EP1522251B1 - Washing or rinsing machine with electronic control system - Google Patents

Abstract

Sensors (D) detect the motion of dish washing machine spray arms or the drum of clothes washing machines and reed switches (S) energise a coil (L2) in the wet area of the machine and hence the primary (L1) in the dry area for evaluation by a frequency analyzer (5) and corrective control unit (6).

Description

The invention relates to a cleaning machine according to the preamble of claim 1.

Such a cleaning machine is from the DE 44 38 036 C2 known.

Cleaning machines have a wet area, which is commonly referred to as a laundry room and one of them watertight separate dry area in which, inter alia, a mostly electronic control of the machine and other units, such as pumps, valves and the like, are. To control and monitor the operation of the cleaning machine, it is desirable certain physical Measure or sense sizes within the washroom, for example, the rotational speed of a rotatable spray arm, which is set in rotational movement by leaking under pressure rinsing fluid, the speed of a metering pump, a rotatable drum for cleaning hoses, etc.

Cleaning machines, especially dishwashers have such spray arms (hereinafter referred to as rotating arms), the rotation of which greatly influences the cleaning result, namely the fact whether cleaning fluid escapes from the rotating arms and thus the objects to be cleaned are uniformly sprayed. For many reasons, it may happen that this is not the case, be it by clogged nozzles on the rotating arms, by incorrect loading of the dishwasher with objects that protrude into the rotational range of the rotating arms and block their rotation, thus increasing the friction of the storage Rotary arms, by lessening the performance of a circulating pump, by insufficient water in the detergent circuit or by foaming in the cleaning fluid.

It is therefore desirable to monitor the rotational movement of the rotary arms. For this purpose, the said DE 44 38 036 C2 to arrange the pivot bearing of the rotary arm with an axial extension in the wet area, the extension has a transmitting device (eg metal cams, resonant circuit, etc.), their signals with a receiving device (reed contact, proximity switch, Hall sensor, etc.) in the wet or dry area be sensed. Although with this monitoring device, the rotational speed of the rotary arm can be determined, however, there is a need to extend the rotary bearing of the rotary arm and provided with a transmitter in the wet area, which is expensive on the one hand and on the other hand increases the susceptibility of the monitoring device, since the transmitter in the wet area the Spülmitteleinfluß and is exposed to constant temperature changes.

From the DE 40 20 898 A1 It is known to monitor the rotational movement of the rotary arms by a pressure sensor which is arranged in the wall of the spray container. The pressure sensor consists of a rubber-elastic membrane, which bulges when hitting a Spülwasserstrahls and actuates a switch.

The DE 197 32 856 C2 proposes in further development of this principle, to arrange the pressure sensor at the end of a funnel, in which the liquid jet enters during rotations of the rotary arm.

The DE 40 10 066 A1 proposes to apply different rotating arms of the cleaning machine with different water pressure, so that they are operated at different rotational speed. From this and from the rinsing liquid emerging from the rotating arms, different sounds are generated in each case, which lie in characteristic frequency ranges. By means of a microphone, which is arranged outside the washroom, the noise generated on the washroom inner wall is first recorded and then screened with the aid of an electronic filter, the characteristic frequency ranges from the signal mixture. An analysis of the remaining signals allows conclusions about the rotational behavior of the rotating arms.

A fundamental problem with the Dreharmdrehüberwachung is that the rotary arms are not permanently mounted in the washing chamber in many cleaning machines, such as those used in particular for the cleaning of medical equipment, but are on washing inserts that are equipped with objects to be cleaned and in the Washing chamber of the machine can be used. For almost every type of wash insert, the pivot arms are in a different position. In the above-discussed prior art, the receiving devices, such as pressure sensors, microphones or the like are arranged at a fixed predetermined position in or outside the washing chamber, which is in the Use of washing inserts, each with differently arranged rotating arms is not possible.

The same problem also occurs in the sensing of the rotational movement of other mounted on the washing unit units, such as dosing pumps for the supply of cleaning additives, from rotating washing drums for cleaning medical hoses, as shown in DE 31 43 005 C2 are known or of opening and closing operations of flaps, valves or the like, which may also be arranged on the washing insert.

The object of the invention is therefore to improve the cleaning machine of the type mentioned in that monitoring of movements of aggregates is possible, even if they are arranged at different positions in the washing room of the cleaning machine.

