DE102021204949A1 - Method for operating an internal combustion engine - Google Patents

Abstract

The invention relates to a method (56) for operating an, in particular battery-less, internal combustion engine (6) which has a crankshaft (8) and a control unit (38) with an output device (50). The control unit (38) is supplied by means of electrical energy, which is generated on the basis of a rotation of the crankshaft (8), and an operating state (60, 64) is output by means of the output device (50). The invention also relates to an internal combustion engine (6) and an implement (2).

Description

The invention relates to a method for operating an internal combustion engine and an internal combustion engine. The invention also relates to an implement with an internal combustion engine. The internal combustion engine is preferably battery-free.

Tools such as chain saws or lawnmowers are usually driven by motors. An electric motor, for example, is selected as the motor. This has a comparatively low noise emission and is comparatively little maintenance and care-intensive. An efficiency is also comparatively high. However, if the work device is to be self-sufficient, it is necessary to carry batteries or the like that are self-discharging. It is therefore necessary to monitor the batteries in order to be able to operate the implement over a comparatively long period of time.

An alternative to this is to use an internal combustion engine. In this case, a fuel can be refilled comparatively quickly. It is also possible to store implements driven in this way over a comparatively long period of time without restriction in terms of subsequent use. To reduce manufacturing costs, the internal combustion engines usually have only a single cylinder and / or mostly a carburetor.

At comparatively low temperatures, which occur particularly in mountainous locations, however, the fuel condenses and is deposited on the walls of a combustion chamber of the internal combustion engine, which must be taken into account by adjusting the carburetor. However, such a setting is not operationally reliable at comparatively high ambient temperatures. It is therefore necessary to adapt the carburetor to the corresponding ambient conditions. Air pressure and oxygen saturation are also reasons for changing the carburetor setting at different altitudes

In order to achieve a comparatively high degree of efficiency and also to increase operational reliability, it is also necessary to change the ignition times, i.e. the times at which the fuel-air mixture located in the combustion chamber of the internal combustion engine is ignited. In particular, if these ignition times are shifted “early”, an increase in speed is to be expected. Increasing the speed increases fuel consumption, produces more heat and reduces the service life of the mechanics.

Since the work device is usually hand-operated for a comparatively long time, it is desirable that the work device and thus also of the internal combustion engine be comparatively low. As a result, the adjustment devices of the internal combustion engine are usually designed manually, which also increases their robustness. However, it is necessary for the user to set the carburetor manually, for which a deeper knowledge of the functioning of the internal combustion engine is required. As a result, an inexperienced user cannot use the implement, or can only use it to a limited extent.

A manual starting device, for example a pull-wire starter, is also mostly used as the starting device for the internal combustion engine. As a result is
no battery required. The robustness of the internal combustion engine is also increased. The electrical energy required to operate a spark plug of the internal combustion engine is generated using one revolution of a crankshaft of the internal combustion engine, usually by means of what is known as magneto ignition. Alternatively, a generator is used. As a result, however, no electrical energy is available when the crankshaft is at a standstill. Thus, before the motor vehicle is put into operation, it is not possible to check whether the manual settings made by the user lead to safe operation of the internal combustion engine.

If, therefore, a critical state is reached during operation of the internal combustion engine, the internal combustion engine is usually switched off by means of a safety shutdown. In this case, however, it is not clear to an inexperienced user why the internal combustion engine was switched off. It is therefore not possible for the user to restart the internal combustion engine within a short period of time. Rather, it is necessary for the user to check all possible sources of error and to correct them if necessary. In addition, user errors, such as incorrect operation or incorrect calibration, can lead to undesired stoppages of the internal combustion engine or prevent the internal combustion engine from starting completely.

The invention is based on the object of specifying a particularly suitable method for operating an internal combustion engine as well as a particularly suitable internal combustion engine and also a particularly suitable working device, whereby user-friendliness is expediently increased and, in particular, operation is improved even for an inexperienced user, and wherein maintenance and / or repair is advantageously simplified.

With regard to the method, this object is achieved according to the invention by the features of claim 1, with regard to the internal combustion engine by the features of claim 9 and with regard to the working device by the features of claim 12. Advantageous further developments and refinements are the subject of the respective subclaims.

The method is used to operate an internal combustion engine. The internal combustion engine, in particular, a so-called small engine or miniature engine. The internal combustion engine is, for example, a component of a work device, a tool being expediently driven by means of the internal combustion engine. The working device is, for example, a sweeper, a lawn mower or a scarifier. The working device is preferably designed to be portable and, for example, a brushcutter, a cutoff grinder, a chainsaw or a hedge trimmer, the tool being adapted accordingly. The portable working device is particularly preferably a portable water pump, which is used in particular for fighting fires in the intended state. Alternatively or in combination with this, the water pump is used to combat floods. In this case, the tool is a pump wheel.

The internal combustion engine suitably comprises a carburetor, by means of which an air-fuel preparation takes place. In this way, on the one hand, the manufacturing costs are reduced and, on the other hand, the robustness is increased. For example, the internal combustion engine is operated according to the 2-stroke or 4-stroke process.

The internal combustion engine has a crankshaft. In particular, a piston is connected to the crankshaft and is guided in a cylinder liner, for example. The liner is expediently part of a cylinder. For example, the internal combustion engine includes multiple cylinders such as 2 cylinders. However, the internal combustion engine is particularly preferably a single-cylinder (internal combustion) engine and thus has a single cylinder. For example, the internal combustion engine is a single cylinder internal combustion engine which suitably operates in a two-stroke process. In this way it is possible to manufacture the internal combustion engine comparatively inexpensively and / or with a low weight.

