Operating procedure and system for operating a cutting device, hand-held cutting device, detection method for detecting at least one state of a cutting device

The handheld cutting device optimizes lubrication through a controllable pump system that adjusts lubricant delivery based on variable parameters, enhancing reliability and reducing consumption, addressing inefficiencies in existing devices.

DE102024133735A1Pending Publication Date: 2026-05-21ANDREAS STIHL AG & CO KG
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Patent Information

Application Number
DE102024133735
Authority / Receiving Office
DE · DE
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-11-18
Publication Date
2026-05-21

AI Technical Summary

Technical Problem

Existing handheld cutting devices face challenges in achieving reliable and efficient lubrication, particularly at low ambient temperatures and varying operating conditions, leading to potential operational inefficiencies and increased lubricant consumption.

Method used

A handheld cutting device with a controllable pump system that delivers lubricating fluid based on variable parameters such as workpiece properties, cutting mode, tool conditions, and environmental factors, allowing for on-demand lubrication and optimized lubricant consumption.

Benefits of technology

Enables reliable operation with reduced lubricant consumption by adapting lubrication to varying conditions, ensuring efficient performance and maintenance, even at low temperatures.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a detection method for detecting at least one state (FZ1, FZ2, FZ3) of a cutting device (1) which has a reciprocating piston pump assembly (3A) for the controllable delivery of lubricating fluid (SKF), wherein the reciprocating piston pump assembly (3A) comprises: a pump chamber (40) for receiving and discharging lubricating fluid (SKF), a pump piston (5) which is movable for drawing in and displacing lubricating fluid (SKF) in the pump chamber (40), a control element (6) which is movably arranged and configured in the pump chamber (40) in a first control state (SZ1) and in a second control state (SZ2) such that a suction and displacement differential volume (AVDV) is different in the first control state (SZ1) and the second control state (SZ2), and a control device (7) which has an electromagnet (10).wherein the control body (6) and the control device (7) for magnetically controlling the control body (6) are configured into the first control state (SZ1) and / or the second control state (SZ2), wherein the detection method comprises the steps of: monitoring an electrical quantity of the electromagnet (10) to determine an actual value of the electrical quantity and / or an actual value of a quantity dependent on the electrical quantity, comparing the actual value with a corresponding target value, and detecting at least one state (FZ1, FZ2, FZ3) of the cutting device (1) by comparison.
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Description

SCOPE OF APPLICATION AND STATE OF THE ART

[0001] The invention relates, in particular with one aspect, to an operating method for operating a handheld cutting device. The invention further relates, in particular with another aspect, to a system for operating such a handheld cutting device. Furthermore, the invention relates, in particular with another aspect, to such a handheld cutting device. Finally, the invention relates, in particular with another aspect, to a detection method for detecting at least one state of such a handheld cutting device. TASK AND SOLUTION

[0002] It is an object of the present invention to provide an operating method for operating a hand-held cutting device, a system for operating such a hand-held cutting device, such a hand-held cutting device, and a detection method for detecting at least one state of such a hand-held cutting device, each of which, in particular, has improved properties. In particular, the invention aims to enable particularly reliable and / or lubrication-efficient operation of the hand-held cutting device.

[0003] This problem is solved by the subject matter of the independent patent claims. Preferred embodiments are the subject matter of the dependent patent claims. The wording of all claims is made explicit by reference to the content of this description.

[0004] An operating method according to one aspect of the invention serves for the, in particular automatic, operation of a hand-held cutting device. Specifically, the hand-held cutting device is operated according to the operating method. The cutting device comprises a cutting tool, wherein the cutting tool is at least partially designed to move at a certain speed. In particular, the movement or speed of the cutting tool is relative to an outer housing part of the cutting device.

[0005] The cutting tool can be a saw chain, particularly a rotating one. The cutting device also has a pump designed for the controllable delivery of lubricating fluid. This pump is electrically controllable and delivers a controllable flow rate to lubricate the cutting tool. The operating procedure comprises step a) in which at least one variable parameter characteristic of the flow rate to be controlled is provided. The operating procedure also comprises step b) in which the pump is electrically controlled based on the provided variable parameter or a variable determined based on the provided parameter.The electrical control of the pump is achieved in such a way that the delivery rate is variable for the same, i.e., constant and / or unchanged, speed, and / or for a variable speed, it deviates from a proportionality to the speed at least section by section, i.e., at least temporarily and / or intermittently. In this way, on-demand lubrication of the cutting tool can be enabled, which can promote the reliability of the operation of the hand-held cutting device and / or enable on-demand lubricant consumption during operation of the cutting device.

[0006] Advantageously, the pump device can be electrically controlled to deliver a quantity of lubricating fluid when the cutting tool is stationary and thus its speed is zero. For example, it may be possible to flood the lubrication system of the cutting tool with lubricating fluid to remove air bubbles and thus ensure immediate and reliable delivery of lubricating fluid to the cutting tool at the start of movement. Alternatively or additionally, it may be possible to flush out contaminants from the lubrication system of the cutting tool in the same or a similar manner, particularly without movement of the cutting tool. The delivery of lubricating fluid made possible by the invention when the cutting tool is stationary can be advantageous for maintenance purposes, either alternatively or additionally.

[0007] Advantageously, the invention enables robust lubricant delivery, particularly even at low ambient temperatures. Alternatively or additionally, the invention enables power-dependent and / or chain-force-dependent lubricant delivery.

[0008] The terms "encompass" or "have" can be used synonymously with each other and with the term "exhibit".

[0009] The phrase “- as well as alternatively or additionally -” can be replaced by the phrase “and / or” and vice versa.

[0010] A “lubricating fluid” within the meaning of the present disclosure may be designed and / or used for lubricating and / or cooling, in particular the cutting tool.

[0011] The lubricating fluid can be an oil. Alternatively or additionally, the viscosity of the lubricating fluid can be temperature-dependent, in particular so that the lubricating fluid becomes more viscous the lower its temperature.

[0012] In an embodiment of the invention, the variable parameter is characteristic of a variable workpiece property to be cut by the cutting tool. This variable workpiece property can be a variable material, variable moisture content, variable workpiece temperature, and / or variable cutting length. The cutting length is the length of the material-separating engagement of the cutting tool with the workpiece during cutting. When delimbing, especially of tree trunks, a relatively short cutting length may be present. Young stands, in other words, stands of young trees, can have a relatively high moisture content.When pruning and / or cutting young growth, the lubricant requirement and / or power requirement may be relatively low. The process can automatically compensate for this, resulting in a reduction of lubricant consumption of up to 50% compared to standard lubricant consumption when cutting such material. The "cutting length" can be defined as the diameter of the workpiece to be cut, particularly in the form of a branch. Specifically, the smaller the cutting length, the less lubricant is required.

[0013] In a further embodiment of the invention, the variable parameter is characteristic of a variable cutting mode of the cutting device, in particular the cutting tool. Specifically, the cutting mode for which the variable parameter is characteristic is a cutting mode comprised of a set of different cutting modes. This set can include a felling and / or crosscutting cutting mode as well as a delimbing cutting mode. In particular, the feed rate for the felling and / or crosscutting cutting mode, especially at the same speed, is higher than for the delimbing cutting mode. It is understood that alternatively or additionally, other cutting modes are conceivable, in particular a young stand cutting mode and / or further cutting modes. Another cutting mode can, for example, be a firewood cutting mode, especially for cutting particularly dry firewood with particularly low chain free play and a particularly low amount of lubricant.

