EP1455092B1 - Battery-driven pump with control device - Google Patents

Abstract

A battery-driven pump (1) for watering gardens has a control (2) to adjust the power output from the battery to the pump motor (1.4,2.1). Preferably the power is adjusted continuously or in steps and pulse-width modulation is used to control the battery output.

Description

Field of application and state of the art

The invention relates to a battery-powered pump according to the preamble of claim 1.

Battery operated pumps are particularly useful in gardens without their own power supply in the context of garden irrigation or to promote collected rainwater from wells, ponds or reservoirs. Of particular advantage is their use as a submersible pump, since the low battery voltage compared to the high mains voltage for the user is not critical.

Battery-powered pumps, however, like all battery-powered devices, have the problem that battery life limits battery life.

The WO 00/67368 describes an electric motor for a liquid pump, which is controlled by a PWM generator. It is not explained in detail, where a power specification comes from an operator for the electric motor.

The US 4,836,147 describes a pump that can work with two different power levels and is used in a motor vehicle. The adjustment of the power levels is also done by pulse width modulation. More details about a performance specification by an operator are not mentioned here.

The US 6,206,298 describes a pump with an electric motor that can be powered by a battery. However, an adjustment of the power of the electric motor is not mentioned herein at all.

The US 6,189,811 describes a portable water pump that can be operated either with a battery or with a vehicle electrical system of a motor vehicle. An adjustment of the power of the pump is not mentioned.

Task and solution

The object of the invention is therefore to avoid disadvantages of the prior art and in particular to increase the operating time of a battery-operated pump with a charge of the battery and to avoid overloading the battery.

This object is achieved with the features of claim 1. The dependent claims relate to advantageous embodiments and further developments of the invention, which are described below. The wording of the invention is incorporated herein by express reference.

The main idea of the invention is to loop in between an engine and a battery for driving the motor, an adjustable control device, with which a power output of the battery to the engine is variably adjustable. As a result, it is advantageously possible to carry out a power consumption of the pump motor with little loss compared to a direct connection to the battery. Preferably, the power output of the battery is switchable by the control device in several stages, wherein in one stage, the pump motor is coupled via the control device without limiting the power output directly to the battery, and in at least one further stage, the controller output the power delivered by the battery for the Pump motor limited. Alternatively, the power output can be adjusted continuously. Preferably, it is possible that the control device reduces the motor input voltage with respect to the battery voltage as a function of the predetermined power output.

The term battery according to the invention of course also includes rechargeable batteries such as accumulators or the like.

Preferably, at least two further different stages are provided, in which the control device reduces the power consumption of the pump motor compared to the direct coupling to the battery. In addition, a stage "off" may be provided, in which the controller completely disconnects the battery from the pump motor.

Preferably, the individual possible power adjustment stages for the pump motor are visibly indicated by numbers. Alternatively or in addition to a pure numbering, however, it is also possible to provide symbols which identify a particular application. The markings of the individual stages can be applied to the operating element and / or on a housing of the control device in the environment of the control element.

In one possible embodiment of the invention, the individual stages are set individually by the user with the operating element, i. by selecting discretely adjustable positions on the operating element, wherein the discretely adjustable positions are realized for example by haptic sensible by the user on the control detent positions, which relate to the individual applications of the pump.

In another embodiment of the invention, the selection of the individual applications of the pump with the control element is continuous or quasi-continuous. That is, the control does not have locking positions, via which the user receives a haptic feedback on a certain set position on the control, and the power output of the battery is continuously or quasi continuously adjustable by the control device. In this embodiment, it is particularly advantageous if appropriate designations of the individual applications of the pump are present on the control element and / or on the housing of the control device.

In a particularly advantageous embodiment of the invention, a control circuit is provided to reduce a transmission loss in the control device, for example a DC-DC converter. With this can be adjusted according to an application of the pump a transmission measure. The type of setting the transmission measure may be different. In a particularly simple embodiment, the control circuit is designed as a pulse width modulator (PWM), the duty cycle (switching time to period time) is adjustable according to the application of the pump, for example, over a range of 30% for a lowest power consumption of the engine to 100% for a maximum power consumption the pump motor. The duty cycle of 100% corresponds to a direct coupling of the pump motor to the battery.