The internal combustion engine expediently comprises an ignition system which comprises a spark plug. The spark plug is here at least partially rotated into the cylinder, if any, a corresponding spark plug being suitably assigned to each cylinder. A magneto ignition is suitably used to supply the spark plug (s) with electrical energy. A coil is wound on an armature and interacts with a magnet attached to the crankshaft. When the crankshaft moves, i.e. when it rotates, an electrical voltage is induced in the coil which is used to supply the spark plug (s). In an alternative to this, the internal combustion engine comprises a generator that interacts with the crankshaft.

The internal combustion engine particularly preferably does not include a battery. At least, however, the possible system is not fed by a battery, rather all components of the internal combustion engine are expediently supplied with electrical energy only when the internal combustion engine is operating, which is generated on the basis of the rotation of the crankshaft. For example, any magneto ignition and / or any generator, which are electrically connected to the respective components, is used for this purpose. In other words, when the internal combustion engine is in operation, the kinetic energy of the crankshaft is at least partially converted into electrical energy. As a result, the internal combustion engine is comparatively light in weight

For example, the internal combustion engine comprises an electrical energy store, which is used to temporarily store the electrical energy, suitably a capacitor. This is expediently charged during operation on the basis of the rotation of the crankshaft, in particular by means of the possible magneto ignition and / or the possible generator. It is thus possible to supply the individual components with energy independently of the current position of the crankshaft, the weight of the internal combustion engine not being increased or only being increased slightly.

The internal combustion engine expediently has a manual starting device, such as a pull-wire starter. The pull starter includes in particular a rope that acts directly on the crankshaft, preferably via a freewheel. This means that no battery is required to start the internal combustion engine either. As an alternative or in combination with this, the internal combustion engine comprises a carburetor, which is preferably configured to be manual or semi-automatic, in particular the electrical energy required for setting being generated on the basis of the rotation of the crankshaft. As an alternative or in combination with this, the internal combustion engine comprises a characteristic map within which the ignition times are stored as a function of a speed and / or other parameters. In particular, the map is a component of the ignition system, which for this purpose includes an adjustment device, for example. In particular, this is also by means of electrical during operation Energy supplied that is created based on the rotation of the crankshaft.

The internal combustion engine also has a control unit with an output device. The output device is used to output information or other data or signals for a user of the internal combustion engine. The output device is suitable for this, in particular provided and set up. For example, the output device is designed haptically so that the information is output haptically. As an alternative to this, the output device is an acoustic output device and is formed, for example, by means of a loudspeaker or a buzzer or at least comprises these. However, the output device is particularly preferably designed optically so that the information is reproduced or output optically. It is thus possible for the user to reliably acquire the information even during operation of the internal combustion engine and the associated noises. The user is also referred to as the user in the following.

The method provides that the control unit is supplied with electrical energy that is generated on the basis of a rotation of the crankshaft. For this purpose, the control unit is expediently electrically contacted with the possible magneto ignition and / or the possible generator and is thus energized by means of them. The control unit itself particularly preferably has no battery or other energy storage device. It is possible that the control unit includes a button cell, e.g. to supply an internal (real-time) clock. However, the control unit, and also the complete internal combustion engine, preferably does not have a power battery. In another alternative, there are no batteries at all. As a result, the control unit is only supplied with electrical energy during / during the rotation of the crankshaft and is thus energized. If the crankshaft is not rotating, there is consequently no supply to the control unit. The control unit is therefore only energized when the crankshaft is rotated due to ignition processes, for example while another object is being driven, for example any tool, or also when the internal combustion engine is idling. In addition, the control unit was already supplied with electrical energy during a starting process, that is to say, for example, when a possible pull cord of the pull cord starter is pulled / actuated.

In summary, at least the energy generated during a starting process and / or when the internal combustion engine is idling, or a fraction thereof, is preferably used and / or drawn upon to operate the control unit and consequently also the output device. The method is expediently started directly at the start of the rotation of the crankshaft. If the crankshaft consequently comes to a standstill again, for example because a starting process was unsuccessful, the method is in particular terminated and suitably restarted at a subsequent start of the rotation of the crankshaft.

An operating state of the internal combustion engine is output by means of the output device, the operating state being in particular the information that can be output by means of the output device. The output device is also supplied by means of the electrical energy that is generated on the basis of the rotation of the crankshaft. The operating state is expediently output essentially immediately after the control unit has been supplied with electrical energy by means of the output device. The operating state is, for example, an engine state and / or the presence of a malfunction.

On the basis of the method, the operating state is thus output to the user, in particular signaled, so that the user is informed of this as soon as the internal combustion engine is started. As a result, it is possible for a user to change and / or correct any settings of the internal combustion engine, so that the internal combustion engine can be brought into a safe state. If, on the other hand, a starting process of the internal combustion engine is unsuccessful, for example, the user is informed of the operating state during the starting process, that is, while the crankshaft is still rotating. It is thus possible for the user to first change the settings when trying to start again, so that the subsequent start attempt is more likely to be successful. As a result, operation is improved even for an inexperienced user and user-friendliness is increased. This also enables the internal combustion engine to be used in system-relevant areas that require high reliability and where on-site repairs may be essential in an emergency.

In addition, the user is also informed of the operating status while using the internal combustion engine, since the crankshaft rotates during this. The user can therefore adapt the functioning of the internal combustion engine, in particular depending on current requirements. In this way, user-friendliness is also increased. In addition, maintenance and repair are simplified, since conclusions can already be drawn for the work steps required for maintenance and / or repair via the operating state output when the internal combustion engine is started.

