EP2674526B1 - Household appliance comprising a temperature sensor and at least one position sensor for an element of the household appliance - Google Patents

Description

The present invention relates to an appliance comprising a temperature sensor and at least one position sensor of an element of the appliance.

It relates generally to the field of household appliances used to dry a product, including a dryer or a washer-dryer (see, for example US 2011/0041260 ).

In a household appliance for drying a product, and especially laundry, the measurement of the temperature in the drum is carried out so as, for example, to regulate the temperature in the drum according to a drying program selected by a user.

The measurement of the temperature is carried out by a temperature sensor, for example, a CTN (Negative Temperature Coefficient) sensor. The temperature sensor is connected to an input of a microcontroller of the appliance.

The microcontroller is generally adapted to receive as input an analog signal, for example a DC voltage transmitted by the temperature sensor and whose amplitude is representative of the temperature measured in the drum. The microcontroller is adapted to digitize this signal for exploitation by an appropriate algorithm for determining the temperature in the drum.

In a household appliance for drying a product, and especially laundry, it is important to detect the position of certain elements of the appliance. For example, it is important to detect whether a fluff filter is in an operating position, which is tantamount to detecting the presence of the fluff filter. This filter is arranged in the drying air circuit, generally in a housing of the household appliance accessible to the user so that it can be extracted for example to clean it.

The filter prevents damage to certain lint-sensitive elements in the air system.

In addition, the fluff filter reduces clogging of the air circuit, especially heat exchangers in a condenser or heat pump dryer.

In addition, the presence of the lint filter prevents laundry in the drum from entering the air circuit and blocking the fan turbine (causing the dryer to fail).

The installation of a position sensor of a component of the appliance, for example a filter presence sensor, can be used to prevent the initiation of a drying cycle in the absence of a filter.

In the example of a presence sensor of a filter, the filter presence sensor function is generally implemented by a switch (microswitch, flexible blade switch or ILS) coupled with a magnet which is placed in the filtered. This set is connected to an "all or nothing" input of the microcontroller. The operation of the switch is triggered by the presence or absence of the filter.

The implementation of at least one function of the detection of the position of an element of the household appliance adds an additional cost related to the ILS switch, as well as to the connection wires of the assembly with the microcontroller and requires to modify an electronic card including the already existing microcontroller. The present invention aims to integrate the function of detecting the position of an element of a household appliance taking advantage of the existence of the means used for the operation of a temperature sensor.

For this purpose, it relates to a household appliance comprising a temperature sensor and at least one position sensor of an element of the appliance, the position sensor having a component having a switch function, the temperature sensor being connected to an input of a microcontroller of said appliance.

According to the invention, the component having a switch function is electrically connected to the temperature sensor and to said microcontroller input.

The coupling on the same input of the microcontroller of the temperature sensor and the position sensor of the element of the appliance, limits the number of inputs to the microcontroller and the number of connectors and tracks on the electronic card carrying the microcontroller. The manufacturing cost of the appliance is thus limited.

Moreover, when the installation of a position sensor of the element of the appliance is implemented using an already existing electronic card, the manufacturing cost of the appliance is even more limited.

In practice, the appliance has a temperature sensor for measuring resistance.

Thus, the microcontroller is able to determine the temperature measured by the sensor as a function of the value of the input voltage, this voltage value being a function of the value of a resistor.

According to one embodiment, the component having a switch function is connected in series with the temperature sensor.

According to another embodiment, the component having a switch function is connected in parallel with the temperature sensor.

In one example, the element is a filter and said at least one position sensor is able to detect an operating position corresponding to the presence of the filter.

In another example, the element is a heat exchanger and said at least one position sensor is able to detect an operating position corresponding to the presence of the heat exchanger.

In another example, the element is a door and said at least one position sensor is able to detect an operating position corresponding to the closed position of the door.

In yet another example, the element is a device indicating a water level in a water recovery tank and said at least one position sensor is able to detect the position of said device with respect to a water level predefined in said water collection tank.