In the control device can be looped between a battery terminal and a connection for the pump motor, a switching element, in particular an electronic switching element, such as a field effect transistor. This is switched on and off by switching cycles. These measures have the advantage that a power loss occurs at the switching element substantially only on the switching edges, which can be kept very short. The power losses in the switching element can be reduced in conventional circuits to a few percent.

In a particularly simple embodiment of the invention, the control element is used to set a specific duty cycle in the control circuit, wherein discretely adjustable positions on the operating element for the duty cycles 0% position "off", battery is completely disconnected from the pump motor, about 33%, approx 67% and 100% - Direct coupling of the battery to the pump motor - are present.

By means of the described control device according to the invention, the electrical power drawn from the battery can be better adapted to the mechanical power required in the various applications and thus a battery life can be extended.

It is also possible to adapt the motor input voltage to a specific operating mode. If no extra power is required, the motor input voltage can be lowered to save battery life.

In a further advantageous embodiment of the invention, a standard connection is provided on the control device, with which the control circuit can be connected to a corresponding low-voltage connection to a motor vehicle. As a result, the power required for the operation of the pump can be taken from a motor vehicle electrical system.

A charging process for a rechargeable accumulator can also be controlled via the control device. For example, it can be adapted to different DC voltages. Furthermore, it is possible to provide a connection for a power cable and form the switching element with another part of the control circuit as a charger with rectifier. So an accumulator could be charged to a mains connection.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections as well as intermediate headings do not restrict the general validity of the statements made thereunder.

Brief description of the drawings

Fig. 1

eine schematische Darstellung von Komponenten einer erfindungsgemäßen Pumpe;

Fig. 2

ein Blockschaltbild einer Steuerschaltung aus einer in Fig. 1 dargestellten Steuereinrichtung;

Fig. 3

ein Diagramm zur Darstellung von Druck- und Wirkungsgradkennlinien bezogen auf eine Durchflussmenge für unterschiedliche Einstellungen eines Übertragungsverhältnisses.

Hereinafter, a practical embodiment with reference to the schematically Fig. 1 to Fig. 3 will be described in more detail. Show it:

Fig. 1

a schematic representation of components of a pump according to the invention;

Fig. 2

a block diagram of a control circuit of a controller shown in Figure 1;

Fig. 3

a diagram illustrating pressure and efficiency characteristics with respect to a flow rate for different settings of a transmission ratio.

Detailed description of the embodiment

Fig. 1 shows a conventional pump 1, which is designed for example as a submersible pump, with a pump housing 1.1 and a length-adjustable vertical outlet pipe 1.2. Instead of the outlet pipe 1.2, other types of lines can be connected to a corresponding connection on the pump housing 1.1. Within the pump housing 1.1 an unillustrated pump motor is arranged, which is supplied via a supply line 1.3, which is connectable to a control device 2 according to the invention, supplied by the control device 2 with energy. The control device 2 is shown for better representation of the connections to an operating position in the reverse position.

The control device 2, which may be generally waterproof, comprises in the illustrated embodiment an output port 2.1, which is designed as an electrical connection socket. It can be connected to the supply line 1.3 via the mating connection 1.4 in order to supply the pump motor with energy. Furthermore, an operating element 2.2 for setting a power output required for an application of the pump, an input terminal 2.3 for an external power supply of the control device 2, which is designed as a socket for connecting a charger, and in the illustrated position to the rear by about 90 ° hinged hook for hanging the control device to a container wall and a housing 2.5 provided.

As can be seen from FIG. 2, a control circuit 2.6 designed as a pulse width modulator with a switching element 2.7, and a rechargeable battery 2.8 are arranged within the housing 2.5 of the control device 2, which are connected to one another via corresponding electrical connections as shown. The switching element 2.7 is preferably designed as an electronic switching element, for example as a field effect transistor.

In the illustrated simple embodiment, the operating element 2.2 is used to set a specific duty cycle in the control circuit 2.6, with which the control circuit 2.6 switches the switching element 2.7 on and off by means of corresponding clock signals.

As can be further seen from FIG. 2, to simplify the power output setting, designations are provided which have a position '0' - duty cycle 0% or pump is switched off -, a position, 1 '- duty cycle approx. 33% -, a position 2 '- duty cycle about 67% - and a position, 3' - duty cycle 100% or direct connection of the battery with the pump motor - denote.

