JPS6243717B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to laundry or dishwashing machines.

Such a washing machine consists of a water tank containing the washing liquid, means for heating the washing liquid, a temperature transducer submerged in the washing liquid, a controlled temperature selector, and a continuous process of the washing cycle as it progresses. and a thermostatic device for controlling the temperature of the cleaning liquid, the heating means being operative for at least one of the programmer positions.

Such cleaning machines are certified with the French National Publication No.
It is known from the publication No. 2360124. The washer's thermostat allows the cleaning fluid to be compared to a single control temperature, typically determined by a programmer. It has been found that wash machine users often wish to select a control temperature that does not correspond to the wash program set by the programmer at a particular starting position. In this case, the thermostat has to tolerate this change required by the user.

The washing machine of the present invention has the features as described in the claims.

The washer of the present invention accepts changes in the control temperature when decreasing the temperature, but accepts changes in the control temperature when the user desires to increase the wash temperature relative to the wash temperature dictated by the selection program. Refuse. The user can therefore intervene only if there is no risk of inadvertently overheating the item to be washed.

In a preferred embodiment of the invention, the temperature transducer comprises a resistor with a negative temperature coefficient provided in a resistive bridge connected between a constant voltage source, and the temperature transducer is arranged such that as the temperature of the cleaning liquid increases, supplying a decreasing voltage Vt, said thermostat comprises two voltage comparators IC1 and IC2, which comparators have at their non-inverting input terminals a voltage supplied by said temperature converter. receiving at each inverting input terminal of said comparator two control voltages Vc1, Vc2 which vary in inverse proportion to two control temperatures; The electrical signals supplied by these comparators are interconnected so that the voltage Vt from the temperature transducer is equal to the control voltage.
When the higher value of Vc1 or Vc2 is reached,
controlling the progress of the programmer;

In order to ensure a high degree of safety of the washing machine of the present invention, the two voltage comparators IC1 of the constant temperature device must be
and the output terminal of IC2 is connected to the center point of two resistor bridges connected in series between low voltage sources,
and to the inverting input terminal of a third voltage comparator IC3, which third voltage comparator has at its non-inverting input terminal the voltage supplied by the temperature converter.
Preferably, receiving a voltage held above Vt, the output of the third voltage comparator IC3 controls the progress of the programmer. Therefore, if a fault occurs in the temperature converter circuit, although the fault is often a short circuit or disconnection of the converter, the voltage comparator IC3 will receive at its non-inverting input terminal and the voltage at its inverting input terminal. Receive a signal that is always louder than the signal. In case of these two faults, comparator IC1
Alternatively, the series combination of the change in state of IC2 and comparator IC3 controls the progression of the programmer and stops the heating cycle of the cleaning program.

In a special embodiment of the washing machine according to the invention, the output terminals of said two voltage comparators IC1 and IC2 are connected to their non-inverting input terminals via resistors, so that from said output terminals to said non-inverting input terminals It is preferable to provide a feedback of 100 Hz, so that when the cleaning liquid reaches the control temperature, the change in state of the thermostatic device can be reversed by means of hysteresis. This circuit arrangement allows the heating cycle of the cleaning fluid to be activated immediately after the cleaning fluid reaches the control voltage, either automatically or by user intervention, when the programmer advances to the part of the program that requests a "heat" cycle again. Prevent restart.

Since the thermostat operates as a voltage comparator, it is independent of how the control voltage is generated. These control voltages can be obtained, for example, by connecting a voltage divider to the power supply. This connection can be controlled by the washer user or programmer.

In the embodiment of the washing machine of the present invention, the first control voltage Vc
1 connected in series between constant voltage sources R1
and R2 and by electrical contacts controlled by the programmer or user of the washer to select the first control voltage.
Preferably, it is possible to insert an additional resistor in parallel with each of the bridge resistors R1 and R2. This embodiment has the advantage of greater security. In fact, even if the electrical contacts that allow you to insert an additional resistor fail, the bridge R
1, R2 remains connected and, by design, the voltage supplied by said bridge does not reach the temperature required by the user (30° or 40° or 50°...) in the event of a failure. Even if the temperature is not dangerous for the washing machine, e.g. 90
Corresponds to the control temperature in °C. The electrical contacts associated with the programmer can be electromechanical contacts or electronic switches, depending on the type of programmer.

