current sensor 12, each connected to the drive motor 2 and configured to provide the controller 7 with the speed and operating current of the drive motor 2. The electric hand tool 1 may alternatively or additionally include other sensors. For example, the electric hand tool 1 may include a torque sensor for measuring the torque applied to the tool holder 6 during operation of the electric hand tool 1.

[0026] The speed sensor 11, the current sensor 12, and / or other sensors can, for example, be used to determine and monitor work progress. For instance, it may be possible to monitor whether a final tightening torque has been reached when tightening a screw connection. To indicate work progress, the electric hand tool 1 has a quality indicator 13, which is connected to the control unit 7, but this indicator can also be omitted. Likewise, the electric hand tool 1 does not necessarily have to have sensors 11 and 12.

[0027] To connect the electric hand tool 1 to a mobile device 14, the electric hand tool 1 has a communication module 15 that is connected to the controller 7. Settings that can be made via the HMI 10 can also be made via the mobile device 14. Work progress can also be displayed via the mobile device 14. Furthermore, data can be stored in a cloud 17 via the mobile device 14. The communication module 15 can, for example, be configured to establish a Bluetooth connection to the mobile device 14. The electric hand tool 1 and the mobile device 14 can also be connected via another wireless connection or a wired connection. However, the communication module 15 is optional and can also be omitted.

[0028] Electric hand tools 1 that are used or operated frequently require regular maintenance. If an electric hand tool 1 fails unexpectedly, this can disrupt work progress. This is especially true when multiple electric hand tools 1 are used in a complex assembly process. While a user can decide independently when to perform maintenance, this decision is purely subjective and, even with extensive user experience, can lead to maintenance being performed too early, unnecessarily hindering work progress, or too late, potentially causing unnecessary damage to the electric hand tool 1, for example, if it has been used for too long in a demanding task.

[0029] The electric hand tool 1 of the Fig. 1 For this reason, it has a maintenance indicator 16, which is connected to the controller 7. The maintenance indicator 16 and the HMI 10 can be used as described in Fig.1 The maintenance indicator 16 can be displayed separately. For example, it can be designed as a light-emitting diode (LED). Alternatively, it can be part of the HMI 10.

[0030] The maintenance indicator 16 enables the electric hand tool 1 to be operated in such a way as to avoid premature or delayed maintenance. The maintenance indicator 16 is designed to issue a warning that maintenance of the electric hand tool 1 is required. This warning is issued when, during operation of the electric hand tool 1, it is determined that a critical operating time has been reached.

[0031] Fig. 2 Figure 1 schematically shows process steps 21 and 22 of such a process 20 for monitoring the electric hand tool 1, in which the operating time is monitored.

[0032] In a first process step 21, the operating time of the electric hand tool 1 is determined. In a second process step 22, a message is displayed indicating that maintenance of the electric hand tool 1 is required if the operating time is greater than or equal to a predefined threshold value. In this case, the maintenance indicator 16 is activated.

[0033] Fig. 2 This shows that determining the operating time in the first process step 21 comprises, for example, three sub-steps 23, 24, and 25. In the first step 23, the operating times of the electric hand tool 1 are recorded. In the second step 24, effective operating times are determined, for example, by weighting individual recorded operating times. In the third step 25, the weighted operating times are added together and compared with the predefined threshold value. The second step 24 can also be omitted. In this case, the operating time is determined in the third step 25 based on the recorded operating times, without weighting individual operating times or generally determining effective operating times.

[0034] Fig. 3 Figure 26 schematically shows further procedural steps 26, 27, and 28 that can be carried out within the framework of procedure 20.

[0035] In a first step 26, the electric hand tool 1 can be sent for maintenance. In a second step 27, the predefined threshold value can be reset once the maintenance has been completed. The threshold value can be reset either in the control unit 7 of the electric hand tool 1 or in an application on the mobile device 14. In a third step 28, the maintenance indicator 16 can be deactivated after the maintenance has been performed. Simultaneously, a maintenance report can be stored in the control unit 7 and / or on the mobile device 14 and / or in the cloud 17.

Claims

1. Method (20) for monitoring an electric hand tool (1), in particular an impact wrench (1), comprising the following method steps (21, 22): - Determining the operating time of the electric hand tool (1), - Outputting a notification that maintenance of the electric hand tool (1) is required when the operating time is greater than or equal to a predefinable threshold.

2. Method (20) according to claim 1, wherein effective operating times of the electric hand tool (1) are taken into account when determining the operating time.

3. Method (20) according to claim 2, wherein the effective operating times are determined by weighting operating times and the operating duration is determined by summing the weighted operating times.

4. Method (20) according to one of the preceding claims, wherein the determined operating time is stored in a memory and reset after maintenance of the electric hand tool (1).

5. Method (20) according to one of the preceding claims, wherein the threshold is adjusted when the maintenance of the electric hand tool (1) is carried out by a predefinable further threshold before or after the threshold has been exceeded.

6. Computer program product comprising instructions which, when executed on a computer, cause it to execute a method (20) according to one of the preceding claims.

7. Machine-readable storage medium on which the computer program product according to claim 6 is stored.

8. Electric hand tool (1), in particular impact wrench (1), comprising a control (7) and a maintenance indicator (16) connected to the control (7), wherein the control (7) is configured to determine the operating time of the electric hand tool (1), wherein the maintenance indicator (16) is configured to output a message indicating that maintenance of the electric hand tool (1) is required when the operating time is greater than or equal to a predefinable threshold.

9. Electric hand tool (1) according to claim 8, comprising a communication module (15) connected to the control (7) for exchanging data with a mobile terminal (14).

10. Electric hand tool (1) according to claim 8 or 9, wherein the control (7) is configured to adjust the threshold when the maintenance of the electric hand tool (1) is carried out by a predefinable further threshold before or after the threshold has been exceeded.

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