The maximum power output - 100% - is provided, for example, for a use case of the pump as a sprinkler, in which a high pressure and a large flow is needed. An average power output - 67% - is provided, for example, for a use case of the pump as a pouring shower or as a syringe in which a medium pressure and a medium flow rate is required. A low power output - 33% - is intended, for example, for a pump application to fill watering cans or for other water withdrawals that require low pressure at a pump outlet.

In accordance with the duty cycle set by the user with the operating element 2.2, the motor input voltage is reduced from typically 12 volts in the position '1' to 8 volts and in the position '2' to 10 volts. The stages are advantageously arranged in ascending order of performance. In the illustrated embodiment, the user accessible on the control device housing 2.5 arranged control element 2.2 is designed as a rotary switch with fixed detent positions, via which the power output for the pump motor from the battery 2.8 is adjustable in several discrete stages. Of course, a control can be used with which the settings are made continuously without discrete steps and thus the power output is also continuously adjustable.

The arranged at the end of the electrical supply line 1.3 mating connector 1.4 is preferably designed as a plug that does not fit into a mains voltage outlet. However, the plug can be designed so that it fits on a standard 12-volt connection and can be connected, for example, to a motor vehicle electrical system, so that the pump can be operated without the control device and without its own battery. Likewise, the input terminal 2.3 for charging the battery 2.8 may be designed to be except a charger can be connected via a corresponding connection line with a motor vehicle electrical system. Thus, the output from the vehicle electrical system power with the control circuit 2.6 is also adjustable.

Instead of the sketched pump, any known 12 volt DC pump may be connected to the control device.

Fig. 3 shows a diagram in which - based on the flow rate - pressure curves and efficiency curves (η) for different settings of the control device (motor input voltage is 8 volts, 10 volts, 12 volts) are entered on the flow rate. Values for the battery currents at selected measuring points are indicated along the pressure curve. As an electric motor, a standard DC motor is generally used to advantage, in this example it may be a Mabuchi RS-555SH-4525.

Claims (13)

1. Battery-driven pump (1) with a motor and a battery, an adjustable control device (2) for adjusting the power output of the battery (2.8) to the motor being connected between said battery (2.8) and said motor, characterized in that the power output of the battery (2.8) to the motor can be preset by a user, the power output being presettable by the user using an operating element (2.2) as a function of and/or in conjunction with a given use of the pump.
2. Pump according to claim 1, characterized in that the power output of battery (2.8) to the motor can be adjusted in several stages or continuously.
3. Pump according to claim 1 or 2, characterized in that the control device (2) reduces the motor input voltage with respect to the battery voltage in stages or continuously as a function of the preset power output.
4. Pump according to one of the preceding claims, characterized in that the control device (2) comprises a control circuit (2.6) with an adjustable transmission constant, which is preferably in the form of a pulse width modulator.
5. Pump according to claim 4, characterized in that the transmission constant is adjustable by varying a keying ratio of through-connection time to cycle time and preferably the keying ratio is adjustable from approximately 30% for the lowest possible power output to 100% for the highest possible power output.
6. Pump according to one of the preceding claims, characterized in that the control device (2) comprises an electronic switching element (2.7), which can be switched on and off as a function of switching cycles and which is connected between the motor and battery (2.8).
7. Pump according to one of the preceding claims, characterized in that the control device (2) has an electrical connection (2.3) by means of which the control device (2) can be connected to a vehicle power supply.
8. Pump according to claim 1, characterized in that on the operating element (2.2) and/or on a control device casing (2.5) the power output corresponding to a given use is indicated by figures and/or symbols (2.8), which give the particular use.
9. Pump according to one of the claims 1 or 8, characterized in that in a first selectable position (off) of the operating element (2.2) battery (2.8) is completely separated from the motor.
10. Pump according to one of the claims 1 or 8 or 9, characterized in that in a second position of the operating element (2.2) a first use type with a high pressure and high flow can be selected.
11. Pump according to one of the claims 1 or 8 to 10, characterized in that in a third position of the operating element (2.2) a second use type with an average pressure and an average flow can be selected.
12. Pump according to one of the claims 1 or 8 to 11, characterized in that in a fourth position of the operating element (2.2) a third use type with a lower pressure and low flow can be selected.
13. Pump according to one of the preceding claims, characterized in that the battery (2.8) and/or control device (2) can be provided separately from the pump casing (1.1) and preferably a supply line (1.3) is provided for the connection between the pump casing (1.1) and control device (2).

Images