Pressure detection device for cooking appliances and cooking equipment

Abstract

A pressure sensing means (26) for a cooking appliance includes a measuring tube (36) for a cooking space atmosphere that has at least one inlet (38) and at least one outlet (46) for the cooking space atmosphere. The measuring tube (36) has at least one opening (50, 52, 54) in a peripheral wall (48) to which a pressure measuring component (56, 58, 60) is attached. The pressure measuring component (56, 58, 60) includes a measuring chamber (62) delimited by a membrane (64), and the membrane (64) is arranged in the area of ​​the opening (50, 52, 54). In a cooking appliance, the outlet (46) of the measuring tube (36) is in fluidic communication with a relief valve that is suitable for venting the cooking space atmosphere to the outside. Fig. 3

Description

Title of the invention: Pressure detection means for cooking appliances and cooking equipment

[0001] The invention relates to a pressure detection means for a cooking appliance and to a cooking appliance having a pressure detection means for a cooking appliance.

[0002] Cooking appliances with a pressure cooking function often include a pressure sensing device that monitors and controls the pressure in the cooking chamber. For example, a pressure sensor is present, which detects the pressure in the cooking chamber. Most often, a pressure switch and a relief valve are also provided, which reduce the pressure in the cooking chamber before a lid of the cooking appliance is opened and also ensure that the pressure in the cooking chamber does not rise above a predetermined level.

[0003] As a general rule, the cooking space in a cooking appliance of this type is sealed against pressure. The pressure in the cooking space is generated by heating the atmosphere of the cooking space.

[0004] A pressure-sensing means for a cooking appliance is known, for example, for a cooking appliance with a pivoting pan. Such cooking appliances are also called tilters; they are general-purpose appliances in which one can, for example, heat, bake, roast, or fry. The pans are usually pivoted forward by the user to empty them. The cooking chamber is optionally closed by a pivoting lid. A seal is usually arranged between the pan and the lid so that overpressure can be established in the cooking chamber for the pressure cooking function.

[0005] The object of the invention is to provide a means of pressure detection in a cooking appliance in such a way as to make it less sensitive to soiling.

[0006] This objective is achieved by a pressure detection means in a cooking appliance, comprising a measuring tube for a cooking space atmosphere which has at least one inlet and at least one outlet for the cooking space atmosphere. The measuring tube has at least one opening in a peripheral wall to which a pressure measuring component is attached, the pressure measuring component comprising a measuring chamber delimited by a membrane, and the membrane being arranged in the area of ​​the opening.

[0007] Thanks to the positioning of the membrane in the area of ​​the opening, the flow section between a main flow path through the measuring tube and the The membrane is enlarged. Furthermore, it allows for a surface as flat as possible on the inner peripheral side of the peripheral wall at the transition from the main flow path to the membrane. This significantly reduces the tendency for dirt to adhere, and consequently, the risk of blockage in the connections of the pressure measuring components is also considerably reduced. The accumulation of food particles introduced into the measuring tube and the cooking atmosphere in the area of ​​the opening can be minimized.

[0008] The measuring tube can thus be designed without constricted passages and steps between the main flow path and the diaphragm of the pressure measuring components. Due to the enlarged cross-sections and the flatter transition between the edge of the opening and the diaphragm, the velocity of the cooking chamber atmosphere flowing through the measuring tube is also increased in the area of ​​the diaphragm. Solid matter is thus transported instead along the pressure measuring components.

[0009] The cross-sectional surface of the opening may in particular have a shape and size which are identical to a free face of the membrane.

[0010] In one variant, a stepless transition between the edge of the opening and the diaphragm is thus possible for pressure measuring components whose diaphragm, due to its design, is integrated into a connecting piece in the form of a tube attached radially to the measuring tube.

[0011] In another embodiment, it is possible to arrange pressure measuring components such that a peripheral edge of its diaphragm is flush with the inner peripheral side of the measuring tube at the edge of the opening. In this embodiment, the transition between the edge of the diaphragm and the inner peripheral side of the measuring tube is preferably made to be flat and without steps.

[0012] Another advantage of this embodiment is that it is thus possible to maximize the surface area of ​​the membrane, which leads to an improved pressure measurement.

[0013] The transition between the edge of the opening on the inner peripheral side of the measuring tube and the membrane should be as seamless as possible. In this way, structures where soiling from the cooking environment could accumulate are reduced.

[0014] The pressure measuring component is, for example, a pressure sensor or a pressure switch. The pressure switch can be implemented in the form of a pressure switch. The pressure switch is generally advantageously designed to open a relief valve connected to the outlet.

