CN111699052B - Method for controlling a high-pressure cleaning appliance and high-pressure cleaning appliance, in particular for carrying out the method - Google Patents

Abstract

The invention relates to a method for controlling a high-pressure cleaning appliance (10) having an electric motor (16), a high-pressure pump (20) driven by the electric motor (16), and a control device (30). In order to be able to counteract the danger of dry running in a simple manner, the control device (30) determines an actual value of the electrical power consumption of the electric motor (16) and switches off the electric motor (16) if the actual value falls below a predefined minimum value of the electrical power consumption of the electric motor (16) after a predefined starting phase has elapsed after switching on the electric motor (16). A high-pressure cleaning device (10) is also proposed, in particular for carrying out the method.

Description

Method for controlling a high-pressure cleaning device and in particular a high-pressure cleaning device for carrying out the method

technical field

The invention relates to a method for controlling a high-pressure cleaning device having an electric motor, a high-pressure pump driven by the electric motor, and a control device.

Furthermore, the invention relates to a high-pressure cleaning device having an electric motor, a high-pressure pump driven by the electric motor and a control device, in particular for carrying out the above-mentioned method.

Background technique

With the aid of a high-pressure cleaning device, a cleaning fluid, preferably water, can be pressurized and directed at the surface to be cleaned. The cleaning fluid can be supplied to the high-pressure pump of the high-pressure cleaning device via a fluid supply line, for example a suction hose. The cleaning liquid can be pressurized by a high-pressure pump and then output via a liquid output line (eg a pressure hose). In order to control the electric motor that drives the high-pressure pump, the high-pressure cleaning device has an electric control unit. The electric motor can be switched on and off by means of the control unit.

When operating high-pressure cleaning systems, care must be taken to ensure that sufficient cleaning fluid is supplied to the high-pressure pump, because otherwise there is a risk of dry running. Dry running of the high-pressure pump can lead to overheating and to increased wear and even damage to the high-pressure pump. In particular for high-pressure pumps which are at least partially made of plastic material, there is a risk of damage in the event of dry running.

To detect dry running, pressure or flow sensors are usually used. By means of the pressure sensor, a sensor signal can be obtained which corresponds to the pressure of the cleaning fluid prevailing within the high-pressure pump. In the event of a pressure drop, which may indicate the onset of dry running, the electric motor is switched off by the control due to the sensor signal of the pressure sensor. In a corresponding manner, a sensor signal corresponding to the flow rate of the cleaning fluid can be obtained by means of the flow sensor. A drop in flow rate may indicate the onset of dry running, and to counteract this dry running, the electric motor would be switched off based on the sensor signal provided by the flow sensor.

Temperature sensors have also been proposed, by means of which the temperature inside the high-pressure pump influenced by the cleaning fluid can be detected. If no cleaning fluid is delivered to the high pressure pump, the temperature sensor detects a change in temperature and this change may indicate dry running. On the basis of the sensor signal provided by the temperature sensor, an already initiated dry running is counteracted by switching off the electric motor.

Pressure, flow and/or temperature sensors are usually positioned inside the high-pressure pump and require considerable installation space.

Contents of the invention

It is therefore the object of the present invention to provide a method for controlling a high-pressure cleaning device which counteracts the risk of running dry in a simple manner.

According to the invention, this task is solved with respect to a method of the type mentioned at the outset in that the control device determines the actual value of the electrical power consumption of the electric motor, and when the electric motor is switched on, a predetermined start-up phase has elapsed The electric motor is then switched off when the actual value of the electrical power consumption is less than a predetermined minimum value of the electrical power consumption of the electric motor.

A predetermined start-up phase is to be understood as a time interval which starts anew each time the electric motor is switched on and has a predetermined duration. The duration of this time interval and thus of the start-up phase can be, for example, at least one minute, in particular two to three minutes.

