Household microwave oven with microwave trap and method for its manufacture

Description

[0001] The invention relates to a household microwave appliance according to claim 1.

[0002] The invention also relates to a method for producing a microwave trap of a household microwave appliance according to claim 12.

[0003] The basic forms of shielding devices in household microwave ovens, based on the basic principle of a quarter-wave trap, have long been known and are adopted virtually unchanged from one generation of appliances to the next. Typical examples are traps that extend into the cooking chamber, as described in DE 33 287 48 A1. Also common are variants positioned behind an inner glass pane of a cooking chamber door, see, for example, EP 1 426 692 A1 or DE 28 536 16 A1.

[0004] The most common variant, which is also the simplest and cheapest to manufacture, involves a trap structure on the outer edge of the cooking chamber door, which is covered with a microwave-transparent material to protect it from damage and contamination. This trap structure has been known for a long time, for example, from US 2011 / 0290230 A1 and US 5,973,305.

[0005] EP 3 358 908 A1 (GORENJE GOSPODINJSKI APARATI DD [SI]) 8 August 2018 (2018-08-08) discloses the features of the preamble of claim 1.

[0006] Fig.1 shows, as a sectional side view, a sketch of the basic structure of a household microwave appliance in the form of a microwave cooking appliance 101 of the latter variant. The microwave cooking appliance 101 has a cooking chamber 102 capable of receiving microwaves, the loading opening 103 of which can be closed by means of a microwave-tight door 104. To prevent microwaves from passing through a gap between the door 104 and a flange 105 surrounding the loading opening 103, the door 104 is provided around its edge with a microwave trap 106 in the form of a quarter-wave trap. The microwave trap 106 is protected here by a cover 107 made of a microwave-transparent material, e.g., plastic. The microwaves are generated by a microwave generator 108 and guided into the cooking chamber, e.g. via a rotating antenna 109. The "working frequency" of the microwaves generated by the microwave generator 108 can, for example,2.45 GHz ± 20 MHz or, more rarely, between 902 MHz and 928 MHz.

[0007] To manufacture the microwave trap 106, a bending process is typically used to bring it into the desired shape. Fig.2 shows a plan view of a section of a sheet metal part 110 with three parallel bending lines B1 to B3 drawn in to create the microwave trap 106. Fig.3 shows an oblique view of a section of the finished microwave trap 106. The sheet metal part 110, which is still flat at least in one edge region R before the start of the bending process, has a free edge 111 running along a longitudinal extent x, from which a series of equidistant recesses ("tooth recesses" or "tooth gaps") 112 protrude, in particular perpendicularly, into the sheet metal part 110. The tooth recesses 112 of length L3 can be created, for example, by punching, laser cutting, etc. The tooth recesses 112 create teeth 113 of length L2 between them or separate teeth 113 from one another. The length L2 can be determined at the free edge 111, at a first bending line B1 closest to the free edge 111, or at a second bending line B2 next but one from the free edge 111. A length L2 of teeth 113 is typically in a range between 1.5 cm and 3 cm.

[0008] While the first bending line B1 and the second bending line B2 run parallel to the longitudinal extension x through the tooth recesses 112 and teeth 113, a third bending line ("main bending edge") B3 runs behind the tooth recesses 112 and teeth 113 from the perspective of the free edge 111.

[0009] A series of equidistant slots ("bending slots") 114 runs along the main bending edge B3. The bending slots 114 are aligned along the longitudinal direction x and are located on the same longitudinal section as the teeth 113, which is Fig.1 for a bending slot 114 is indicated by the two transverse lines in the longitudinal direction x. This can also be expressed as the bending slots 114 being arranged parallel to the teeth 113 with respect to the longitudinal extent x. Typically, L1 = L2 applies, meaning that the bending slots 114 are as long as the teeth 113, i.e., 1.5 cm to 3 cm. The bending slots 114 thus interrupt the material of the sheet metal part 110 in the area of ​​the teeth 113. Without these slots or bending slots 114, a bending process would be technically difficult to implement due to the continuous material at the main bending edge B3.

[0010] Fig.4A shows the sheet 110 as a sectional view through a tooth 113 in side view before the edge bending to form the microwave trap 106. Fig.4B shows the sheet 110 as a sectional view in side view after bending along the first bending line B1 by -90° (ie, viewed vertically counterclockwise). Fig.4C shows the sheet 110 as a sectional view in side view after a subsequent bending along the second bending line B2 by -90°. Fig.4D shows the sheet metal 110 as a sectional side view after subsequent bending along the main bending edge B3 by -90°. The bent teeth 113 can also be referred to as "septal teeth" in their resulting shape.