In another embodiment of the invention, the second control voltage
Vc2 is supplied by a bridge of two resistors R3 and R4 connected in series between constant voltage sources, and the voltage thus obtained is applied to the slider of a voltage divider connected to said constant voltage source. Preferably, the second control voltage is selected by changing the voltage obtained, and the partial pressure meter is operated by a user of the washing machine. The advantage of this embodiment is that it has the same safety as described above,
Furthermore, the risk of failure due to shearing is greater for manually operable partial pressure gauges than for electromechanical or electronic contacts provided in the programmer.

In the embodiment of the present invention, the second control voltage Vc2
is supplied to the thermostat by an operational amplifier connected as a voltage follower, the inverting input terminal of this operational amplifier being connected to the zero voltage point, and the output voltage of the operational amplifier being connected to the bridges R3, R4 and the associated Preferably, it is held at a value independent of the voltage supplied by the partial pressure meter. This possibility of overriding the control voltage set by the user of the washing machine can be used, for example, during a "prewash" program if a "prewash" cycle is required.

In fact, in many cases lower temperatures (e.g.
30℃).

Changes in the state of the output of the thermostat used in accordance with the present invention control the progress of the washer programmer. This programmer can be an electromechanical or completely electronic device. The use of an electromechanical programmer driven by a small synchronous motor connected to a power supply is disclosed in the aforementioned French Patent Application No. 2360124. In one embodiment of the invention, the output of the thermostatic device is applied to the base of a transistor which, when conducting, shorts a bridge of four diodes connected in series with the alternating current supply of the small motor. It is preferable to do so. Some electromechanical programmers include coils that control the engagement and disengagement of portions of their programming cams to interrupt the cleaning sequence when the cleaning fluid is heated. In this case, the constant temperature device of the present invention controls the state of the coil.

The programmer of the cleaning machine can be of the type with low voltage sliding contacts. The progress of this programmer is controlled by an electronically controlled time base device. This programmer may include a complete electronic logic device and supplies command electrical signals to the cleaning machine elements via an amplifier circuit (buffer). In these last two cases, the inventive thermostat starts or stops an electronically controlled time base device which directly controls the programmer by means of the output of comparator IC3.

Hereinafter, embodiments of the washing machine of the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view of the washing machine. The water tank 2 is attached to the bottom of the washing machine by an elastic shock absorbing support member 5. At the bottom of the water tank 2, an electric heating member 6 and a temperature converter Rt are provided. These are provided in the washing liquid.

The washing machine is controlled by a programmer 8. The washing program can be controlled by the user of the washing machine by pressing button 9.
Select by. After making a selection, the user starts the selection program. The evolution of the program, and thus the operation of the various elements of the washing machine, results from the evolution of the programmer. These elements are
In particular, the electric motor driving the washing drum, the washing liquid injection valve, the water tank drain valve, and the heating member 6. In this case, the heating element consists of a resistor through which an electric current flows. The temperature converter Rt is electrically connected to the programmer 8 via a constant temperature device. This thermostatic device advances the programmer when the wash liquor reaches the controlled temperature during the programmer's "heat up" cycle. Said control temperature is determined by a selected program or by actuation of one of the control buttons 9.

