EP2636355B1 - Household appliance with door - Google Patents

Description

The present invention relates to a domestic appliance having the features of the preamble of claim 1.

Domestic appliances of the aforementioned, that is generic type are known from the prior art. They have a pivotable about a horizontal axis formed door, by means of which an opening to the treatment room can be closed.

Usually, these doors are hinged to the lower side to allow a Aufklappbewegung. Often, the household appliance doors are spring loaded to slow down or dampen the door especially when swinging down. Typically, so-called door springs are used for this purpose, which are arranged at one end optionally with the interposition of a cable to the door and the other end on the machine base. Depending on the configuration of the household appliance, one or more door springs can be used. In the case of two door springs preferably a first door spring on the left side of the door and a second door spring on the right side of the door is used. The springs described are often designed as coil springs.

Moreover, about from the DE4013571A1 a device known to tune the springs used for damping on the weight of the household appliance doors or readjust. This is advantageous because the structures used for aesthetic reasons such as decorative panels have a different weight depending on the material and shape. The weight of the decorative plate therefore has a significant influence on the opening and closing behavior of the appliance door.

Furthermore, for example, from the WO 2009132813 A1 Devices for automatic door opening in dishwashers known. Therein, in particular, a sensor for detecting an opening request is used, which detects a force acting on the decorative panel force.

The use of the described door springs has proven itself in everyday practice. There is still room for improvement, especially with regard to increased operational safety.

From the EP 2 336 469 A2 is a household appliance with the features of the preamble known.

In the known household appliances breakage of the door spring is neither detected, nor avoided an uncontrolled swinging the household appliance door. In addition to the break, the incorrect or missing readjustment of the springs can also lead to hazards.

If the door spring breaks, this will cause the door to open unchecked. This represents a significant security risk, because the door falls unchecked when opened in the fully open position, which is a danger to the user, as he may be hit and injured by the unrestrained falling door. In particular, for children who are in the vicinity of the household appliance, an unchecked falling down household appliance door is a particular danger. This danger is particularly great when the appliance door, due to a front-mounted decorative plate has a particularly high weight. In particular, by automatic opening mechanisms there is a considerable potential for injury, especially for children.

In addition to the risk of injury, there is also the possibility of additional damage to the appliance, for example due to the breakage of the hinge, which may require extensive repairs.

It is therefore an object of the invention to improve a household appliance of the type mentioned in that with respect to the door springs used increased reliability is given.

According to the invention, this object is achieved by the characterizing features of the independent claims. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The household appliance according to the invention has a door pivotable about a horizontally extending axis for closing an opening of a treatment room. The door is provided with at least one door spring, which serves to slow down the movement of the door when swinging down. In addition, the household appliance has a sensor with which the functionality of the door spring can be monitored. On the basis of the monitoring of the functionality by the sensor can thus be recognized in particular whether the door spring is working properly or whether a failure of the door spring, i. a malfunction of the door spring, such as a breakage of the door spring or at least an insufficient braking effect by the door spring, is present.

The domestic appliance according to the invention further comprises an additional braking means, which is activated in the event of a detected by the sensor failure of the door spring and is suitable to slow down the movement of the door when swinging down. The braking agent acts on the door or its door hinge in such a way that a free, ie unrestrained swung down the door is avoided.

The additional braking means is preferably activated only when a failure of the door spring has been detected. In order to stop the swiveling movement of the door immediately, the activation takes place immediately as soon as the failure of the door spring has been detected.

For this purpose, the domestic appliance advantageously has a device control which evaluates the signals detected by the sensor and draws conclusions about the functionality of the door spring from the signals and their evaluation. Determines whether the door spring is working properly or if there is a malfunction of the door spring. Upon detection of a malfunction or a failure of the door spring, the device control activates the deceleration.