[0011] The disadvantage of a microwave trap 106 resulting from this bend(s) has been found to be that it often cannot satisfactorily fulfill its purpose of achieving microwave tightness in the door gap of the door 104, but rather the leakage rate is significantly (e.g., by a factor of 10) higher than would be expected from simulations and experience. The reason for this was previously unknown.

[0012] It is the Aufgabe The present invention aims to at least partially overcome the disadvantages of the prior art and, in particular, to provide a microwave trap with teeth produced by bending a sheet metal part in a structurally simple manner, which shows improved microwave tightness.

[0013] This object is achieved according to the features of the independent claims. Advantageous embodiments are the subject of the dependent claims, the description, and the drawings.

[0014] The problem is solved by a household microwave appliance according to claim 1.

[0015] This household microwave oven offers the advantage that a structurally simple, practically cost-neutral modification of the bending slots can significantly improve microwave sealing, or the achieved microwave sealing is close to the values ​​calculated from conventional simulations, thus eliminating the need for complex, non-targeted modifications to the dimensions of the teeth and recesses. The effective microwave sealing also advantageously allows for more metallic components to be planned in the immediate vicinity of the trap, or for previously required distances to the microwave trap to be reduced.

[0016] The modification of the bending slots is based on the surprising discovery that conventional bending slots cause, on the one hand, a noticeable shift in the effective frequency of the microwave trap and, on the other hand, a noticeably increased field leakage to neighboring metal parts. Commercial microwave devices have an operating frequency of 2.45 GHz ± approx. 20 MHz. To achieve a high shielding effect, the effective frequency of the microwave trap should be in the same frequency range as the operating frequency. If the microwave trap is designed for microwave technology without taking the bending slots into account, the actual effective frequency will deviate from the calculated / expected effective frequency. It has been shown that conventional bending slots result in a frequency deviation of the effective frequency, which increases the leakage radiation on average by a factor of approximately 10.To achieve a microwave trap with low leakage radiation in practice, the dimensions of the teeth are modified through laborious trial and error until the effective frequency of the microwave trap is at the desired value. The introduction of the webs according to the invention significantly reduces the undesirable shift in the effective frequency, thus eliminating the need for complex experiments to dimension the teeth. In particular, the effective frequency can be precisely predicted through simulations that take the bending slots and webs into account.

[0017] A further negative effect occurs due to evanescent microwave fields. Since even the conventional bending slot is impermeable to microwave radiation, the electromagnetic microwave field on the outside of the door behind the bending slot drops exponentially in strength and can no longer propagate. However, if there is an electrically conductive component on the outside of the door in the immediate vicinity of a bending slot, the evanescent field can couple into this component, so that it now acts as an antenna. Microwaves can then radiate again in the form of locally greatly increased leakage radiation. Such metallic components are frequently found in practical doors, for example in the form of a hinge or other fastening device on the door. The occurrence of such evanescent fields orThe evanescent field coupling on the outside of the bending slots cannot be influenced by varying the geometry of the teeth, since a frequency mismatch is not the cause of the occurrence of the evanescent fields. Thus, the only solution to date has been to keep critical metal parts away from the outside of the bending slots, which can be functionally disadvantageous and / or structurally complex. It has now been shown that inserting a web into the bending slot largely suppresses the coupling of evanescent fields on the outside of the bending slots and thus virtually prevents the escape of leakage radiation.

[0018] The household microwave appliance can, in particular, be a microwave cooking appliance. The household microwave appliance can be a standalone microwave appliance or a microwave combination appliance, for example, a microwave appliance with an additional IR heat source (e.g., at least one resistance heating element) and / or steam treatment functionality. In a further development, the household microwave appliance can be an oven with microwave functionality.

[0019] The microwave treatment chamber is capable of handling microwaves. In the case of a microwave cooking appliance, it can also be referred to as the cooking chamber. The loading opening is, in particular, a front-facing loading opening. The door is microwave-tight.

[0020] The fact that a row of teeth is spaced apart from the main bending edge means that the teeth, or the recesses / gaps separating the teeth, do not extend to the main bending edge. Rather, there is a continuous strip of material in the longitudinal direction or lengthwise extension between the main bending edge and the teeth.

[0021] A bending slot can generally be understood as a material weakening (e.g. an opening or a hole) in the sheet metal part, which lies at least partially on the main bending edge or which is arranged at the main bending edge. The bending slot can be designed, for example, as a hole with a straight, oval, rectangular, circular, or polygonal contour. In a further development, the bending slot is at least as long (along the extension of the main bending edge) as it is wide (transverse to the extension of the main bending edge). In a further development, the bending slot is longer than it is wide, in particular at least twice as long.

