JPS6314638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a washing machine having a rotating drum with a rectifier fridge consisting of at least two controlled rectifiers for the supply voltage of the motor driving the drum and a single heating element. laundry
This invention relates to a device for accelerating heating of washing liquid in a washing machine.

Traditionally, washing machines drive their drums with a DC motor whose rotational speed is controlled by two diodes to control the induced current by modulating the induction time during a quarter cycle of the mains voltage. and 2
It is controlled by a power supply unit consisting of a hybrid bridge made up of several thyristors and an electronic circuit responsive to the emf of the motor (if such motor acts as a generator).

If it is necessary to heat with the maximum power of the immersion heater, the supply bridge of the motor is short-circuited, which of course causes the motor to stop.

However, in the case of a precise washing process,
It is generally known that it is necessary to agitate the washing liquid while increasing its temperature.

Current washing machines have two washing rhythms:
For example, "normal" which is energized for 12 seconds and deactivated for 4 seconds.
It has a rhythm and a "slow" rhythm that is opposite to this initial rhythm, energizing for 4 seconds and deactivating for 12 seconds.

Under these conditions, agitation at a normal rhythm prevents the temperature of the wash solution from rising too quickly. This is because the average current flowing through the immersion heater as the motor rotates is approximately half the maximum current during the standstill period when the heating element is directly connected to the mains voltage.

In order to avoid excessively long heating times, a slow rhythm is chosen, but in some cases this compromise affects the performance of the washing process. On the contrary,
For example, in winter, especially if the temperature of the water supplied to the washing machine is low, the heating time becomes excessively long.

This drawback can be easily overcome by using a second immersion heater that is continuously energized by the mains voltage, but this reduces the simplification and efficiency of a single immersion heater. and sacrificing credibility benefits.

It is an object of the invention to provide a washing machine provided with a single heating element which, when connected directly to the mains voltage, transforms the output during rotation of the motor to approximately the maximum power.

Another object of the invention is to provide an accelerated heating device that operates entirely electronically without the provision of any electromechanical components.

The invention shows that at very slow speeds of rotation and under heavy loads, the current consumed by the motor is
This was achieved based on the recognition that when an immersion electric heater is directly connected to the mains voltage, the current flowing through the electric heater is approximately equal to that of the electric heater.

The present invention provides a device for accelerated heating of wash liquor in a washing machine having a rotating drum with a rectifying bridge consisting of at least two controlled rectifiers for the supply voltage of the motor driving the drum and a single heating element. electrons coupling the heating element in series with the rectifying bridge during the first time interval of a half period of the period and then coupling said heating element to the mains voltage during the remaining time interval of said half period. The apparatus is characterized in that it comprises a switching means, and the apparatus comprises a control means for controlling the switching means.

The electronic switching means include, for example, a controlled rectifier of a rectifying bridge.

During the quarter-period subdivision, the drum drive motor acts with a substantial resistive torque, so that a current approximately equal to the current drawn during the reset of the time interval when the immersion heater is connected directly to the mains voltage is Occurs in electric heaters.

For this purpose, any washing rhythm required by the type of laundry to be washed can be used while maintaining an almost constant heating period.

Furthermore, contamination of the power source can be avoided due to the substantial absence of power fluctuations during the heating cycle.

Finally, the completely static operation of the device of the invention ensures completely silent operation, and this low control power allows the device to be used to be controlled by a mechanism with electromechanical and hybrid program control and a microprocessor. It can be made possible in the mechanism.

The invention will now be described with reference to the accompanying drawings.

As shown in FIG. 1, a permanent magnet induction motor is placed between the common anodes of the two diodes 2 and 3 and the common cathodes of the two thyristors 4 and 5.

The common cathode and anode of the diode 2 and the thyristor 4 are connected to a mains terminal 7 via the immersion heater 6, and the other mains terminal 8 is connected to the common cathode and anode of the diode 3 and the thyristor 5.

The rectifier bridge constituted by diodes 2, 3 and thyristors 4, 5 is shunted by a triac 9.

The two contacts of electronic switch 10 are connected respectively to the common gates of thyristors 4 and 5 and to the gate of triax 9, and the common contacts of such switch 10 are connected to a source of 25 kHz trigger pulses.

Electronic switch 10 consists of an input controlled by twice the main frequency (100Hz).