[0014] In a further embodiment of the invention, the speed of the cutting unit is variable. The variable parameter is characteristic of the variable speed. At low speeds, the ratio of the flow rate to the speed is higher than at high speeds. Specifically, the flow rate itself is higher at low speeds than at high speeds. In particular, the speed is proportional to the drive speed of the motor drive system and can therefore be determined by it.

[0015] In a further embodiment of the invention, the variable parameter is characteristic of a variable tool property of the cutting tool. The variable tool property can be a variable tool length and / or a variable design and / or a variable tool temperature of the cutting tool. In this respect, an automatic adjustment of the lubricant quantity is enabled when the cutting device is retooled.

[0016] In a further embodiment of the invention, the variable parameter is characteristic of a variable movement duration and / or a variable standstill duration of the cutting tool. In particular, the variable parameter is characteristic of a variable speed profile over time. The standstill duration can optionally be recorded and / or stored and / or queried by a mobile delivery device.

[0017] For example, a communication unit can detect the start and end of a cutting machine's operation and send this information to a mobile processing unit. This mobile processing unit could be the mobile staging unit or another device. Within the cutting machine, the detected time parameters can be compared to a predefined downtime threshold. If this threshold is exceeded, the lubricant flow rate at the start of a work process can be increased compared to a start without exceeding the downtime threshold. A measure of the downtime threshold could be, for example, a day or 24 hours. To increase the lubricant flow rate, a signal can be sent to a controller after a downtime is detected, increasing the lubricant delivery rate.

[0018] In a further embodiment of the invention, the cutting device has a lubricant tank designed to store lubricant. The pump assembly is configured to deliver lubricant from the lubricant tank to the cutting tool. The variable parameter is characteristic of variable emptying and / or refilling of the lubricant tank with lubricant. This parameter can depend on the variable fill level of the lubricant tank. A level sensor can be provided on the cutting device to detect the parameter and / or the fill level. Optionally, the fill level can be determined based on a signal supplied by the level sensor in combination with a consumption calculation.

[0019] In a further embodiment of the invention, the cutting device comprises a motor drive system, wherein the motor drive system is configured to drive the cutting tool. A variable parameter is characteristic of a variable operating characteristic of the motor drive system. This variable operating characteristic can be a variable drive speed and / or a variable torque and / or a variable power input and / or a variable power output and / or a variable load. In particular, information about the speed is available in a control unit of the cutting device for controlling the drive motor. Specifically, a torque can be determined via an electrical motor current of the motor drive system, which is expediently measured in the control unit, in order to determine the power input in conjunction with the drive speed.

[0020] In a further embodiment of the invention, the variable parameter is characteristic of a variable environmental property of the cutting device's environment. The variable environmental property can be a variable meteorological parameter, in particular a variable ambient temperature and / or a variable ambient humidity. Alternatively or additionally, the variable environmental property can be variable air pollution, in particular a variable dust concentration and / or a variable season. The ambient temperature can, for example, be estimated based on the control unit temperature or determined via a temperature sensor.

[0021] In a further embodiment of the invention, step a) includes determining, in particular detecting, the variable parameter.

[0022] In a further embodiment of the invention, the variable parameter is a variable tool temperature of the cutting tool. Step b) includes determining the variable tool temperature based on the determined variable parameter. Furthermore, step b) includes electrically controlling the pump device based on the determined variable tool temperature. The tool temperature can be determined using a temperature sensor, for example, in a rail stop of the cutting device.

[0023] In a further embodiment of the invention, step a) comprises providing, in particular acquiring, a variable position and / or a variable height of the cutting device and / or a variable season of the cutting device's surroundings. Furthermore, step a) comprises providing, in particular determining, the variable parameter based on the provided variable position and / or the provided variable height and / or the provided variable season. The variable position can be referenced to geographical coordinates. The variable height can be referenced to sea level. The variable season can be referenced to geographical coordinates, in particular to a geographical latitude and / or a hemisphere. Such a parameter can potentially be determined and provided by means of a mobile provisioning device.

[0024] The variable parameter can be usefully characterized by the presence of lubricating fluid itself and / or by power and / or by motor speed and / or by chain pull force on the cutting tool and / or by temperature of the cutting tool.

[0025] In a further embodiment of the invention, the operating method comprises a wireless transmission of the variable parameter to the cutting device, in particular from a mobile delivery unit. Alternatively or additionally, the operating method comprises a wireless transmission of a variable quantity determined based on the variable parameter to the cutting device, in particular from the mobile delivery unit. Alternatively or additionally, the operating method comprises a wireless transmission of the delivery quantity to be controlled to the cutting device, in particular from the mobile delivery unit.

[0026] It may be useful to provide a basic setting option that allows the user to preset the delivery rate of lubricating fluid directly on the cutting device and / or on the mobile delivery device, in particular via an app.

[0027] Advantageously, the lubricant supply may be provided by a separate lubricant pump, in particular a lubricant pump with its own electric drive motor. In other words, an advantageously further developed cutting device has at least two electric motors, wherein a first motor serves as the main drive for the cutting tool and a second electric motor serves as the drive for the lubricant supply, in particular for driving the lubricant pump. In particular, the first motor may have an electrical power output that is approximately five times that of the second motor.

[0028] In a further embodiment of the invention, the pump assembly comprises a reciprocating piston pump assembly. The pump speed of the reciprocating piston pump assembly depends on the velocity, at least section by section, and in particular mechanically. The intake and displacement stroke of a pump piston of the reciprocating piston pump assembly and / or the intake and displacement differential volume of a pump chamber can be electrically controlled to control the delivery of lubricating fluid. Step b) comprises electrically controlling the intake and displacement stroke and / or the intake and displacement differential volume based on the provided variable parameter or on the variable determined based on the provided parameter.

[0029] A system according to a further aspect of the invention serves to operate a hand-held cutting device. In particular, the system is designed to carry out an operating method according to the invention. The system comprises the cutting device, a supply device, and an electrical control device. The cutting device has a cutting tool, the cutting tool being at least partially designed for movement at a controlled speed. Furthermore, the cutting device has a pump device, the pump device being electrically controlled for the controllable delivery of lubricating fluid with a controllable delivery rate for the controllable lubrication of the cutting tool with the delivered lubricating fluid. The pump device of the cutting device, which can be operated according to the operating method and / or is comprised of the system, can be designed as a reciprocating piston pump device.The system's provisioning device is designed to provide at least one variable parameter characteristic of the flow rate to be controlled. Furthermore, the control device is designed to electrically control the pump based on the provided variable parameter or on a variable quantity determined based on the provided parameter. The control device is designed to electrically control the pump such that the flow rate is variable for the same velocity and / or deviates from a proportionality to the velocity at least section by section for a variable velocity.