[0015] A pressure sensor and two pressure switches are arranged, for example, the along the main flow path of the measuring tube. A pressure switch can be activated to cut off the supply in the event of a failure when an upper safety limit for overpressure in the cooking chamber is exceeded. The other pressure switch is, for example, intended to relieve overpressure in the cooking chamber before the cooking chamber lid is opened.

[0016] All pressure measurement components are preferably continuously connected to a control unit of the cooking appliance when the pressure sensing means for cooking appliance is installed in a cooking appliance.

[0017] The membrane is, for example, surrounded peripherally by a seal which rests on the edge of the opening. The seal is, in particular, an O-ring.

[0018] In one possible embodiment, at least one pressure measuring component is attached to the measuring tube by at least one fastener. This allows for simple mounting and, if necessary, simple removal of the pressure measuring component for maintenance or replacement.

[0019] The pressure measuring component is for example fixed to the measuring tube by two diametrically opposed fasteners.

[0020] The fastener preferably has two identical end zones. This simplifies assembly since it is not necessary to consider the orientation of the fastener. The fastener can be made symmetrically with respect to its end zones.

[0021] The attachment can for example be made in the shape of a U.

[0022] The measuring tube is preferably made of a plastic material. For example, it is manufactured in one piece using an injection molding process.

[0023] Thus, a flange can be formed simply directly on the measuring tube for the arrangement of the pressure measuring component.

[0024] At least one retaining structure on which a pressure measuring component can be fixed is preferably made on the measuring tube, and the measuring tube is made in one piece together with all the retaining structures.

[0025] A first retaining structure on the measuring tube is for example made by radially projecting ribs having a transverse bar which connects the ribs and behind which the end areas of the fasteners can engage. This connection can be a snap-fit ​​connection. This allows, in particular, the mounting of push-button switches.

[0026] A second retaining structure is, in particular, a thread formed in a protruding section of the peripheral wall of the measuring tube. It is possible to attach a pressure indicator to such a thread.

[0027] The measuring tube has, for example, a trapezoidal cross-section, and the opening is provided in a flat lateral face on the inner peripheral side of the Measuring tube. When the longer side of the trapezoid faces the opening, there is sufficient space in this area to create the opening in a flat area on the inner peripheral side of the measuring tube. This facilitates a flat, stepless transition between the edge of the opening and the diaphragm of the pressure measuring components.

[0028] The aforementioned objective is also achieved by a cooking appliance comprising a pressure sensing means for a cooking appliance as described above, the outlet of the measuring tube being in fluidic communication with a relief valve capable of venting the atmosphere from the cooking space to the outside. In this case, the measuring tube also serves to vent a portion of the atmosphere from the cooking space to the outside during the release of overpressure. A portion of the atmosphere from the cooking space then flows through the main flow path of the measuring tube. Dirt is thus naturally introduced into the measuring tube.Due to the positioning of the pressure measuring component(s)' membrane(s) within the respective opening and the resulting flat transitions between the opening's edge and the membrane, these contaminants are largely transported along the pressure measuring components without settling. Contamination of the measuring tube during the venting of the cooking chamber atmosphere is thus considerably reduced.

[0029] Dirt may even detach from the membranes and the edge of the opening due to the high flow velocities inside the measuring tube during the venting of the cooking chamber atmosphere. When using a cleaning function in the cooking appliance that includes the pressure cooking function, it is possible to use the venting of the cooking chamber atmosphere in a targeted manner for cleaning the measuring tube and the membranes.

[0030] The relief valve is for example integrated into a hollow pivot axis of a lid of the cooking appliance, and the measuring tube is attached to a conduit in the pivot axis of the lid which is in fluidic communication with the relief valve.

[0031] The relief valve is preferably electrically actuated and can be controlled by the control unit of the cooking appliance.

[0032] The measuring tube can, for example, be arranged together with the pressure measuring components between an upper and a lower face of a cooking appliance lid. Said at least one inlet of the measuring tube is then connected to a guided supply line within the cooking space.