For example, the microcontroller is able to prevent operation of the appliance according to the voltage at the input of the microcontroller, the voltage at the input of the microcontroller being representative of the position of the element.

With this feature, items that can be damaged when the item is not in a certain position are preserved.

In addition, the microcontroller is able to implement a warning, for example sound and / or visual, when the microcontroller prevents operation of the appliance.

The present invention finds particular application in a washer-dryer or dryer.

Other features and advantages of the invention will become apparent in the description below.

• la figure 1 est un schéma simplifié illustrant un montage d'un capteur de température et d'un capteur de position d'un élément de l'appareil électroménager selon un premier mode de réalisation de l'invention ;
• la figure 2 est un schéma illustrant un montage d'un capteur de température et d'un capteur de position d'un élément de l'appareil électroménager selon un deuxième mode de réalisation de l'invention.

In the accompanying drawings, given as non-limiting examples:

• the figure 1 is a simplified diagram illustrating a mounting of a temperature sensor and a position sensor of a component of the appliance according to a first embodiment of the invention;
• the figure 2 is a diagram illustrating a mounting of a temperature sensor and a position sensor of a component of the appliance according to a second embodiment of the invention.

We will first describe with reference to the figure 1 , a first embodiment of a mounting of a temperature sensor and a position sensor of an element of the household appliance according to the invention.

In one example, the element is a filter and the position sensor is able to detect an operating position corresponding to the presence of the filter in the appliance.

The appliance may be a dryer or a washer-dryer, in which a temperature sensor measures the temperature in the drum to, for example, regulate the temperature in the drum according to a drying program selected by a user.

In the example described, the filter is a fluff filter and the position sensor therefore corresponds to a filter presence sensor.

In this example, the temperature sensor comprises a thermo-resistance 1 with a negative temperature coefficient (thermo-resistance CTN).

The presence sensor function of a filter is implemented by a component having a switch function (called a switch in this description). Here, this component is an ILS switch (microswitch, switch with flexible blade) 2. The switch 2 is in a first state in case of presence of filter and in a second state in case of absence of filter. The first and second states respectively correspond to the open state and the closed state, respectively to the closed state and the open state.

In the embodiment described, the switch 2 is coupled to a magnet (not shown in the figures) placed in the filter (not shown in the figures).

Here, in the presence of a filter, the switch 2 is in the closed state and in the absence of a filter, the switch 2 is in the open state.

Of course, in other exemplary embodiments, the switch may be in the open state in the presence of the filter and in the closed state in the absence of a filter.

In addition, in other embodiments, other means may be used to switch the switch to the open state or closed state depending on the presence or absence of the filter.

For example, a device may implement a mechanical action on the switch to put it in open or closed state depending on the detection of the presence or absence of the filter.

In other examples, the element of the appliance may be a heat exchanger, a door or a device indicating a water level in a water tank.

In this first embodiment described, the switch 2 is connected in series with the thermoresistor 1.

A first terminal 1a of the thermoresistor 1 is connected to a first terminal 2a of the switch 2, and a second terminal 1b of the thermoresistor 1 is connected to the negative pole Vss of the power supply of the microcontroller 3, which is connected in turn to the reference potential 4, here of 0V.

A second terminal 2b of the switch 2 is connected to an input of the microcontroller 3, as well as to a first terminal Ra of a resistor R.

This input E of the microcontroller 3 here receives an analog signal.

A second terminal Rb of the resistor R is connected to the positive pole Vcc of the power supply of the microcontroller 3, which is in turn connected to the supply voltage V _REF .

In other embodiments, several switches are connected in series with the thermoresistor 1.

Each switch is associated with an element of the appliance.

Thus, for example, a first switch is associated with a lint filter, a second switch is associated with a heat exchanger, a third switch is associated with the closing door of the drum and a fourth switch is associated with a device indicating the water level in a water tank.

The operation of the assembly shown in FIG. figure 1 .