The control unit has, for example, a microprocessor and / or comprises, for example, several electrical and / or electronic components. The control unit (“electronic control unit”) has, for example, only the output device (“user interface module”). As an alternative to this, the control unit also takes on further tasks during / for the operation of the internal combustion engine, for example determining an ignition point so that existing components can be used, which is why hardware costs and weight are not increased or are only slightly increased.

The output device includes, for example, a display and / or a light-emitting diode (LED) and is formed, for example, by means of this. To output the operating state, for example, the light-emitting diode is continuously activated so that the light-emitting diode lights up continuously in a certain operating state and is continuously extinguished in another operating state. Particularly preferably, the light-emitting diode is additionally or alternatively activated successively so that it flashes. In this case, for example, a third operating state is signaled by means of the flashing, or there are several flashing codes, that is to say different patterns, by means of which the light-emitting diode is activated. A different operating state is assigned to each of the patterns, so that several operating states can be signaled by means of the light-emitting diode.

The light-emitting diode is particularly preferably a multicolor light-emitting diode, which is also referred to as a multicolor LED (“multicolor LED”). This has several individual light-emitting diodes which are arranged in a common housing, so that only a single component is visible to a user, which, however, can be operated with different colors. For example, two or three individual light-emitting diodes are integrated in the housing. This increases the number of different operating states that can be output by means of the output device. Because of the light-emitting diode (s), the weight is essentially not increased and, moreover, manufacturing costs are comparatively low. This also increases the robustness of the internal combustion engine compared to a display.

For example, the output device is only operated for a short period of time, such as 5 seconds, 2 seconds or 1 second. In particular, the operating status is only output once. Particularly preferably, however, the output device is operated as long as the control unit is energized, that is, as long as the crankshaft is rotating.

For example, the current operating state of the internal combustion engine, that is to say the operating state present / realized at the current point in time, is output as the operating state by means of the output device. The current status of the internal combustion engine can thus be seen by the user during the start-up process. Particularly preferably, however, the operating state is read out from a memory in the control unit. The operating state, which is output immediately after the power supply to the control unit, i.e. the supply of electrical energy, has started, is not the current operating state, but an operating state that has already been implemented, especially when the internal combustion engine was used immediately before. As a result, it is not necessary to determine the current operating state within a comparatively short period of time, so that the susceptibility to errors is reduced in this case. Nevertheless, valuable information is output for the user by means of the output device, especially since conclusions can be drawn about the current state of the internal combustion engine on the basis of the operating state that has already been implemented and is stored in the memory.

In this case, maintenance and / or repair is also simplified, since, based on the operating state that has already been implemented, it is possible to deduce wear or damage without first having to check the internal combustion engine itself, which is comparatively time-consuming. As a result, maintenance of a fleet of such internal combustion engines is facilitated. Furthermore, in this way, the performance of the internal combustion engine can be checked, provided it is at least partially mapped in the operating state, within a comparatively short period of time, whereas the determination of the performance itself, namely the determination of the operating state, can take place over a comparatively long period of time.

For example, the operating state stored in the memory relates to a previous false start, or at least the operating state contains information relating to a previous false start. Consequently, when attempting to start after a false start, the user can see why the false start occurred.

In particular, the memory is designed to be non-volatile, so that the operating state is still stored in the memory, the energization of the control unit, that is to say the supply of electrical energy, is ended, that is to say in particular when the crankshaft is at a standstill. The memory is expediently an EPROM or an EEPROM. In an alternative, the memory is a flash or data flash.

Particularly preferably, the output of the operating state that is or has been read from the memory of the control unit is ended, and the current operating state is output by means of the output device when a condition is met. The current operating state corresponds or at least corresponds to the state of the internal combustion engine at the current point in time. Since this is only output after a certain period of time, namely until the condition is met, the period of time is available for determining the current operating state, so that the accuracy in determining the current operating state is increased and the susceptibility to errors is reduced. The hardware requirements are comparatively low. The current operating state is preferably determined by means of the control unit which is suitable, in particular provided and set up, for this purpose. The operating status is preferably output until the condition is met, and the current operating status is output immediately thereafter, so that the user can see that the output device is in continuous operation.

Since the current operating state is also output according to the method, as soon as the condition is met, the user can see what the current state of the internal combustion engine is, so that the user can change and / or adapt settings of the internal combustion engine so that certain requirements are met . Due to the output of the operating status and the current operating status, it is therefore also possible for an inexperienced user to use the internal combustion engine. Furthermore, troubleshooting during maintenance / repair is facilitated in this way, since when the internal combustion engine is started and the condition is subsequently met, a comparatively large amount of information about the internal combustion engine is output by means of the output device.

For example, the condition is met if the crankshaft has already been rotating for a certain period of time, for example 10 seconds, 20 seconds or 30 seconds. The specific time period can preferably be parameterized. In other words, the condition is met in particular if the operating state has already been output for the specific period of time. However, the condition is particularly preferably fulfilled when a user input occurs, that is to say an actuation of the internal combustion engine. The user can thus understand whether the operating state read from the memory or the current operating state is currently being output by means of the output device. In a further development, the condition is met if either the operating state has already been output for the specific period of time, or if the user input is made.