In the method according to the invention, the control device of the high-pressure cleaning device determines the actual value of the electrical power consumption of the electric motor. If the actual value is less than a predetermined minimum value for the electrical power consumption of the electric motor after a predetermined start-up phase, the electric motor is switched off by the control device because after a predetermined start-up phase A minimum value below the electrical power consumption indicates dry running. During the start-up phase, even during normal operation, that is to say even during normal delivery of cleaning fluid, the electric motor does not in all cases have an electrical power consumption that exceeds a predetermined minimum value. This may be due to the fact that, at the start of the pumping process, the liquid is first drawn from a storage container, such as a storage tank, or eg from a body of water, wherein the electrical power consumption of the electric motor is gradually increased. However, after a predetermined start-up phase (which starts with the electric motor switched on and can last, for example, 2 to 3 minutes), in normal operation, especially when delivering cleaning fluid normally, the high-pressure pump The cleaning fluid is full and the electrical power consumption of the electric motor exceeds a predetermined minimum value.

The predetermined minimum value of the electrical power consumption of the electric motor is smaller than the value of the electrical power consumption of the electric motor during normal operation. The minimum value of the electrical power consumption may for example be less than 350W, in particular between 250W and 350W, for example 320W. In normal operation, the power consumption of the electric motor may eg be at least 400W.

If after the start-up phase the electrical power consumption of the electric motor is greater than a predetermined minimum value, the high-pressure cleaning device is functioning normally, in particular the high-pressure cleaning device is then sufficiently supplied with cleaning fluid. If after the start-up phase the electrical power consumption of the electric motor falls below a predetermined minimum value, then there is a fault, which indicates that the high-pressure cleaning device is not sufficiently supplied with cleaning fluid, so that there is a risk of running dry. In this case, the electric motor is switched off by the control unit. Thus, the risk of dry running can be identified on the basis of the electrical power consumption of the electric motor without having to integrate additional sensors in the high pressure pump.

It can be provided that the control device detects the actual values of the supply current and the supply voltage of the electric motor and calculates from these actual values the actual value of the electrical power consumption of the electric motor. The actual value of the electrical power consumption of the electric motor is obtained by multiplying the actual value of the supply current by the actual value of the supply voltage of the electric motor. In order to operate an electric motor, the electric motor must be supplied with electrical energy from an electrical energy source. The current supplied by the energy source represents the supply current of the electric motor, and the output voltage of the energy source represents the supply voltage of the electric motor. The control device advantageously detects the actual value of the supply current and the actual value of the supply voltage, and from this calculates the actual value of the electrical power consumption of the electric motor. The calculated actual value is compared with a predetermined minimum value for the power consumption by the control unit. If the calculated actual value of the electrical power consumption of the electric motor after a predetermined start-up phase is less than a predetermined minimum value, the control device switches off the electric motor.

Detection of the actual value of the supply current also has the advantage that an overload of the electric motor, for example due to a blocking of the electric motor shaft, can be reliably detected in a simple manner. If the actual value of the supply current exceeds a predetermined maximum current value, the control device advantageously switches off the electric motor in order to counteract the risk of damage due to overloading.

In an advantageous refinement of the method according to the invention, the high-pressure cleaning device has at least one rechargeable battery, and the control device detects the battery current and the battery voltage and calculates an actual value for the electrical power consumption of the electric motor therefrom. The use of at least one rechargeable battery makes it possible to operate the high-pressure cleaning device independently of an external energy source, in particular independently of the public power supply network. The current supplied to the electric motor by the at least one battery forms the supply current of the electric motor, and the output voltage of the at least one battery forms the supply voltage of the electric motor. The battery current and the battery voltage are advantageously detected by the control device of the high-pressure cleaning device, and the actual value of the electrical power consumption of the electric motor is calculated by the control device by multiplying the battery current and the battery voltage. This actual value is compared with a predetermined minimum value for the power consumption of the electric motor. If the calculated actual value after a predetermined start-up phase is less than a predetermined minimum value, the control device switches off the electric motor because there is a risk of dry running.