This object is achieved by the features specified in claim 1. Advantageous embodiments and further developments of the invention can be found in the dependent claims.

The basic principle of the invention is to provide sensors for monitoring the movement of aggregates on the wash insert. This then results in the subsequent problem of transmission of the sensor signals from the respective washing insert for controlling the cleaning machine, which is located outside the washroom, ie from the wet area of the machine to the drying area. A galvanic coupling between the sensors and an evaluation circuit through contacts, plugs, etc. is excluded due to the prevailing in the wash chamber moisture and temperature effects due to the high susceptibility to interference. The invention therefore proposes a galvanically isolated coupling.

Preferably, an electromagnetic coupling with two coils is used. The primary coil is located outside the washroom in the dry area or in waterproof Execution in the washroom (wet area) and is connected to an oscillator. The secondary coil is located on the washing insert in the wet area and is connected to one or more also arranged on the washing insert sensors. The sensors are, for example, reed contacts, which are actuated by magnets attached to the units. Each time a magnet passes the reed contact, the reed switch intermittently closes and reopens, momentarily shorting the secondary coil. This acts on the primary coil back to the oscillator, thereby changing at least one of its parameters, such as frequency, current and / or voltage. The change of these parameters is evaluated by an evaluation circuit to the effect that the number of closing or opening operations of the switches per unit time are determined. The number of closing and opening operations depends on the number of units and their rotational speed, these values are each characteristic of individual washing inserts. When individual units are blocked or the speed is too low, the number of closing and opening operations of the switches drops below a predetermined threshold and an alarm is triggered. As sensors, other types of sensors can be used, such as inductive or capacitive proximity switches, by which a parameter of the oscillator is changed.

Are on the washing rack several units, such as several rotating arms, arranged, so all sensors are connected in parallel in an advantageous manner, so that only a single pair of coils is needed. The units or rotating arms usually rotate asynchronously to each other, so that only relatively rarely occur overlaps of pulses, that at the same time several switches open or close. From the total number of pulses can then determine whether one or more of the units or rotating arms do not rotate correctly. Any overlaps that may occur can be eliminated by a correction factor. Also exists the possibility for a larger number of aggregates or rotary arms to combine them into several groups, in which case each group is assigned a pair of coils and an oscillator. Of course, individual units, such as rotating arms, can be monitored.

According to a more advantageous embodiment of the invention, the secondary coil is formed on the washing carrier by an additional capacitance to a series or parallel resonant circuit, which is in resonance with the frequency of the oscillator. As a result, the sensitivity is increased.

With the invention, not only rotational movements of rotating arms can be detected but any rotational movements of moving or rotating parts in the washroom, such as a rotating washing drum for cleaning medical hoses, as shown in DE 31 43 005 C2 is known. In addition, any kind of opening or closing operations or pulses generated on the washing cartridge can be transferred to the controller of the machine. Sensors can be pressure switches, flow meters, flow meters or the like.

According to a development of the invention, an identification device is provided for identifying the washing carrier, for example a magnetic reading device and a magnetic coding on the washing carrier. Since different washing carriers also have different numbers of rotating arms or rotating parts, this information is to be transmitted to the evaluation device, which takes this information into account in the evaluation.

The evaluation device preferably outputs an alarm signal when it is determined that one or more rotating arms are not rotating at the expected speed.

• Es wird keine elektrische, d.h. galvanische Kopplung zwischen Wascheinsatz und Trockenbereich der Maschine durch Stecker oder Kontakte benötigt;
• es können unterschiedliche Arten von Wascheinsätzen mit unterschiedlicher Anordnung und unterschiedlicher Zahl von Dreharmen in ein und derselben Maschine verwendet werden, wobei die elektrische Ausrüstung für die Drehzahlüberwachung unabhängig vom Wascheinsatz ist;
• eine individuelle Anpassung an die Zahl der Dreharme erfolgt auf dem jeweiligen Wascheinsatz;
• auch zukünftig entwickelte Wascheinsätze können ohne Problem an die Reinigungsmaschine angepaßt werden und in die Drehzahlüberwachung integriert werden;
• mit an sich bekannten Identifikationssystemen für Wascheinsätze, wie z.B. eine Magnetcodierung können die jeweiligen Sollwerte und Grenzwerte ohne zusätzlichen Schaltungsaufwand für alle Arten von Wascheinsätzen verarbeitet werden.