In the example described, the element of the appliance is a lint filter.

Nevertheless, the operation of the assembly is similar for any element of the appliance associated with the switch.

When the filter is absent, the switch 2 is open and the thermoresistor 1 is disconnected from the input E of the microcontroller 3.

Thus, the voltage at the input E of the microcontroller 3 has a value substantially equal to the value of the supply voltage of the microcontroller 3. This voltage value (corresponding to a value incoherent temperature) corresponds to a first predetermined value representative of the absence of the filter.

The microcontroller 3 is able to prevent or allow the operation of the appliance according to the voltage at the input E of the microcontroller 3.

The voltage at the input E is representative of the position of the element, here of the position of the filter.

Thus, the microcontroller 3 is able to prevent operation of the appliance when the voltage value at the input E of the microcontroller 3 is substantially equal to the first predetermined value.

For example, when the apparatus is a dryer or a washer-dryer, operation of the appliance may be a drying cycle.

When the absence of the filter is detected, the microcontroller 3 may implement a warning, audible and / or visual to prevent the user from preventing the operation of the appliance.

When the filter is present, that is to say when the filter is in the operating position, the switch 2 is closed and the thermoresistor 1 is then connected to the input E of the microcontroller 3.

In this case, the input voltage E of the microcontroller 3 corresponds to the temperature measured by the thermoresistor 1.

The microcontroller 3 is able to determine the temperature measured by the thermoresistor 1 as a function of the value of the voltage at the input E of the microcontroller 3.

It will be noted that the thermoresistor 1 forms with the resistor R a voltage divider, the voltage at the input E of the microcontroller 3 being the voltage of the midpoint of the voltage divider.

In addition, the microcontroller 3 is able to determine that the temperature at the input E of the microcontroller 3 is a possible value of the temperature measured by the thermoresistor 1 and thus detect the presence of the filter.

Thus, in this case, the microcontroller 3 allows operation of the appliance, for example allows a drying cycle in a dryer or washer-dryer.

Note that the appliance only operates when the filter is present and the temperature measurement is required only during operation of the appliance.

In addition, the assembly according to the invention is useful during a functional test of the appliance, for example in the factory or during the detection of a failure.

When the voltage at the input E of the microcontroller 3 has a value equal to or close to the supply voltage of the microcontroller 3, a fault is detected by a test software.

For example, such a defect can be detected when the connection wires of the thermoresistor 1 and / or the switch 2 are disconnected or when the switch 2 is blocked in the open state.

When the voltage at the input E of the microcontroller 3 has a value equal to or close to the value of the reference potential (here, 0V), a short circuit is detected in the assembly of the thermoresistor 1 and the switch 2.

When the element is a heat exchanger, the position sensor is able to detect an operating position corresponding to the presence of the heat exchanger.

Thus, when the heat exchanger is present, the switch 2 is closed and operation of the appliance is allowed. When the heat exchanger is absent, the switch 2 is open and operation of the appliance is prevented.

When the element is a door, for example the door closing the drum of a dryer or a washer-dryer, the position sensor is able to detect an operating position corresponding to a closed position of the door.

Thus, when the door is closed, the switch 2 is closed and operation of the appliance is allowed. When the door is open, switch 2 is open and operation of the appliance is prevented.

When the element is a device indicating a level of water in a water collection tank, the position sensor is able to detect the position of the device relative to a predefined water level in the recovery tank of water.

Thus, for example, when the device has reached a predefined water level, the switch 2 is open and the drain pan is drained or operation of the appliance is prevented. When the device has not reached a predefined water level, the switch 2 is closed and the water collection tank is not drained and operation of the appliance is allowed.

In an embodiment in which several switches 2 are connected in series with the thermoresistor 1, all the switches 2 must be closed so that the thermoresistor 1 is connected to the input E of the microcontroller, and for the voltage at the input E of the microcontroller 3 corresponds to the temperature measured by the thermoresistor 1.

