EP1982117B1 - Cooking appliance, espeically built-in wall cooking appliance, and method for controlling a cooking appliance - Google Patents

Abstract

A cooking appliance including a high-level cooking appliance having a muffle including a muffle compartment defining a cooking compartment with a muffle opening, a door for movement between an open and closed relationship with the muffle opening and a drive device controlled by a control device for moving the door, the cooking appliance including a detector for determining a trapping condition wherein an object becomes trapped as the door is being moved, wherein the detector is configured for detecting the trapping state by comparing a door movement parameter with a threshold value associated with door movement.

Description

The present invention relates to a cooking appliance, in particular a high-installation cooking appliance, with at least one muffle delimiting a cooking chamber, which has a muffle opening, a door for closing the muffle opening and a controlled by a control device drive means for moving the door.

Out DE 102 28 140 A1 a high-installation cooking appliance is known in which pinching of objects on the bottom door can be detected by a plurality of independently operable anti-pinch switch between the bottom door and the muffle frame. In addition, an increase in pressure in a door seal with a hollow profile can be evaluated.

In DE 101 64 239 A1 is described an anti-trap, which is triggered by different tensile forces on the floor door driving traction cables. A torque sensor is also described which detects a load torque on the drive shaft of an electric motor. Tensile force sensors, piezoelectric sensors and deformation or stress / strain sensors are listed as sensors.

DE 102 88 141 A1 also describes an optoelectronic sensor for detecting a pinch case that switches over the amount of reflected light.

The disadvantage is that the Einklemmerkennungen described either either relatively sluggish (tensile force sensor) or inaccurate or error-prone (optical sensor) and also require increased installation costs.

Above all, it is disadvantageous that the detection of the pinching of a small and elastic object, for example a child's finger, with pinch protection arrangements is not detected or only after damage due to excessive squeezing. A further disadvantage is that in the case of a front end of the cooking appliance built-in limit switch or anti-pinch switch at high load on the door whose front edge is lower relative to the rear edge by bending, so that the switches may not work absolutely safe.

A disadvantage is also a control of a closing operation for the door, in which shortly before reaching the closed state of a clamping backup operation in which a switch or a function for detecting a pinching state, is switched to a closing operation for detecting a closing state.

WO 2007/020166 A relates to a cooking appliance, in particular a high-installation cooking appliance having at least one muffle delimiting a cooking chamber, whose muffle opening is surrounded by a muffle frame, a door for closing the Muffelöffnung and controlled by a control device drive means for moving the door, wherein a speed measuring device for determining a traversing speed of the door is present, wherein pinching at the door is detectable by monitoring the traversing speed.

WO 2007/033927 A concerns a cooking appliance, in particular a high-installation cooking appliance comprising at least one muffle with a muffle opening delimiting a cooking space, a door for closing the muffle opening and a drive device controlled by a control device for moving the door. The drive device comprises at least one drive motor through which ropes connected to the door can be moved. The cables are pitch cables, which are linearly movable by the drive motor.

The document WO 03 056 244 discloses the preamble of claims 1 and 12.

It is therefore the object of the present invention to provide a quick, easy and accurate Einklemmerkennung for a cooking appliance of the type described above.

This object is achieved according to the features of the independent claims.

Preference is thus given to a cooking appliance, in particular a high-installation cooking appliance, with at least one muffle defining a cooking chamber, which has a muffle opening, a door to Closing the muffle opening and a drive device controlled by a control device for moving the door, wherein a jamming state is detected in the case of jamming of an object, the jamming state being determined by comparing a parameter associated with the movement of the door with a parameter associated with this parameter Threshold and reaching and / or exceeding the threshold is detected. Exceeding here means crossing from below or from above (also called undershooting). In this case, the comparison between the current value and the threshold value always refers to the current direction of movement of the door, ie, the speed comparison is performed independently of the direction of movement, that is to say, above all, refers to the absolute speed. In the same sense, it is assumed that when the door is positively accelerated (accelerated), Δv and Δv / Δt> 0, respectively, and Δv and Δv / Δt <0 in negative acceleration (deceleration).

The threshold value corresponds to a permissible minimum speed and / or a differential speed or speed difference per unit time or acceleration. Such a threshold can be set as an additional or independent criterion. The determination of a differential speed can be detected simply by an extending period of a measurement signal of a Hall sensor for monitoring the rotation of a drive shaft. Also usable are other parameters such as a motor current or a load of the bottom door.

The threshold value can be determined as a difference from the setpoint value (eg threshold speed vS <setpoint speed vR * x%), so that the trapping case is detected when the current speed vL of the bottom door reaches the threshold value vS or exceeds it from above, ie falls below it if it moves with only x% of the target speed. This corresponds to the condition vS ≥ vL. Similarly, the threshold value can be determined as a difference of the threshold differential speed vS as the desired differential speed ΔvR * y%, so that the Einklemmfall is detected when the current differential speed .DELTA.VL or acceleration of the bottom door reaches the threshold .DELTA.vS or exceeds from above, ie falls below, if it moves with only y% of the target speed. Here, a faster deceleration than intended (as in Einklemmfall) means that the trapping case at ΔvS ≥ ΔvL is triggered for a given period of time. The threshold value is preferably dependent on the desired value, ie, for example, vS = vS (vR) or ΔvS = ΔvS (ΔvR) may apply. But it can also be a solid one predetermined threshold value can be assumed, for example, if this anti-trap protection is applied only in sections, z. B. only in an area of a ramp or in the range of a constant desired speed. For example, the threshold value can then be fixed in relation to the setpoint speed that is actually reached in most cases (eg, vR = 50 mm / s). B. in a memory unit of a control unit, for. B. vS = 40 mm / s. This can be specified for several sections, eg. From a lookup table.