Amongst others, the following advantages are achieved with the invention:

• There is no electrical, ie galvanic coupling between the wash and dry area of the machine needed by plug or contacts;
• different types of washing inserts with different arrangements and number of rotating arms can be used in one and the same machine, the electrical equipment for speed monitoring being independent of the washing application;
• an individual adaptation to the number of rotating arms takes place on the respective washing insert;
• also future developed wash inserts can be adapted without any problem to the cleaning machine and integrated into the speed monitoring;
• With known identification systems for washing inserts, such as a magnetic coding, the respective setpoints and limits can be processed without additional circuitry for all types of washing inserts.

Fig. 1

eine Prinzipskizze der Reinigungsmaschine nach der Erfindung;

Fig. 2

ein Blockschaltbild einer Überwachungsschaltung; und

Fig. 3

ein detailiertes Schaltbild der Schaltung der Fig. 2.

In the following the invention will be explained in more detail by means of embodiments. It shows:

Fig. 1

a schematic diagram of the cleaning machine according to the invention;

Fig. 2

a block diagram of a monitoring circuit; and

Fig. 3

a detailed circuit diagram of the circuit of Fig. 2 ,

first, be on Fig. 1 Referenced. Although in the following embodiment reference is made to rotary arms, it is expressly understood that with the invention, the movement of any aggregates can be detected. Such units may be: rotary arms, washing drums, pumps, flaps, valves, valves, moving into the washroom door handles or the like. A washing insert 1, which is for example an insert basket, which is charged with objects to be cleaned and is inserted into a washroom of a cleaning machine, has a plurality of spray arms or rotating arms D1 ... Dn, which are rotatably mounted on one or more axes of rotation A. These rotary arms have spray nozzles, not shown, from which cleaning liquid emerges under pressure in known manner, whereby the respective rotary arm is set in a rotary motion. In the illustrated embodiment, a magnet M1 ... Mn is attached to each rotary arm D1 ... Dn, which is associated with a reed switch K1 ... Kn. Each time one of the magnets M1 ... Mn is moved past the assigned reed switch K1 ... Kn, it switches over briefly. This switching should not be, for example, a brief closing followed by re-opening of the reed contact. Conversely, it is also conceivable that the reed contact is normally closed and briefly opens when passing the magnet. All reed contacts K1 ... Kn are connected in parallel and connected to a secondary coil L2.

As an additional option, the secondary coil L2 may be connected in parallel with a capacitor C1 or, alternatively, a capacitor C2 may be connected in series with a terminal of the secondary coil L1, thus forming a resonant circuit tuned to resonant frequency with an oscillator.

Each washing insert 1 additionally has a coding 2, for example in the form of a magnetic coding, wherein a reading device 3 is located inside the washroom into which the washing insert 1 is inserted, which reads the corresponding code and thus provides a signal for a washing insert identification which is supplied to a controller 6 of the cleaning machine.

The secondary coil L2 is coupled via an air gap Sp with a primary coil L1. The primary coil (L1) can be in watertight execution in the washroom or outside the washroom in the drying room, in which case between the primary coil (L1) and secondary coil (L2) a window of non-magnetic material is present. The primary coil (L1) is connected to an oscillator 4 and forms together with this a resonant circuit which is coupled via the coupling through the air gap Sp also with the secondary coil L2. Both coils L1 and L2 are thus components of a resonant circuit with the oscillator 4. Changes at least one of the switches K1 ... Kn its switching state, so it also affects the resonant circuit of oscillator 4 and primary coil L1. For example, if one of the switches K1 ... Kn closed, the secondary coil L2 is shorted. As a result, at least one parameter of said resonant circuit changes, for example its frequency and / or its power consumption or its current or its voltage. This process can be detected by a frequency evaluation circuit 5 and reported to the controller 6 of the machine, which outputs an error signal at an output 6a or initiates a termination of the cleaning process. The error signal can be output, for example, optically or acoustically or be printed in a cleaning protocol.

Alternatively or cumulatively to the frequency evaluation 5, an evaluation circuit 7 can also be used for the evaluation of other parameters of the oscillator 4, e.g. its power consumption, its current or its voltage, be provided, which also reports its evaluation result to the controller 6. Via additional outputs 9, the evaluation result can also be output otherwise, be it as an error signal or as a cleaning protocol.