2 and 3, the apparatus of FIG. 1 is operated as follows: At the instant of a quarter period, switch 10 is placed on the right side, and thyristors 4 and 5 receive the trigger pulse.
the current IP in the rectifying bridge (FIG. 2) increases until the instant t ₁ at which the switch ₁₀ is switched to the left;
At this instant the triac 9 fires, the input terminals of the bridge are short-circuited, and the thyristors 4 and 5 are turned off, at which point the current IP (FIG. 2) drops to zero and remains zero until the instant _t1 . _The current IT (FIG _{. 3} ) in _the triax, which was at The process described above is repeated.

The motor is energized between t ₀ and t ₁ and driven by the inertia between t ₁ and t ₂ and the motor is turned off due to the fact that thyristors 4 and 5 are turned off during that time interval. Completely disconnected from the source.

Between t ₀ and _{t 1} , the current flowing through the heating element 6 is the current IP
(Fig. 2) and equal to the current IT (Fig. 3) between t ₁ and t ₂ ; motor 1
Assuming that the internal resistance of the immersion heater 6 becomes negligible compared to the internal resistance of the immersion heater 6, the current IR in the heater (Figure 4) is the sum of the currents IP and IT (Figures 2 and 3). and the immersion heater 6 receives its full power supply when driving the motor 1.

In practice, it has been confirmed that there is a loss in heating power compared to the power supply of an immersion electric heater that is supplied directly from the mains terminal, but this loss is 5.
% and is almost negligible with respect to power changes caused by mains voltage fluctuations within normal tolerance limits.

In FIG. 5, the first
The input is coupled to the terminals of the motor 1 via an integrated circuit consisting of a resistor 12 and a capacitor 13, while the second input is triggered by two zero crossing detection diodes connected in parallel with the supply bridge of the motor 1. is connected to the sawtooth wave generator 14.

The output of the comparator circuit 11 is AND gate 1
7, its second input is coupled to a 25 kHz trigger pulse generator 18, and the output of such gate is connected to the common gate electrode of thyristors 4 and 5.

Further, the output of the comparator 11 is connected to the input of another AND gate 19, and this second input is connected to an input terminal 21 using a logic value "1" via a switch 20 which is switched during heating.

The output of gate 19 is connected to a first input of another AND gate 22, whose second input is connected to generator 18 and whose output is connected to the gate of triac 9.

When opening the switch 20 changing to heating operation, only the part of the circuit located to the right of the vertical dash line in the drawing is activated and constitutes the circuit controlling the speed of the motor 1; The electromotive force generated is integrated and then compared by circuit 11 with the slope of the sawtooth voltage produced by generator 14 triggered by diodes 15 and 16 at each zero crossing of the main sine wave.

If the emf is less than the voltage slope, comparator 11 produces a logic "0" level at its output, so that a 25 kHz trigger pulse from generator 18 is sent to gate 17 by its supplementary input.

If the speed of the motor 1 increases, the electromotive force also increases, and the instant at which the comparator 11 changes is delayed, reducing the time the motor operates. The opposite operation also occurs.

Figure 6 shows the supply circuit of the rectifying bridge during the control circuit mode corresponding to, for example, ``rinsing'' or ``washing'' operation at the stabilization temperature of the washing liquid, and shows the phase difference with the mains voltage in the dash line. It shows.

When the heating switch 20 is closed, the part located to the left of the dash line in the drawing is actuated.

During start-up, if the output of the comparator 11 is "0", the motor 1 starts operating as soon as the thyristors 4 and 5 reverse after the zero crossing of the main sine wave.

Since the motor starts at a zero crossing of the mains voltage, the zero crossing detection diodes 15 and 16 are suppressed;
Generator 14 does not start and as a result of this the negative input of comparator 11 is fixed at a voltage level of +0.7V which is detected by a diode (not shown) and then the motor supply at the positive input of the comparator. It is compared with the voltage gradient obtained by integrating the voltage.

At the instant when the voltage slope reaches 0.7V, the output of the comparator 11 changes to "1", and for this purpose the trigger pulse from the generator 18 via the gate 22 is sent to the gate of the triac 9. At this moment,
The voltage across the rectifying bridge drops to zero and thyristors 4 and 5 are immediately turned off.

As a result of this, the voltage at the positive terminal of the comparator drops again below 0.7V, and for this reason the comparator output is reset to "0", but the triax 9 is activated until the moment when the main sine wave again passes through zero, and the process repeat.

In this mode of operation during heating, the operation of the part of the circuit located to the right of the dart line suppresses the generator 14, brings the negative input of the comparator 11 to a fixed relatively low voltage level, and reduces the voltage at the motor 1. The operation differs from that during a washing operation in two respects: in comparison with the integral supply voltage; and in that the low speed of rotation of the motor makes it possible to ignore the electromotive force generated during free rotation.