We will then describe with reference to the figure 2 , a second embodiment of mounting a temperature sensor and a position sensor of an element of the household appliance according to the invention.

In this example, a switch 2 'is connected in parallel with a thermoresistor 1'.

A first terminal 1a 'of the thermoresistor 1' is connected to a first terminal 2a 'of the switch 2', and a second terminal 1b 'of the thermoresistor 1' is connected to a second terminal 2b 'of the switch 2 '.

The first terminal 1a 'of the thermoresistor 1' and the first terminal 2a 'of the switch 2' are connected to an input E 'of a microcontroller 3'. This input E 'is here an analog input.

The second terminal 1b 'of the thermoresistor 1' and the second terminal 2b 'of the switch 2' are connected to the negative pole Vss' of the supply microcontroller 3 ', which is in turn connected to the reference potential 4', here of 0V.

A resistor R 'is connected by a first terminal Ra' to the input E 'of the microcontroller 3', as well as to the first terminal 1a 'of the thermoresistor 1' and to the first terminal 2a 'of the switch 2 ', and by a second terminal Rb' to the positive terminal Vcc 'of the supply of the microcontroller 3', which is in turn connected to the supply voltage V _{REF '} .

In other embodiments, several switches are connected in parallel with the thermoresistor 1.

As for the first embodiment described, each switch is associated with an element of the appliance, an element that can be for example a fluff filter, a heat exchanger, a door, or a device indicating a water level. in a water collection tank.

The operation of the assembly shown in FIG. figure 2 .

As for the figure 1 in the example described, the element of the appliance is a fluff filter.

Nevertheless, the operation is similar for any element of the appliance associated with a switch.

When the filter is absent, the switch 2 'is closed, making a short circuit of the thermoresistor 1'.

The input E 'of the microcontroller 3' is connected to the positive pole of the supply of the microcontroller 3 ', the voltage at the input E' thus having a value substantially equal to the value of the reference potential (here, 0V).

This voltage value (corresponding to an incoherent temperature value) corresponds to a first predetermined value representative of the absence of the filter.

The microcontroller 3 'is able to prevent or allow the operation of the appliance according to the voltage at the input E' of the microcontroller 3 '.

The voltage at the input E 'is representative of the position of the element, here of the position of the filter.

Thus, the microcontroller 3 'is able to prevent operation of the appliance when such a voltage value is present at the input E' of the microcontroller 3 '.

For example, when the apparatus is a dryer or a washer-dryer, the operation of the appliance may be in the drying cycle.

As for the first embodiment described, when the absence of the filter is detected, the microcontroller 3 'can implement a warning, audible and / or visual to prevent the user from preventing the operation of the device home appliance.

When the filter is present, the switch 2 'is open and the thermoresistor 1' is connected to the input E 'of the microcontroller 3' and the input voltage E 'of the microcontroller 3' corresponds to the temperature measured by the thermoresistance 1 '.

As for the assembly described with reference to the figure 1 , the voltage at the input E 'of the microcontroller 3' corresponds to the voltage of the midpoint of the voltage divider formed by the thermoresistance 1 'and the resistor R'.

The microcontroller 3 'is able to determine the temperature measured by the thermoresistor 1' as a function of the value of the voltage at the input E of the microcontroller 3 '.

The microcontroller 3 'is able to determine that the temperature at the input E' of the microcontroller 3 'is a possible value of the temperature measured by the thermoresistor 1' and thus detect the presence of the filter.

The microcontroller 3 'then allows operation of the appliance, for example a drying cycle in a dryer or a washer-dryer.

As for the first embodiment described with reference to the figure 1 , editing the figure 2 is useful during a functional test of the appliance, for example in the factory, or during the detection of a failure.

When the voltage at the input E 'of the microcontroller 3' has a value equal to or close to the supply voltage V _{REF '} of the microcontroller 3', a fault is detected by a test software.

For example, such a defect can be detected when the thermoresistor 1 'is disconnected or when the connection wires of the thermoresistor 1' and / or the switch 2 'are disconnected.