FIG. 2 shows an embodiment of the constant temperature device used in the washing machine of the present invention. This constant temperature device consists of two voltage comparators connected to a DC constant voltage source U (not shown).
It includes IC1 and IC2. These two voltage comparators have a common non-inverting input terminal.
This input terminal receives the voltage Vt supplied by the temperature transducer Rt. In the example shown in Figure 3,
This converter Rt is constituted by a resistor RCTN having a negative temperature coefficient connected in series with a fixed resistor R25. The series connection of these two resistors is shunted by a parallel fixed resistor R24. As the temperature increases, this circuit ensures that the total resistance decreases more slowly than the decrease in the resistance of the NTC resistor. Furthermore, in the case of continuous production, the temperature transducer must have certain characteristics so that it can be replaced. By adjusting the resistance value of R25, the
NTC resistors or obtained from different manufacturing groups
Differences in NTC resistance characteristics can be corrected.

In the example shown in FIG. 2, the converter Rt is connected to the voltage source U
The two fixed resistors R10 and R11 are connected in series between the two fixed resistors R10 and R11. A voltage V1 is available across the converter Rt.

The inverting input terminal of voltage comparator IC1 is connected to resistor R1.
The control voltage Vc1 obtained by the control voltage Vc1 is received. Resistance R1
together with resistor R2 constitutes a voltage divider bridge.
R1 and R2 are connected in series between voltage source U. The control voltage Vc1 corresponds to a control temperature Tc1 which is compared with the temperature of the washing liquid in which the transducer Rt is submerged by means of a voltage comparator IC1. Control voltage Vc1 can be varied by inserting one or more resistors in parallel with resistor R1 or R2. For example, resistors R60, R50, R40,
By inserting . . . in parallel with resistor R2, the control voltage Vc1 and thus the corresponding control temperature can be reduced. If the voltage Vc1 obtained by resistors R1 and R2 alone corresponds to a temperature of 90°, for example, then the insertion of R60, R50, R40... reduces the control temperature to 60°C, 50°C, 40°C, etc., respectively. . Switch 6 related to programmers
Insert these resistors by 0, 50, 40... These switches can be mechanical or electronic switches, depending on the type of programmer. Closing of these switches is controlled by a program selected by the user. Other resistors can be connected to resistor R1 or R2 by a manual switch operated by the user. Other resistors, such as manual switch E
Accordingly, the resistor RE can be connected in parallel to the resistors R2, R60, R50, R40, . . . .
This resistance RE increases the voltage Vc1 economically,
Decrease the control temperature Tc1 compared to the temperature commanded by the selection of the washing program. This can also be done by a resistor RF connected in parallel with resistor R1 when the manual switch is closed. By opening switch F, the user increases voltage Vc1 and thus decreases control temperature Tc1. A small resistance value of RF compared to R1 will lead to cancellation of the "heat" cycle ("cold" wash control set to eg 10 DEG C.).

The voltage comparator IC2 has at its inverting input terminal two resistors R3, connected in series between the voltage source U,
The second control voltage obtained by the bridge of R4
Receive Vc2. The constant voltage across resistor R3 is varied by a variable voltage available on the slider of voltage divider RP. A voltage divider RP is connected between the voltage source U. The slider of the partial pressure meter RP is connected to the resistor R
5 and connects to the connection point of bridges R3 and R4. The variable voltage supplied by this double voltage divider bridge RP, R3, R4 has a second control temperature Tc
Corresponds to 2. This control temperature is controlled by the voltage comparator IC
2 is compared with the temperature of the washing liquid represented by the voltage Vt obtained across the resistor Rt. For reasons explained below, voltage Vc2 is supplied to comparator IC2 via operational amplifier IC4. This operational amplifier is
Typically, it is connected as a voltage follower by connecting its output terminal to its inverting input terminal through a resistor R19.

The output terminals of the two comparators IC1 and IC2 are interconnected. The output voltage has a polarity determined by a resistive bridge R7, R8 connected in series between the voltage source U. The resulting signal Vs
controls the progress of the washing machine programmer and aborts the heating cycle of the washing program in progress.