A differential speed for monitoring is particularly advantageous with a view to pinching a partially elastic and small object such as a child's finger. In such a case, the door may not slow down abruptly, which would certainly be detectable in a pure speed monitoring. Here, monitoring the differential speed may be more sensitive. Particularly preferred is a combination of the two methods.

Monitoring the threshold dependent pinch state is within a given travel distance the door is activated. If this movement distance of the door, in particular within the last movement distance before a zero position corresponding to a closed position of a closed door is located, also an area can be monitored, in which, for example, a limit switch has already been activated or other methods for monitoring a clamping state can no longer be used , The monitoring of the pinching state is preferably activated within the last 15 mm, in particular 10 mm, in particular 5 mm, movement distance of the door before reaching the zero position. Under the activation of the limit switch is to understand not only the detection of a secure end-closed position but optionally also a first activation even before an end-closed position of the door upon reaching a certain approach distance of the door to the muffle.

The monitoring of the threshold-dependent pinching state is active, in particular after switching off a first pinching state monitoring method, ie it is still activated or then switched on. When the door approaches the muffle at a distance of less than 1 cm in particular, it can be assured that a door closing operation from a jamming operation using a switch or a jam detection function to a lock operation for safe detection a closing state are switched. This is ensured by the fact that after switching a continued monitoring is performed alternatively or at least still by monitoring the closing speed. The monitoring of the threshold-dependent pinching state takes place in accordance with, in particular, after switching off a first type of monitoring for monitoring a pinching condition by means of Eg switches shortly before a final closing movement of the door.

Advantageously, even after a deactivation of a particularly dependent on a constant speed monitoring method, in particular during a deceleration of the door, d. H. during a time-varying speed, a pinch protection method may be provided.

The monitoring of the threshold value is preferably activated after activation of a limit switch for signaling a last closing area, so that even in a narrow distance range in which a child's finger could be clamped, a clamping protection method can be provided.

The monitoring of the threshold value dependent Einklemmzustands during a switch to a force-controlled closing movement of the door is activated in particular when the final closing operation is no longer speed-controlled but force-controlled.

For this purpose, the cooking appliance, which is in particular a high-installation cooking appliance, but can also be a cooking appliance with a baking tray, preferably equipped with a speed measuring device for determining a travel speed of the door. The speed measuring device can detect trapping on the door by monitoring the traversing speed. The traversing movement does not have to be speed-controlled, but can also be regulated, for example, as a function of the load via the motor voltage or the motor current. Advantageously, but also the movement of the door speed-dependent - that is also independent of load - controlled or regulated, z. B. via a central control unit.

It is particularly favorable for the case of closure, if in addition at least one limit switch is provided which is arranged in the area between the muffle opening or frame and the door, wherein an actuation of the at least one limit switch deactivates the anti-jamming device or a first, different type of anti-jamming device. So protective measures ended. This limit switch preferably switches at an opening dimension of less than one centimeter, in particular in a range of 9-4 mm, which is so small that no household objects can be clamped more. When the at least one limit switch is actuated, the door is moved onto the muffle opening with a defined force-and no longer speed-controlled. Nevertheless, it is advantageously ensured that the door does not unintentionally reverse during closing, but can nevertheless reverse it in the event of a probable jamming of an object in the final phase of closing.

In particular, the case of a non-abrupt premature stopping of the closing movement is an indication of a trapped child's finger, so that the door is opened immediately in such a case again in particular by a sufficient opening for pulling out opening. Such a non-abrupt premature stopping of the closing movement can be detected particularly reliably by monitoring a speed difference value.

However, in order to avoid pinching even smaller objects or in particular a child's finger, preferably no complete deactivation is provided, but switched over to a modified fuse.

This speed-based anti-pinch protection has the advantage that it reacts relatively quickly, can receive accurate input data and can be implemented relatively easily without major design measures.

The monitoring of the traversing speed may be directed to a reduction of the traversing speed, which is uncontrolled and therefore not deliberately regulated. This can be done so that a value measured by the speed measuring device deviates by a fixed or a percentage value from a desired value. If the deviation exceeds or falls below a certain threshold value, a trapping case is assumed. For example, a door can no longer be moved with the set target speed because an object prevents it, then their speed drops accordingly. This evaluation and monitoring can be carried out for example in a central control device, for. B. via suitable microcontroller.

Alternatively or additionally, a - usually too fast - temporal change in the traversing speed trigger the Einklemmfall, for example, when trapped the door is decelerated faster than intended.

Of course, the values are chosen so that speed fluctuations caused by the control process for moving the door usually no jamming case. In addition, the anti-jamming methods described in the prior art may be used, such as a motor current measurement.

It is advantageous if the speed measuring device comprises at least one sensor on a motor shaft of the drive device, in particular of a drive motor, through which corresponding sensor signals can be generated upon rotation of the motor shaft. This allows a comparatively fast reaction. The sensor signals are directly or indirectly a measure of the travel speed of the door. Then it is particularly advantageous if the at least one sensor is a Hall sensor that outputs two sensor signals per revolution of the motor shaft. The Hall sensor system is easy to install, fast and insensitive. Advantageously, two Hall (part) elements are mounted on the motor shaft, so that two signals are output during a revolution of the motor shaft. By time evaluation of these signals, a bottom door speed can be determined, for example, by comparison tables or real-time conversion. Preferably, the travel speed is detected by a time difference between the sensor signals.

For stable velocity determination, advantageously, several, in particular more than two, sensor signals are evaluated. It is also advantageous if several, in particular more than two, sensor signals are averaged.

In particular, it is advantageous if reversing the direction of travel of the door after detecting the Einklemmfalls.

For this purpose, an anti-pinch device may be present, which takes over the monitoring of the Einklemmfalls and / or an implementation of the measures to be carried out in Einklemmfalls measures. The anti-trap device may be a separate device or functionally integrated with existing control circuits, e.g. B. in the central control circuit or in a control board or an elevator board.