[0022] It is a further development that all bending slots have the same shape and / or size. It is a further development that at least two bending slots have a different shape and / or size from each other.

[0023] The shape of the web can also be varied, e.g., rectangular, concave, convex, polygonal, etc., perpendicular to the main bending edge. The key function is to provide an electrically conductive connection for bridging the bending slot.

[0024] For implementing a bend along the main bending edge while ensuring high mechanical stability, it is advantageous for the bending slots to be arranged parallel to the teeth. This means that each of the bending slots is located entirely along a longitudinal section of the main bending edge, which is also covered by the corresponding tooth. In other words, the bending slot is then located within the longitudinal section of the corresponding tooth. In this case, if a length of the bending slot is designated L1 and a length of the corresponding tooth is designated L2, the condition L1 ≤ L2 applies.

[0025] A further development is that no bending slots are arranged in a longitudinal section of a recess, which offers the advantage that leakage radiation caused by evanescent fields can be reduced particularly effectively, since bending slots are omitted in the recess area. This is not critical from a material engineering perspective because material bent in the recess area can deform relatively easily due to its short distance from a free edge.

[0026] In general, however, a bending slot can also extend beyond the longitudinal section of the associated tooth, in one or both longitudinal directions, but in particular not to the adjacent tooth or to the longitudinal section covered by an adjacent tooth. In general, L1 = L2 ± 10% can advantageously apply.

[0027] It is a further development that L1 and / or L2 are in a range [1.5 cm; 3 cm].

[0028] A length L3 of a recess can advantageously be between 0.4·L2 and 0.6·L2, in particular approximately 0.5·L2.

[0029] The fact that a bending slot is interrupted by a web includes or means in particular that the web crosses the bending slot.

[0030] One design is that several, in particular all, bending slots are interrupted by at least one web. This effectively reduces the leakage rate for particularly long sections of the door gap, especially along the entire circumference of the loading opening or door gap.

[0031] In one embodiment, the length of the slot sections separated by the at least one web is less than 1 cm, in particular not greater than 0.95 cm, in particular not greater than 0.9 cm, in particular not greater than 0.85 cm, in particular not greater than 0.8 cm, in particular not greater than 0.75 cm. Surprisingly, it has been shown that noticeable evanescent microwave fields escape outward from a slot or slot section longer than 1 cm. However, shortening the slot section to less than 1 cm results in a significant reduction in the associated leakage rate, and at approximately 0.8 cm, the evanescent microwave fields are practically negligible. This provides the advantage that simply setting a slot length of less than 1 cm can significantly reduce the leakage rate. The bending slots can be arranged anywhere along the main bending edge, i.e., even parallel to tooth gaps, etc.However, it is particularly advantageous if the bending slots are arranged parallel to the teeth.

[0032] A possible further development, in the event that a length of the slot sections is less than 1 cm, is that the slot sections, in particular all of the slot sections, are arranged equidistantly along the main bending line, similar to a perforation. The distance between two adjacent slot sections of different bending slots corresponds to the distance between the slot sections of a common bending slot. This is particularly easy to implement in terms of manufacturing technology. It is advantageous if at least 75% of the length of the main bending edge is cut out or formed as slot sections parallel to a tooth, in particular at least 80%, in particular at least 85%, in particular at least 90%. It is also advantageous if no more than 95% of the length of the main bending edge is cut out or formed as slot sections parallel to a tooth.

[0033] It is an advantageous development for easy bending and insertion of the bending slots that the length of the slot sections is at least 0.5 cm.

[0034] One embodiment is that at least one of the bending slots is interrupted by exactly one web. This embodiment is particularly easy to implement. A further development is that exactly one web crosses the bending slot centrally, and the resulting slot sections separated by the web are of equal length. A further development is that all bending slots provided with at least one web are each interrupted by exactly one web.

[0035] In one embodiment, at least one of the bending slots is interrupted by a plurality of webs. This embodiment provides the advantage that the effective frequency of the microwave trap can be adjusted particularly closely to the effective frequency of a main bending edge that is unperforated or provided with bending slots. In another embodiment, the plurality of webs are arranged equidistantly in the bending slot, and the resulting slot sections separated by the web are therefore of equal length. In another embodiment, all bending slots provided with the at least one web are each interrupted by a plurality of webs.

[0036] A further development is that the web or webs of a bending slot are not centered or are all arranged equidistant from one another. This results in at least two slot sections of different lengths. This can be advantageous for further increasing the effectiveness of microwave shielding. It is therefore generally possible to design the slot sections of a bending slot created by the at least one web to be of equal or different lengths.

