EP1982114B1 - Cooking appliance - Google Patents

Abstract

The cooking appliance comprises a muffle opening (6) and a muffle (5), which isolates a cooking compartment (3). A door (7) closes the muffle opening, where a control device controls a drive device for displacing the door. A switch transmits actuation signals to determine a zero position of the door, to the control device when the door touches the muffle. The control device is designed, so that the actuation signal is required to determine the zero position. An independent claim is also included for a method for determining a zero-position of a door.

Description

The present invention relates to a cooking appliance, in particular a high-installation cooking appliance, with at least one muffle a muffle opening defining a cooking chamber, a door for closing the muffle opening and controlled by a control device drive means for moving the door, wherein the drive means comprises at least one drive motor through which ropes connected to the door can be moved. The present invention further relates to an associated method of operation.

Out DE 102 28 140 A1 and DE 102 28 141 A1 High-installation cooking appliances are known in which a driving up a bottom door actuates a limit switch on the muffle frame, whereupon the drive unit is switched off. A disadvantage here is that the switches have high switching point tolerances and thus a correct closing of the bottom door is not guaran teeing. This can lead to improper operation of the cooking appliance, for example, for heating the muffle in still slightly open bottom door.

A similar cooking appliance is in the post-published WO 2007/020 186 A shown.

It is the object of the present invention to provide a cooking appliance with a more reliable zero point determination.

The present object is achieved by the cooking appliance with the features of claim 1 and by a method according to claim 11. Advantageous embodiments are in particular the dependent claims individually or in combination removed.

For this purpose, the cooking appliance, which is in particular a high-installation cooking appliance, but which may also be a cooking appliance with a baking tray, with at least one muffle defining a cooking space with muffle opening, a door for closing the muffle opening and a controlled by a control device drive means for the method Door and equipped with at least one switch that sends operating signals to the control device when placing the door on the muffle. The control device is set up in such a way that the actuation signals of the at least one switch are processed to determine a zero or closed position of the door. The presence of the actuation signals of the at least one switch is a necessary but not sufficient condition for determining a zero position or closed position of the door.

It is also advantageous if a zero position is detected when the at least one switch is actuated and at the same time a measurement of a travel of the door reaching the zero position P0 at least within a certain tolerance range, for. B. ± 1%, indicates. Then also the travel can be reset to a predetermined zero value. For example, a 'swallowing' of sensor pulses within a tolerance range can be compensated.

It is metrologically favorable if the travel is determined by measuring a number of revolutions of the engine or a zughörigen gear or a fraction of this number. It is particularly advantageous if at least one sensor unit in particular a Hall sensor unit, for measuring a number of revolutions of a motor shaft or a fraction thereof and with the Control unit is connected. Furthermore, it is advantageous if, starting from an initial zero position, the control unit counts the sensor pulses transmitted by the sensor unit when the door is moved and converts it into a travel path.

Additionally or alternatively, further conditions can be used to determine the zero point position. For example, it may be advantageous if a zero position P0 is determined when the at least one switch is actuated and at the same time the door can not be moved further when the drive device is activated. This condition may additionally or alternatively occur to the condition of the measured travel path. The standstill of the bottom door or the drive device can be arbitrarily determined, for example by measuring the engine or transmission speed, the direct measurement of the traversing speed of the bottom door, the engine power or the motor current, etc.

The at least one switch can advantageously be two switches, which are each mounted in particular on each side of the cooking appliance, wherein a presence of the actuating signals of both switches is a necessary, but not sufficient condition for determining the zero position.

To avoid deterioration of the circuit tolerance, the at least one switch is conveniently attached to the body and is actuated by the lifting element, in particular by a telescopic rail.

1. (a) der mindestens eine Schalter betätigt worden ist und
   • (b1) gemessen worden ist, dass ein Verfahrweg der Tür der Nullposition P0 zumindest innerhalb eines Toleranzbereiches (z. B. ± 2 Sensorimpulse oder ± 0,1 cm) entspricht und / oder
   • (b2) bei angesteuerter Antriebseinrichtung die Tür nicht weiter verfahrbar ist.

It is particularly favorable if, for determining a zero position P0 of a door of a cooking appliance, the zero position of the door is then determined - typically by the control circuit - if at the same time

1. (A) the at least one switch has been actuated and
   • (b1) has been measured such that a travel path of the door corresponds to the zero position P0 at least within a tolerance range (eg ± 2 sensor pulses or ± 0.1 cm) and / or
   • (b2) when the drive device is driven, the door can not be moved further.

Upon occurrence of condition (a) and at least one of conditions (b1) and (b2) - or another condition for determining the zero point position P0, this position is set as the new zero position P0.

However, the travel path need not have a tolerance range, but can also be met as an exact condition, for. For example, the Hall pulse counter must correspond exactly to the value for the zero position.

It is particularly advantageous if, at least when the condition (a) occurs and at least one of the other conditions (b1, b1) used to determine the zero position P0 does not occur or when the condition (a) does not occur, but all other conditions (b1, b1) used to determine the zero position (P0) occur, an error is detected or an associated error routine is traversed, the z. B. may include reversing the door.