Next, the operation of the constant temperature device will be explained. The temperature of the washing liquid is compared simultaneously with two control temperatures Tc1 and Tc2. In the cold state, the voltage Vt is maximum. This voltage decreases as the temperature of the liquid increases.
When the voltage Vt is greater than the two control voltages Vc1 and Vc2, i.e. when the temperature of the liquid is lower than the two control temperatures Tc1 and Tc2, the outputs of the comparators IC1 and IC2 are in a high state (bridges R7, R8 resulting voltage). When the temperature of the liquid reaches the lower control temperature, one output of the comparator changes to a low state (zero output voltage). This change in the state of one of the comparators IC1 and IC2 is
Change the voltage Vs. This change is used to control the progress of the washing machine programmer.

Voltage Vs can be used directly to control the programmer, but for safety, voltage Vs can be connected in series with resistors R10 and R to temperature transducer Rt.
It is preferable to compare the voltage Vt1 obtained between Vt1 and Vt11. The voltages U, Vt, and Vt1 are related to each other by the following equation.

U/R10+R11+Rt=Vt/Rt=Vt1
/R10+Rt Here, R10, R11, and Rt are the resistance values of the corresponding resistors, and the resistors R7, R8, and R9 are ignored because R9 has a high resistance value. Resistance R10, R11,
Rt, R7, R8 may have resistance values such that switching the output terminal of comparator IC1 or IC2 to a low level reduces the voltage Vs from a value higher than Vt1 to a value lower than Vt1. In this case, a change in the state of comparator IC1 or IC2 is caused by comparator IC
Change the state of the output No. 3 from low level to high level. This change in the output voltage of comparator IC3 is expressed as
Used to control the progress of the washing machine programmer.

The safety of washing machines achieved in this way is
Two possible cases of damage to the transducer Rt are also improved by advancing the programmer. On the one hand, when the converter Rt is briefly turned off, the voltages Vt and Vt1 are approximately equal to the voltage U, and the outputs of the comparators IC1 and IC2 are in a high state (Vs
= voltage required by bridges R7, R8)
However, according to the design, if Vs<Vt1, the output of comparator IC3 is also high. On the other hand, if the converter Rt is short-circuited,
The voltage Vt becomes zero and the outputs of comparators IC1 and IC2 become low (Vs minimum), but if the minimum value of Vs < U × R10 / (R10 + R11) by design, the comparator IC
3 output will be higher. In these two cases of damage, the programmer advances and prevents the programmer from remaining in a "heat" cycle.

In the embodiment shown in FIG. 2, the comparator IC1 of the constant temperature device
and IC2 is operated with hysteresis due to the presence of high resistance value resistor R9. Resistor R9
connect the output terminals of these comparators (voltage Vs) to their input terminals (voltage Vt). When the washing liquid is heated, the outputs of comparators IC1 and IC2 go high and resistor R9 connects the voltage Vt to the resistor bridge.
It can be increased slightly relative to the voltage supplied by Rt, R10, R11. Voltage Vt
When equals the higher of the control voltages Vc1 or Vc2, one of the comparators changes state and the voltage
Vs decreases. The presence of resistor R9 therefore provides a slight reduction in voltage Vt relative to the actuating value. This circuit is particularly useful if the washing machine programmer has several successive "heat" positions. Once the washing liquid has reached the required temperature there is no new heating cycle.

In the embodiment described above, the second control voltage Vc2 is connected to the operational amplifier IC4, which is normally connected as a voltage follower.
It has already been mentioned that the signal is transmitted to the comparator IC2 via the . The variable voltage obtained from bridges R3, R4 and voltage divider RP is applied to the non-inverting input terminal of operational amplifier IC4, whose output terminal and inverting input terminal are interconnected by resistor R19.
Furthermore, the output terminal of amplifier IC4 is connected to resistor R18.
Bias by. Resistor R18 is the amplifier
Connect the output terminal of IC4 to potential U. amplifier ic
By grounding the inverting input terminal of 4 by switch 30, a suitable control voltage can be established. This control voltage is connected to resistors R18 and R1
9, the partial pressure meter circuit R3, R4, RP
replaces the control voltage normally obtained from The switch 30 is, for example, associated with a washing machine programmer and is operated during the heating cycle of a "prewash" program, which in some cases precedes a washing operation. Such "prewash" is carried out at the selected temperature (30, 40, 50,...
90℃), regardless of fairly low temperatures e.g. 30
Generally carried out at ℃.