The control device switches off the electric motor if, after the start-up phase has elapsed, a comparison of the actual value of the power consumption of the electric motor with a predetermined minimum value of the power consumption reveals that there is a risk of dry running. In addition, in an advantageous embodiment of the method according to the invention it is provided that the control device is activated if the pressure of the cleaning fluid delivered by the high-pressure cleaning device in the outlet line of the high-pressure cleaning device exceeds a predetermined cut-off value. The electric motor is switched off, and the control device switches on the electric motor again when the pressure of the cleaning fluid in the outlet line drops again, in particular below a predetermined switching value. This refinement of the method according to the invention makes it possible for the user to control the electric motor by actuating a manually closable applicator device arranged in a on the free end of the liquid output line. For example, a pressure hose can be used as the liquid outlet line, and a spray gun can be used, for example, as a manually closable applicator device, which is in fluid connection via the pressure hose to the outlet line of the high-pressure cleaning device. To deliver the cleaning fluid pressurized by the high-pressure cleaning device, the user can open the applicator. The outlet pressure of the cleaning fluid is then built up in the outlet line of the high-pressure cleaning device. If the user wishes to interrupt the delivery of the pressurized cleaning fluid, the dispensing device can be closed. This leads to an increase in the pressure of the cleaning fluid in the outlet line, so that a predetermined cut-off value is exceeded. This excess can be detected by a pressure detection element, for example in particular a pressure switch, and a corresponding control signal of the pressure detection element can cause the control device to switch off the electric motor. If the user opens the dispensing device again, the pressure of the cleaning fluid in the outlet line drops, wherein the pressure is preferably below a predetermined switch-on value, and a corresponding control signal of the pressure detection element can then trigger the control unit to Switch on the electric motor again.

The control of the electric motor by manual actuation of the dispensing device facilitates the operation of the high-pressure cleaning device. If the high-pressure cleaning device also has at least one rechargeable battery, the operation of the high-pressure cleaning device is additionally simplified, since the high-pressure cleaning device can still be operated even when no external energy source is available for the electric motor. However, in the case of battery-operated high-pressure cleaning equipment, the electric motor of which can be controlled by switching the dispensing device on and off, the user may, after switching off the dispensing device, mistakenly believe that since the electric motor has been switched off by the control device, the It is not necessary to finally actuate the main switch to move it into the off position to end the operation of the high-pressure cleaning device. Such erroneous assumptions can lead to the user ending the supply of cleaning fluid to the high-pressure cleaning device, for example, by separating the liquid supply line from the high-pressure cleaning device and subsequently storing the liquid supply line in the storage space. In practice, however, as long as the main switch remains in its on position, the control device is still monitoring and reacts to possible pressure drops in the outlet line. Subsequently, if a pressure drop occurs in the outlet line of the high-pressure washer, for example due to a leak from the dispensing device, the control unit switches it on again despite the fact that no cleaning fluid is supplied to the high-pressure washer due to the use of batteries to ensure the energy supply electric motor. However, the risk of dry running is counteracted by the control device switching off the electric motor again after the start-up phase if the actual value of the electrical power consumption of the electric motor falls below a predetermined minimum value of the electrical power consumption. This aspect has been elaborated previously.

It can be provided that the control device determines the actual value of the electrical consumption continuously or periodically.

In particular, it can be provided that the control device periodically determines the actual value of the power consumption of the electric motor after switching on the electric motor at short intervals, in particular at intervals of at most 1 minute, for example at intervals of 10 seconds , and if the actual value of the electrical power consumption of the electric motor is less than a predetermined minimum value of the electrical power consumption of the electric motor, the electric motor is switched off after the start-up phase has elapsed.

In a preferred refinement of the method according to the invention, the actual value of the electrical power consumption of the electric motor is compared continuously or periodically with a predetermined minimum value of the electrical power consumption, and if the electrical power obtained by the comparison If the actual value of the consumption is less than the minimum value, the electric motor is switched off after the starting phase.

The periodic comparison of the actual value of the electric power consumption of the electric motor with the minimum value of the electric power consumption of the electric motor can take place, for example, at time intervals of at most one minute, for example at intervals of at most ten seconds.