The user input is in particular the actuation of a throttle valve of the internal combustion engine, by means of which, in particular, a fresh air supply to the possible cylinder and / or to the carburetor of the internal combustion engine is regulated. In particular, the condition is the first actuation of the throttle valve after the crankshaft has started to rotate. In other words, the condition is met as soon as the user first accelerates. As a result, the condition is only fulfilled when the internal combustion engine is already running, that is to say it is in particular in a stable idling state. Additional input devices are not required because of the use of the operation of the throttle valve as a condition. As a result, hardware requirements are not increased. The actuation of the throttle valve is preferably also used to change a further setting of the internal combustion engine, for example to switch over a characteristic map.

The actuation of the throttle valve is detected, for example, by means of a sensor which interacts with a possible gas handle or some other actuating device of the internal combustion engine, by means of which the throttle valve is controlled. Alternatively or in combination with this, the sensor is a sensor for determining a current position of the throttle valve. However, the actuation of the throttle valve is particularly preferably detected on the basis of a speed of the internal combustion engine. In other words, the first condition is met when the speed of the internal combustion engine exceeds a specific speed threshold. When the throttle valve is actuated, the fresh air supply to the internal combustion engine is increased, which is why the speed of the internal combustion engine increases, that is to say the speed of the crankshaft. If this exceeds a certain limit value, namely the speed threshold, it is concluded that the throttle valve has been actuated. In particular, the speed threshold is selected here in such a way that it is not reached when the internal combustion engine is idling.

The current operating state is particularly preferably determined on the basis of a temperature of the internal combustion engine. For this purpose, the internal combustion engine expediently has a temperature sensor. The temperature sensor is, for example, a component of the possible ignition module, in particular a possible controller of the ignition module, or a separate component. The temperature is, for example, an oil temperature or a temperature of any cylinder of the internal combustion engine. As a result, it is possible to identify overheating of the internal combustion engine based on the current operating state.

In this way, a possible operating state is also a warm-up phase of the Internal combustion engine, i.e. if it has not yet reached its operating temperature. In other words, a warm-up phase of the internal combustion engine is output as the current operating state by means of the output device, i.e. in particular the information that the internal combustion engine should initially be operated in idle until a certain minimum temperature is reached in order to reduce wear.

Alternatively or particularly preferably in combination with this, the current operating state is determined on the basis of a rotational speed of the crankshaft. For this purpose, the internal combustion engine has a corresponding sensor, for example, or the rotational speed is determined by means of the possible ignition system, preferably by means of the magneto ignition, so that no separate sensor is required. Owing to the use of the rotational speed to determine the current operating state, over-revving of the internal combustion engine is therefore also possible as an operating state for detection. In particular, the control unit is electrically or at least signal-technically connected to any sensors. The sensors, if any, are suitably supplied with current by means of the control unit, that is to say in particular only when the crankshaft is rotating.

In a further development, the current operating state is determined on the basis of further available data that are provided, for example, by means of the possible ignition system. In this way, the current operating state corresponds comparatively precisely to the current actual state of the internal combustion engine. As an alternative to this, only the temperature, only the rotational speed or only the temperature and the rotational speed are used to determine the current operating state. In this way, accuracy is reduced, but robustness is increased.

Alternatively or in combination, the current operating state is determined on the basis of the plausibility check of existing sensor values, with some or all of the existing sensor values being used, for example. Each of the sensor values is created in particular by means of a respective sensor. For plausibility checks, it is particularly checked whether the sensor value used is outside the respective measuring range. In this case it is assumed that there is a fault in the wiring, such as a broken wire or a short circuit. Alternatively or in combination, the current operating status is determined on the basis of a further plausibility check. For example, it is monitored whether the control unit is being supplied with electrical energy, but no speed information is available, that is to say the rotational speed of the crankshaft is zero or has no specific value. This also indicates a broken cable.

For example, the current operating state is only determined once, in particular if the condition is met. Particularly preferably, however, the current operating state is determined anew several times. In this case, the determination takes place, for example, continuously or, for example, at certain time-related discrete points in time, for example every second, every 5 seconds or every 10 seconds. After the current operating state is newly determined, the newly determined current operating state is expediently output by means of the output device, that is to say the output is adapted. In particular, the current operating state is output unchanged until it has been determined again, so that the user can essentially see continuous operation of the output device.

Due to the continuous determination, the user is thus signaled a change in the current operating status due to certain circumstances. Consequently, the user can adapt his use of the internal combustion engine to this and, for example, change certain settings as a function thereof. This enables safe operation even for an inexperienced user.

The current operating state is particularly preferably stored in the memory. The current operating state is thus the operating state which is output by means of the output device when the internal combustion engine is restarted. As a result, after the restart, the operating status of the last operation is presented to the user so that he can, for example, adjust or reverse a setting. It is thus also possible to correct an incorrect behavior during the last use, which is stored in the memory on the basis of the operating state, when it is used again.

For example, the current operating state is only stored once in the memory, expediently as soon as it has been determined. Particularly preferably, however, the current operating state is continuously re-determined and, for example, every time the current operating state has been re-determined, it is stored in a memory. As an alternative to this, saving takes place every 10 seconds, every 5 seconds or every second. Here, for example, the operating state already present in the memory is overwritten with the current operating state, so that only a comparatively small memory is required. As an alternative to this, the newly determined current operating state is also stored in the memory, with a current time in particular is also saved, i.e. a so-called time stamp. In this way, a comparatively precise analysis of the performance data or the other state of the internal combustion engine is made possible by reading out the memory, which is why maintenance / repair is simplified. As an alternative to the time stamp, only an index is expediently used. A change in the current operating state over time can also be traced on the basis of the current operating states stored with different indices.