Fig. 2 shows a block diagram of an evaluation circuit. As in Fig. 1 one or more switches K1 are connected in parallel to the secondary coil L2. A series connection of a resistor R5 and the primary coil L1 is connected between supply voltage Vcc and ground. The oscillator 4 is connected in parallel with the primary coil L1. A first low-pass filter Tp1 whose output is connected to the non-inverting input of a comparator 10 is connected to the center tap between the resistor R5 and the primary coil L1. The output of the first low pass Tp1 is via a second Low pass Tp2 connected to the inverting input of the comparator 10.

If the switch K1 is closed and thus the secondary coil L2 short-circuited, the current through the series circuit of the resistor R5 and the primary coil L1 decreases. The first low-pass filter Tp1 smoothes the voltage drop across the primary coil L1, so that the oscillator frequency does not flow into the measurement. The output of the second low-pass filter, whose cut-off frequency is lower than that of the first low-pass filter, serves as the reference voltage for the comparator 10. When switched switch K1, the output voltage of the low-pass filter Tp1 is greater than that of the low-pass filter Tp2, so that the comparator 10 turns on and a high Gives level at its output. Opens the switch K1 again, the comparator 10 switches off again, so that per switching operation of the switch K1 a pulse appears at the output of the comparator 10. These pulses are supplied to a counter 11, which is, for example, part of an arithmetic circuit which makes further evaluations, such as e.g. Number of pulses per unit of time, comparison of these results with given setpoints, etc.

Fig. 3 shows a more detailed circuit diagram of the circuit Fig. 2 , The primary coil L1 is divided here into two partial coils L11 and L12. The primary coil L1 and the secondary coil L2 are each divided into two partial coils L11, L12 and L21, L22. The respective sub-coils may be arranged spatially separated from each other and are pairwise associated with each other, so electromagnetically coupled together via an air gap, ie L11 with L21 and L12 with L22. A first terminal of the first partial coil L11 is connected to a first capacitor C1 whose second terminal is connected in series with a resistor R2, a collector-emitter path of a transistor T1 and a resistor R1, the latter being connected to ground. The base of the transistor T1 is located at a Voltage dividers from resistors R3 and R4. The resistor R4 is connected to ground and the resistor R3 is connected via a further resistor R5 to the supply voltage Vcc. One terminal of the second partial coil L12 is connected via a capacitor C2 to the base of the transistor T1. The second terminal of the partial coil L12 is grounded. The two partial coils L11 and L12, the capacitors C1 and C2, the resistors R1 to R4 and the transistor T1 thereby form a Meissner oscillator whose output is the first terminal of the first partial coil L11. This output is connected via a capacitor C3 to ground, wherein the resistor R5 and the capacitor C3 form the first low-pass filter TP1. The common connection point between the resistor R5 and the capacitor C3 forms the output of the first low-pass filter TP1 and is connected via a capacitor C4 to the non-inverting input of the comparator 10 and via a resistor R6 to ground. The capacitor C4 and the resistor R6 form a high pass whose output is the common connection point between the capacitor C4 and the resistor R6. The output of this high pass is connected via a series circuit of a resistor R7 and a capacitor C5 to ground, wherein the common connection point between the resistor R7 and the capacitor C5 is connected to the inverting input of the comparator 10. The resistor R7 and the capacitor C5 form the second low-pass filter TP2 whose output serves as a reference voltage for the inverting input of the comparator 10. At the output of the comparator 10 then appear in connection with Fig. 2 explained switching pulses.

At the resistor R5 a voltage drops, which is anti-proportional to the current consumption of the Meissner oscillator. The capacitor C3 smooths this voltage and forms together with R5 a low-pass filter TP1, so that the oscillator frequency is not included in the measurement. The cut-off frequency of this low-pass filter TP1 is for example 100 Hz. The capacitor C4 and the resistor R6 form a high-pass filter HP whose filtered Output is at the non-inverting input of the comparator 10 and at the input of the second low-pass filter R7 and C5 (TP2). The cutoff frequency of the high-pass filter HP is, for example, 10 Hz and that of the second low-pass filter TP2 is 1 Hz. The output signal of the second low-pass filter TP2 serves as a reference voltage at the inverting input of the comparator 10. The oscillator frequency is in the order of 120 kHz. The coil L11 is a direct component of the oscillator and inductively coupled to the feedback coil L12. This causes the power consumption of the oscillator when closing the switch is lower because the positive feedback decreases, so that the voltage at the output of the first low-pass filter Tp1 increases. The following high-pass filter is used only for direct-current separation of the signal, so that only the alternating component is evaluated at the comparator. The first low-pass filter thus essentially serves for suppressing the oscillator frequency, the high-pass filter for suppressing the DC component and the second low-pass filter for the automatic generation of a reference value with long-term stability.