It is particularly advantageous if the electric motor is switched off only by manual actuation of an actuating element of the high-pressure cleaning device after the electric motor has been switched off by the control device after a start-up phase because the electric power consumption has fallen below a minimum value for the electric power consumption of the electric motor. able to connect again. As already explained, the electric motor is switched off by the control device when the actual value of the electrical power consumption of the electric motor falls below a predetermined minimum value after the start-up phase has passed. In order to be able to continue the operation of the high-pressure cleaning device, the user must advantageously manually actuate an actuating element of the high-pressure cleaning device, for example a main switch of the high-pressure cleaning device, so that the electric motor cannot be switched on automatically. For example, it can be provided that the main switch has to be moved from its on position into its off position and then moved back into the on position again in order to prevent the power consumption from falling below the minimum value of the electrical power consumption after passing through the startup phase. After the electric motor is turned off by the control device, the high-pressure cleaning device can continue to run.

As stated at the outset, the invention also relates to a high-pressure cleaning device with an electric motor, a high-pressure pump driven by the electric motor, and a control device, in particular for carrying out the above-mentioned method.

In order to improve a high-pressure cleaning device in such a way that the risk of dry running can be counteracted in a simpler manner, it is proposed according to the invention that a control device is provided to determine the actual value of the electrical power consumption of the electric motor and to compare it with the electrical power compared with a predetermined minimum value of the electric power consumption of the electric motor, and when the actual value of the electric power consumption of the electric motor is less than the minimum value of the electric power consumption of the electric motor after a predetermined start-up period after switching on the electric motor, the electric motor The motor can be switched off by the control device. As already mentioned, such an embodiment of the high-pressure cleaning device makes it possible to counteract the risk of running dry without having to locate a sensor within the high-pressure pump for this purpose. Rather, the danger of dry running is identified by evaluating the electrical power consumption of the electric motor.

The control device preferably has a current detection element for detecting the actual value of the supply current of the electric motor and a voltage detection element for detecting the actual value of the supply voltage of the electric motor, and the control device is set up for determining from the supply current and the supply voltage The actual value to calculate the actual value of electrical power consumption. As already stated, the current supplied by the energy source to the electric motor represents the electric motor's supply current, and the output voltage of the energy source represents the electric motor's supply voltage. The control device is advantageously designed in such a way that the control device calculates the actual value of the electrical power consumption of the electric motor from the actual values of the supply current and the supply voltage. For this purpose, the control device can have a signal processing unit, in particular a multiplication unit.

It is advantageous if the electric motor can be switched off by the control device if the actual value of the supply current exceeds a predetermined maximum permissible current value. Exceeding the maximum allowable current value of the supply current indicates an electric motor overload. This overload can be caused, for example, by a blocked shaft of the electric motor. If there is an overload, this is detected by the control device when the actual value of the supply current exceeds a predetermined maximum permissible current value. The control device can then switch off the electric motor.

Preferably, the control device has a memory element for storing a predetermined minimum value for the electrical power consumption of the electric motor. The minimum value can be stored in a memory link, for example, during manufacture of the control device.

It is particularly advantageous if, in addition to the minimum value of the electrical power consumption, a maximum permissible current value for the supply current of the electric motor can also be stored in the memory link. As mentioned, by comparing the actual value of the supply current of the electric motor with the maximum permissible current value, the presence of an overload can be detected and the electric motor can be switched off.

As already mentioned, it is advantageous if the high-pressure cleaning device has at least one rechargeable battery for supplying energy to the electric motor. The use of rechargeable batteries allows the high-pressure cleaning device to be operated even when no external energy source, in particular no public power grid, is available.

In an advantageous embodiment of the high-pressure cleaning device according to the invention, the high-pressure cleaning device has an outlet line and can be switched off by the control device when the pressure of the cleaning fluid in the outlet line exceeds a predetermined shut-off value The electric motor can be switched on again by the control device when the pressure of the cleaning fluid in the outlet line drops again, in particular below a predetermined switch-on value. As mentioned above, in this refinement the user can control the electric motor by actuating the dispensing device which is connected via the liquid output line to the high-pressure cleaning device. If the user closes the dispensing device, the pressure of the cleaning fluid in the outlet line increases so that a predetermined cut-off value is exceeded. A corresponding control signal can then cause the control device to switch off the electric motor. If the user opens the dispensing device again, the pressure of the cleaning fluid in the outlet line falls below a predetermined switch-on value, and a corresponding control signal can cause the control device to switch on the electric motor again.