[0030] A hand-held cutting device according to a further aspect of the invention comprises a cutting tool. The cutting device also includes a pump assembly in the form of a reciprocating pump assembly, wherein the pump assembly, designed as a reciprocating pump assembly, is configured for the controllable delivery of lubricating fluid for the controllable lubrication of the cutting tool with the delivered lubricating fluid. The reciprocating pump assembly has a pump chamber, the pump chamber being configured for receiving and discharging lubricating fluid. Furthermore, the reciprocating pump assembly has a pump piston, the pump piston being arranged and configured in the pump chamber for axial movement to draw lubricating fluid into the pump chamber and to displace the drawn-in lubricating fluid out of the pump chamber.Furthermore, the reciprocating pump assembly has a control element, wherein the control element is movably arranged and configured within the pump chamber for contact with lubricating fluid, at least partially in a first control state and / or in a second control state different from the first. The control element is arranged and configured such that the intake and displacement differential volumes for controlling the delivery of lubricating fluid through the control element differ between the first and second control states. The reciprocating pump assembly also has a control device, wherein the control device is configured to control the control element in the first and / or second control state. In particular, the reciprocating pump assembly enables particularly reliable and / or lubricant-saving operation of the cutting device.The cutting device can be configured for operation using one of the operating procedures described above. Alternatively, the cutting device can be configured for use in a system described above, in particular one configured to execute the operating procedure.

[0031] In an embodiment of the invention, particularly in the embodiment of the cutting device, the control element is arranged on an end face of the pump piston, specifically in contact with the lubricating fluid. The intake and displacement differential volume can be located at least partially between the control element and the end face of the pump piston. Alternatively or additionally, the control element is configured for axial movement to control the delivery of the lubricating fluid.

[0032] Within the scope of the present disclosure, the phrase “on a [...] side” and / or the phrase “on a [...] side” may be appropriately understood as indicating the direction of a lateral arrangement relative to a body surface section adjacent to the [...] side in question, in particular such that contact with a body surface section bounding this [...] side may be present but need not be, especially unless otherwise specified.

[0033] In a further embodiment of the invention, in the first control state, the control body moves together with the pump piston, in particular in phase, at least section by section in a cyclical fashion. In the first control state, the control body can move in contact with the pump piston together with the pump piston in a cyclical fashion, at least section by section. Alternatively or additionally, in the second control state, the control body does not move together with the pump piston and / or with respect to the pump chamber. In particular, in the second control state, the control body does not move in phase with the pump piston.

[0034] In a further embodiment of the invention, the reciprocating piston pump assembly, in particular the pump chamber, has at least one limiting element. This at least one limiting element, which limits the axial movement of the control body, particularly in the first control state, is jointly formed with the pump piston and is designed only for a section. In particular, this section is a segment of a piston stroke movement of the pump piston.

[0035] In a further embodiment of the invention, the control device includes a control element. The control element is designed to apply force to the control body in the first control state, particularly towards the pump piston. In particular, the control element is guided within the control body.

[0036] In a further embodiment of the invention, the pump chamber has a chamber cross-sectional area, wherein the control body has a control cross-sectional area.

[0037] The control cross-sectional area corresponds to the chamber cross-sectional area in such a way that the control element blocks an axial flow of lubricating fluid past the control element. In a further embodiment of the invention, the pump chamber has a control opening, in particular on an end face of the pump piston. This end face serves specifically for contact with the lubricating fluid. In the first control state, the control element allows a flow of lubricating fluid through the control opening and out of the pump chamber. In the second control state, the control element blocks a flow of lubricating fluid through the control opening and out of the pump chamber.

[0038] In a further embodiment of the invention, the pump chamber has a control opening at its end face. The pump chamber has a chamber cross-sectional area, the control opening has an opening cross-sectional area, and the control body has a control cross-sectional area. The control cross-sectional area is smaller than the chamber cross-sectional area such that, at least in the first control state, the control body allows an axial flow of lubricating fluid past the control body. The control cross-sectional area is larger than the opening cross-sectional area such that, in the second control state, the control body blocks the control opening.

[0039] In a further embodiment of the invention, the pump chamber has an intake opening on one circumferential side for a flow of lubricating fluid, particularly radial, through the intake opening into the pump chamber. Furthermore, the pump chamber has a displacement opening on a farther, particularly opposite, circumferential side for a flow of lubricating fluid, particularly radial, through the displacement opening out of the pump chamber. The intake opening and the displacement opening are arranged at approximately the same axial length.

[0040] In a further embodiment of the invention, the pump chamber has an intake opening on one circumferential side for a flow of lubricating fluid, particularly radial, through the intake opening into the pump chamber, and a displacement opening on a opposite circumferential side for a flow of lubricating fluid, particularly radial, through the displacement opening out of the pump chamber. The pump piston is designed for a cyclical rotary movement to temporarily open the intake opening, temporarily close the displacement opening, temporarily close the intake opening, and temporarily open the displacement opening.

[0041] In a further embodiment of the invention, the control body and the control device are designed for contactless, in particular magnetic, control of the control body into the first state and / or the second state.

[0042] In a further embodiment of the invention, the control device comprises an electromagnet and a magnetic cage. The electromagnet surrounds the pump chamber on one circumferential side. The magnetic cage surrounds the electromagnet on one, and preferably another, circumferential side. The magnetic cage is a deep-drawn and / or stamped part. In other embodiments of the invention, the magnetic cage may be manufactured using a different manufacturing process, which may not involve deep drawing and / or stamping.

[0043] In a further embodiment of the invention, the control device is designed to be electrically controllable, wherein the electrical energy input by the control device for controlling the control body into the first control state and / or into the second control state depends on the presence of lubricating fluid.

[0044] The cutting device may have a detector device, wherein the detector device is designed to detect power consumption and to detect lubricating fluid based on the detected power consumption.

[0045] One, and in particular a further, operating method according to the invention can serve to operate a hand-held cutting device described above. In particular, the hand-held cutting device is operated according to the operating method. The operating method, and in particular a further, includes a step in which the control element is controlled into the first control state or into the second control state by means of the control device.

[0046] A detection method according to a further aspect of the invention serves to detect at least one state, in particular a fault state, of a hand-held cutting device. Specifically, at least one state of the hand-held cutting device is detected according to the detection method. The cutting device for the detection method has a pump unit in the form of a reciprocating pump unit for the controllable delivery of lubricating fluid, in particular for the controllable lubrication of a cutting tool of the cutting device. The reciprocating pump unit has a pump chamber for receiving lubricating fluid and for discharging the received lubricating fluid. Furthermore, the reciprocating pump unit has a pump piston which is arranged and designed in the pump chamber for axial movement to draw lubricating fluid into the pump chamber and to displace the drawn-in lubricating fluid out of the pump chamber.Furthermore, the reciprocating pump assembly has a control element that is movably arranged and configured, at least partially, in the pump chamber for contact with lubricating fluid in a first control state and / or in a second control state different from the first control state. The control element is designed such that the intake and displacement differential volumes for controlling the delivery of lubricating fluid through the control element differ between the first and second control states. The reciprocating pump assembly also includes a control device, the control device comprising an electromagnet. The control element and the control device are configured for controlling the control element, particularly magnetically, into the first control state and / or the second control state.

[0047] The detection method for recognizing at least one state, as described in the preceding paragraph, comprises a step in which at least one electrical parameter of the electromagnet is monitored to determine an actual value of the electrical parameter and / or an actual value of a parameter dependent on the electrical parameter. Furthermore, the detection method comprises a step in which the determined actual value is compared with the corresponding target value. The detection method also includes a step in which at least one state, in particular at least one fault state, of the handheld cutting device is detected based on, in particular, the result of, this comparison. The detection method can, in particular, enable particularly reliable operation of the cutting device designed for carrying out the detection method.

[0048] In an embodiment of the invention, at least one state, in particular from a number of several different states, in particular from a number of several different fault states, is identified and / or qualified exclusively by comparison.