The current operating state is particularly preferably stored in the memory when it is switched off. As soon as the ignition of the internal combustion engine, in particular, is interrupted, that is to say that the possible spark plugs are not supplied with electrical energy, the current operating state that is now present is expediently stored in the memory. In particular, the present current operating state is stored when the shutdown is to take place or when this is at least initiated. When it is switched off, there is still sufficient electrical energy available so that it is still possible to safely write the current operating state in the memory when it is stored there. As a result, when the internal combustion engine is restarted, it is immediately apparent from the operating state why the internal combustion engine was switched off the previous time. In this case, the control unit expediently has an interface to the possible ignition system, which is also referred to as the ignition module, and / or to an emergency stop switch, for example a switch of the ignition module, preferably its safety shutdown. As a result, the current operating state is expediently stored in the memory, which is why a safety shutdown took place, for example due to exceeding a certain maximum speed and / or a certain temperature and / or due to the actuation of the emergency stop switch. This is output by means of the output device when the internal combustion engine is restarted, so that it is easier for the user to rectify the error that led to the safety shutdown. Alternatively or in combination with this, the current operating state is stored in the memory when a minimum speed threshold is reached, so that it can be assumed that the internal combustion engine will inadvertently go out by itself, for example because a fuel tank has been emptied.

In summary, the shutdown takes place in particular intentionally by the user, for which purpose a stop switch is expediently operated by the user. Alternatively or in combination with this, the shutdown takes place unintentionally, for example because the fuel tank, if any, is empty. This unwanted shutdown is recognized by the rotational speed of the crankshaft, in particular when the rotational speed of the crankshaft falls below a minimum speed (threshold), so that the storage is subsequently carried out. If the rotational speed of the crankshaft subsequently increases again, there is no actual shutdown, but in this case the current operating state has already been stored in the memory. The current operating state is expediently determined again subsequently and is stored again at least when it is subsequently switched off.

In the assembled state, the internal combustion engine is, for example, a component of a work device, preferably a portable work device. The internal combustion engine is suitable, expediently provided and set up for this purpose. The internal combustion engine is preferably a small engine or a very small engine. In particular, a maximum power output of the internal combustion engine is less than 5 kW or 10 kW. The internal combustion engine comprises a crankshaft, a piston, for example, interacting with the crankshaft, in particular via a connecting rod. The piston is expediently guided in a cylinder liner of a cylinder. In particular, the internal combustion engine has only a single cylinder or, for example, several, for example two, cylinders.

The internal combustion engine is suitably operated according to the 2-stroke or 4-stroke principle. The internal combustion engine preferably includes an ignition system, which is also referred to, for example, as an ignition module. This includes, for example, a spark plug that is activated at certain (ignition) times during operation, so that an ignition spark is created. In particular, the internal combustion engine includes a map in which the ignition times are stored as a function of a position of the crankshaft. On the basis of the characteristic map, the spark plug (s) are activated during operation. In particular, several characteristic curves for different operating modes are stored in the characteristic map. The ignition system comprises in particular a magneto ignition or is formed by means of it. A magnet is connected to the crankshaft, which interacts with a stationary coil during operation, so that an electrical voltage is induced in it. This is used in particular to energize the spark plug (s).

The internal combustion engine further comprises a control unit which has an output device. For example, the control unit is part of the ignition module, or the ignition module is part of the control unit, or the ignition module and the control unit are independent of one another. In other words, the control unit and the ignition module are, for example, by means of a integrated hardware module or by means of two separate hardware modules. The internal combustion engine is operated according to a method in which the control unit is supplied with electrical energy that is generated on the basis of a rotation of the crankshaft. An operating state of the internal combustion engine is output by means of the output device. For this purpose, the control unit is expediently interconnected with further components of the internal combustion engine, in particular with the possible magneto ignition or other parts of the ignition system. As soon as the crankshaft is rotated, the control unit in particular is supplied directly with electrical energy. In other words, as soon as the crankshaft is rotated, the electrical energy is generated, with the aid of which the control unit is energized. No additional component is therefore required, which is why robustness is increased.

The control unit particularly preferably comprises an interface which is particularly preferably wireless. The interface is expediently operated in accordance with the Bluetooth standard or, in particular, fulfills these requirements. It is thus possible to read out the operating status via the interface by radio. Alternatively or in combination with this, the interface is designed to be wired and, for example, a USB interface, so that a signaling connection with the control unit can be implemented by means of a cable. It is also possible here to supply the control unit with electrical energy via the USB interface, so that it can be operated independently of the rotation of the crankshaft, in particular during maintenance and / or repair. It is preferably possible to update any software in the control unit via the interface, that is to say in particular a computer program product that causes a computer in the control unit, such as a microprocessor, to carry out the method. For example, a setting of certain parameters is transmitted here, on the basis of which the respective operating state is determined, if this is done by the internal combustion engine, expediently by the control unit.

Alternatively or particularly preferably in combination with this, the control unit comprises a memory which is expediently designed to be non-volatile. Information stored in the memory, such as the operating state, is thus retained even if a current supply to the control unit is interrupted. The memory is, for example, a flash, flash data, EPROM or an EEPROM. The memory is used in particular to store the operating status, for example the current operating status.

The interface and the memory are particularly preferably connected to one another in terms of signaling, so that the operating state can be read from the memory via the interface. The interface is particularly preferably at least partially wired, for example the USB interface, so that the operating state can be read out from the memory, even if the crankshaft is not rotating. In this case, when the crankshaft is at a standstill, the memory is at least partially energized via the interface for reading out.