It is advantageous if the high-pressure cleaning device has a signal transmitter, which is connected in a signal-conducting manner to the control device and which supplies a control signal to the control device as a function of the pressure of the cleaning fluid in the outlet line.

The signal transmitter is preferably designed as a pressure switch.

Advantageously, the control device is designed to periodically determine the actual value of the electrical power consumption and compare it with a predetermined minimum value of the electrical power consumption of the electric motor.

In particular, it can be provided that the control device is set up to periodically determine the electrical power of the electric motor at short intervals, in particular at intervals of at most 1 minute, for example at intervals of at most 10 seconds, after switching on the electric motor. The actual value consumed. If the actual value of the electrical power consumption of the electric motor is less than a predetermined minimum value of the electrical power consumption of the electric motor, the electric motor is switched off after the start-up phase has elapsed.

In a preferred embodiment of the high-pressure cleaning device according to the invention, the actual value of the electrical power consumption of the electric motor can be continuously or periodically compared with a predetermined minimum value of the electrical power consumption by the control device, and the After the start-up phase, the electric motor can be switched off if the actual value of the electrical power consumption obtained by comparison is less than the minimum value.

The periodic comparison of the actual value of the electric power consumption of the electric motor with the minimum value of the electric power consumption of the electric motor can preferably take place at time intervals of at most one minute, for example at time intervals of at most 10 seconds.

In a particularly preferred embodiment, the high-pressure cleaning device according to the invention has an actuating element, and the electric motor, which is switched off by the control device after a start-up phase because the electrical power consumption has fallen below a minimum value, can only be activated by manually actuating the actuating element. Connect again.

The actuating element is advantageously designed as a main switch.

The high-pressure pump of the high-pressure cleaning device is preferably designed as a reciprocating piston pump. Reciprocating piston pumps have a plurality of pistons which are each sunk in a pump chamber and which can be moved back and forth linearly relative to their longitudinal axis. Such reciprocating piston pumps are known per se to those skilled in the art and do not need to be explained in detail at present.

With the aid of a high-pressure pump, the cleaning fluid can be placed under high pressure. Preferably, the pressure of the cleaning fluid is at least 70 bar, in particular the pressure of the cleaning fluid can be at least briefly 100 bar.

Advantageously, the electric motor of the high-pressure cleaning device according to the invention is connected to the high-pressure pump via a transmission. In particular, planetary gears have proven to be advantageous.

The electric motor of the high-pressure cleaning device according to the invention preferably has a fixed rotational speed. In this configuration, the control device can switch the electric motor on and off, but it cannot change the rotational speed of the electric motor.

In an advantageous configuration of the invention, the rotational speed of the electric motor is at least 15,000 revolutions per minute, in particular 15,000 to 18,000 revolutions per minute.

Description of drawings

The following description of a preferred embodiment of the present invention is used for a more detailed explanation in conjunction with the accompanying drawings.

in:

Figure 1 shows a perspective view of a preferred embodiment of a high-pressure cleaning device according to the invention;

FIG. 2 shows a schematic block diagram of a control device of the high-pressure cleaning device of FIG. 1 .

Detailed ways

A preferred embodiment of a high-pressure cleaning device according to the invention is shown schematically in FIG. 1 and assigned the reference number 10 overall. The high-pressure cleaning device 10 has a housing 12 in which a motor-pump unit 14 with an electric motor 16 and a high-pressure pump 20 driven by the electric motor 16 via a transmission 18 are arranged. The electric motor 16 is operated at a constant rotational speed of at least 15,000 revolutions per minute, in particular 15,000 to 18,000 revolutions per minute, for example 16,500 revolutions per minute. The high-pressure pump 20 has a pump inlet 22 and a pump outlet 24 . The high-pressure pump 20 is designed as a reciprocating piston pump and has a plurality of pistons 21, 23, 25, which are driven by the electric motor 16 via a transmission 18 for reciprocating movement along their respective longitudinal axes, and here In the customary manner, each sinks into a pump chamber whose volume is cyclically increased and decreased by the reciprocating movement of the respective piston in order thereby to convey the cleaning fluid. A liquid supply line (not shown in the figure), for example a suction hose, can be connected to the pump inlet 22 . A liquid outlet line, for example a pressure hose, can be connected to the pump outlet 24 . On its free end, the pressure hose can carry a dispensing device for cleaning liquid, such as a spray gun, which can be closed manually by the user.