[0049] In a further embodiment of the invention, the monitoring process captures the actual temporal profile of the electromagnet's electrical parameter during the time it is magnetically controlled, i.e., adjusted, to the second control state within a specific pull-in period. Based on this captured actual temporal profile of the electromagnet's electrical parameter, an actual value for the pull-in period, particularly as a parameter dependent on the electrical parameter, is determined.

[0050] In a further embodiment of the invention, the monitored electrical quantity of the electromagnet is an electric current flowing through an electrical coil of the electromagnet.

[0051] In a further embodiment of the invention, a particularly first state is recognized in which the reciprocating piston pump device, especially when the supply of lubricating fluid is exhausted, draws in air instead of lubricating fluid if the actual value of the pull-in time is less than the corresponding target value. The actual value and / or the target value can be a moving average.

[0052] In a further embodiment of the invention, at least one electrical parameter of the electromagnet, particularly when deactivated, is monitored over time while the control element is being switched to the first control state. At least one monitored electrical parameter of the electromagnet is an electrical voltage induced in the electromagnet's coil.

[0053] In a further embodiment of the invention, a state, particularly a second one, is a standstill of the control element in the pump chamber, especially a permanent standstill, when the actual value of the electrical voltage induced in the electrical coil is less than the corresponding setpoint value. In particular, the standstill of the control element in the pump chamber is detected when no electrical voltage is induced in the electrical coil.

[0054] In a further embodiment of the invention, the electrical voltage induced in the electrical coil of the electromagnet is detected by means of an electronic comparator circuit of the cutting device.

[0055] In a further embodiment of the invention, at least one electrical parameter of the electromagnet is monitored immediately after the reciprocating pump assembly is deactivated, particularly when the cutting device stops. The stop can be a cessation of movement of the cutting tool. Immediately after the reciprocating pump assembly is deactivated, the control element is returned to its first control state within a reset time, particularly automatically. At least one monitored electrical parameter of the electromagnet is an electrical inductance, particularly of the electrical coil, of the electromagnet.

[0056] In a further embodiment of the invention, the inductance is detected, in particular by means of an electrical resonant circuit of the cutting device, more specifically by means of an LC resonant circuit of the cutting device.

[0057] In a further embodiment of the invention, an actual value of a temporal change in inductance is determined and compared with the corresponding target value in order to detect, as a third condition in particular, at least a partial blockage on the pump outlet side.

[0058] In a further embodiment of the invention, the actual value of the inductance is determined, in particular as a quantity dependent on the electrical quantity, on the basis of one, in particular half, period of an oscillation of the electrical resonant circuit.

[0059] In a further embodiment of the invention, the inductance is monitored immediately before activation of the piston pump device, particularly when the cutting device is started, and during the time the control element is switched, particularly automatically, to the first control state, in order to determine the target value for the inductance and / or for a time-dependent change in the inductance. The start of the cutting device can be the commencement of movement of the cutting tool.

[0060] A hand-held cutting device designed for carrying out the detection method described above, according to a further aspect of the invention, comprises a reciprocating piston pump for the controllable delivery of lubricating fluid. Furthermore, the hand-held cutting device has an electrical control device for electrically controlling the reciprocating piston pump, wherein the control device is configured and / or programmed to carry out the detection method according to the invention. The reciprocating piston pump has a pump chamber for receiving and discharging lubricating fluid. The reciprocating piston pump also has a pump piston that is arranged and configured in the pump chamber for axial movement to draw lubricating fluid into the pump chamber and to displace the drawn-in lubricating fluid from the pump chamber.Furthermore, the reciprocating pump assembly has a control element which is movably arranged and configured, at least partially, in the pump chamber for contact with lubricating fluid in the first control state and / or a second control state different from the first control state, such that the intake and displacement differential volumes for controlling the delivery of lubricating fluid through the control element differ in the first and second control states. In addition, the reciprocating pump assembly has a control device comprising an electromagnet, wherein the control element and the control device are configured for magnetically controlling the control element in the first control state and / or the second control state.

[0061] The aforementioned aspects of the invention can be implemented jointly, particularly in all conceivable combinations, or individually. The aspects of the invention can, if necessary, expediently enhance one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Further advantages and features of the invention will become apparent from the claims and from the following description of preferred embodiments of the invention, which are illustrated with reference to the drawings. In this context, identical reference numerals refer to identical, similar, or functionally equivalent components.

[0063] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention. Fig. Figure 1 shows in a schematic perspective view an embodiment of a system according to the invention for operating a hand-held cutting device, wherein the system comprises an embodiment of a cutting device according to the invention and is designed to carry out an embodiment of an operating method according to the invention, wherein the cutting device is designed to carry out an embodiment of a recognition method according to the invention for recognizing at least one state of the cutting device. Fig. Figure 2 shows a schematic side view detail of the internal workings of the cutting device. Fig. 1, Fig. 3 in schematic sectional view of a pump device cutting device according to Fig. 1, Fig. 4 in schematic sectional view the pump device of a further embodiment of the cutting device according to the invention, Fig. 5 in schematic sectional view the pump device of a further embodiment of the cutting device according to the invention, Fig. 6 the pumping equipment after Fig. 5, wherein a control body of the pump device is located in one of Fig. 5 different control states are located Fig. 7 schematically a time course of an electric current of an electric coil current to illustrate an embodiment of the detection method according to the invention, Fig. 8 schematic time profiles of an electrical coil voltage and an electrical comparator output voltage to illustrate a further embodiment of the detection method, Fig. 9. Schematic time profiles of a lubrication fluid system pressure and a coil inductance to illustrate a further embodiment of the detection method and Fig. 10 a scheme for a state machine for a further embodiment of the recognition method. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0064] A handheld cutting device 1 has a cutting tool 2. In this case, the cutting device 1 is a chainsaw whose cutting tool 2 has a continuously driven saw chain. Alternatively, the cutting device 1 could be, for example, a pole pruner or a brush cutter. In particular, the cutting device 1 is battery-powered. The cutting device 1 can be a battery-operated power tool.

[0065] The hand-held cutting device 1 can be operated according to an operating procedure. The cutting tool 2 is at least partially designed to move at a speed n2. Therefore, at least a part of the cutting tool 2 can perform the movement at speed n2. In this case, the saw chain of the cutting tool 2 can be driven continuously at speed n2.

[0066] The cutting device 1 has a pumping device 3 which is electrically controllable for the controllable delivery of SKF lubricating fluid with a controllable delivery quantity Q3 for the controllable lubrication of the cutting tool 2 with delivered SKF lubricating fluid.

[0067] The operating procedure for operating the hand-held cutting device 1 includes a step a) according to which at least one variable parameter is provided, wherein the at least one variable parameter is characteristic of the delivery quantity Q3 to be controlled.

[0068] The operating procedure also includes a step b) according to which the pump device 3 is electrically controlled based on the provided variable parameter or a variable quantity determined based on the provided parameter. The electrical control of the pump device 3 based on the variable parameter or the quantity determined based on the parameter is such that the flow rate Q3 is variable for the same velocity n2 and – alternatively or additionally – deviates from a proportionality to the velocity n2 at least section by section for a variable velocity n2.

[0069] For example, the variable parameter is characteristic of a variable piece property SE of a workpiece 70 to be cut by the cutting tool 2. For example, the workpiece 70 is cut by the cutting tool 2 during the execution of the operating procedure. The variable piece property SE of the workpiece 70 can be a variable material WE of the workpiece 70. Alternatively or additionally, the variable piece property SE can be a variable moisture content FE of the workpiece 70. Alternatively or additionally, the variable piece property SE can be a variable temperature T70 of the workpiece 70. Alternatively or additionally, the variable piece property SE can be a variable cutting length SL of the workpiece 70.