The actuation signals of the switches can be arbitrary, z. B. include a high or a low level.

In one embodiment of the cooking appliance, two pitch cables are provided, each of which is fixed on one side to one side of the door. The pitch cables are guided by an encapsulation to a drive wheel of a drive motor, whereby they are hinged on opposite sides on a motor shaft. By rotation of the drive wheel, the pitch cables are linearly displaced in the opposite direction, accordingly, the door is moved linearly. The use of the pitch cable drive in the cooking appliance firstly results in the 'advantage of a space-saving construction, since the otherwise existing cable drum is no longer needed on the drive motor. Second, an assembly and adjustment compared to the drive with cable drum is much easier, since the costly winding on the cable drum accounts, for example, a cable tensioner is required. The fact that the pitch cables are connected to the door in the general case means that they are attached to the door directly or to an element connected to the door, e.g. B a telescopic rod, can be attached.

It is advantageous for increased reliability if each switching device is connected to a control circuit which is set up in such a way that it recognizes a trapping situation by evaluating the signals of the switching devices.

Particularly advantageously, the invention can be used in a high-installation cooking appliance with a bottom-side muffle opening and a bottom door.

• 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 in Vorderansicht eine weitere Ausführungsform eines Hocheinbau-Gargeräts.

The invention will be described in more detail below with reference to the embodiments shown in the attached schematic figures. The embodiments do not limit the scope of the invention. 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 in front view of another embodiment of a high-installation cooking appliance.

The figures are not necessarily drawn to scale for better representation of the individual elements.

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. 3 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 closed 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 on. The drive device 9, 10 has a in the Fig. 1 . 2 and 3 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 3 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. 3 each lifting element 10 is designed as a telescopic linkage, which is attached, for example, on the one hand to the bottom door 7 (for example on a supporting angle protruding from the upper side of the bottom door 7) and on the other hand to a body 33 of the cooking device (for example a cooking appliance mount) the drive motor 9 are operated 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. 3 shown, the control circuit 13 is located behind the control panel 12 within the bottom door 7. The control circuit 13, which is composed here of several spatially and functionally separated and communicating via a communication bus circuit boards, is a central control unit for the device operation is and controls and / or regulates z. As a heating, a method of the bottom door 7, 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 two spaced apart, different large hotplate radiator, while the radiator 18 is provided between the two cooking area radiators 16,17 surface heating element, which almost encloses the hotplate heaters 16, 17.

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 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. 3 shown.

In Fig. 3 is a schematic and not to scale a Hocheinbau-cooking appliance shown from the front, in which the bottom door 7 is open to rest with the worktop 8. The closed state is shown in dashed lines.

In this embodiment, two traversing panels 25 are located on the front of the fixed housing 1. Each traversing panel 25 comprises two push buttons, namely an upper CLOSE button 25a for an upwardly in closing direction traversing bottom door 7 and a.unterere ON push button 25b for a bottom door 7 moving downwards in the opening direction. Without automatic operation (see below), the bottom door 7 moves upwards only if the TO buttons 25a of both travel panels 25 are pressed simultaneously at the same time, 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). As in manual operation increased user attention is given and also here Both hands are used, a anti-trap then only optional.

In this exemplary embodiment, the control circuit 13 comprises a memory unit 27 for storing at least one destination or travel position P0, 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 after operating one of the keys 25a, 25b of the traversing panels 25 as long as in the set direction to move independently until the next target position is reached or one of the Tasten.25a, 25b again is pressed (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 automatic mode, an anti-pinch protection is preferably activated.

A target position P0, P1, P2, PZ may be any position of the bottom door 7 between and including the zero position P0 ("closed position") and the maximum opening position PZ. However, the maximum stored opening position PZ need not be the position with abutment on the work surface 8.

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 adding or subtracting the measurement signals with knowledge of the travel between two sensor signals, an absolute travel or a absolute 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.

Zero-point determination can be determined in several ways. The use of switches 24 alone is not optimal due to their comparatively high switching point tolerances.

In this embodiment, two switches 24 are attached to a dash-dot indicated support 34 of the body '33 such that they are actuated when closing the bottom door 7 by the elevating lifting mechanism 10 when the bottom door 7 below a predetermined gap dend between bottom door 7 and muffle opening. The switches 24 are located above the muffle 5, for reasons of cooling on the body 33 with a distance from the walls of the muffle 5. The mechanical actuation of the switch 24 (see curved arrows) by the lifting mechanism 10 - dotted here purely schematically in an almost contracted Position is shown before pressing, the straight arrows indicate the associated direction of movement - in contrast, for example, for direct operation through the bottom door 7 has the advantage that a circuit is not affected by a tilting or inaccuracy of the position of the bottom door 7. In addition, can be dispensed with an elaborate thermal insulation of the switch, the otherwise z. B. when switching through the bottom door or the surface of the bottom door forming hob would be necessary.

The switches 24 can also deactivate anti-trap protection when actuated.

The predetermined gap is here between 12 mm and 4 mm, preferably between 6 mm and 10 mm. The switches are here twice for security; it can, for. B. for reasons of cost savings, but, for example, even be present only a switch.