Preferably, the braking means is designed as an electromagnetically actuated brake. This can act for example on a brake pad frictionally on the hinge and thereby prevent the pivoting movement. An advantage of this embodiment is the particularly short reaction time of the braking agent. Instead of an electromagnetically actuated brake but also the Einstz a centrifugal brake or a wedge brake or other positive or frictional braking means is conceivable, which has an analog functionality.

Preferably, the sensor is designed so that temporal changes in the angle of inclination of the door can be detected. The signals detected by the sensor can thus be used to determine at which speed and which acceleration the pivotal movement of the door takes place, i. how fast the door is opened. The detected signals are compared with predetermined reference values, which are associated with a proper, braked by an intact door spring pivotal movement of the door. Preferably, the reference values are entered when setting up the household appliance and setting the correct door spring preload of the door spring in the device control or automatically read by this by pivoting and swiveling the door.

According to a particularly advantageous embodiment, the sensor is able to measure signals in three independent spatial directions. It is therefore a sensor measuring in three dimensions, the three measuring directions preferably being orthogonal to one another.

The sensor is arranged and designed so that vibrations of the household appliance and / or acoustic pulses can be detected. If the door spring breaks when the door swings open, it strikes against the body, the hinge or other components of the household appliance. In this case, vibrations and / or acoustic pulses are generated, which can be detected by the sensor. Characterized that the sensor detects signals from three independent spatial directions, it is designed so that the spatial direction of the source of the detected vibrations and / or acoustic pulses with respect to the sensor can be determined. In this way, the source of the signals can be located and thereby a spring break with great certainty can be identified. The sensor or device controller is thus able to reliably distinguish signals resulting from breakage of the spring from interference signals originating from another source. Preferably, the sensor also detects frequencies in the range of 1-4 kHz, which can be assigned to a stop signal of a broken spring and excludes frequencies from outside frequency ranges at least partially. This further increases the security in the identification of a door spring break.

It is furthermore advantageous that the sensor is a monolithic element. Thus, synergistically, less cabling and assembly costs are incurred than would be the case with the use of two or more sensors. However, a concatenation of several uniaxial acceleration sensors would also be conceivable, but associated with an additional effort during assembly.

The inclination sensor is preferably a three-axis acceleration sensor. These types of sensors are also referred to as XYZ acceleration sensors. Such a sensor measures accelerations, where a vibration is proportional to the acceleration. One possible measuring principle of such a sensor is that according to which the sensor capacitively measures the deflection of a reference mass. The deflection of the reference mass is proportional to the acceleration. Such sensors can be designed as a micro-electro-mechanical system (MEMS). Advantageously, accelerations can be precisely measured with such a sensor, while at the same time having a fully integrated design, low costs and a small installation space. However, the inclination sensor may also be designed as a three-axis vibration sensor or the like. The decisive factor is that he is able to measure signals in three independent spatial directions

Advantage of the tilt sensor is the low installation costs, since the sensor can be positioned, for example, directly on the control electronics. At the same time cost-effective installation results in a more reliable system.

According to a particular embodiment of the invention, the inclination sensor, preferably in the aperture, as part of the device control, arranged. For the arrangement of the inclination sensor various embodiments are conceivable. The inclination sensor can be carried in particular by an electronics. Preferably, the sensor may be carried by the control board which is disposed within the device control in a bezel. A further preferred embodiment represents the arrangement of the sensor on the display or operating board, within the display and operating control. Other arrangements of the inclination sensor are also conceivable. In the case of an integrated or fully integrated household appliance, the sensor is preferably mechanically decoupled from the decorative plate. This means that there is no direct operative connection between decorative plate and sensor. The sensor is thus not, as known from the prior art sensors, attached to the decorative plate, but rather spatially spaced therefrom. Advantageously, thus acting on the decorative plate signals, such as structure-borne noise, not directly transmitted to the sensor. This reduces the susceptibility to interference.