[0037] One embodiment provides that the at least one web has a length of at least approximately 2 mm. This has proven to be a particularly good compromise between increasing the effectiveness of microwave shielding and a mechanically robust and cost-effective design.

[0038] It is a design that the webs and slots are arranged cyclically along the entire bending edge - also in the area of ​​the recesses 112 - thus creating a continuous perforation.

[0039] In a further development, the tooth is a so-called "septal tooth." This allows for a particularly effective microwave trap. A septal tooth is understood, in particular, to be a tooth that, starting from the main bending edge toward the free edge, is bent twice in the same direction, specifically by at least approximately 90° or -90° each time. Therefore, starting from the main bending edge, the septal tooth has a U-shape, particularly in cross-section, with the section between the free edge and the adjacent first bending edge being shorter than the parallel section between the main bending edge and the adjacent second bending edge.

[0040] In one embodiment, the microwave trap is a part or region of a door of the household microwave appliance. Alternatively or additionally, the microwave trap can be a part or region of a flange covering the loading opening and thus the door when closed. In one embodiment, the microwave trap is produced by bending an edge region of a door panel or housing panel.

[0041] The problem is also solved by a microwave trap as described above. In this case, bending slots provided with webs are introduced into the sheet metal part, particularly along a designated main bending edge, parallel to a row of teeth arranged at the edge.

[0042] The object is also achieved by a door of a household microwave appliance and / or a flange of a household microwave appliance surrounding a loading opening, which are equipped with such a microwave trap.

[0043] The object is also achieved by a method for producing a microwave trap of a household microwave appliance from a sheet metal part, in which Bending slots provided with webs are introduced into the sheet metal part along a designated main bending edge, parallel to a row of teeth arranged at the edge, and the sheet metal part is bent at the main bending edge.

[0044] The process can be designed analogously to the household microwave oven, and vice versa, and has the same advantages.

[0045] The webs are created in particular by inserting the slot sections into the sheet metal part at a distance from one another, not by inserting the bending slots into the sheet metal part as one piece and then adding the webs again subsequently.

[0046] One embodiment provides for a sheet metal part used to manufacture the microwave trap to be additionally formed by deep drawing, e.g., advantageously, before and / or after the bending process for manufacturing the microwave trap. This provides the advantage that the sheet metal part can be formed into particularly complex shapes.

[0047] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an embodiment, which is explained in more detail in connection with the drawings. Fig. 1 shows a sectional side view of a sketch of the basic structure of a household microwave appliance in the form of a microwave cooking appliance with a microwave trap; Fig. 2 shows a plan view of a section of a sheet metal part from which a conventional microwave trap can be produced by bending; Fig. 3 shows an oblique view of a section of the finished conventional microwave trap; Figs. 4A to 4D show a sketch of the sheet metal part as sectional side views. Fig.3 in different stages of a bending process for the production of the microwave trap from Fig.3 ; Fig.5 shows a plan view of a section of a sheet metal part from which a microwave trap according to the invention can be produced by bending according to a first embodiment; Figs.6A and 6B show, as sectional views in side view, a sketch of the sheet metal part from Fig.5 in different sections of a bending process for producing the microwave trap according to the first embodiment of Fig.7 ; Fig. 7 shows an oblique view of a section of the finished microwave trap according to the first embodiment; Fig. 8 shows a plan view of a section of a sheet metal part from which a microwave trap according to the invention according to a second embodiment can be produced by bending; Fig. 9 shows an oblique view of a section of the finished, bent microwave trap according to the second embodiment; and Fig. 10 shows a plot of a microwave attenuation S21 in dB against a microwave frequency in GHz, plotted for microwave traps with septal teeth without bending slots, with a conventional bending slot and the bending slots according to the first and second embodiments.

[0048] Fig.5 shows a top view in a Fig.2 An analogous representation shows a section of a sheet metal part 3 that can be bent into a microwave trap 2. This microwave trap 2 can be installed in a microwave cooking appliance 1 instead of the conventional microwave trap 106. The microwave cooking appliance 1 can otherwise be constructed analogously to the conventional microwave cooking appliance 101.