The output device comprises, for example, a display or several individual LEDs. The LEDs light up, for example, in different colors when in use. Depending on the type and / or number of the activated, that is to say illuminated, LEDs, a specific operating state is expediently output by means of the output device. For example, when two LEDs are lit, a different operating state is signaled than when only a single LED is lit and / or when at least one of the LEDs is flashing. Particularly preferably, however, the output device is formed by means of a multicolor LED (multicolor light-emitting diode, “multicolor LED”) or at least includes it. The multiple LED comprises several individual LEDs, each of which light up in different colors, and which are arranged in a common housing. For example, the multicolor LED has only two individual LEDs or particularly preferably three or more LEDs. Thus, only a single component is visible to the user as an output device, so that it is easier for the user to record the operating state output by means of the output device. In particular, the individual LEDs of the multicolor LED are controlled in accordance with the respective operating state, with these, for example, flashing or glowing continuously. It is thus possible to output a large number of different error states, which are thus in particular an operating state, by means of the output device.

The tool is, for example, hand-held or not hand-held. The working device is preferably designed to be portable. The work device comprises an internal combustion engine which is, for example, a single-cylinder or two-cylinder (internal combustion) engine. The internal combustion engine expediently comprises an ignition module / ignition system which is provided, for example, by means of a magneto ignition, or at least comprises this. For example, the internal combustion engine works according to the diesel principle or the Otto principle. The internal combustion engine is expediently operated according to the 2-stroke or 4-stroke principle. The internal combustion engine has a crankshaft and a control unit with an output device. In addition, the Internal combustion engine operated according to the method in which the control unit is supplied by means of electrical energy that is generated based on a rotation of the crankshaft. In addition, an operating state is output by means of the output device.

A tool of the implement is driven by means of the internal combustion engine and is adapted to the respective use of the implement. For example, the tool is a knife, a chain or some other saw blade. In particular, the work device is thus a lawn mower, a saw or a cut-off machine. Alternatively, the tool is a fan wheel and the tool is, for example, a leaf blower or leaf vacuum. The tool is particularly preferably a pump wheel, and the working device is a portable pump which is expediently suitable, in particular provided and set up, for rescue teams. In other words, it is possible to use the implement in a disaster area, for example in a flood area or in a fire area.

The developments and advantages described in connection with the method can also be applied to the internal combustion engine / the work device and to one another, and vice versa.

• 1 schematisch vereinfacht ein Arbeitsgerät mit einem Verbrennungsmotor,
• 2 ein Verfahren zum Betrieb des Verbrennungsmotors,
• 3, 4 jeweils einen zeitlichen Verlauf einer Drehzahl und eines Betriebszustands.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. Show in it:

• 1 schematically simplified a working device with an internal combustion engine,
• 2 a method for operating the internal combustion engine,
• 3 , 4th in each case a time profile of a speed and an operating state.

Corresponding parts are provided with the same reference symbols in all figures.

In 1 is schematically simplified a working device 2 shown in the form of a pump. The working device 2 is designed to be portable and is used to pump water in a disaster area. The tool is for this 2 suitable as well as provided and furnished. For example, the pump is used to pump water in a floodplain (flood area) or for fire fighting. For this purpose, the implement 2 a tool 4th on, in this case an impeller. The pump wheel is rotatably mounted in a housing, not shown in detail, which has an inlet and an outlet, and optionally a filter.

The tool 4th is by means of an internal combustion engine 6th driven by a crankshaft 8th having. On the crankshaft 8th is the tool 4th non-rotatably attached, for example directly or via a gear, not shown in detail. On the crankshaft 8th is about a connecting rod 10 a piston 12th hinged in a cylinder 14th is led. Here the internal combustion engine 6th just a single cylinder 14th on, so the internal combustion engine 6th is designed as a single cylinder engine.

In the cylinder 14th opens a suction line 16 , the remaining end of which fluidly with the environment of the implement via an air filter, not shown in detail 2 connected is. Inside the suction line 16 is a throttle valve 18th pivotally mounted by means of the operating device 20th , which is also referred to as an actuating device, is actuated. The operating device 20th is for example a throttle or a rotary switch. When operating the control device 20th becomes the throttle 18th pivoted so that one in the cylinder 14th incoming fresh air can be adjusted. Between the throttle 18th and the cylinder 14th a carburetor, not shown, is also arranged, by means of which fuel, such as gasoline, is dusted into the fresh air. This mixture enters the cylinder during operation 14th and is there by means of a spark plug 22nd an ignition system 24 exploded so that the piston 12th inside the cylinder 14th is moved.

As a result, the crankshaft will 8th rotates on which a magnet 26th a magneto 28 of the ignition system 24 is rotatably attached. The magneto 28 also has a stationary (electrical) coil 30th on that on a yoke 32 is wound from a soft magnetic material. When the crankshaft rotates 8th becomes the magnet 26th on the yoke 32 moved past so in the spool 30th an electrical voltage is induced. This is attached to the spark plug 22nd created so that there is another ignition spark, which is why the meanwhile renewed mixture of fresh air and fuel is ignited.

Between the coil 30th and the spark plug 22nd is a safety shutdown 34 arranged, by means of which the electrical connection between the magneto ignition 28 and the spark plugs 22nd can be interrupted if necessary. This is actuated when the internal combustion engine 6th or other components of the equipment 2 have a critical condition, so that by means of the spark plug 22nd no further ignition sparks are created. As a result, the internal combustion engine 6th shut down. The safety shutdown 34 includes an emergency stop switch for manual operation or certain sensors or is connected to existing sensors for signaling purposes, so that the respective critical state can be recorded.