When the voltage at the input E 'of the microcontroller 3' is equal to or close to the reference potential (here, 0V), a short circuit is detected in the mounting of the thermoresistor 1 'and the switch 2' . This short circuit can be implemented by a short circuit of the connection wires of the thermoresistor 1 'and / or the switch 2', or by the switch 2 'locked in closed state.

When the element is a heat exchanger, the position sensor is able to detect an operating position corresponding to the presence of the heat exchanger.

Thus, when the heat exchanger is present, the switch 2 'is open and operation of the appliance is allowed. When the heat exchanger is absent, the switch 2 'is closed and operation of the appliance is prevented.

When the element is a door, for example the door closing the drum of a dryer or a washer-dryer, the position sensor is able to detect an operating position corresponding to a closed position of the door.

Thus, when the door is closed, the switch 2 'is open and operation of the appliance is allowed. When the door is open, the switch 2 'is closed and operation of the appliance is prevented.

When the element is a device indicating a level of water in a water collection tank, the position sensor is able to detect the position of the device relative to a predefined water level in the recovery tank of water.

Thus, when the device indicating a water level in a water collection tank reaches a predefined water level in the water collection tank, the switch 2 'is closed and an operation of the household appliance is prevented. When the device does not reach the predefined water level, the switch 2 'is open and operation of the appliance is allowed.

In an embodiment in which several switches 2 'associated with several elements respectively are connected in parallel with the thermoresistor 1, all the switches 2' must be open for the thermoresistor 1 'to be connected to the input E of the microcontroller 3 'and that the input voltage E' of the microcontroller 3 'corresponds to the temperature measured by the thermoresistor 1'.

Of course, the present invention is not limited to the embodiments described above, given purely by way of illustration.

Claims (11)

1. A household appliance comprising a temperature sensor (1; 1') and at least one position sensor for sensing position of a member of said household appliance, said position sensor comprising a component (2; 2') having a switch function, the temperature sensor (1; 1') being connected to an input (E; E') of a microcontroller (3; 3') of said household appliance, characterized in that the component (2; 2') having a switch function is electrically connected to the temperature sensor (1; 1') and to said input (E; E') of the microcontroller (3; 3').
2. A household appliance according to claim 1, comprising a temperature sensor (1; 1') operating by resistance measurement.
3. A household appliance according to one of claims 1 or 2, in which the component having a switch function (2; 2') is mounted in series with the temperature sensor (1; 1').
4. A household appliance according to one of claims 1 or 2, in which the component having a switch function (2; 2') is mounted in parallel with the temperature sensor (1; 1').
5. A household appliance according to one of claims 1 to 4, in which the member is a filter and said at least one position sensor is capable of detecting an operating position corresponding to the presence of said filter.
6. A household appliance according to one of claims 1 to 4, in which the member is a heat exchanger and said at least one position sensor is capable of detecting an operating position corresponding to the presence of said heat exchanger.
7. A household appliance according to one of claims 1 to 4, in which the member is a door and said at least one position sensor is capable of detecting an operating position corresponding to a closing position of said door.
8. A household appliance according to one of claims 1 to 4, in which the member is a device indicating a water level in a water collection tank and said at least one position sensor is capable of detecting the position of said device relative to a predefined water level in said water collection tank.
9. A household appliance according to one of claims 1 to 8, in which said microcontroller (3;3') is capable of preventing or allowing an operation of said household appliance according to the voltage at said input (E;E') of the microcontroller (3;3'), the voltage at said input (E;E') of the microcontroller (3; 3') representing the position of said member.
10. A household appliance according to claim 9, in which the microcontroller (3;3') is furthermore capable of providing a warning when said microcontroller (3;3') prevents an operation of said household appliance.
11. A household appliance according to one of claims 9 or 10, and in particular which is a washing-drying appliance or clothes drying appliance, in which said operation is a drying cycle.

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