FIG. 7 shows the immersion electric heater 6 during the above mode of operation.
It shows the current flowing through. The supply current of the motor at each zero crossing of the main sine wave shifts slightly in phase and brings the currents flowing through the immersion heater 6 and the triac 9 into phase in the case of time reset.

The control of rotational speed during the heating operation is not as good as that obtained during the washing operation, but provides sufficient agitation action when heating the wash liquor.

In FIG. 8, in which reference numerals correspond to those shown in FIGS. 1 to 5, the washing machine comprises a power supply control unit 23 connected to the motor 1 via a polarity changer 24. In FIG.

The programming device 25 has inputs connected to a temperature detector 26 and water level detectors 27a and 27b, an output connected to a device 28 for accelerated heating according to the invention, "rhythm" and "speed" outputs connected to a power supply unit 23, electrical Control output for valves 29a and 29b, control output for polarity changer 24, and motor 31 that drives the drain pump.
It consists of a control output for a switch 30 connected in series with the switch 30.

In the block diagram of FIG. 8, which shows only the essential components, the programmer 25 receives instructions regarding the desired wash program and precisely operates the various working components of the machine in accordance with the information provided by the detector. do.

The device 28 according to the invention receives instructions from the programmer 25 to switch during heating and the detector 2
6 detects that the programmed temperature of the wash liquid has been reached, the heating is stopped.

Furthermore, the device 28 is coupled to the power supply control unit 23 to receive the necessary signals for its operation.

The programmer 25 is of the conventional manual electromechanical type or of the automatically operated hybrid type, or of the all-electronic type controlled by a microprocessor, and the device for accelerated heating of the invention is easily adapted to these different types of washing machines. be able to.

In FIG. 9, with reference symbols corresponding to those shown in FIGS. 1, 5 and 8, diodes 2 and 3 are shown.
The common anode of consists of the negative pole of the rectified pulsating supply voltage to the motor 1 and is connected to a common ground 32.

The switch 24 for reversing the rotational direction of the motor 1 is a reversible circuit (not shown in the figure).
It is controlled by a coil 33 or a relay energized by a circuit.

The gates of the thyristors, connected together by two current limiting resistors 34 and 35, are connected to one end of the secondary winding of the transformer 37 and the other end to the positive terminal of the rectifying bridge. An overvoltage limiting diode 38 is provided between the connection of resistors 34 and 35 and the positive terminal of the rectifying bridge.

It is connected via a resistor 39 to one end of a secondary winding 40 of a transformer 41 at the gate of the triax 9, and the other end of this secondary winding is connected to the main terminal 8.

Primary windings 42 and 4 of transformers 37 and 41
Connect the two connection ends of 3 to the positive terminal 44 of the DC voltage source Vb.
and its negative terminal 45 is connected to the ground terminal 32.

The two other ends of the primary windings 42 and 43 are connected to the collectors of two NPN transistors 46 and 47, respectively, and their emitters are connected to the ground terminal 32.
Connect to.

A dividing bridge constituted by two resistors 48 and 49 is arranged between the common cathode of the zero crossing detection diodes 15 and 16 and the ground terminal 32,
The combination of these resistors is made up of two cascaded NOR gates 50.
and 51 to the cathode of a limiting diode 52 , the anode of such diode 52 is connected to the negative input of the comparator 11 , and a relaxation oscillation network consisting of a capacitor 54 and a resistor 53 connected to the ground terminal 32 is connected to the negative input of the comparator 11 . Negative input and +Vb
It is provided between the terminal 44 and the terminal 44.

The positive input of comparator 22 is connected to the integrating network 12, 13 via two resistors 55 and 56, with resistor 55 being decoupled with a capacitor 57. The combination of resistors 55 and 56 is connected to a switchable voltage source (V.ESS), not shown, for the "spin-drying" action of the machine.

At the positive input of comparator 11 there is provided a temperature compensation network consisting of a diode 58 in series with a resistor 59 connected to ground terminal 32 and decoupled by a capacitor 60.

The output of the comparator 11 is +
Vb and to the first input of two NOR gates 62 and 63, this common second input is connected to a common contact of switch 64, and its two other contacts are connected to a normal-rhythm circuit not shown in the figure. (CN) or slow rhythm (CL) circuit, respectively.