With the crankshaft 8th is a pull starter via a freewheel (not shown) 36 in operative connection, which can be operated manually. For operating the pull starter 36 a rope is pulled, causing the (initially stationary) crankshaft 8th is set in a rotation. Due to the rotation takes place by means of the magneto ignition 28 the provision of electrical energy, which is why by means of the spark plug 22nd The spark can be created so that the rotation of the crankshaft 8th can be sustained. Consequently it is necessary for the operation of the internal combustion engine 6th namely to create the spark and start rotating the crankshaft 8th , no external electrical energy storage required, and this is also not available. In other words, it is the internal combustion engine 6th and the complete work tool 2 battery-free.

The internal combustion engine 6th further comprises a control unit 38 who have a discovery unit 40 includes. The investigative unit 40 is signaling with the safety shutdown 34 and a temperature sensor 42 connected to an outer wall of the cylinder 14th attached and thermally contacted with this. In addition, the determination of his 40 signaling with a speed sensor 44 connected, which in this example is a separate component or is provided only by means of software routines, by means of which by means of the magneto ignition 28 provided electrical voltage peaks determines the speed. By means of the investigation unit 40 is based on the data provided, i.e. the temperature, the speed and the setting of the safety shutdown 34 , the condition of the internal combustion engine 6th determined.

Furthermore, the control unit 38 an interface 46 which in the example shown is a USB interface, namely a USB plug. Alternatively or in combination with this is the interface 46 a radio interface and operated according to the Bluetooth standard. Using the interface 46 it is possible to establish a signaling connection to an external device and to exchange data and / or other parameters with it. So it is possible through the interface 46 to receive an update, in particular to adapt certain parameters on the basis of which the determination unit 40 determines the current state.

In addition, the control unit 38 a non-volatile memory 48 in the form of an EPROM. The memory 48 is signaling with the interface 46 connected so through the interface 48 those in the store 48 stored data can be retrieved. This is done via the interface 46 the energization of the memory 48 secured for reading. The control unit 38 further comprises an output device 50 which is formed by means of a multicolor LED. This has a red LED 52 and a green LED 54 which are arranged in a common housing. For a user of the implement 2 only the multi-color LED is visible, which consequently lights up in different colors.

The internal combustion engine 2 is according to an in 2 presented procedure 56 operated, the method at least partially by means of the control unit 38 is carried out. The procedure 56 is done with a first step 58 started, with the first step 58 is executed as soon as a rotation of the crankshaft 8th begins. Due to the rotation of the crankshaft 8th is about the magneto 28 the control unit 38 supplied with electrical energy. In this case, the electrical energy is supplied by actuating the pull-rope starter 36 , so even before an independent rotational movement of the crankshaft 8th occurs due to successive ignition of the fresh air / gasoline mixture. Due to the rotation of the crankshaft 8th and the generation of electrical energy by means of the magneto ignition 28 is by means of the spark plug 22nd Ignition sparks are created at each ignition point so that the internal combustion engine is idling 6th set. In this the speed (n) of the crankshaft fluctuates 8th due to the subsequent ignition of the mixture of fresh air and gasoline in the cylinder 14th .

In summary, according to the procedure 56 the control unit 38 powered by electrical energy based on the rotation of the crankshaft 8th is generated, and the process 56 is started as soon as due to the rotation of the crankshaft 8th by means of the magneto ignition 28 sufficient electrical energy was provided. In the first step 58 also becomes one in the memory 48 the control unit 38 saved operating status 60 read out.

In a subsequent second step 60 becomes the operating state 60 by means of the output device 50 issued. The multi-color LED is controlled accordingly for this purpose. In 3 is a time profile of a speed (n) of the crankshaft 8th as well as by means of the output device 50 displayed information. After the crankshaft starts rotating 8th is by means of the output device 50 the one in the store 48 saved operating status 60 output, which in this example is a correct operation without malfunction. The green LED is continuously used to signal this 54 controlled so that during the second work step 62 only the green LED 54 lights up continuously. Furthermore, in the second step 62 by means of the determination unit 40 a current operating status 64 determined. To determine the speed of rotation of the crankshaft 8th , i.e. the speed (n) determined by means of the speed sensor 44 is detected, as well as the temperature used, which by means of the temperature sensor 42 is captured. This is also the current operating status 64 based on the status / setting of the safety shutdown 34 certainly.

In a third step 66 , which essentially coincides with the second work step 62 is carried out, it is checked whether a certain condition 68 is satisfied. The condition 68 is the actuation of the throttle valve 18th , namely the first actuation of the throttle valve after the crankshaft has started to rotate 8th . Due to the operation of the throttle valve 18th by the user by means of the operating device 20th is carried out, the one in the cylinder 14th existing amount of mixture of fresh air and gasoline increased. As a result, the speed (n) of the crankshaft increases 8th via a speed threshold 70 . If consequently the speed (n) the speed threshold 70 is the condition 68 fulfilled, and this is done by means of the speed sensor 44 determined.

In a subsequent fourth step 72 is now by means of the output device 50 no longer the operating state 60 that from memory 48 read out, but the current operating status 64 . In the example shown, the internal combustion engine 6th does not yet appear as an operating temperature, so that it is still in a warm-up phase74. The green LED is used to signal this to the user 54 successively activated so that it flashes. The output of the operating status is thus summarized 60 finished and the current operating status 64 by means of the output device 50 issued when the condition 68 is satisfied. Here the current operating status 64 continuously re-determined. In other words, in this case, as long as the crankshaft 8th rotates and consequently the control unit 38 is energized, checks whether the internal combustion engine 6th still in the warm-up phase 74 is located, i.e. whether it has still not reached operating temperature.