It is favorable if the anti-trap protection or anti-pinch protection device can only be activated when a travel setpoint, In particular, a target speed, the door is reached, which reduces the risk of incorrect triggering of the anti-trap.

To protect the object trapped on the door, a maximum force time curve through the door is advantageously not exceeded. The pinching 'on' the door involves pinching between the door and an outer boundary, e.g. As the worktop, as well as pinching between the door and muffle frame or housing. For both cases, different force time curves can be provided.

It is particularly favorable for the case of closure, if in addition there is at least one limit switch which is arranged in the area between the muffle opening or frame and the door, wherein an actuation of the at least one limit switch deactivates the anti-jamming device or the anti-trap protection, thus exposing protective measures. This limit switch switches, typically at an opening dimension of 4 - 9 mm, which is so small that no objects can be clamped. On the other hand, it is ensured that the door does not unintentionally reverse when closing. When the at least one limit switch is actuated, the door is moved to the muffle opening with a defined force and no more speed control. However, it remains advantageous that a threshold-activated anti-trap protection - also speed-dependent - remains active.

However, the speed measuring device can also be used for other purposes, such as an adjustment of the speed of movement of the door. This alone is not yet known and not suggested.

The invention is particularly suitable for high-installation cooking appliances, in which the muffle opening is a bottom-side muffle opening, and the door is a bottom door, which preferably moves linearly.

• Fig. 1 eine perspektivische Ansicht eines an einer Wand montierten Hocheinbau-Gargeräts mit abgesenkter Bodentür;
• Fig. 2 eine perspektivische Ansicht des Hocheinbau-Gargeräts mit verschlossener Bodentür;
• Fig. 3 eine perspektivische Ansicht eines Gehäuses des Hocheinbau-Gargeräts ohne die Bodentür;
• Fig. 4 eine schematische Seitenansicht in Schnittdarstellung entlang der Linie I-I aus Fig. 1 des an die Wand montierten Hocheinbau-Gargerät mit abgesenkter Bodentür;
• Fig. 5 in Vorderansicht eine weitere Ausführungsform eines Hocheinbau-Gargeräts;
• Fig. 6 bis 11 Diagramme von Verfahrbewegungen einer Bodentür unter verschiedenen Randbedingungen;
• Fig. 12 und 13 Kraftzeitprofilkurven für eine Bodentür; und
• Fig. 14 ein Diagramm einer bevorzugten Verfahrbewegung beim Einklemmen eines dünnen Objekts zwischen einer Bodentür und einer Muffel.

The invention will be described in more detail below with reference to the attached schematic figures. Show it:

• Fig. 1 a perspective view of a mounted on a wall high installation cooking appliance with lowered bottom door;
• Fig. 2 a perspective view of the high-mounted cooking appliance with locked bottom door;
• Fig. 3 a perspective view of a housing of the Hocheinbau-cooking appliance without the bottom door;
• Fig. 4 a schematic side view in section along the line II Fig. 1 the wall-mounted high-installation cooking appliance with lowered bottom door;
• Fig. 5 in front view another embodiment of a high-installation cooking appliance;
• Fig. 6 to 11 Diagrams of movements of a floor door under different boundary conditions;
• FIGS. 12 and 13 Force time profile curves for a floor door; and
• Fig. 14 a diagram of a preferred movement movement when pinching a thin object between a bottom door and a muffle.

In the Fig. 1 a high-installation cooking appliance with a housing 1 is shown. The back of the housing 1 is mounted on a wall 2 in the manner of a hanging cabinet. In the housing 1, a cooking chamber 3 is defined, which can be controlled via a front side in the housing 1 introduced viewing window 4. In the Fig. 4 It can be seen that the cooking chamber 3 is bounded by a muffle 5, which is provided with a heat-insulating sheath, not shown, and that the muffle 5 has a bottom-side muffle opening 6. The muffle opening 6 is closable with a bottom door 7. In Fig. 1 the bottom door 7 is shown lowered, being with its underside in abutment with a worktop 8 a kitchen equipment. To close the cooking chamber 3, the bottom door 7 is in the in the Fig. 2 shown position, the so-called "zero position" to adjust. To adjust the bottom door 7, the high-installation cooking appliance has a drive device 9, 10. The drive device 9, 10 has a in the Fig. 1 . 2 and 4 shown with dashed lines drive motor 9, which is arranged between the muffle 5 and an outer wall of the housing 1. The drive motor 9 is arranged in the region of the rear side of the housing 1 and stands, as in the Fig. 1 or 4 shown in operative connection with a pair of lifting elements 10 which are connected to the bottom door 7. It is according to the schematic side view of the Fig. 4 each lifting element 10 designed as an L-shaped carrier whose vertical leg extends from the housing-side drive motor 9. To adjust the bottom door 7 of the drive motor 9 can be actuated by means of a control panel 12 and a control circuit 13, which according to the Fig. 1 and 2 front side is arranged on the bottom door 7. As in Fig. 4 shown, the control circuit 13 is located behind the control panel 12 within the bottom door 7. The control circuit 13, which here consists of several spatially and functionally separate and communicating via a communication bus circuit boards composed, represents a central control unit for the device operation and controls and / or regulates z. As a heating, a method of the bottom door 3, a conversion of user input, a lighting, a pinch protection, a clocking of the radiator 16, 17, 18, 22 and much more.

Of the Fig. 1 It can be seen that a top of the bottom door 7 has a hob 15. Almost the entire surface of the hob 15 is occupied by radiators 16, 17, 18, in Fig. 1 dash-dotted lines are indicated. In Fig. 1 the radiators 16, 17 are two spaced apart, different sized cooking surface heaters, while the radiator 18 is provided between the two cooking area heaters 16,17 surface heating element, which almost encloses the cooking surface heaters 16, 17. The hotplate heaters 16, 17 define for the user associated cooking zones or hobs; the hotplate heaters 16, 17 together with the surface heating element 18 define a bottom heat zone. The zones may be indicated by a suitable decoration on the surface. The radiators 16, 17, 18 are each controlled via the control circuit 13.