FIG. 4 shows an example of a circuit in which the output of the constant temperature device can be used to control the progress of the programmer of the washing machine of the present invention. In this case, the programmer is of an electromechanical type, and a synchronous motor M to which AC power is supplied is connected to a switch (contacts 30, 40, 50, 60) as shown in FIG. (Figure) acts to drive a cam that opens and closes the power contacts.

The output terminal of the comparator IC3, biased to the potential U by a resistor R6, is connected to the base of the transistor T. The load resistor R12 is in series with the collector-emitter circuit of the transistor and constitutes the diagonal of the diode bridge D1, D2, D3, D4. The other diagonal of the bridges D1-D4 has an electric motor M in series with the AC mains voltage source. The electric motor is driven by this voltage source. Furthermore, the emitter of transistor T is grounded.

This output circuit operates as follows. comparator
When the output of IC3 goes high, the transistor T
conducts, and the bridge D1-D is connected by the resistor R12.
4 is shorted and the motor is driven. Comparator IC3
When the output of is low, transistor T is cut off and motor M is not driven. The leakage current of transistor T is insufficient.

When the programmer reaches the "heat" cycle of the washing program, i.e. when the motor M closes the contacts for heating, the thermostatic device switches the motor M on until one of the control temperatures is achieved (comparator IC3 in low state). prevent. When the liquid reaches the lower control temperature, motor M is energized (comparator IC3 high) and the heating contacts open.

As an example, the elements used to realize the circuits shown in FIGS. 2, 3, and 4 are shown in the following table. in this case,
Voltage U is +10V.

FIG. 2: Comparators IC1, IC2, IC3, IC4 are installed in an integrated circuit as four voltage comparators of the LM339 type (SIGNETICS).

R1=121KΩ R11=52.3KΩ R2=54.9KΩ R18=33.2KΩ R3=33.2KΩ R19=39.2KΩ R4=121KΩ R40=11.5KΩ R5=37.4KΩ R50=18.2KΩ R7=33.2KΩ R60=30.9KΩ R8=110KΩ RE = 30.9KΩ R9 = 374KΩ RF = 8.45KΩ R10 = 5.36KΩ RP = Voltage divider 47KΩ Additionally, smoothing capacitors are connected to the input terminals of comparators IC1 and IC2 to protect these comparators against spurious signals.

Capacitor C3 between ground and the inverting input terminal of comparator IC1 = 3.3 μF, capacitor C4 between ground and the inverting input terminal of comparator IC2 = 10 μF.

Capacitor between two input terminals of comparator IC1
C2=1μF.

Figure 3: RCTN=100KΩ, at 25℃, NTC resistance R24=300KΩ R25=330Ω Figure 4: D1, D2, D3, D4 = Diode, 1N4007 type T=NPN transistor, ED232 R6=10KΩ R12=4.7KΩ, 0.5W.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the washing machine, Fig. 2 is a circuit diagram of a constant temperature device used in the washing machine of the invention, Fig. 3 is a diagram showing an example of a temperature converter circuit, and Fig. 4 is a diagram of the washing machine of the invention. FIG. 3 is a diagram illustrating an example of a circuit that controls the progress of a programmer. 2... Water tank, 6... Electric heating member, 8... Programmer, 9... Control button, 30, 40, 50...
...Switch, Rt...Temperature converter, IC1, IC2...
...Voltage comparator, R24, R25...Fixed resistance, U
... Voltage source, E... Manual switch, RP... Partial pressure meter, IC4... Operational amplifier, M... Synchronous motor,
T...transistor, D1, D2, D3, D4...
…diode.