[0070] For example, the variable parameter is characteristic of a variable cutting mode of the cutting device 1. The variable cutting mode of the cutting device 1 can be a variable cutting mode of the cutting tool 2. For example, the cutting mode is comprised of a set of different cutting modes of the cutting device 1. This set of cutting modes can include a felling and / or crosscutting cutting mode as well as a delimbing cutting mode. For the felling and / or crosscutting cutting mode, the feed rate Q3, especially for the same speed n2, can be higher than for the delimbing cutting mode.

[0071] For example, the speed n2 of the cutting tool 2 is variable. The variable parameter is characteristic of the variable speed n2. For a low speed n2, the ratio of the flow rate Q3 to the speed n2 can be higher than for a high speed n2. In particular, the flow rate Q3 is higher for a low speed n2 than for a high speed n2.

[0072] The variable parameter is characteristic, for example, of a variable tool property W2 of the cutting tool 2. The variable tool property W2 can be a variable tool length L2. Alternatively or additionally, the variable tool property W2 can be a variable design B2 of the cutting tool 2, which in particular determines a tool type of the cutting tool 2. Alternatively or additionally, the variable tool property W2 can be a variable tool temperature T2 of the cutting tool 2.

[0073] For example, the variable parameter is characteristic of a variable movement duration as well as – alternatively or additionally – of a variable standstill duration of the cutting tool 2. The variable parameter can be characteristic of a variable time course of the velocity n2.

[0074] The cutting device 1, for example, has a lubricant tank 8. The lubricant tank 8 is designed to store SKF lubricant. The pump unit 3 is designed to pump SKF lubricant from the lubricant tank 8 to the cutting tool 2. For example, the variable parameter allows for variable emptying and – alternatively or additionally – variable refilling of the lubricant tank 8 with SKF lubricant.

[0075] The cutting device 1, for example, has a motor drive system 4. The motor drive system 4 is designed to drive the cutting tool 2. The variable parameter is characteristic of a variable operating property B4 of the operation of the motor drive system 4. The variable operating property B4 can be a variable drive speed n4 of the motor drive system 4. Alternatively or additionally, the variable operating property B4 can be a variable torque M4 of the motor drive system 4. Alternatively or additionally, the variable operating property B4 can be a variable power input and / or a variable power output PA4 of the motor drive system 4. Alternatively or additionally, the variable operating property B4 can be a variable load LA4 of the motor drive system 4.

[0076] For example, the variable parameter is characteristic of a variable environmental property E60 of an environment 60 of the cutting device 1. The variable environmental property E60 can be a variable meteorological characteristic M60 of the environment 60. For example, the variable meteorological characteristic M60 can be a variable ambient temperature T60 of the environment 60. Alternatively or additionally, the variable meteorological characteristic M60 can be a variable air pollution V60 of the environment 60. Alternatively or additionally, the variable meteorological characteristic M60 can be a variable air dust concentration S60 of the environment 60. Alternatively or additionally, the variable meteorological characteristic M60 can be a variable season J60 of the environment 60.

[0077] For example, step a) of the operating procedure involves determining, in particular recording, the variable parameter.

[0078] For example, the variable parameter of the variable tool temperature T2 of the cutting tool 2 is different. Step b) can involve determining the variable tool temperature T2 based on the determined variable parameter and electrically controlling the pump device 3 based on the determined variable tool temperature T2.

[0079] For example, step a) includes providing, in particular acquiring, a variable position PO of the cutting device 1. Alternatively or additionally, step a) may include providing, in particular acquiring, a variable height HE of the cutting device 1. Alternatively or additionally, step a) may include providing, in particular acquiring, the variable season J60 of the environment 60 of the cutting device 1.

[0080] For example, step a) includes providing, in particular determining, the variable parameter based on the provided variable position PO of the cutting device 1. Alternatively or additionally, step a) includes providing, in particular determining, the variable parameter based on the provided variable height HE of the cutting device 1. Alternatively or additionally, step a) may include providing, in particular determining, the variable parameter based on the provided variable season J60 of the environment 60 of the cutting device 1.

[0081] For example, the method includes wireless transmission of the variable parameter PR to the cutting device 1. Alternatively or additionally, the method can include wireless transmission of a variable quantity determined based on the variable parameter to the cutting device 1. Alternatively or additionally, the method can include wireless transmission of the flow rate Q3 to be controlled to the cutting device 1. The wireless transmission of the variable parameter and / or the variable quantity determined based on the variable parameter and / or the flow rate Q3 to be controlled to the cutting device 1 can be performed from a mobile delivery device 55. The mobile delivery device 55 can be configured to send the corresponding data, and the cutting device 1 can be configured to receive the data sent by the mobile delivery device 55.

[0082] The pump unit 3 of the cutting device 1 is designed in this case as a reciprocating piston pump unit 3A. In particular, alternatively or additionally, other cutting devices 1 with differently designed pump units 3 can be operated in accordance with corresponding embodiments of the operating procedure.

[0083] In the present case, the pump speed of the reciprocating pump assembly 3A can depend on the velocity n2, at least section by section, in particular mechanically. For example, the suction and displacement stroke HS of a pump piston 5 of the reciprocating pump assembly 3A, as well as – alternatively or additionally – the suction and displacement differential volume AVDV of a pump chamber 40 for controlling the delivery of SKF lubricant, can be electrically controlled. Step b) of the operating procedure can, for example, involve electrically controlling the suction and displacement stroke HS and – alternatively or additionally – the suction and displacement differential volume AVDV based on the provided parameter or based on the variable determined based on the provided parameter.

[0084] A system 50 serves to operate the hand-held cutting device 1. In particular, the system 50 is designed to execute the operating procedure. The system 50 comprises the cutting device 1, a supply unit 51, and an electrical control unit 52. The supply unit 51 is configured to provide at least one variable parameter characteristic of the flow rate Q3 to be controlled. The control unit 52 is configured to electrically control the pump unit 3 of the cutting device 1 based on the provided variable parameter or based on a variable determined based on the provided parameter.The control device 52 is designed to electrically control the pump device 3 in such a way that the delivery rate Q3 is variable for the same speed n2 and - alternatively or additionally - deviates from a proportionality to the speed n2 at least section by section for a variable speed n2.

[0085] The reciprocating piston pump assembly 3A of the cutting device 1 is designed for the controllable delivery of SKF lubricant for the controllable lubrication of the cutting tool 2 with the delivered SKF lubricant. As already indicated, the reciprocating piston pump assembly 3A has the pump chamber 40. The pump chamber 40 is designed for receiving and discharging SKF lubricant. SKF lubricant can therefore be delivered through the pump chamber 40. The pump piston 5 is arranged and designed in the pump chamber 40 such that it can perform an axial movement to draw SKF lubricant into the pump chamber 40 and to displace the drawn-in SKF lubricant from the pump chamber 40. The axial movement of the pump piston 5 can correspond to the intake and displacement stroke HS.