[0033] The invention is described below in more detail with the aid of an exemplary embodiment and with reference to the accompanying figures. In the drawings: - [Fig.1] shows a schematic representation of a cooking appliance according to the invention comprising a pressure detection means for a cooking appliance according to the invention; - [Fig.2] shows a schematic top view of the cooking appliance according to the [Fig.1] with the lids closed; - [Fig.3] shows a schematic perspective representation of a pressure detection means for a cooking appliance according to the invention; - [Fig. 4] shows a schematic perspective representation of a component pressure measurement of the pressure detection means for cooking appliance according to [Fig.3]; - [Fig.5] shows a schematic cross-sectional view of the pressure detection means for cooking appliance according to [Fig.3]; - [Fig.6] shows a schematic partial cross-sectional representation of a detail of the pressure sensing means for cooking appliance according to [Fig.3] with a pressure measuring component shown in cross-section; - [Fig. 7] shows a schematic partial cross-sectional representation of the assembly of a pressure measuring component on the measuring tube of the pressure detection means for cooking appliance according to [Fig.3]; - [Fig.9] shows another partial cross-sectional view of the detection means pressure for cooking appliance according to [Fig.3]; and - [Fig. 9-10] show schematic perspective representations of the tube of pressure detection means measurement for cooking appliance according to [Fig.3].

[0034] For reasons of clarity, identical components are not always provided with reference numbers.

[0035] The cooking apparatus 10, exemplified in Figures 1 and 2, comprises at least one, here two tilting pans 12, each of which can be individually pivoted around a pan axis. In the situation shown, the upright pan 12 is tilted to empty the contents of the pan.

[0036] The pan axis is fixed to a frame 14, in this case a central bar of the frame 14. A control unit 16 comprising here a touch screen and by means of which control can be carried out from the outside is housed in the housing of the central bar.

[0037] Each pan 12 defines in its interior a so-called cooking space 18 which can be closed and opened by an associated pivoting lid 20.

[0038] The covers 20 can be pivoted manually and / or by an electric motor. At least one pressure-reducing opening 22 leading into the interior of the cover 20 is provided on the inner side of each of these covers 20.

[0039] The pressure reducing opening 22 is connected by a supply line 24 to a pressure sensing means 26 for a cooking appliance. This is in turn in fluidic communication with a discharge line 28 which terminates in a relief valve 30. The relief valve 30 connects the cooking space 18 to the environment of the cooking appliance 10.

[0040] In this example, the pressure sensing means 26 for cooking appliance is arranged in the cooking appliance 10 between an upper face and an lower face of the lid 20 and is thus separated from the cooking space 18 except for the pressure reducing openings 22.

[0041] In this example, the discharge pipe 28 is guided through a hollow pivot axis 29 of the cover 20, so that the atmosphere from the cooking space, discharged by the relief valve 30, is guided into the frame 14. The relief valve 30 is, in particular, in fluid communication with a condensing box 32 in which the steam condenses, for example, through the fresh water inlet. A pipe 34, guided away from the condensing box 32, leads here to the wastewater discharge connection of the cooking appliance 10.

[0042] In the example shown here, two pressure reduction openings 22 are provided by a cover 20, each of which is in fluidic communication with a supply line 24.

[0043] As can be clearly seen, for example, in [Fig. 3], the pressure sensing means 26 for the cooking appliance comprises a measuring tube 36 which has an inlet 38 for each pressure-reducing opening 22. This inlet is connected to the respective supply line 24 when the pressure sensing means 26 for the cooking appliance is mounted in the cooking appliance 10. Two inlets 38 are thus formed on the measuring tube 36 in this example. Each of the two inlets 38 projects radially from a central pipe 40 which forms a main flow path with a flow direction R through the pressure sensing means 26 for the cooking appliance.

[0044] A first end 42 of the central pipe 40 is made so as to be closed. The opposite end 44 forms an outlet 46 which, in the assembled state, is in fluidic communication with the relief valve 30.

[0045] A peripheral wall 48 of the measuring tube 36, more precisely of the central pipe 40, has at least one, here several openings 50, 52, 54 arranged one behind the other according to the direction of flow R. A pressure measuring component 56, 58, 60 is attached to each of the openings 50, 52, 54.

[0046] Here, the pressure measuring components 56, 60 attached to the openings 50, 54 are pressure switches (also called pressure switches). Here, the pressure measuring component 58 attached to the opening 52 is a pressure sensor.

[0047] A number of openings 50, 52, 54 higher or lower could naturally be provided in the measuring tube, and / or other types of pressure measuring components could be attached to it.

[0048] The pressure measuring components 56, 58, 60 are used to monitor and / or control a pressure in the cooking space 18 when applying a pressure cooking function of the cooking appliance 10. All the pressure measuring components 56, 58, 60 are here connected to the control unit 16.