In the exemplary embodiment shown, the radiators 16, 17, 18 are configured as radiant heaters, which are covered by a glass ceramic plate 19. The glass ceramic plate 19 has approximately the dimensions of the top of the bottom door 7. The glass ceramic plate 19 is further equipped with mounting holes (not shown) through the base for holding support members 20 for Gargutträger 21 protrude, as well as in Fig. 4 shown. Instead of a glass ceramic plate 19, other - preferably quick-responding - covers can be used, for. B. a thin sheet.

With the help of a control panel 12 provided in the control knob, the high-installation cooking appliance can be switched to a cooking or a bottom heat mode, which will be explained below.

In the hob mode, the cooking surface heaters 16, 17 can be controlled individually by means of control elements 11, which are provided in the control panel 12, via the control circuit 13, while the surface heating element 18 remains out of operation. The hob mode is executable with lowered bottom door 7, as in Fig. 1 is shown. But it can also be operated with closed cooking chamber 3 with raised floor door 7 in an energy saving function.

In the lower heat mode, not only the hotplate heaters 16, 17 but also the surface heating element 18 are activated by the control device 13.

In order to achieve the most uniform possible tanning image of the food during the bottom heat, it is crucial that the cooking surface 15 providing the bottom heat has a uniform distribution of the heat output over the surface of the hob 15, although the heating elements 16, 17, 18 have different nominal powers. Preferably, therefore, the radiators 16, 17, 18 are not switched by the control circuit 13 to a continuous operation, but the power supply to the radiators 16, 17, 18 is clocked. The different sized nominal heating powers of the radiator 16, 17, 18 are individually reduced so that the radiators 16, 17, 18 provide a uniform over the surface of the hob 15 distribution of the heat output.

Fig. 3 schematically shows the location of a fan 23, z. B. for generating circulating air in a hot air operation or for supplying fresh air. In addition, a mounted on an upper side of the muffle 5 Oberhitzeheizkörper 22 is provided, the single-circuit or mehrkreisig, z. B. with an inner and an outer circle, can be executed. Also can - not shown here for clarity - another radiator such as a ring heater between the rear wall of the housing 1 and the muffle be present. By the control circuit 13, the various operating modes, such as, for example, top heat, hot air or Schnellaufheizbetrieb, by an appropriate activation and adjustment of the heating power of the radiator 16, 17, 18, 22, possibly with activation of the fan 23, are set. The adjustment of the heating power can be done by appropriate timing. In addition, the hob 15 can also be designed differently, for. B. with or without roasting zone, as a pure - one or mehrkreisige - warming zone without cooktops and so on. The housing 1 has a seal 24 towards the bottom door 7.

The control panel 12 is arranged mainly at the front of the bottom door 7. Alternatively, other arrangements are conceivable, e.g. at the front of the housing 1, divided into different sub-fields and / or partially on side surfaces of the cooking appliance. Further designs are possible. The controls 11 are not limited in their design and can, for. As control knob, toggle switch, pushbuttons and membrane keys include the display elements 14 include z. B. LED, LCD and / or touch screen displays.

In Fig. 5 is a schematic and not to scale a Hocheinbau-cooking appliance shown from the front, in which the bottom door 7 open on plant with the worktop 8 is located. The closed state is shown in dashed lines.

In this embodiment, two traversing panels 25 are located on the front side of the fixed housing 1. Each traversing panel 25 comprises two pushbuttons, namely an upper CLOSE button 25a for a bottom door 7 traveling upwards in the closing direction and a lower OPEN button 25b for one Without automatic operation (see below) moves the bottom door 7 only by continuous simultaneous pressing the CLOSE buttons 25a both traversing panels 25 upwards, if possible; also moves the bottom door 7 only by continuous simultaneous pressing of the UP buttons 25b both traversing panels 25 down, if possible (manual operation). Since in manual operation an increased operator attention of the user is given and also both hands are used here, an anti-trap is then optional. In an alternative embodiment, traversing panels 26 are mounted on opposite outer sides of the housing 1 with corresponding ZU buttons 26a and UP buttons 26b, as shown in dotted lines.

The dot-dashed control circuit 13, which is located inside the bottom door 7 behind the control panel 12, the drive motor 9 switches so that the bottom door 7 gently anfährt, d. H. not abruptly by simply hiring the drive motor 9, but by means of a defined ramp.

In this exemplary embodiment, the control circuit 13 comprises a memory unit 27 for storing at least one target or travel position P0, PE, P1, P2, PZ of the bottom door 7, preferably with volatile memory modules, eg. B. DRAMs. If a target position P0, P1, P2, PZ is stored, the bottom door can after actuation of one of the keys 25a, 25b or 26a, 26b of the traversing panels 25 or 26 independently in the set direction until the next target position is reached or one of the keys 25a, 25b or 26a, 26b is pressed again ( automatic mode). In this embodiment, the lowest target position PZ corresponds to the maximum opening, the (zero) position P0 corresponds to the closed state, and P1 and P2 are freely adjustable intermediate positions. If the last target position for one direction has been reached, manual operation must also be continued if this is possible (ie the last end positions do not correspond to a maximum open or closed final state). Analog must then, if for one direction no target position is stored - which z. B. for an upward movement into the closed position would be the case if only PZ is stored, but not P0, P1, P2 - are driven in this direction in manual mode. If no target position is stored, eg. B. in a new installation or after a power disconnection, no automatic mode is possible. If the bottom door 7 is moved in particular in automatic mode, an anti-pinch protection is preferably activated.