The determined malfunction, such as the breakage of the door spring, can be displayed to the user of the household appliance via a visual and / or audible warning signal, for example as a warning light or warning sound. The user is forewarned in this way and will not be surprised by an unobstructed falling door when the door is opened. If the door is still in its closed position upon detection of the malfunction, it is preferable to block an automatic door opening device, i. the automatic opening mechanism is omitted. The user can then be given the opportunity to open the door in a controlled manner, which minimizes the security risk already explained, whereby the reliability for the use of the door springs can be significantly increased.

According to a preferred embodiment of the invention, the voltage supply of the sensor takes place in front of the main switch of the household appliance. It is advantageous here that monitoring of the door spring is made possible even when the household appliance is switched off. According to another particular embodiment of the invention, the voltage supply of the braking means takes place in front of the main switch of the household appliance. This advantageously allows activation of the deceleration even when the household appliance is switched off.

To achieve the object of the invention, a method for operating a domestic appliance with the features of the preamble of claim 14 is proposed in the method. According to the invention thus signals are measured by means of a sensor, the signals evaluated and concluded on the basis of the signals on a functioning of the door spring. Upon detection of a malfunction of the door spring, a deceleration means for slowing down the movement of the door is activated when swinging down.

The invention is suitable for all types of household appliances in which a door is pivoted about a horizontal axis, in particular for integrated or fully integrated household appliances, in which the weight of the decorative plate increases the risk of injury. In particular, the invention is suitable for ovens, Dampfgargeräte, microwave ovens, refrigerators and dishwashers.

Figur 1

eine schematische Seitenansicht des Türbereichs eines Haushaltgeräts (Stand der Technik)

Figur 2

eine schematische Seitenansicht des Türbereichs eines erfindungsgemäßen Haushaltgeräts

Figur 3

schematische Darstellung des Neigungssensors

Figur 4

Ausgangssignale bei Türöffnung mit intakter Feder

Figur 5

Ausgangssignale bei Türöffnung mit gebrochener Feder

Figur 6

Ausgangssignale bei Bruch der Feder

Figur 7

eine schematische Seitenansicht des Türbereichs eines erfindungsgemäßen Haushaltgeräts.

An embodiment of the invention is shown purely schematically in the drawings and will be described in more detail below. It shows

FIG. 1

a schematic side view of the door portion of a household appliance (prior art)

FIG. 2

a schematic side view of the door portion of a household appliance according to the invention

FIG. 3

schematic representation of the tilt sensor

FIG. 4

Output signals at door opening with intact spring

FIG. 5

Output signals with door opening with broken spring

FIG. 6

Output signals at break of the spring

FIG. 7

a schematic side view of the door portion of a household appliance according to the invention.

Fig. 1 schematically represents the door area of a dishwasher 100 together with mounted decorative plate 3. Further essential components of the household appliance door 1 are the device control 4 with the control panel 2. In this embodiment, a partially integrated dishwasher is shown by way of example in which a portion of the front covered by a decorative plate 3 and a control panel 2 even when the device 100 is closed, ie closed position P1 is visible.

The appliance door 1 is further connected via a hinge 8 with the device 100, which allows a pivoting movement, starting from the closed position P1 of the door 1 to the open position P2 about the pivot point 9. In addition, the hinge 8 has a door-side mount point 7, in which a door spring 5 is fixed, which on the Device side is hooked in the mount point 6. The purpose of the door spring 5 is to decelerate the door 1, in particular during opening, so that it does not fall under gravity into the open position P2. By means of a spindle mechanism, the position of the device-side Einhängepunkts 6 along the path S3 and thus the bias of the door spring 5 can vary and so tune the force of the often designed as a spiral tension spring door spring 5 on the door weight. If the door spring is adjusted correctly, it is ensured that the door remains in any angular position and does not open or close again on its own.