The output of gate 62 is connected to a first input of another NOR gate 65 whose second input is connected to +Vb via resistor 66 and to heating switch 20 which is connected to ground terminal 32.

The combination of resistor 66 and switch 20 is connected to another NOR gate 67 arranged as an inverter;
Its output is coupled to the base of an NPN transistor 69 via a resistor 68, the emitter of which is grounded, and its collector is connected via a resistor 70 to the combination of resistors 55 and 56; A resistor 71 is placed between such a bond and the ground terminal 32.

The output of gate 65 is connected to another NOR gate 73 via another gate 72 connected as an inverter.
, and its output is coupled through a resistor 74 to the base of a transistor 47, the base of which is decoupled to ground by a capacitor 75.

Another NOR gate 7 connected as an inverter
6, the output of gate 63 is connected to the first input of another NOR gate 77, and its output is connected to resistor 78.
to the base of transistor 46 through.

The common second inputs of gates 73 and 77 are connected to a trigger pulse generator 18, which consists of two NOR gates 79 and 80 connected as an inverter, whose inputs and outputs are connected to two resistors 81 and 82. and a capacitor 83.

The operation of the logic circuit shown in the diagram of FIG. 9 is chosen such that a "0" is obtained by connecting it to ground and a "1" is obtained by a pull-up resistor. This makes the circuit insensitive to spurious signals that are always positive. This is because such false signals are corrected by the supply bridge of the motor 1. For this reason we have two inputs:
Using only NOR gates and requiring two inputs to be ``0'' for these switches, the logic operation in any case can be similar to that of the simplified circuit of FIG.

When the heating switch 20 is opened, the resistor 53
The capacitor 54, which charges gradually through the mains voltage, suddenly discharges through the diodes, gates 50 and 51, and small value resistor 49 when the mains voltage passes through zero, and this creates a sawtooth waveform at the negative input of the comparator 11. voltage is obtained and this voltage is R1
2. Compare with emf voltage integrated by C13.

If the emf voltage becomes less than the sawtooth voltage, the output of the comparator 11 will be "0"; if the rhythm signal "0" is applied to its second input, the gate 63 will be conductive, and the generator 18
In case of a negative pulse from gate 77, gate 7
Start via 6.

During the application of these pulses, transistor 46 is in a defined state and pulses are sent to the gates of thyristors 4 and 5.

As soon as the selected speed is reached, the output of the comparator becomes ``1'' and the control enters phase as a function of the comparison between the average emf and the departure of the sawtooth wave during a quarter period of the mains voltage (Figure 6). It is carried out by.

When switch 20 is open, triac 9 is not triggered by the presence of a ``1'' level at one input of gate 65, which results in a ``0'' level at the output of gate 73.

When closing the heating switch 20, the triax 9 is controlled by the information received from the comparator 11 via the gate 62.

When the output of the comparator and the output of the rhythm signal from the inverter 64 are "0", the output of the gate 72 becomes "1", and the gate 73 receives the trigger pulse starting at "0" obtained from the generator 18. cannot be sent to the base of transistor 47; conversely, motor 1 is energized as soon as thyristors 4 and 5 are activated after the main sine wave passes through zero.

When the output of the comparator 11 becomes "1", the output of the gate 62 becomes "0", and the output of the gate 7 becomes "0".
3 acts to bring transistor 47 into a defined state for the duration of the negative trigger pulse from generator 18.

As depicted in the diagram of FIG. 5, the start of the motor 1 at the beginning of a quarter period of the mains voltage and the conduction of the triax 9 at the reset of such period inhibits the operation of the sawtooth generators R53, C54. , the negative input of the comparator 11 is fixed at a potential of 0.7V determined by the diode 52.

Also, when the heating switch 20 is closed via the inverting gate 67, the transistor 69 is in the defined state and for this purpose the resistor 70 is switched so that the energization time of the motor during the quarter cycle is "not heated". Condition washing” action or “rinsing”
Compensation for the loss of machine drum speed is obtained by being shorter during operation.

In the case of a "heating/stirring" action, the rotational speed of the drum is fixed at approximately 30 revolutions per minute instead of the usual 50 revolutions per minute, which increases the current in the immersion heater, and the control system is as shown in Figure 6. The phase control process shown in Figure 1-2 is inoperable.

The gate 62 receives a command for controlling the triax 9 as a function of the phase complement from the comparator 11 when the motor 1 is activated, or a signal "1" obtained from the rhythm inverter 64 during periods of stopping of such motor. , and for this reason the triax 9 remains full-wave conductive during these periods.