[0086] The reciprocating piston pump assembly 3A has a control element 6. The control element 6 is arranged and configured to be movable in the pump chamber 40 in a first control state SZ1 and – alternatively or additionally – in a second control state SZ2, which differs from the first control state SZ1, in order to contact SKF lubricating fluid in the pump chamber 40, particularly in both control states SZ1 and SZ2. The control element 6 is arranged and configured in the pump chamber 40 such that the intake and displacement differential volume AVDV for controlling the delivery of SKF lubricating fluid through the control element 6 differs in the first control state SZ1 and the second control state SZ2.In particular, the intake and displacement differential volume AVDV can be changed by controlling the control body 6 from the first control state SZ1 to the second control state SZ2 or from the second control state SZ2 to the first control state SZ1.

[0087] The reciprocating piston pump assembly 3A also includes a control unit 7. The control unit 7 is designed to control the control body 6 into the first control state SZ1 and – alternatively or additionally – into the second control state SZ2.

[0088] The pump piston 5, for example, has an end face 5S. The control element 6 is, for example, arranged on the end face 5S. The end face 5S of the pump piston 5 can be designed to come into contact with SKF lubricant. The suction and displacement differential volume AVDV can be located, at least partially, between the control element 6 and the end face 5S of the pump piston 5.

[0089] For example, the control body 6 is designed for axial movement, whereby the axial movement of the control body 6 can be used to control the delivery of SKF lubricant.

[0090] For example, in the first control state SZ1, the control body 6 moves cyclically axially at least in segments together with the pump piston 5. In the first control state SZ1, the control body 6 can move cyclically axially at least in segments together with the delivery piston 5 while in contact. For example, in the first control state SZ1, the control body 6 and the pump piston 5 move cyclically axially in phase at least in segments together.

[0091] For example, in the second control state SZ2, the control element 6 does not move together with, and in particular not in phase with, the pump piston 5. Alternatively or additionally, in the second control state SZ2, the control element 6 does not move relative to the pump chamber 40. Therefore, in the second control state SZ2, the control element 6 can be stationary relative to the pump chamber 40.

[0092] For example, the reciprocating piston pump assembly 3A has at least one limiting element 80. The limiting element 80 can be located within the pump chamber 40. The limiting element 80 is designed to restrict the axial movement of the control body 6 to only one section AS. The section AS, to which the axial movement of the control body 6 can be restricted by means of the at least one limiting element 80, can be a section AS of the axial intake and displacement stroke HS of the pump piston 5. In particular, the limiting element 80 restricts the axial movement of the control body 6, which the control body 6 performs jointly with the pump piston 5 in the first control state SZ1, only to the section AS.

[0093] The control device 7, for example, has a control element 9. The control element 9 can be designed as an elastically deformable spring device. In this case, the control element 9 is designed to apply force to the control body 6 in the first control state SZ1, in particular towards the pump piston 5. The control element 9 can be guided in and / or directly on the control body 6.

[0094] The pump chamber 40, for example, has a chamber cross-sectional area 4Q. The control body 6, for example, has a control cross-sectional area 6Q. The control cross-sectional area 6Q and the chamber cross-sectional area 4Q correspond to each other such that the control body 6 blocks an axial flow of SKF lubricant past the control body 6, see in particular Fig. 3 and / or Fig. 4.

[0095] For example, the pump chamber 40 has a control opening 4SO. The control opening 4SO can be located on the end face 5S of the pump piston 5. For example, in the first control state SZ1, the control element 6 allows a flow of SKF lubricant through the control opening 4SO out of the pump chamber 40, whereas in the second control state SZ2, the control element 6 blocks a flow of SKF lubricant through the control opening 4SO out of the pump chamber 40.

[0096] The pump chamber 40 in particular has a body or is a body which has inside a chamber interior for receiving SKF lubricating fluid and for discharging received SKF lubricating fluid.

[0097] For example, the pump chamber 40 has an end face 4S. The control opening 4SO is, for example, located on the end face 4S of the pump chamber 40.

[0098] The control opening 4SO, for example, has an opening cross-sectional area of ​​4SOQ. This can be seen, for example, from the Fig. 5 and Fig. 6, especially in contrast to Fig. 3 and / or 4, comprehensibly, the control cross-sectional area 6Q is smaller than the chamber cross-sectional area 4Q such that the control body 6 releases an axial flow of SKF lubricant past the control body 6 at least in the first control state SZ1, whereas the control cross-sectional area 6Q is larger than the opening cross-sectional area 4SOQ such that the control body 6 blocks the control opening 4SO in the second control state SZ2.

[0099] For example, the pump chamber 40 has a circumferential side 4UA. An intake opening 4AO of the pump chamber 40 can be formed on the circumferential side 4UA for a flow of SKF lubricant, for example, radially, through the intake opening 4AO into the pump chamber 40. The pump chamber 40 has, for example, a circumferential side 4UV, which faces away from the circumferential side 4UA and / or the intake opening 4AO. On the circumferential side 4UV, for example, a displacement opening 4VO of the pump chamber 40 is formed, for example, opposite the intake opening 4AO, for a flow of SKF lubricant, for example, radially, through the displacement opening 4VO and out of the pump chamber 40.

[0100] The intake opening 4AO and the displacement opening 4VO are arranged, for example, at approximately, and in particular at exactly, the same axial length z. The axial length z can be measured parallel to an axial direction of the reciprocating pump assembly 3A. A radial direction R of the reciprocating pump assembly 3A extends perpendicular to the axial direction or axial length z. A circumferential direction U of the reciprocating pump assembly 3A runs in a plane extending perpendicular to the axial direction or axial length z, in particular around a central axis of the pump chamber 40 and / or the pump piston 5.

[0101] For example, the pump piston 5 is designed for a cyclical rotary movement to temporarily open the intake port 4AO and temporarily close the displacement port 4VO. The pump piston 5 can therefore function both as a displacement element and as a control element of the reciprocating piston pump assembly 3A.

[0102] For example, the control body 6 and the control device 7 are configured for contactless control of the control body 6 into the first control state SZ1 and – alternatively or additionally – into the second control state SZ2. For example, the control body 6 and the control device 7 are configured for magnetic control of the control body 6 into the first control state SZ1 and / or into the second control state SZ2.

[0103] The control device 7, for example, comprises an electromagnet 10 and a magnet cage 11. The electromagnet 10 can enclose the pump chamber 40 on one circumferential side 4U of the pump chamber 40. The magnet cage 11 can enclose the electromagnet 10 on one circumferential side 10U of the electromagnet 10. The magnet cage 11 can, for example, be a deep-drawn and / or stamped part 12. It is understood that the magnet cage 11 can also be manufactured using a manufacturing process other than deep drawing and / or stamping.

[0104] For example, the control unit 7 is designed to be electrically controllable. The electrical energy input by the control unit 7 for controlling the control body 6 into the first control state SZ1 and / or the second control state SZ2 can depend on the presence of SKF lubricant. The cutting device 1 can have a detector unit 13, wherein the detector unit 13 is designed to detect the power input and to detect SKF lubricant based on the detected power input.

[0105] The above-mentioned or another operating procedure for operating the cutting device 1 may include a step according to which the control body 6 is controlled to the first control state SZ1 or to the second control state SZ2 by means of the control device 7.

[0106] A detection method serves to detect at least one state FZ1, FZ2, FZ3 of the hand-held cutting device 1. In particular, fault states FZ1, FZ2, FZ3 of the hand-held cutting device 1 are detectable by means of the detection method.

[0107] For the detection method, the cutting device 1 has the reciprocating piston pump assembly 3A for the controllable delivery of SKF lubricant. The control unit 7 of the reciprocating piston pump assembly 3A of the cutting device 1 configured for the detection method has the electromagnet 10. The control body 6 and the control unit 7 are configured for magnetically controlling the control body 6 into the first control state SZ1 and / or into the second control state SZ2.