Above the treatment space 107 is an automatic opening device consisting of a motor 101 which drives a rack 102 and displaces it horizontally by the path S1. In this case, the door is pressed in the first phase of the automatic door opening in a slightly open position. The spring 5 here slows down the unfolding movement S2 in the normal case, i. acts against the gravity of the door 1, which would otherwise cause a complete unfolding. A break of the spring can have serious consequences here, as the door opens up unchecked.

In Fig. 2 the door region of a dishwasher 100 is shown schematically. In addition to the features already described, the inclination sensor 10, preferably in the diaphragm 2, is shown here as being arranged as part of the device control 4. Other arrangements of the inclination sensor are also conceivable, but not shown further. The tilt sensor 10 is preferably a three-axis sensor, in particular a three-axis acceleration sensor. This measures signals in the in the Fig. 2 illustrated three orthogonal spatial directions X, Y, Z.

A schematic illustration of the tilt sensor 10 can be found in FIG Fig. 3 , In addition to the three signal outputs for the three spatial directions X, Y, and Z, there is also a test input T for the sensor test. At the three signal outputs X, Y, and Z, an amplitude-invariant signal or idle signal is tapped, as long as the sensor 10 is not inclined by the three solid angles φ _x , φ _y or φ _z , or as long as no accelerations a _x , a _y or a _{z act} on the sensor 10. If one of these parameters changes, another signal is output at the outputs X, Y and Z. In the device controller 4, the three signals of the sensor 10 by means of a control computer (not shown) are read and evaluated.

If the spring is intact and set correctly, the waveform will be at the X signal output during door opening as in Figure. 5 illustrated example. In Fig. 4 the signals of the sensor for monitoring the opening movement are displayed. If the appliance door is in the closed position P1, the signal at the signal output X points For example, an amplitude-invariant high first level. This only changes when the motor-driven rack travels the path S1 and swings the door open. In the second phase of the door opening, the signal level at the signal output X continues to drop during the opening stroke S2 until the door in position P2 is fully swung open by the user by hand. In this position, the signal at the signal output X has a second, compared to the first level lower level. If the door spring 5 intact, the opening process takes place depending on the set spring tension more or less damped. The slope or the gradient of the signal is relatively low in this case.

In the event that the door spring 5 is defective, so broken or wrong or set too weak, the door 1 experiences a stronger acceleration a _x , this is reflected in a higher slope or a higher gradient in the signal of the signal output X. A corresponding signal course is exemplary in Fig. 5 shown.

The gradient of the signal or the gradient in the signal of the outputs X, Y, Z, represents a measure of the inclination rate of the domestic appliance door 1. The inclination rate is in turn determined by the bias of the door spring 5 and an intact spring system. Reference parameters for the gradient are preferably entered when setting up the household appliance 100 and setting the correct bias of the door spring 5 in the device control 4 or are read by this automatically by opening and pivoting the door 1.

If there is a spring break, then it may also be detected by the acceleration sensor 10 preferably directly. Due to its spatial orientation, the XYZ acceleration sensor 10 offers the possibility of directly detecting the breakage of the door spring 5. The household appliance door 1 and the integrated acceleration sensor 10 are connected via the door hinge 8 mechanically and thus acoustically with the door spring 5. At a break, the spring 5 strikes against the body of the household appliance 100 or directly against the hinge 8, which propagates as an acoustic pulse and thus as acceleration to the XYZ acceleration sensor 10. Depending on the spatial orientation of the acoustic pulse, the signal outputs of the sensor 10 provide a different signal intensity, whereby a spring break can be identified and located.

In Fig. 6 the signal outputs for a spring break are shown by way of example. One axis in each case measures a signal in one of the spatial directions X, Y, Z. The respective signal level is in Fig. 6 applied over time. An in Fig. 6 Dashed value L, which can also be different depending on the direction of space, can also be used, for example, as a threshold value, whose violation is evaluated by the device controller 4. If at least one threshold is exceeded, the device control 4 closes on a spring break. By evaluating all three signals, for example by checking which of the three threshold values or for which of the three spatial directions the threshold value has been exceeded, the source of the signals can be localized by the device controller 4. Depending on the result of this localization, the device controller 4 determines whether the signals are due to breakage of the spring 5 or to another cause.