More reliable is the zero point determination by the use of the measurement of the travel path. If it is typically determined that the travel path is zero, that is, the zero position P0 should be reached, the bottom door 7 is stopped. The travel can be determined, for example, by counting the sensor pulses. However, it can lead to a miscalculation of the pulse, which is transmitted without further measures.

Another method is to determine whether the bottom door still rotates despite activation of the motor 9 or not. However, pinching the floor door, where it stops, can pre-mirror a wrong zero position in the near range.

Therefore, in this embodiment, the zero-point determination of the floor door 7 is performed by a combination of these methods. In order for the control circuit 13 to determine the zero position P0 as such and to control the movement of the bottom door 7 during a next opening operation, firstly both switches 24 must be actuated and secondly the travel path must be measured, if appropriate within a specific tolerance range, as belonging to the zero position and / or it may be the engine 9 no longer move when pulling the bottom door, z. B. continue to turn left. In this embodiment, even all three conditions must be met. If this is the case, the control circuit 13 initializes the zero position and sets z. For example, the sensor pulse count returns to zero or another value predetermined for the zero position P0.

If only one or two conditions occur, an error message can be output and if necessary the bottom door 7 can be reversed. Thus, an error message can be output if the sensor pulse count indicates a zero position P0, but the switches 24 have not yet been actuated, or the motor exceeds the tolerance range (eg 1 to 4 sensor pulses, corresponding to, for example, one half to two revolutions of the Motor shaft or gear shaft).

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.

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

lower telescopic rod part

23

Upper telescopic rod part

24

The home switch

25

Verfahrschaltfeld

25a

Travel switch upwards

25b

Travel switch down

27

storage unit

28

confirmation key

29

main switch

30

motor shaft

31

Hall element

32

sensor

33

corpus

34

edition

DEND

Endzone gap

P0

zero position

P1

intermediate position

P2

intermediate position

PZ

end position

Claims (13)

1. Cooking appliance, particularly a high-level cooking appliance, comprising at least

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

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

   - a drive device (9, 48), which is controlled by a control device (13), for moving the door (7), and

   - at least one switch (24) which on placing the door (7) against the muffle (5) transmits to the control device (13) actuating signals for determination of a zero position (P0) of the door (7),

   characterised in that the control device (13) is so arranged that a presence of the actuating signals of the at least one switch (24) is a necessary, but not sufficient, precondition for determination of the zero position (P0).
2. Cooking appliance according to claim 1, characterised in that a zero position (P0) is determined if the at least one switch (24) is actuated and at the same time a measurement of a movement travel of the door (7) indicates reaching of the zero position (P0) at least within a specific tolerance range.
3. Cooking appliance according to claim 2, characterised in that the movement travel is determined by measurement of a number of revolutions of the motor (9) or a fraction thereof.
4. Cooking appliance according to claim 3, characterised in that at least one sensor unit (31, 32), particularly Hall sensor unit, for measurement of a speed of rotation of a motor shaft (30) or a fraction thereof is present and is connected with the control unit (13).
5. Cooking appliance according to claim 4, characterised in that the control unit (13) starting from an initial zero position (P0) counts the sensor pulses transmitted by the sensor unit (31, 32) when the door (7) is moved and converts them into a movement travel.
6. Cooking appliance according to any one of the preceding claims, characterised in that a zero position (P0) is determined when the at least one switch (24) is actuated and at the same time the door (7) is not further movable when the drive device (9, 48) is subjected to drive control.
7. Cooking appliance according to claim 6, characterised in that a standstill of the door (7) is determined by standstill of the drive device (9, 48).
8. Cooking appliance according to any one of the preceding claims, characterised in that the at least one switch (34) is two switches (34) which in particular are each mounted at a side of the cooking appliance, wherein a presence of the actuating signals of the two switches (34) is a necessary, but not sufficient, precondition for determination of a zero position (P0) of the door (7).
9. Cooking appliance according to any one of the preceding claims, characterised in that the at least one switch (34) is fixedly connected with a body (33) and actuated by a stroke element (10), particularly by a telescopic rail (22, 23).
10. Cooking appliance according to any one of the preceding claims, characterised in that it is a high-level cooking appliance and the muffle opening is a muffle opening (6) at the bottom and the door is a bottom door (7).
11. Method of determining a zero position (P0) of a door (7) of a cooking appliance according to any one of the preceding claims, characterised in that the zero position (P0) of the door (7) is determined when simultaneously

    (a) the at least one switch (24) has been actuated and

    (b1) it has been measured that a movement travel of the door (7) corresponds with the zero position (P0) at least within a tolerance range and/or

    (b2) the door (7) is not further movable when the drive device (9, 48) is subjected to drive control.
12. Method according to claim 11, characterised in that after determination of the zero position (P0) this is determined as the exact new zero position (P0).
13. Method according to claim 11 or 12, characterised in that an error is determined at least when the condition (a) occurs and at least one of the other conditions (b1, b2) used for determination of the zero position (P0) does not occur or when the condition (a) does not occur, but all other conditions (b1, b2) used for determination of the zero position (P0) occur.

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