The pump inlet 22 forms the free end of an outlet line 26 of the high-pressure cleaning device 10 . The outlet line 26 is assigned a signal transmitter which, in the exemplary embodiment shown, is designed as a pressure switch 28 and supplies a control signal as a function of the pressure of the cleaning fluid prevailing in the outlet line 26 . This is discussed in more detail below.

In addition to the motor pump unit 14 , a control unit 30 and a rechargeable battery 32 are arranged in the housing 12 . A rechargeable battery 32 is the energy source for the electric motor 16 and the electric motor 16 can be switched on and off by means of the control device 30 . FIG. 2 shows a schematic block diagram of the control device 30 .

The control device 30 is in a signal-conducting connection to the pressure switch 28 via a signal line 34 . This allows the control device 30 to switch the electric motor 16 on and off depending on the pressure of the cleaning fluid present in the outlet line 26 . If the dispensing device arranged at the free end of the pressure hose is closed by the user, the pressure of the cleaning fluid increases in the region of the outlet line 26 . If the pressure exceeds a predetermined cut-off value, a pressure signal is transmitted from the pressure switch 28 to the control device 30 , which causes the control device to switch off the electric motor 16 . If the applicator is opened again by the user, the pressure of the cleaning fluid in the outlet line 26 drops. If the pressure falls below a predefined switch-on value, a control signal is transmitted from pressure switch 28 to control device 30 , which causes control line 30 to switch on electric motor 16 again.

The control device 30 is connected via a connecting line 36 to a display device 38 of the high-pressure cleaning device 10 . At least one operating value of the high-pressure cleaning device 10 , in particular the state of charge of the battery 32 , is displayed on the display device 38 .

The state of charge of the battery 32 is monitored by the control device 30 .

The control device 30 has a current detection link 40 and a voltage detection link 42 . The battery current provided by the battery 32 , that is to say the supply current of the electric motor 16 is periodically detected by means of the current detection element 40 , and the output voltage of the battery 32 is periodically detected by means of the voltage detection element 42 , that is to say the electric motor 16 supply voltage. The periodic detection of the battery current and battery voltage can take place, for example, at intervals of 10 seconds.

The actual value of the battery current is transmitted from the current detection link 40 to the signal processing link 44 , and the actual value of the battery voltage is transmitted from the voltage detection link 42 to the signal processing link 44 . The actual value of the battery voltage is multiplied by the actual value of the battery current by the signal processing unit 44 . This product results in an actual value for the electrical power consumption of the electric motor 16 , and this calculated actual value is compared with a predetermined minimum value for the electrical power consumption of the electric motor 16 via a comparison element 46 of the control device 30 . The minimum value is stored in a storage element 48 of the control device 30 .

By means of comparison element 46 it is possible for control device 30 to detect whether the actual value of the electrical power consumption of electric motor 16 is less than a predetermined minimum value of the electrical power consumption.

The control device 30 also has a timing element 50 which determines whether the start-up phase has expired, which starts anew each time the electric motor 16 is switched on. The duration of the start-up phase can be eg 2 or 3 minutes.

To switch electric motor 16 on and off, control device 30 has an electrically controllable switching element 52 . When the actual value of the electric power consumption of the electric motor 16 calculated by the signal processing part 44 is less than the predetermined minimum value of the electric power consumption of the electric motor 16 stored in the storage part 48, the switch part 52 turns off the electric motor 16 in order to counteract the risk of dry running of the high-pressure pump 20 thereby.