Automatic mode and manual operation are not mutually exclusive: by permanently actuating the positioning panel (s) 25, 26, the bottom door 7 also moves in manual mode if a target position could be approached in this direction. It can be z. B. a maximum actuation time of the traversing fields 25 and 26, respectively, of the associated keys 25a, 25b and 26a, 26b, are set to activate the automatic mode, z. B. 0.4 seconds.

A target position P0, P1, P2, PZ may be any position of the bottom door 7 between and including the zero position P0 and be the maximum opening position PZ. However, the maximum stored opening position PZ need not be the position with abutment on the work surface 8. Storing the target position P0, P1, P2, PZ can be achieved with the bottom door 7 at the desired target position P0, P1, P2, PZ, by means of, for example, several seconds (eg two seconds), pressing a confirmation key 28 in the control panel 12 be performed. Existing optical and / or acoustic signal transmitters which output corresponding signals after storing a target position are not shown for the sake of clarity. A start-up of the desired target position P0, P1, P2, PZ to be set takes place, for example, by - in this embodiment - ambidextrous operation of the movement panels 25 or 26 and manual method to this position.

In the memory unit 27, only one or, as shown in this embodiment, a plurality of target positions P0, P1, P2, PZ can be einspeicherbar. In the case of several target positions P0, P1, P2, PZ, these can be approached successively by actuating the corresponding travel keys 25a, 25b or 26a, 26b. Through several target positions P0, P1, P2, PZ, the high-installation cooking appliance can be easily adapted to the desired operating height of multiple users. The target position (s) are advantageously erasable and / or overwritten. In one embodiment, for example, only one target position can be stored in the opened state, while the zero position P0 is automatically recognized and can be approached automatically. Alternatively, the zero position P0 must be stored in order to be automatically approachable.

It is particularly advantageous for ergonomic use if the or a target position P1, P2, PZ, the bottom door 7 at least approx. 400 mm to approx. 540 mm (ie P1-P0, P2-P0, PZ-P0 ≥ 40cm to 54 cm). In this opening dimension the food supports 21 are easy to insert into the support members 20. It is advantageous if the viewing window 4 is mounted approximately at eye level of the user or slightly below, z. B. by means of a template that indicates the dimensions of the cooking appliance.

Not shown is an existing power failure override for bridging of about 1 to 3 s power failure, preferably up to 1.5 s power failure.

The drive motor 9 off Fig. 1 has at least one sensor unit 31, 32 on a motor shaft 30, possibly in front of or behind a transmission arranged to measure a travel or a position and / or a speed of the bottom door 7. For example, the sensor unit may include one or more induction, reverberation, opto, SAW sensors, and so forth. Here are for easy distance and speed measurement here two Hall (part) elements 31 offset by 180 ° - ie opposite - attached to the motor shaft 30, and a Hallmessaufnehmer 32 is fixedly mounted at this area of the motor shaft spaced. If a Hall element 31 then moves past the measuring sensor 32 when the motor shaft 30 rotates, a measuring or sensor signal is generated which is, to a good approximation, digital. With (not necessarily) two Hall elements 31, therefore, two signals are output during one revolution of the motor shaft 30. By time evaluation of these signals, z. B. their time difference, the speed vL of the bottom door 7 can be determined, for example via comparison tables or a conversion in real time in the control circuit 13. By addition or subtraction of the measurement signals, a travel or a position of the bottom door 7 can be determined.

A speed control can realize the speed, for example via a PWM-controlled power semiconductor.

For zero point determination, the distance measurement is automatically re-adjusted by initialization in the zero position P0 of the bottom door 7 at each start, so z. B. a faulty sensor signal output or recording is not traditional.

The drive motor 9 is operated by actuation of both traversing panels 25 and 26, even when the main switch 29 is turned off.

Instead of two separate switches per traversing field 25, 26 and a single switch per traversing field is possible, for. B. a toggle switch with a neutral position, which switches only under pressure. Other shapes are possible. Also, the nature and arrangement of the controls 28,29 of the control panel 12 is not limited.

The arrangement and distribution of the control circuit 13 is flexible and not limited, so it can be several boards, z. B. include a display board, a control board and an elevator board, which are spatially separated.

A 4 mm opening dimension, for example, can be detected by limit switches 33, which deactivate anti-pinch protection when actuated. It is possible deactivation of the anti-trap but also for example by counting pulses of the sensor signals upon reaching a count, which corresponds to a closing size of eg 8.6 mm. The deactivation of the anti-trap protection is thereby independent of such mechanical limit switches 33. Alternatively, only anti-jamming measures are disabled that do not work with thresholds, e.g. As mechanical switches, in particular not a movement parameter of the door using anti-jamming mechanisms.

The high-installation cooking appliance can also be designed without a storage unit 27, in which case no automatic operation is possible. This can be for increased operating safety, eg. B. as protection against pinching, be useful.

Fig. 6 shows a non-scale diagram of a plot of the travel speed vL of the bottom door 7 in mm / s against the position of the bottom door in mm from the zero position P0 for a procedure of the bottom door 7 from the closed state at P0 = 0 mm on PZ = maximum opening at here 530 mm in manual travel mode (ie without automatic procedure) and, as indicated by the dotted arrow, stopping the movement between P0 and PZ. The curve is traversed in the direction of the arrow, ie from right to left. The downward arrows present above the curve indicate actuations of the control panel 12.

The movement of the bottom door 7 downwards begins with two-handed operation of the movement panels 25, 26 and the ON-switch 25b and 26b, as indicated by the upper left vertical arrow. The control circuit 13 controls the drive motor 9 so that the bottom door 7 gently, d. h .: with a defined ramp R1, is approached to their target speed of here vL = 50 mm / s. The ramp R1 is linear here. The drive motor 9 is therefore not simply turned on.

The movement is thereby load-independent, in particular independent of the payload of the bottom door 7 or changed Friction conditions of the mechanics. An input for this can be the speed of the drive motor 9, the z. B. can be measured by Hall sensors.