[0108] The detection method includes a step in which at least one electrical quantity of the electromagnet 10 is monitored in order to determine an actual value of the electrical quantity as well as - alternatively or additionally - an actual value of a quantity dependent on the electrical quantity.

[0109] The detection process also includes a step in which the determined actual value is compared with a corresponding target value.

[0110] Furthermore, the method includes a step according to which at least one state FZ1, FZ2, FZ3, in particular a fault state, of the hand-held cutting device 1 is detected by comparison.

[0111] For example, at least one state FZ1, FZ2, FZ3 is identified solely based on comparison, in particular on the result of a comparison. At least one state FZ1, FZ2, FZ3 can be qualified solely based on comparison. In particular, the at least one state FZ1, FZ2, FZ3 is identified and / or qualified from a number of several distinct states FZ1, FZ2, FZ3.

[0112] For example, when monitoring at least one electrical parameter of the electromagnet 10, a time-dependent actual profile of the electrical parameter of the electromagnet 10 is recorded. The time-dependent actual profile of the electrical parameter can be recorded during the time the control element 6 is magnetically controlled into the second control state SZ2, in particular precisely, within a pull-up time tA. Based on the recorded time-dependent actual profile of the electrical parameter of the electromagnet 10, a current value of the pull-up time tA is determined. The current value of the pull-up time tA can thus be determined as a parameter dependent on the electrical parameter.

[0113] For example, at least one electrical quantity of the electromagnet 10 monitored according to the detection method is an electric current I flowing through an electric coil 10A of the electromagnet 10, in particular coil current.

[0114] In the Fig. Figure 7 shows an example of the time course of the electric current I in amperes over time t in milliseconds. Time t1 corresponds to the switch-on time of the electric coil 10A. Time t3 refers to the time at which the control element 6 has just assumed the second control state SZ2. Time t2 represents the beginning of an adjustment of the control element 6, as a result of which it is controlled into the second control state SZ2. Between times t2 and t3, the control element 6 is therefore in motion.

[0115] For example, the first condition FZ1, and in particular the first fault condition, is detected when the reciprocating pump unit 3A draws in air instead of SKF lubricant if the actual value of the pull-in time tA is less than the corresponding target value. Specifically, the first condition FZ1 represents an exhausted supply of SKF lubricant. The SKF lubricant supply can be exhausted if the lubricant tank 8 is empty or if the SKF lubricant level in the lubricant tank 8 has reached a minimum value. It is also possible that air is drawn in instead of SKF lubricant if a lubricant system of the cutting unit 1 has a leak.

[0116] For example, according to the detection method, at least one electrical parameter of the electromagnet 10 is monitored while the control body 6 is being switched to the first control state SZ1. The at least one electrical parameter of the electromagnet 10 can be monitored while the electromagnet 10 is deactivated. The at least one monitored electrical parameter of the electromagnet 10 can be an electrical voltage U induced in the electrical coil 10A of the electromagnet 10, in particular the coil voltage.

[0117] For example, the second state FZ2, and in particular the second fault state, can be a standstill – for example, a permanent standstill – of the control element 6 in the pump chamber 40. The second state FZ2 is detected, for example, when the actual value of the electrical voltage U induced in the electrical coil 10A is less than the corresponding setpoint value. Specifically, the standstill of the control element 6 in the pump chamber 40 can be detected when no electrical voltage U is induced in the electrical coil 10A.

[0118] For example, the electrical voltage U induced in the electrical coil 10A of the electromagnet 10 is detected by means of an electronic comparator circuit KS of the cutting device 1. In the Fig. Figure 8 shows an example of the electrical voltage U in volts induced in the 10A electrical coil over time t in milliseconds. Furthermore, it shows Fig. Figure 8 shows the curve of a comparator output voltage UKA, particularly the resulting voltage, of the comparator circuit KS over time t. At time t4, the supply voltage of the electromagnet 10 can be deactivated. At time t5, the comparator voltage UKA indicates that the supply voltage of the electromagnet 10 has been deactivated. A timer can then be started. At time t6, the comparator voltage UKA indicates that an electrical voltage U has been induced in the coil 10A, which is greater than the corresponding setpoint value, in this case greater than 0 V. The timer is then stopped to determine half a period T / 2, which is representative of the actual inductance L, or rather, based on which the actual inductance can be determined.

[0119] For example, according to the detection method, at least one electrical parameter of the electromagnet 10 is monitored immediately after the reciprocating pump unit 3A is deactivated, in particular when the cutting device 1 is stopped. Immediately after the reciprocating pump unit 3A is deactivated, the control element 6 is, in particular automatically, switched to the first control state SZ1 within a reset time. The at least one monitored electrical parameter of the electromagnet 10, which is monitored immediately after the reciprocating pump unit 3A is deactivated, can be an electrical inductance L, in particular a coil inductance, of the electromagnet 10. In particular, the electrical inductance L of the electromagnet 10 is an electrical inductance L of the electrical coil 10A of the electromagnet 10.

[0120] For example, the inductance L is detected. The inductance L can be detected using a resonant circuit SK of the cutting device 1. The resonant circuit can be designed as an LC resonant circuit. In the Fig. Figure 9 shows a curve of the inductance L in µH over time t and a curve of a pump output pressure p, in particular a lubrication system pressure, in bar over time t.

[0121] For example, the detection method can be used to identify a third state FZ3, in particular a third fault state, which represents at least a partial blockage on the pump outlet side. An actual value of a time-dependent change in the inductance L can be determined and compared with the corresponding target value in order to identify the third state FZ3.

[0122] For example, according to the detection procedure, an actual value of the reset time duration, particularly as a quantity dependent on the electrical quantity, is determined based on the actual value of the inductance L and / or based on the actual time course of the inductance L. The actual value of the reset time duration can be compared with the corresponding target value to detect the third state FZ3.

[0123] For example, the inductance L is monitored immediately before the reciprocating pump unit 3A is activated, particularly when the cutting device 1 is started. The inductance L can be monitored immediately before the reciprocating pump unit 3A is activated, specifically during the time the control element 6 is being moved to the first control state SZ1, in order to determine the target value for the reset time and / or for a time-dependent change in the inductance L.

[0124] The hand-held cutting device 1, designed for the recognition procedure, has, for example, an electrical control device 52, in particular its own and / or internal one. The control device 52 can be configured and / or programmed to carry out the recognition procedure.

[0125] The recognition process can be implemented using a state machine, the structure of which is exemplified in the representation of the Fig. Figure 10 is illustrated. The control device 52 of the cutting device 1 can be programmed on the basis of the state machine.

[0126] In this case, field S0 of the state machine represents a boot process of the cutting device 1. The boot process can be carried out in particular immediately after switching on, i.e. after making the cutting device 1 ready for operation.

[0127] After the boot process has been completed, a self-test of the cutting device 1 can be performed, where the self-test is represented in this case by a field S1 of the state machine. During the self-test, the motor drive system 4 and / or at least the moving part of the cutting tool 2 is stationary.

[0128] As part of the self-test, an inductance measurement L can first be performed, which is represented here by field 1000 of the state machine. Specifically, during the measurement of the inductance L, the control element 6 is initially in the first control state SZ1. During the measurement of the inductance L, field 1000 checks whether the actual value of the inductance L is less than the corresponding target value. If this is not the case, i.e., the actual value of the inductance L is greater than the corresponding target value, the presence of the third state FZ3 is automatically detected. Provided that the third state FZ3 has not been detected, the motor drive system 4 can be started after field S1, specifically to drive the reciprocating pump unit 3A for pumping SKF lubricant. This is illustrated here by the arrow labeled "Start" on the state machine.