Claims (1)

[Scope of Claims] 1. A water tank containing a cleaning liquid; means for heating the cleaning liquid; a temperature converter submerged in the cleaning liquid; and a control temperature selector for controlling the successive stages of the cleaning cycle as it progresses. A cleaning machine comprising: a programmer for operating the heating means for at least one of the programmer positions; and a constant temperature device for controlling the temperature of the cleaning liquid, wherein the temperature converter is connected between constant voltage sources. a resistor with a negative temperature coefficient in a resistive bridge, the temperature transducer providing a voltage Vt that decreases as the temperature of the cleaning liquid increases, and the constant temperature device comprising at least two voltage comparators.
IC1 and IC2, the comparators receiving at their non-inverting input terminals the voltage Vt supplied by the temperature transducer and each inverting input terminal of the comparator being selectable independently of each other. Two control voltages Vc that change in inverse proportion to the two control temperatures
1, Vc2, thereby causing the constant temperature device to apply a voltage Vt proportional to the temperature detected by the temperature converter to the two control voltages Vc1, Vc2.
The temperature of the cleaning liquid is compared with the control temperature by comparing the temperature of the cleaning liquid with the control temperature, and when the cleaning liquid reaches the lower of these control temperatures, the change in the state of the output of the constant temperature device is determined. A washing machine characterized in that the programmer is advanced by moving the programmer. 2. In the washing machine according to claim 1, the output terminals of the two voltage comparators Ic1 and Ic2 of the constant temperature device are connected to the output terminals of two resistors connected in series between constant voltage sources. connected to the center point of the bridge and to the inverting input terminal of a third voltage comparator Ic3, which third voltage comparator has at its non-inverting input terminal the voltage Vt supplied by said temperature converter.
A cleaning machine, characterized in that the third voltage comparator IC3 receives a voltage which is held higher than that of the third voltage comparator IC3, and the output of the third voltage comparator Ic3 controls the progress of the programmer. 3. In the washing machine according to claim 1 or 2, the output terminals of the two voltage comparators Ic1 and Ic2 are connected to their non-inverting input terminals via resistors, and the output terminals are connected to their non-inverting input terminals through resistors. A washing machine, characterized in that feedback is provided from the terminal to the non-inverting input terminal, so that the change in state of the constant temperature device can be reversed by hysteresis when the cleaning liquid reaches the control temperature. 4. In the washing machine according to any one of claims 1 to 3, the first control voltage
Vc1 is supplied by a bridge of two resistors R1 and R2 connected in series between constant voltage sources;
By means of electrical contacts controlled by the programmer or the user of the washer to select the control voltage.
A washing machine characterized in that an additional resistor can be inserted in parallel to each of the two bridge resistors R1 and R2. 5. In the washing machine according to any one of claims 1 to 4, the second control voltage
Vc2 is supplied by a bridge of two resistors R3 and R4 connected in series between constant voltage sources, and the voltage thus obtained is applied to the slider of a voltage divider connected to said constant voltage source. A washing machine characterized in that the second control temperature is changed depending on the voltage obtained, and the second control temperature can be selected by operating the partial pressure gauge by the user of the washing machine. 6. In the washing machine according to any one of claims 1 to 5, the second control voltage
Vc2 is supplied to the thermostat by an operational amplifier connected as a voltage follower, the inverting input terminal of this operational amplifier is connected to the zero voltage point, and the output voltage of the operational amplifier is applied to the bridges R3, R4 and the A washing machine characterized in that the voltage is maintained at a value independent of the voltage supplied by the partial pressure meter. 7. In the washing machine according to any one of claims 1 to 6, the output of the constant temperature device is supplied to the base of a transistor, and when the transistor is conductive, the washing machine A cleaning machine characterized by short-circuiting a bridge of four diodes connected in series to an alternating current power source of a small electric motor configured to drive a programmer. 8. The washing machine according to any one of claims 1 to 6, characterized in that the output of the constant temperature device starts or stops an electronically controlled time base device that controls the progress of the programmer. Washing machine.