After reaching the desired speed of vL = 50 mm / s, the bottom door 7 constantly moves downwards until it approaches the maximum opening PZ, which results from the design-dictated maximum travel of the bottom door 7 or reaching the worktop 8. In this figure, it is assumed that the constructive maximum opening PZ is achieved. In this case, the control circuit 13 recognizes this approach and brakes the bottom door 7 automatically, d. H. with a defined ramp R2, down to PZ. Both ramps R1 and R2 may have other slopes or shapes. The approach to the bottom plate can be detected by limit switch 33 and / or by monitoring the travel.

If one or both of the travel switches 25b, 26b is released, as indicated by the upper left vertical arrow, the bottom door 7 abruptly stops without a ramp, as indicated by the dotted arrow. In this mode, it is therefore gently approached, but - except when reaching the end position - abruptly stopped.

The cooking chamber 3 is not opened, the bottom door 7 so do not proceed from the zero position P0 when an opening backup is active, so if, for example, a certain temperature in the oven, z. B. 425 ° C or 600 ° F, is exceeded or a child safety device is activated.

Fig. 7 indicates one Fig. 6 Analog, not true to scale diagram for a method of the bottom door 7 from the closed state to a stored position P1 = 476 mm in the automatic traversing operation.

In this case, by briefly pressing one of the UP switch 25b or 26b, as indicated by the upper right vertical arrow, the bottom door 7 begins to move automatically to the position P1. Again, the bottom door 7 is gently approached (right ramp) and automatically braked (left ramp). In this embodiment, in automatic mode, it is possible to choose between two fixed target speeds, namely 75 mm / s (dashed line) and 50 mm / s (solid line), the slower speed being particularly favorable for older users. Default, z. B. at delivery, is the slower speed level. It can also be provided more than two speed levels or target speeds; Also, a free adjustment of the desired speed (s) by the user is conceivable. Conveniently, at least between two speed levels of 50 mm / s and 65 mm / s switchable, z. B. at a device initialization.

Fig. 8 shows a diagram not to scale for a method of the bottom door 7 from the maximum opening position PZ to the zero position P0, ie in the closed state, in manual mode.

The movement of the bottom door 7 upward begins with two-handed operation of the to-switch 25a and 26a, as indicated by the upper left vertical arrow. The control circuit 13 controls the drive motor 9 so that the bottom door 7 is gently approached from PZ to their desired speed of vL = 50 mm / s, and then with this target speed constant (to the right) is moved.

The control circuit 13 detects an approach to the zero position P0 and brakes the bottom door 7 in good time in advance from. But instead of using the linear ramp to move straight down to the zero position P0, the speed-dependent control is switched to control with a defined voltage 4 mm before the zero position P0, ie by supplying the motor 9 with a corresponding voltage. This allows a maximum force development when blocking the drive motor 9 set. This voltage differs depending on the history of the process (payload, friction conditions, etc.). The detection of the 4 mm opening dimension is done via the distance measurement or additionally or alternatively via the limit switch 33. In the range of P0 to P0 + 4 mm can also be dispensed with an anti-trap.

Will, as in Fig. 6 , one or both of the travel switches 25b, 26b released, as indicated by the upper right vertical arrow, the bottom door 7 stops abruptly without a ramp, as indicated by the dotted arrow.

Fig. 9 shows a diagram not to scale for a method of the bottom door 7 from a stored position P1 = 476 mm in the closed state P0 in the automatic movement operation. Unlike the in Fig. 8 shown manual traversing now only one of the to-switch 25a, 26a needs to be pressed briefly, as indicated by the upper vertical arrow. Then moves the bottom door 7 analogous to Fig. 7 just in the other direction. When approaching the zero position P0, the procedure is analogous to the situation Fig. 8 the deceleration ramp for the last 4 mm opening from a speed-controlled state to a load or Schließkraftgesteuerte state.

Fig. 10 indicates one Fig. 8 similar diagram, in which now at a target speed of vL = 50 mm / s pinching occurs as indicated by the upper vertical arrow. When pinching, for example, a hand or a pot, etc. between the bottom door 7 and the housing 1, the speed of the bottom door 7 drops, since the object obstructs another method. The monitoring of the lift speed happens here, for example, by evaluating the sensor signals of the motor shaft, wherein z. B. the time between the measurement signals or pulses is evaluated. Only in the second instance is the motor current monitored, which is a rather slower method. In particular, the force that can be generated by the motor 9 for the method is limited in order to avoid accidents due to excessive pinching (see also FIG FIGS. 12 and 13 ). The deviation from the desired speed is detected by the control circuit 13, z. B. by a speed deviation or a temporal change in speed. Then reverses the bottom door, so that the object can be removed; if necessary, a, z. B. acoustic, warning signal issued. The bottom door 7 then moves on only when a corresponding actuation of a movement load field 25, 26 again.

Thus the Einklemmfall is not triggered by mistake, z. B by a change in payload or a change in the operating characteristics of the mechanics, firstly the anti-trap only be activated when the bottom door 7 has reached its target speed (previously a traversing button 25a, 25b, 26a, 26b released, the bottom door 7 remains immediately secondly, several sensor signals may be evaluated, for example averaged.

Fig. 11 shows the Einklemmfall (upper vertical arrow) in the opening process of the bottom door 7 in the automatic mode to a target position P1, in which an object between the bottom of the bottom door 7 and the countertop 8 is clamped. In this Case, the Einklemmerkennung can be done via two redundant limit switches, which recognize a - especially non-uniform - relief of the bottom door 7, whereupon the drive motor 9 reverses. The maximum permissible force time profile (see FIGS. 12 and 13 ) is not exceeded.

Fig. 12 shows a trapped case in the process in a closing direction (ie upwards) maximum applicable to the bottom door 7 force F in N against the elapsed time t in s as a first force time profile FT1.