The following fact forms the background for switching off the electric motor 16 below a predetermined minimum value of the electrical power consumption after the start-up phase has passed, that is, when the high-pressure pump 20 is insufficiently supplied with cleaning fluid, the electric motor 16 consumes only a small amount of power. To switch on the high-pressure cleaning device 10 , the user can move the actuating element in the form of the main switch 54 into the ON position. The electric motor 16 is then switched on by the control device 30 by means of the switching element 52 and at the same time a timer element 50 is started which measures the time since the electric motor 16 is switched on and is reset to zero each time the electric motor 16 is switched off. Cleaning fluid, for example from a storage container, can then be drawn in by the high-pressure pump 20 via the pump inlet 22 and the fluid delivery line coupled thereto. The high-pressure pump 20 is filled with cleaning fluid, and the electrical power consumption of the electric motor 16 is increased. The electrical power consumption is periodically calculated by the signal processing unit 44 from the actual value of the battery current provided by the current detection unit 40 and the battery voltage provided by the voltage detection unit 42 . A control signal is provided by comparison element 46 , which is dependent on a comparison of the actual value of the electrical power consumption of electric motor 16 with a predetermined minimum value of the electrical power consumption of electric motor 16 . For example, timing element 50 emits a signal at the end of a starting phase which may last 2 or 3 minutes after switching on electric motor 16 . After the start-up phase has passed, the switching element 52 switches off the electric motor 16 if the actual value of the electrical power consumption is less than a predetermined minimum value, since being below the minimum value of the electrical power consumption indicates that there is not enough cleaning fluid delivered , and there is a danger of running dry. If not below the minimum value of the power consumption, the electric motor 16 continues to be supplied with energy, and the actual value of the power consumption is still periodically compared with the minimum value of the power consumption of the electric motor 16 .

When the electric motor 16 is switched off by the control device 30 after the start-up phase because the minimum value of the electrical power consumption has been fallen below, the electric motor can only be switched on again by the user turning the main switch 54 to its off position. in the off position, and then transfers to its on position again. However, if the electric motor 16 is switched off by closing the applicator arranged at the free end of the pressure hose, the electric motor can be switched on again at any time by opening the applicator again No additional actuation of the main switch 54 is required. Switching off the electric motor 16 due to the lower than the minimum value of the electrical power consumption results in a blockage of the switching element 52, which can only be eliminated by actuating the main switch 54, whereas switching off the electric motor 16 due to the closure of the application member does not cause switching Link 52 of this block.

The control device 30 therefore monitors the electrical power consumption of the electric motor 16 and switches it off if the electrical power consumption after the start-up phase is below a predetermined minimum value for the electrical power consumption. Damage to the high-pressure pump 20 due to an insufficient supply of cleaning fluid can thus be avoided.

Control device 30 also monitors the supply current of electric motor 16 , that is to say the battery current. If the battery current exceeds the predetermined maximum admissible current value stored in the storage element 48, this situation is also detected by the comparison element 46, so that the switching element 52 is prompted to switch off the electric motor 16, because there is an overload and There is a risk of damage to the electric motor 16 .

Claims (16)