As soon as this is the case, the current operating status changes 64 , and the internal combustion engine 6th is in an operational phase 76 . In this there is an essentially undisturbed operation of the internal combustion engine 6th and thus also of the implement 2 possible. The changed operating status is also output. In this case, the green LED is continuously activated 54 signals that the internal combustion engine 6th is operational and in the operational phase 76 is located. As a result, it is safe for the user to adjust the speed of the crankshaft 8th to increase.

In the example shown, the internal combustion engine is overheating 6th what by means of the temperature sensor 42 is determined. Overheating is used as the current operating status 64 at a shutdown time 78 , at which the recorded temperature exceeds a maximum temperature, in a fifth work step 80 established. As a result, by means of the control unit 38 the safety shutdown 34 operated, so that the successive creation of the spark by means of the spark plug 22nd is omitted. As a result, the internal combustion engine 6th in a shutdown phase 82 transferred that lead to a standstill of the crankshaft 8th will lead. During the shutdown phase 82 the changed current operating status becomes in turn 64 issued, so the overheating. The red LED is used for this 52 continuously controlled so that it flashes. The green LED 54 however, it is no longer activated.

Also in a sixth step 84 which is carried out as soon as the shutdown phase 82 has started, the current operating status 64 , so the overheating, in the memory 48 saved. This means that the current operating status is displayed when the vehicle is switched off 64 in the memory 48 is saved. After the crankshaft has stopped 8th the control unit is not energized 38 more, which is why by means of the display device 50 no further information can be output either. Then there is also the procedure 56 completed. In a variant not shown in detail, the current operating state 64 already in the memory at earlier times 48 stored, for example continuously or whenever this has changed.

If at a later point in time the internal combustion engine 6th is restarted, the one in the memory will again be the first 48 stored, i.e. saved, operating status 60 by means of the output device 50 output, in this case the overheating, as in 4th shown. Thus the red LED 52 successively activated so that it flashes. If now the condition below 68 is fulfilled, the then current operating state is again 64 output, in this case the warm-up phase again. In the in 4th The shutdown phase begins in the example shown 82 based on user input what the throttle valve is for 18th it is closed completely manually the creation of the ignition spark is stopped. There is no fault in this case and during the shutdown phase 82 is therefore the current operating status 64 the correct operation continues without malfunction, so that this occurs when the internal combustion engine is operated again 6th by means of the output device 50 is shown.

In summary, the in 4th shown, restarting the internal combustion engine 6th informs the user that the engine overheated the last time it was used 6th so that they can adapt their usage habits to this. In this way, the user is also informed why the internal combustion engine is to be switched off 6th if this took place comparatively promptly the internal combustion engine 6th want to start again. If the start attempt fails, the user is signaled why the failure occurred. As a result, the user is informed not to attempt the next start until the internal combustion engine is activated 6th has cooled down sufficiently.

The invention is not restricted to the exemplary embodiment described above. Rather, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention

List of reference symbols

2

Working device

4th

tool

6th

Internal combustion engine

8th

crankshaft

10

Connecting rod

12th

Pistons

14th

cylinder

16

Suction line

18th

throttle

20th

Control device

22nd

spark plug

24

Ignition system

26th

magnet

28

Magneto ignition

30th

Kitchen sink

32

yoke

34

Safety shutdown

36

Pull starter

38

Control unit

40

Investigation unit

42

Temperature sensor

44

Speed sensor

46

interface

48

Storage

50

Dispenser

52

red LED

54

green LED

56

procedure

58

first step

60

Operating condition

62

second step

64

current operating status

66

third step

68

condition

70

Speed threshold

72

fourth step

74

Warm-up phase

76

Operational phase

78

Shutdown time

80

fifth step

82

Shutdown phase

84

sixth step

Claims (12)

Method (56) for operating an, in particular battery-less, internal combustion engine (6) which has a crankshaft (8) and a control unit (38) with an output device (50), in which - the control unit (38) is supplied by means of electrical energy which is generated by rotating the crankshaft (8), - An operating state (60, 64) is output by means of the output device (50). Method (56) according to Claim 1 , characterized in that the operating state (60) is read out from a memory (48) of the control unit (38). Method (56) according to Claim 2 , characterized in that the output of the operating state (60) ends and the current operating state (64) is output by means of the output device (50) when a condition (68) is met. Method (56) according to Claim 3 , characterized in that the actuation of a throttle valve (18) is used as the condition (68). Method (56) according to Claim 3 or 4th , characterized in that the current operating state (64) is determined on the basis of a temperature and / or a rotational speed of the crankshaft (8). Method (56) according to one of the Claims 3 until 5 , characterized in that the current operating state (64) is continuously re-determined. Method (56) according to one of the Claims 3 until 6th , characterized in that the current operating state (64) is stored in the memory (48). Method (56) according to Claim 7 , characterized in that when it is switched off, the current operating state (64) is stored in the memory (48). Internal combustion engine (6), which has a crankshaft (8) and a control unit (38) with an output device (50), and which according to a method (56) according to one of the Claims 1 until 8th is operated. Internal combustion engine (6) after Claim 9 , characterized in that the control unit (38) has an interface (46) and a memory (48) which are connected to one another for signaling purposes. Internal combustion engine (4) after Claim 9 or 10 , characterized in that the output device (50) is formed by means of a multicolor LED. Tool (2) with a tool (4), which by means of an internal combustion engine (6) according to one of the Claims 9 until 11th is driven.

Images