In case of trapping at t = 0 s, the possible closing force is limited to 100 N, corresponding to approx. 10 kg, for 5 s. This is z. B. useful if the motor 9 is up-regulated by the controller 13 to hold the target speed. This ensures in particular that body parts are not injured. If the floor door is tightened for a maximum of 100 N for 5 s, the maximum force that can be applied is reduced further to 25 N, eg. For 5 seconds. In the following, this level of force can be kept or z. B. continue to be lowered to 0 N. It should be emphasized that this force time profile FT1 indicates only the maximum applicable force, and the actually applied force is usually lower, for. B. if the Einklemmfall detected by the controller 13, and the bottom door 7 is reversed accordingly after t = 0.5 s, after which the applied force of 100 N to z. B. 0 N decreases.

The maximum force threshold of 100 N can also apply to other traversing situations.

Fig. 13 shows a trapped case in the process in an opening direction (ie down) maximum applicable to the bottom door 7 force F in N against the elapsed time t in s as a second Force time profile FT2. Here, the drive motor 9 in a first block of t = [0 s; 0.5 s] up to 400 N to the bottom door 7, then at t = [0.5 s; 5 s] 150 N and then 25 N.

Of course, the time intervals and force threshold values of the force time profiles FT1, FT2 can be adapted to the structure and further boundary conditions.

Fig. 14 shows an exemplary flowchart in which a speed vL, with which the door 7 is moved, is sketched above a current position P. However, the speeds given in millimeters per second mm / s or in millimeters are to be regarded as purely exemplary.

Starting from an end position PZ, in which the door 7 is at a standstill, the door 7 is accelerated by the drive motor 9 until reaching a lower intermediate position P2 and / or to a target speed vR. From the lower intermediate position P2, the door 7 is moved upwards at a constant speed until it reaches another upper intermediate position P1. From this upper intermediate position P1, the speed is decelerated until reaching a zero position P0, which corresponds to a closed state, so that a deceleration-speed course in turn assumes a ramp shape.

Optionally, during the startup of the door 7, a method for monitoring an entrapment state may be activated, such a method being deactivated, in particular in the case of pure speed monitoring when switching to the deceleration mode, that is to say in particular after reaching the upper intermediate position P1, according to an exemplary embodiment. According to another exemplary Embodiment, such monitoring a pinching state only after reaching an even higher switching position PS or not at all disabled. The switching position PS can be detected for example by reaching a limit switch 33 or detecting a predetermined approach state of the door 7 to the muffle 5 due to an accumulated number of Hall pulses.

In particular, it can be provided that a switchover between an anti-jamming monitoring operation and a closing operation is performed, for example, the limit switches 33 serve during the initial startup of the door 7 for monitoring an anti-jamming while the same limit switch 33 during the final approach of the door 7 to the Muffel 5 serve for closed-state monitoring to monitor a safe and firm closing of the door 7. In particular, in such a switching, the switch is advantageously a piece before reaching the zero position P0. In particular, the switching takes place approx. 4 - 10 mm before reaching the zero position P0.

With such an approach of the door 7 to the muffle 5 or a flange mounted on the underside of the muffle, trapping of common objects used in the household can be ruled out. However, there is a risk that a narrow child's finger, a pen, etc., can still get into such a narrow gap, which can lead to a serious injury to the child's finger by pinching.

Preferably, therefore, an additional or alternative method for monitoring a pinching condition is activated, which, however, may in principle also be activated during the rest of the start-up procedure. In this method is the cooking appliance is equipped with a functionality which detects a pinching condition by a threshold dependent on a movement, in particular a speed of movement of the door 7.

The threshold value used here is preferably the undershooting of a minimum speed (threshold value) vS and / or the increase in a period of measurement signals of a Hall element 31, that is to say a change in a differential speed. But also the monitoring of a motor current or a power drawn by the motor can be used as a threshold value.

In the illustrated sequence, the door 7 approaches the zero position P0 at the speed of a deceleration speed curve. As from the enlarged detail in Fig. 14 can be seen, however, an object in the last closing portion just before reaching the zero position P0 between the door 7 and the muffle 5 and causes an increasing speed reduction which is outlined as a decreasing pinching speed course.

In contrast to a hard body causes a partially elastic body, in particular a child's fingers when pinching not abruptly stopping the speed to a zero value but at least initially only a reduced decrease in speed. As a criterion, the undershooting of the minimum speed vS, which is predefined for this section of the route, and / or the increase of the differential speed ΔvS or period of measuring pulses of the Hall elements 31, which is predefined for this section, can be detected.

After detecting a pinching condition, the speed of the door 7 is preferably reduced to zero and then briefly increased in the opposite direction. During a sketched return speed curve v2 and a subsequent renewed deceleration speed curve v3, the door 7 is preferably again moved a distance away from the muffle 5 by an opening distance s, so that the jammed object can be removed.

Preferably, for such a monitoring of a pinching condition in the remaining opening gap s, a measuring signal of Hall elements is used which monitor a rotation of a drive shaft between the drive motor 9 and a lifting element 10 for lifting the door 7. However, other signal receivers can be used which monitor a current distance of the door 7 to the muffle 5 directly by means of optical or mechanical displacement sensor, speed sensor or accelerometer. Also, a changing engine performance, that is, a power consumption of the drive motor 9 can be used as a measurement signal.

In addition to the use of such a procedure for monitoring the method of the door 7 during a final closing operation, such a method can be used in principle during the entire travel distance. In particular, it is also possible to use such a method in addition to the use of further methods for monitoring an entrapment state, possibly also other methods based on hardware, that is to say in particular of switches.