[0129] Following the start-up, field S2 of the state machine is activated. During the processes encompassed by field S2, the motor drive system 4 is operated. When the control element 6 is switched to the second control state SZ2, which is represented here by arrow 3000 of the state machine, a measurement of the pull-up time tA is performed. This measurement of the pull-up time tA is represented here by field 4000 of the state machine. Based on the measurement of the pull-up time tA, it is checked whether the actual value of the pull-up time tA is greater than or equal to the corresponding target value.

[0130] If the actual value of the pull-in time tA is less than the corresponding setpoint, the first state FZ1 is recognized, particularly automatically. Otherwise, a measurement of the voltage U induced in the coil 10A is performed concurrently with the control element 6 being switched to the first control state SZ1. This is represented here by an arrow line 5000 and by a field 7000 of the state machine. Here, it is checked, particularly automatically, whether the actual value of the electrical voltage U induced in the electrical coil 10A is greater than or equal to the corresponding setpoint.

[0131] If the actual value of the induced voltage U is detected to be lower than the corresponding target value, the presence of the second state FZ2 is recognized. If the control element 6 is in the first control state SZ1 after the motor drive system 4 has been started, the measurement of the induced voltage U can also be taken directly, as illustrated here by an arrow 6000 leading to field 7000 of the state machine. If the control element 6 is then switched to the second control state SZ2, the measurement of the pull-in time tA can follow, as can be seen from an arrow 8000 pointing to field 4000 of the state machine.

Claims

[1] Detection method for detecting at least one state (FZ1, FZ2, FZ3) of a hand-held cutting device (1), wherein the cutting device (1) has a reciprocating pump assembly (3A) for the controllable delivery of lubricating fluid (SKF), wherein the reciprocating pump assembly (3A) has: - a pump chamber (40) for receiving lubricating fluid (SKF) and for discharging received lubricating fluid (SKF), - a pump piston (5) which is arranged and designed in the pump chamber (40) for axial movement to draw lubricant (SKF) into the pump chamber (40) and to displace drawn-in lubricant (SKF) from the pump chamber (40), - a control element (6) which is arranged and designed to be movable and controllable at least partially in a first control state (SZ1) and / or a second control state (SZ2) different from the first control state (SZ1) in the pump chamber (40) for contact with lubricating fluid (SKF) such that an intake and displacement differential volume (AVDV) for controlling the delivery of lubricating fluid (SKF) through the control element (6) is different in the first control state (SZ1) and the second control state (SZ2), and - a control device (7) comprising an electromagnet (10), wherein the control body (6) and the control device (7) are configured for magnetically controlling the control body (6) into the first control state (SZ1) and / or the second control state (SZ2); - the detection procedure comprises the following steps: - Monitoring at least one electrical quantity of the electromagnet (10) in order to determine an actual value of the electrical quantity and / or an actual value of a quantity dependent on the electrical quantity, - Comparing the determined actual value with a corresponding target value, - Detecting at least one condition (FZ1, FZ2, FZ3), in particular a fault condition, of the hand-held cutting device (1) by comparison. [2] Detection method according to claim 1, - wherein at least one state (FZ1, FZ2, FZ3), in particular from a number of several different states (FZ1, FZ2, FZ3), is identified, in particular qualified, solely by comparison. [3] Detection method according to claim 1 or 2, - wherein during monitoring a temporal actual course of the electrical quantity of the electromagnet (10) is recorded, while the control body (6) is magnetically controlled into the second control state (SZ2) within a pull-in time period (tA), - wherein, based on the recorded actual temporal profile of the electrical quantity of the electromagnet (10), an actual value of the pull-in time duration (tA), in particular as a quantity dependent on the electrical quantity, is determined. [4] Detection method according to any one of claims 1 to 3, - wherein the monitored electrical quantity of the electromagnet (10) is an electric current (I) flowing through an electric coil (10A) of the electromagnet (10). [5] Detection method according to any one of the preceding claims, - wherein - if the actual value of a tightening time duration (tA) is less than the corresponding target value - it is recognized as, in particular, the first, state (FZ1) that the reciprocating pump device (3A), especially when the supply of lubricating fluid (SKF) is exhausted, draws in air instead of lubricating fluid (SKF). [6] Detection method according to any one of the preceding claims, - wherein at least one electrical parameter of the, in particular deactivated, electromagnet (10) is monitored while the control body (6) is controlled to the first control state (SZ1), - wherein at least one monitored electrical quantity of the electromagnet (10) is an electrical voltage (U) induced in an electrical coil (10A) of the electromagnet (10), - in particular where - if the actual value of the electrical voltage (U) induced in the electrical coil (10A) is less than the corresponding setpoint value - as, in particular, a second, state (FZ2) is recognized as, in particular, a permanent standstill of the control body (6) in the pump chamber (40). [7] Detection method according to the preceding claim, - wherein the electrical voltage (U) induced in the electrical coil (10A) of the electromagnet (10) is detected by means of an electronic comparator circuit (KS) of the cutting device (1). [8] Detection method according to any one of the preceding claims, - wherein at least one electrical parameter of the electromagnet (10) is monitored immediately after deactivation of the piston pump device (3A), in particular when the cutting device (1) is stopped, - wherein immediately after deactivating the reciprocating piston pump device (3A) the control body (6) is controlled to the first control state (SZ1) within a reset time period, - wherein at least one monitored electrical quantity of the electromagnet (10) is an electrical inductance (L), in particular of an electrical coil (10A), of the electromagnet (10), - in particular, wherein the inductance (L) is detected, in particular by means of an electrical resonant circuit (SK) of the cutting device (1), more specifically by means of an LC resonant circuit of the cutting device (1). [9] Detection method according to the preceding claim, - where an actual value of a time change of the inductance (L) is determined and compared with the corresponding target value in order to detect, in particular as a third state (FZ3), at least a partial blockage on the pump outlet side. [10] Hand-held cutting device (1) comprising: - a reciprocating piston pump unit (3A) for the controllable delivery of lubricating fluid (SKF), and - wherein an electrical control device (52) for electrically controlling the reciprocating piston pump device (3A), wherein the control device (52) is configured and / or programmed to perform a detection method according to one of the preceding claims, - wherein the reciprocating piston pump assembly (3A) comprises: - a pump chamber (40) for receiving lubricating fluid (SKF) and for discharging received lubricating fluid (SKF), - a pump piston (5) which is arranged and designed in the pump chamber (40) for axial movement to draw lubricant (SKF) into the pump chamber (40) and to displace drawn-in lubricant (SKF) from the pump chamber (40), - a control element (6) which is arranged and designed to be movable and controllable at least partially in a first control state (SZ1) and / or a second control state (SZ2) different from the first control state (SZ1) in the pump chamber (40) for contact with lubricating fluid (SKF) such that an intake and displacement differential volume (AVDV) for controlling the delivery of lubricating fluid (SKF) through the control element (6) is different in the first control state (SZ1) and the second control state (SZ2), and - a control device (7) comprising an electromagnet (10), wherein the control body (6) and the control device (7) are configured to magnetically control the control body (6) into the first control state (SZ1) and / or the second control state (SZ2).

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