[0049] The two pressure switches are designed to open the relief valve 30 in the event of an overpressure exceeding predetermined values ​​in the cooking chamber 18. The respective pressure switches detect different overpressure values ​​(respectively, as the differential pressure between the environment and the cooking chamber 18 when the lid 20 is closed). One of the pressure switches is responsible for lowering the pressure in the cooking chamber 18 to an acceptable value when the lid 20 needs to be opened. The purpose of the other pressure switch is to maintain the internal pressure in the cooking chamber 18 below an permissible value.

[0050] The relief valve 30 is here capable of being electrically actuated and in particular of reacting by means of the control unit 16.

[0051] Each of the pressure measuring components 56, 58, 60 has a measuring chamber 62 which is closed to the inside of the central pipe 40 by a membrane 64.

[0052] This is shown in more detail in Figures 4 to 8.

[0053] The membrane 64 is respectively arranged in the area of ​​one of the openings 50, 52, 54.

[0054] As can be clearly seen in Figures 3 and 6, the diaphragm 64 of the pressure sensor, i.e. of the pressure measuring component 58, is directly inserted into the face of the opening 52, so that its peripheral edge 67 is flush with an edge 66 of the opening 52. A transition between the edge 66 of the opening, the diaphragm 64 and an inner peripheral side 68 of the peripheral wall 48 is made in a flat manner and without steps or undercuts.

[0055] A first retaining structure 70, which projects radially outwards from the edge 66 of the opening 52 and here forms a tube with a threaded opening, is formed on the measuring tube 36. A thread of the pressure sensor is screwed into this tube. The connection between the pressure sensor and the measuring tube 36 is sealed gas-tight by suitable sealing elements.

[0056] The pressure sensor together with the measuring chamber 62 and the diaphragm 64 is a prefabricated unit which is connected to the measuring tube 36 as a construction element.

[0057] Figure 4 shows a pressure switch using the example of the component pressure measurement 56. It is visible here that the diaphragm 64 is slightly offset axially towards the rear relative to a connecting piece 72.

[0058] It can be seen in [Fig. 8] that the transition from the edge 66 of the opening 50 through the connecting piece 72 to the diaphragm 64 is flat and without steps. This also applies to the opening 54 and the pressure measuring component 60.

[0059] A second retaining structure 74 (see also figures 5 to 10) on which the pressure measuring components 56, 60 are fixed is respectively arranged on the edge of the openings 50, 54.

[0060] The retaining structure 74 here comprises ribs 76 that project laterally and are connected to a transverse bar 78 (see Figures 5 and 7 to 10). A receiving space is thus formed between the ribs 76 and the transverse bar 78. This serves to receive an end zone 80 of a spring-loaded fastener 82 (see Figures 5, 7 and 8). The fastener 82 has two identical end zones 80 arranged opposite each other. The second end zone 80 is engaged in a recess 86 at the level of a collar 84 radially projecting from the respective pressure measuring component 56, 60. This is clearly visible in [Fig. 8].

[0061] For mounting the pressure measuring component 56, 60, it is placed together with its connecting piece 72 on the edge 66 of the opening 50, 54. A fastener 82 is mounted respectively on diametrically opposite sides so that their end areas 80 engage in the collar 84 and in the second retaining structure 74. Since the fastener 82 is made symmetrical with respect to its end areas 80, it is not necessary to take into account the orientation of the fastener 82 for mounting the pressure measuring components 56, 60 on the measuring tube 36.

[0062] A sealing element 87, here an O-ring, is arranged for sealing between the edge 66 of the respective opening 50, 54 and the pressure measuring component 56, 60 (see [Fig.5]).

[0063] For all pressure measuring components 56, 58, 60, the free surface of the membrane 64 has (at least for practical reasons) the same size and shape as the cross-sectional area of ​​the respective opening 50, 52, 54. The free diameter dM of the membrane 64 therefore corresponds to the diameter d0 of the respective opening 50, 52, 54 (sketched in figures 4 to 6).

[0064] Since different pressure measuring components 56, 58, 60 are used here, the diameters d0 of the openings 50, 52, 54 respectively associated and thus also the diameters dM of the membranes 64 of the individual pressure measuring components 56, 58, 60 can be different from each other.

[0065] The measuring tube 36 is here made in the form of an integral molded part by Plastic injection molding. The inlets 38, outlet 46, openings 50, 52, 54 and retaining structures 70, 74 are already made on the measuring tube 36 during the manufacturing process.

[0066] In this example, the diaphragm 64 is made of stainless steel. For the pressure measuring components 56, 60, it has, for example, a diameter of approximately 30 mm.