1. A method for controlling a high-pressure cleaning device (10) having an electric motor (16), a high-pressure pump (20) driven by the electric motor (16) and a control device (30), characterized in In that the control device (30) determines the actual value of the electrical power consumption of the electric motor (16), and when the electric motor (16) has been switched on after a predetermined starting phase switching off the electric motor (16) when the actual value of the electric power consumption of the motor (16) falls below a predetermined minimum value of the electric power consumption of the electric motor (16), The high-pressure cleaning device (10) has at least one rechargeable battery (32), and the control device (30) detects the battery current and the battery voltage, and calculates the electrical work of the electric motor (16) therefrom the actual value consumed, The control device (30) when the pressure prevailing in the outlet line (26) of the high-pressure cleaning device (10) of the cleaning fluid delivered by the high-pressure cleaning device (10) exceeds a predetermined cut-off value ) switches off the electric motor (16), and when the pressure of the cleaning fluid present in the outlet line (26) drops, the control device (30) switches on the electric motor (16) again . 2. The method as claimed in claim 1, characterized in that the control device (30) switches off the electric motor (16) when the actual value of the battery current exceeds a predetermined maximum permissible current value. 3. The method according to claim 1 or 2, characterized in that the control device (30) periodically determines the actual value of the electrical power consumption of the electric motor (16). 4. The method according to claim 1 or 2, characterized in that after a start-up phase, the electric motor (16) is switched off by the control device (30) due to a minimum value for the electric power consumption of the electric motor (16) The electric motor (16) can only be switched on again by manually actuating the operating element (54) of the high-pressure cleaning device (10). 5. High-pressure cleaning device with an electric motor (16), a high-pressure pump (20) driven by said electric motor (16) and a control device (30), said high-pressure cleaning device for carrying out the cleaning according to claims 1 to 4 The method according to any one of the above, characterized in that the control device (30) is set up to determine the actual value of the electric power consumption of the electric motor (16) and compare the actual value with the electric motor (16) The predetermined minimum value of the electric power consumption of the motor (16) is compared, and when the electric power of the electric motor (16) after switching on the electric motor (16) after passing through the predetermined starting phase When the actual value of power consumption is less than the minimum value of the electric power consumption of the electric motor (16), the electric motor (16) can be shut off by the control device (30), and the high-pressure cleaning equipment (10) has at least a rechargeable battery (32) for supplying energy to said electric motor (16), The control device (30) has a current detection link (40) for detecting the battery current and a voltage detection link (42) for detecting the battery voltage, and the control device (30) is set up to operate from the The actual values of the battery current and the battery voltage calculate the actual value of the electric power consumption of the electric motor (16), The high-pressure cleaning device (10) has an outlet line (26) for pressurizing the cleaning fluid, and when the pressure of the cleaning fluid prevailing in the outlet line (26) exceeds a predetermined cut-off value , the electric motor (16) can be switched off by the control device (30), and when the pressure of the cleaning fluid present in the outlet line (26) drops, the control device ( 30) Turn on the electric motor (16) again. 6. The high-pressure cleaning device according to claim 5, characterized in that the control device (30) can shut down the battery when the actual value of the battery current exceeds a predetermined maximum permissible current value. electric motor (16). 7. The high-pressure cleaning device according to claim 5 or 6, characterized in that the control device (30) has a memory element (48) for storing the minimum value of the electrical power consumption of the electric motor (16) . 8. The high-pressure cleaning device according to claim 5, characterized in that, the high-pressure cleaning device (10) has a signal transmitter (28), and the signal transmitter communicates with the control device (30) in a signal-conducting manner. ) connection and provide the control device (30) with a control signal related to the pressure of the cleaning fluid present in the outlet line (26). 9. The high-pressure cleaning device as claimed in claim 8, characterized in that the signal transmitter is designed as a pressure switch (28). 10. The high-pressure cleaning device according to claim 5 or 6, characterized in that the control device (30) is set up to periodically determine the actual value of the electrical power consumption of the electric motor (16) and A comparison is made with a predetermined minimum value for the electrical power consumption of the electric motor (16). 11. The high-pressure cleaning device according to claim 5 or 6, characterized in that the high-pressure cleaning device (10) has an actuating element (54), and after the electric motor (16) has passed through the start-up phase due to the low After the minimum electrical power consumption of the electric motor (16) has been switched off by the control device (30), the electric motor can only be switched on again by manual actuation of the actuating element (54). 12. The high-pressure cleaning device as claimed in claim 11, characterized in that the actuating element is designed as a main switch (54). 13. The high-pressure cleaning device according to claim 5 or 6, characterized in that the high-pressure pump (20) is designed as a reciprocating piston pump. 14. The high-pressure cleaning device according to claim 5 or 6, characterized in that the electric motor (16) is connected to the high-pressure pump (20) via a transmission (18). 15. The high-pressure cleaning device as claimed in claim 5 or 6, characterized in that the electric motor (16) has a fixed rotational speed. 16. The high-pressure cleaning device according to claim 14, characterized in that the electric motor (16) has a rotational speed of at least 15,000 revolutions per minute.

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