In the event of a detected door spring break, the device control 4 provides for the outputting of an error message, in particular an optical and / or audible warning signal. In addition, the device controller is able to block any existing automatic door opening mechanisms so that the door remains closed, and to activate a braking means for slowing down the movement of the door 1 when swinging down.

In Fig. 7 the door region of a domestic appliance 100 according to the invention is shown schematically. This includes in particular a braking agent 11. This is in the present case designed as an electromagnetically operated brake, which acts via a brake pad 12 frictionally directly to the hinge 8. As a result, the downward movement of the door 1 can be stopped reliably and quickly.

Claims (14)

1. Household appliance (100), in particular a dishwasher, steam cooker or baking oven, comprising a door (1) which is pivotable about a horizontally extending axis, is intended to close a treatment chamber and is provided with a door spring (5) which serves to decelerate the movement of the door (1) when it is pivoted down,
   characterised in that
   the household appliance has a sensor (10), by means of which the operability of the door spring (5) can be monitored, and an additional deceleration means (11) which is activated when there is a failure of the door spring (5), which failure is detected by the sensor (10), and which means is suitable for decelerating the movement of the door (1) when it is pivoted down.
2. Household appliance (100) according to the preceding claim,
   characterised in that
   time changes in the angle of inclination of the door (1) can be detected using the sensor (10).
3. Household appliance (100) according to the preceding claim,
   characterised in that
   the sensor (10) can detect signals from three independent spatial directions.
4. Household appliance (100) according to any of the preceding claims,
   characterised in that
   the sensor (10) is arranged and designed such that vibrations of the appliance (100) and/or acoustic pulses, which are triggered in particular by the door spring (5) breaking, can be detected.
5. Household appliance (100) according to any of the preceding claims,
   characterised in that
   the sensor (10) enables the spatial direction of the source of the detected vibrations and/or acoustic pulses to be determined in relation to the sensor (10).
6. Household appliance (100) according to any of the preceding claims,
   characterised by
   an appliance control device (4), by means of which signals which are detected by the sensor can be evaluated.
7. Household appliance (100) according to any of the preceding claims,
   characterised in that
   the sensor (10) is mechanically connected to the door spring (5) by means of the door hinge (8).
8. Household appliance (100) according to any of the preceding claims,
   characterised in that
   the sensor (10) is one or more linked single-axis acceleration sensors.
9. Household appliance (100) according to any of the preceding claims,
   characterised in that
   the sensor (10) is a triple-axis sensor, in particular a triple-axis acceleration sensor or a triple-axis vibration sensor.
10. Household appliance (100) according to any of the preceding claims,
    characterised in that
    the deceleration means (11) acts on the hinge (8) in a friction-locking manner.
11. Household appliance (100) according to any of the preceding claims,
    characterised in that
    the deceleration means (11) is designed as an electromagnetically operable brake.
12. Household appliance (100) according to any of the preceding claims,
    characterised in that
    the deceleration means (11) is designed as a centrifugal brake or as a wedge brake.
13. Household appliance (100) according to any of the preceding claims,
    characterised in that
    the power for the sensor (10) and/or for the deceleration means (11) is supplied upstream of the main switch of the household appliance (100).
14. Method for operating a household appliance, which comprises a door (1) which is pivotable about a horizontally extending axis, is intended to close a treatment chamber (107) and is provided with a door spring (5) which serves to decelerate the movement of the door (1) when it is pivoted down, characterised by the method steps of:

    - measuring signals by means of a sensor (10);

    - evaluating the signals and drawing a conclusion, based on the signals, as to the operability of the door spring (5);

    - when failure of the door spring (5) is detected:

    - activating a deceleration means (11) in order to decelerate the movement of the door (1) when it is pivoted down.

Images