By means of diode 58 and resistor 59, a constant comparison level can be maintained at the positive terminal of comparator 11 despite temperature changes being applied to the washing machine.

By decoupling the base of transistor 47, inadvertent triggering of triax 9 by a rogue signal is avoided and due to its presence
The trigger pulse with a repetition frequency of 25kHz is sent distorted, but this is not important. This is because the triax 9 is triggered after the start of the quarter period and becomes conductive until the main sine wave crosses zero again.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the device of the present invention, Figures 2, 3 and 4 are the IR, IT and circuit diagrams of the circuit diagram shown in Figure 1.
A diagram showing the current state at the IP point; FIG. 5 is a circuit diagram showing the main elements of the device of the invention; FIGS. 6 and 7 are diagrams showing the state of current at the IP point; FIG. 8 is a simplified block diagram of a washing machine combined with the device of the present invention, and FIG. 9 is a circuit diagram of an example of the device of the present invention. 1...Motor, 2, 3, 58...Diode,
4, 5... Thyristor, 6... Immersion electric heater (heating element), 7, 8... Main line terminal, 9... Triack, 10... Electronic switch, 11... Comparator circuit, 12, 39, 48, 49, 53, 55,
56, 59, 61, 68, 70, 78, 81, 8
2...Resistance, 13, 54, 57, 60, 83...
Capacitor, 14... Sawtooth wave generator, 15,
16, 58...diode, 17, 19, 22...
...AND gate, 18...25kHz trigger pulse generator, 20, 64...Switch, 21...Input terminal, 23...Power supply control unit, 24...Polarizer, 25...Programming device, 26...Temperature Detector, 27a, 27b...Water level detector, 2
8... Device for accelerating heating, 29a, 29b... Electric valve, 30... Switch connected in series with motor 31, 31... Motor for driving drain pump, 32
... Common ground terminal, 33 ... Coil or relay, 34, 35 ... Current control resistor, 37, 41 ...
...Transformer, 38...Overvoltage sine diode, 40
...Secondary winding of transformer 41, 42, 43...Primary winding, 44...Positive terminal of DC voltage source Vb, 45...
...Negative terminal of DC voltage source Vb, 46, 47, 69...
...NPN transistor, 50, 51, 62, 63,
65, 67, 76, 73, 77, 79, 80...
Connection NOR gate, 52...Limiting diode, 6
4...Rhythm inverter, 71...Variable resistor.

Claims (1)

Claims: 1. Device for accelerated heating of washing liquid in a washing machine having a rotating drum with a rectifier bridge consisting of at least two controlled rectifiers for the supply voltage of the motor driving the drum and a single heating element. , the heating element is coupled in series with the rectifying bridge during the first time interval of a half cycle of the mains voltage, and then the heating element is connected to the mains voltage during the remaining time interval of the half cycle. Apparatus for accelerating the heating of washing liquid in a washing machine with a rotating drum, characterized in that the apparatus comprises electronic switching means coupled to the apparatus, said apparatus comprising control means for controlling said switching means. 2. The electronic switching means comprises a parallel circuit of a rectifier and a statically controlled two-way switch connected in series, the heating element being coupled in series to a bridge or mains voltage. equipment. 3. The control means has a first input terminal to an integrator circuit for integrating the motor supply voltage and a second input terminal to a relaxation oscillator circuit.
a comparator coupled to an input terminal, the integrator circuit is coupled to the motor, the relaxation oscillator circuit is coupled to a zero crossing detection circuit for detecting zero crossings of the motor supply voltage, and a bridge is connected to the zero detection circuit. and the control means controls the first or second control means.
a logic circuit for starting each time interval;
3. The device according to claim 1, wherein the first input terminal of the logic circuit is connected to the output terminal of the comparator. 4 a first output terminal of said logic circuit is coupled to a common control electrode of a controlled rectifier, a second output terminal is coupled to a control electrode of said statically controlled two-way switch; Claim 3: connected to a pulse generator so that the first input of the logic circuit alternately couples the pulses generated by the pulse generator to the first or second output terminal of the logic circuit. Apparatus described in section. 5. The logic circuit comprises a third input terminal, the third input terminal being connected to a switch so that the pulses generated by the pulse generator are not coupled to the second output terminal of the logic circuit. The device according to item 4. 6. The device of claim 3, 4 or 5, wherein the first and second outputs of the logic circuit are coupled to each control electrode via a respective transformer.