If one of the magnets M1 ... Mn ( Fig. 1 ) comes in the vicinity of the associated reed switch K1 ... Kn, it is turned on and closes the two sub-coils L21 and L22, which are connected in series and form the secondary coil L2, short. Thus, the current consumption of the oscillator decreases and the voltage at the non-inverting input of the comparator 10 rises above the value at the inverting input, so that the comparator 10 turns on and outputs a high level at its output. By dividing the two coils L1 and L2 into spatially separated partial coils, the energy input to the wash insert and the information feedback can be improved. A partial coil pair, eg L11 / L21, is used to transfer energy to the wash insert and the second partial coil pair, for example L12 / L22, to retransmit the information as to whether a switch is closed or not.

Claims (12)

1. Cleaning machine having a washing space and at least one sensor, arranged within the washing space, for measuring a physical quantity and with a receiving device, which is connected with an evaluation device arranged outside the washing space,
   characterized
   in that the sensor (K1...Kn; M1...Mn) is attached to washing insert (1), which can be inserted into the washing space of the cleaning machine,
   in that the sensor is a switch (K1...Kn) operating without current supply,
   in that the switch (K1...Kn) is connected with a secondary coil (L2), which is also attached to the washing insert (1),
   in that the secondary coil (L2) is electromagnetically coupled with a primary coil (L1),
   in that the primary coil (L1) is connected with an oscillator (4), which is changing at least one of his parameters in dependence from the electrical properties of the secondary coil (L2), and
   in that the evaluation device (5, Tp1, Tp2, 10) is determining said physical quantity based on said changed parameter.
2. Cleaning machine according to claim 1, characterized
   in that the physical quantity is the movement of an aggregate (D1...Dn) attached to the washing insert (1) and the sensor is comprising a magnet (M1...Mn) attached to the aggregate (D1...Dn) and the switch (K1...Kn) operated by the magnet, the switch being connected parallel to the secondary coil (L2).
3. Cleaning machine according to claim 2, characterized
   in that the switch is a Reed-contact (K1...Kn).
4. Cleaning machine according to claim 3, characterized
   in that the Reed-contact is temporary closing on passing of the assigned magnet.
5. Cleaning machine according to claims 1 to 4, characterized
   in that the secondary coil is tuned to resonance with the frequency of the osciallator (4) by a capacitor (C1, C2).
6. Cleaning machine according to one of claims 1 to 5, characterized
   in that the parameter of the oscillator (4) evaluated by the evaluation device is his frequency, power consumption, currency or voltage.
7. Cleaning machine according to claim 6, characterized in that the primary coil (L1) is connected with supply voltage via a resistor (R5), in that the primary coil is connected with a noninverting input of a comparator (10) via a first low pass filter (Tp1) and
   in that the output of the first low pass filter (Tp1) is connected with a inverting input of the comparator (10) via a second low pass filter (Tp2).
8. Cleaning machine according to claim 7, characterized
   in that the output of the comparator is connected with a calculating device (5, 6, 7),
   in that a coding (2) is attached to the washing insert and a reading device (2) for reading the coding is arranged within the wet area of the cleaning machine, wherein said reading device (3) is connected with the calculation device, which determines limit values for the rotational speed of the rotatable arm in dependence from the coding of the washing insert.
9. Cleaning machine according to one or several of claims 1 to 8, characterized
   in that the aggregate is a rotatable arm (D1...Dn) driven in rotational movement by escaping fluid.
10. Cleaning machine according to one or several of claims 1 to 8, characterized
    in that the aggregate is a rotating drum for cleaning tubular objects.
11. Cleaning machine according to one of claims 1 to 10, characterized
    in that several aggregates (D1...Dn) are arranged on the washing insert,
    in that a sensor (M1...Mn; K1...Kn) is assigned to each aggregate (D1...Dn) and
    in that all sensors are connected in parallel to the secondary coil (L2).
12. Cleaning machine according to one of claims 1 to 11, characterized
    in that the primary coil (L1) and the secondary coil (L2) each are divided into two coil sections (L11, L12; L21, L22) spacially separated and are electromagnetically coupled with each other by pairs (L11/L21; L12/L22).

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