LIST OF REFERENCE NUMBERS

1

casing

2

wall

3

oven

4

window

5

muffle

6

muffle opening

7

bottom door

8th

countertop

9

drive motor

10

lifting

11

operating element

12

Control panel

13

control circuit

14

indicators

15

hob

16

Hotplate heating elements

17

Hotplate heating elements

18

Panel heater

19

Glass ceramic plate

20

supporting member

21

food support

22

Top heat radiator

23

Fan

24

poetry

25

Verfahrschaltfeld

25a

Travel switch upwards

25b

Travel switch down

26

Verfahrschaltfeld

26a

Travel switch upwards

26b

Travel switch down

27

storage unit

28

confirmation key

29

main switch

30

motor shaft

31

Hall element

32

sensor

33

Limit switch FT1 first force time profile

FT2

second power time profile

P0

zero position

P1

intermediate position

P2

intermediate position

PZ

end position

PS

changeover

R1

speed ramp

R2

speed ramp

vL

Travel speed of the bottom door

vR

target speed

vS

Schwellwertgeschindigkeit

v

permissible minimum speed

.DELTA.v

differential speed

v2

Recovery rate history

v3

Abbremsgeschwindigkeitsverlauf

s

opening track

Claims (15)

1. Cooking appliance, particularly overhead built-in cooking appliance, comprising at least one

   - muffle (5) which bounds a cooking space (3) and has a muffle opening (6),

   - door (7) for closing the muffle opening (6) and

   - drive device (9, 10), which is controlled by a control device (13), for moving the door (7),

   - wherein in the case of jamming of an object during movement of the door (7) a jammed state is recognised,

   - wherein the jammed state is recognised by comparison of a parameter (vL, fvL), which belongs to the travel movement of the door (7), with a threshold value (vS, fvS), which belongs to this parameter, and reaching and/or exceeding of the threshold value,
   characterised in that

   - the parameter corresponds with a travel speed (vL) of the door (7) and the threshold value corresponds with a minimum permissible speed (vS) and/or that the parameter corresponds with a permissible difference speed (fvL) per unit of time and the threshold value with a permissible minimum difference speed (fvS) for the same unit of time, and

   - the cooking appliance is equipped for the purpose of activating the monitoring of the jammed state, which is dependent on the threshold value, within a predetermined movement path of the door (7),

   - wherein the movement path of the door (7) corresponds with a last movement path ahead of a zero position (P0), which corresponds with a closed position, of a closed door (7).
2. Cooking appliance according to claim 1, characterised in that the cooking appliance is equipped for the purpose of activating the monitoring of the jammed state within the last 15 millimetres of the movement path of the door (7) before reaching the zero position (P0).
3. Cooking appliance according to claim 2, characterised in that the cooking appliance is equipped for the purpose of activating the monitoring of the jammed state within the last 10 millimetres, particularly the last 5 millimetres, of the movement path of the door (7) before reaching the zero position (P0).
4. Cooking appliance according to any one of the preceding claims, characterised in that the cooking appliance is equipped for the purpose of activating the monitoring of the jammed state, which is dependent on the threshold value, in connection with or after switching-off of a first, other jammed-state monitoring procedure.
5. Cooking appliance according to any one of the preceding claims, characterised in that the cooking appliance is equipped for the purpose of activating the monitoring of the jammed state, which is dependent on the threshold value, during switching over to a force-regulated closing movement of the door (7).
6. Cooking appliance according to any one of the preceding claims, characterised in that a speed measuring device (31, 32) for determining a travel speed (vL) of the door (7) is present.
7. Cooking appliance according to any one of the preceding claims, characterised in that jamming of the door (7) is detectable by monitoring the travel speed (vL) and the monitoring of the travel speed (vL) comprises monitoring for an uncontrolled reduction in the travel speed (vL).
8. Cooking appliance according to any one of the preceding claims, characterised in that jamming of the door (7) is detectable by monitoring the travel speed (vL) and the monitoring of the travel speed (vL) comprises monitoring for a deviation of the travel speed (vL) from a target speed.
9. Cooking appliance according to claim 6 or to claim 6 with one of the preceding claims, characterised in that the speed measuring device comprises at least one sensor (31, 32) at a motor shaft (30) of the drive device (9, 10), by which corresponding sensor signals can be generated when the motor shaft (30) rotates.
10. Cooking appliance according to any one of the preceding claims, characterised in that a travel speed (vL) of the door (7) can be regulated.
11. Cooking appliance according to any one of the preceding claims, characterised in that in addition at least one limit switch (33) is present, which is arranged in the region between muffle opening (6) and door (7) and that actuation of the at least one limit switch (33) deactivates an anti-jamming device.
12. Method of operating a cooking appliance, particularly overhead built-in cooking appliance, comprising at least one muffle (5) which bounds a cooking space (3) and has a muffle opening (6), at least one door (7) for closing the muffle opening (6) and at least one drive device (9, 10), which is controlled by a control device (13), for moving the door (7), wherein in the case of jamming of an object during movement of the door (7) a jammed state is recognised, wherein jamming of an object at the door (7) is recognised in that a jammed state is recognised by comparison of a parameter (vL, fvL), which belongs to the travel movement of the door (7), with a threshold value (vS, fvS), which belongs to this parameter, and reaching and/or exceeding of the threshold value, characterised in that a permissible minimum speed (vS) and/or a difference speed (fvS) is or are used as the threshold value and that the monitoring of the jammed state, which is dependent on the threshold value, is activated within a predetermined last movement path of the door before a zero position (P0), which corresponds with a closed position, of the closed door (7).
13. Method according to claim 12, characterised in that the monitoring of the jammed state, which is dependent on the threshold value, is activated in connection with or after switching-off of a first, other jammed state monitoring procedure.
14. Method according to one of claims 12 and 13, characterised in that monitoring of the jammed state, which is dependent on the threshold value, is activated in connection with or after activation of a limit switch (33).
15. Method according to any one of claims 12 to 14, characterised in that monitoring of the jammed state, which is dependent on the threshold value, is activated during switching over to a force-regulating closing movement of the door (7).

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