[0067] The central pipe 40 of the measuring tube 36 has a trapezoidal cross-section in this example (see, for example, Figures 5 and 7). The openings 50, 52, 54 are arranged on the flat face of the trapezoid. This ensures that the edge 66 of each of the openings 50, 52, 54 lies in a plane. This simplifies, on the one hand, the mounting of the pressure measuring components 56, 58, 60. On the other hand, it also simplifies the flat and stepless construction of the transition between the edge 66 and the diaphragm 64 on the respective pressure measuring component 56, 58, 60.Thanks to this cross-sectional shape, it is also ensured that a flow in the direction of flow R in the measuring tube 36 in the area of ​​the openings 50, 52, 54 adopts a higher velocity and that soils transported with the cooking space atmosphere flowing through the measuring tube 36 do not settle in the area of ​​the openings 50, 52, 54 and especially not on the membranes 64, but are carried away by the flow.

[0068] For use with the pressure cooking function of the cooking appliance 10, the appliance is heated, for example, by its heated base when the pan 12 is closed, so that the food being cooked in the pan 12 is also heated. When the respective lid 20 is closed, overpressure is produced in the cooking space 18 due to this temperature increase and the evaporation of water. The relief valve 30 is normally closed at this time.

[0069] The pressure in the cooking space 18 is continuously monitored by the pressure sensing means 26 for the cooking appliance, so that the cooking process can also be controlled according to the pressure by means of the control unit 16.

[0070] If, contrary to expectations, the pressure in the cooking space 18 is too high, one of the pressure switches of the pressure sensing device 26 for the cooking appliance is triggered and the relief valve 30 opens. Optionally, the relief valve 30 can also be opened below this maximum pressure if the pressure is higher than required for the cooking process or if the lid 20 needs to be opened. In this example, the second pressure switch of the pressure sensing device 26 for the cooking appliance is responsible for this and opens the relief valve 30 in this case. It is also possible to release the pressure via the pressure sensing device 26 for the cooking appliance and the relief valve. 30 during cleaning operations.

[0071] The pressure sensing means for cooking appliances described herein can of course be used in cooking appliances of a different type than that of the cooking appliance 10 described herein.

Claims

Demands

1. Pressure sensing means for a cooking appliance, comprising a measuring tube (36) for a cooking space atmosphere having at least one inlet (38) and at least one outlet (46) for the cooking space atmosphere, the measuring tube (36) having at least one opening (50, 52, 54) in a peripheral wall (48) to which a pressure measuring component (56, 58, 60) is attached, the pressure measuring component (56, 58, 60) comprising a measuring chamber (62) delimited by a membrane (64), and the membrane (64) being arranged in the area of ​​the opening (50, 52, 54).

2. Pressure sensing means for cooking appliance according to claim 1, a peripheral edge (67) of the diaphragm (64) being flush with an inner peripheral side (68) of the measuring tube (36) at the edge (66) of the opening (52).

3. Pressure sensing means for cooking appliance according to any one of the preceding claims, a transition between an edge (66) of the opening (50, 52, 54) on the inner peripheral side (68) of the measuring tube (36) and the diaphragm (64) being made without steps.

4. Pressure sensing means for cooking appliance according to any one of the preceding claims, the pressure measuring component (56, 58, 60) being a pressure sensor or a pressure switch.

5. Pressure sensing means for cooking appliance according to any one of the preceding claims, at least one pressure measuring component (56, 60) being attached to the measuring tube (36) by at least one fastener (82).

6. Pressure sensing means for cooking appliance according to claim 5, the attachment (82) having two identical end zones (80).

7. Pressure sensing means for a cooking appliance according to any one of the preceding claims, having at least one retaining structure (70, 74) made on the measuring tube (36), on which a pressure measuring component (56, 58, 60) can be fixed and together with all the retaining structures (70, 74) form the measuring tube (36) as a single unit.

8. A pressure sensing means for a cooking appliance according to any one of the preceding claims, the measuring tube (36) having a trapezoidal cross-section, and the opening (50, 52, 54) being fitted into a flat lateral face on the inner peripheral side (68) of the measuring tube (36).

9. Cooking appliance comprising a pressure sensing means for a cooking appliance according to any one of the preceding claims, the outlet (46) of the measuring tube (36) being in fluidic communication with a relief valve (30) which is suitable for venting the atmosphere from the cooking space to the outside.

10. Cooking appliance according to claim 9, the relief valve (30) being integrated into a hollow pivot axis of a cover (20) of the cooking appliance (10), and the measuring tube (36) being attached to a conduit in fluidic communication with the relief valve (30) in the pivot axis of the cover (20).

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