[0049] Sheet metal part 3 differs from sheet metal part 110 in that the bending slots 4 are interrupted by a web 5 (also referred to as a "connecting web"), or a web 5 crosses the respective bending slot 4. This creates two slot sections 6a and 6b at the respective bending slot 4. Advantageously, the bending slot 4 can have one or more of the following properties: the bending slot 4 is located at the level of or in the longitudinal section of the tooth 113; the length L1 of the bending slot 4 lies in a range L2 ± 10%, in particular between [0.9 L2; L2]; the bending slot 4 is arranged symmetrically (i.e., not offset with respect to the longitudinal extent x) to the tooth 113; the length of the bending slot 4 lies in a range [1.5 cm; 3 cm]; a length L4 of the web 5 lies in a range [1 mm; 3 mm], in particular 2 mm; the web 5 crosses the bending slot 4 centrally, resulting in equal lengths L1-1 and L1-2 of the two slot sections 6a and 6b, respectively; the lengths L1-1 and L1-2 of the two slot sections 6a and 6b, respectively, are each no more than 0.9 cm, in particular no more than approximately 0.8 cm.

[0050] In particular, all bending slots 4 can have the same properties. Alternatively, one, several, or all bending slots 4 can have at least one property that differs from these properties. For example, the web 5 can cross one, several, or all bending slots 4 off-center, in which case the two slot sections 6a and 6b have different lengths L1-1 and L1-2, respectively.

[0051] The length L3 of the recess 112 can advantageously be between 0.4·L2 and 0.6·L2, in particular approximately 0.5·L2.

[0052] Fig.6A shows in a Fig.4A analogous representation of the sheet 3 as a sectional view through a tooth 113 before the edge bending to form the microwave trap 2.

[0053] Here, before the bending process began, sheet metal part 3 was deep-drawn, creating a deep-drawn step TS running in the longitudinal direction x at the edge region R. Deep-drawing does not require bending slots.

[0054] Based on the Fig.6A In the state shown, the sheet metal part 3 can be processed analogously to the Fig.4A bis Fig.4D be bent, which allows you to Fig.6B The microwave trap 2 shown is obtained. The section between the two bending lines B1 and B2 is particularly shallow to the plane of the sheet metal part 3 behind the step TS. In other words, the section between the second bending line B2 and the main bending edge B3 extends over the same height as the step TS.

[0055] Fig.7 shows in a Fig.5 analog representation of a section of the microwave trap 2.

[0056] Fig.8 shows in a Fig.5 An analogous representation shows a section of a sheet metal part 9 that can be bent into a microwave trap 8. This microwave trap 8 can also be installed in a microwave cooking appliance 7 instead of the conventional microwave trap 106. The microwave cooking appliance 7 can otherwise be constructed analogously to the conventional microwave cooking appliance 101 or the microwave cooking appliance 1.

[0057] Sheet metal part 9 differs from sheet metal part 110 in that the bending slots 10 are interrupted by two webs 5, or two webs 5 cross the bending slot 4 at a distance from each other. This creates three slot sections 11a, 11b, and 11c. Advantageously, the bending slot 10 can have one or more of the following properties: the bending slot 10 is located at the level of or in the longitudinal section of the tooth 113; the length L1 of the bending slot 10 lies in a range L2 ± 10%, in particular between [0.9 L2; L2]; the bending slot 10 is arranged symmetrically (ie, not offset with respect to the longitudinal extent x) to the tooth 113; the length of the bending slot 10 lies in a range [1.5 cm; 3 cm]; a length L4 of the respective webs 5 lies in a range [1 mm; 3 mm], in particular 2 mm; the webs 5 cross the respective bending slot 10 equidistantly; the lengths L1-1 and L1-2 of the two slot sections 6a and 6b are each no more than 0.9 cm, in particular no more than approximately 0.8 cm.

[0058] In particular, all bending slots 10 can have the same properties. Alternatively, one, several, or all bending slots 10 can have at least one property that differs from these properties. For example, the webs 5 can cross one, several, or all bending slots 10 non-equidistantly, in which case at least two of the three slot sections 11a, 11b, and 11b have different lengths L1-1, L1-2, and L1-3, respectively.

[0059] The length L3 of the recess 112 can advantageously be between 0.4·L2 and 0.6·L2, in particular approximately 0.5·L2.

[0060] Fig.9 shows in a Fig.7 analog representation of a section of the microwave trap 8.

[0061] Fig.10 shows a plot of a microwave attenuation S21, which represents the ratio of the field strengths of the microwave field inside and outside the cooking chamber 102, in dB against a microwave frequency in GHz, plotted for microwave traps 106, 4 and 8 with septal teeth 113 without bending slots (solid curve K1), with a conventional bending slot 114 (solid curve K2) and the bending slots 4 (dotted curve K3) and 10 (dashed curve K4) according to the first and second embodiments of the invention, respectively.

[0062] In previous simulations of the microwave trap, the bending slots were not included in the simulation and were ignored. In the corresponding attenuation curve K1, the attenuation minimum is located at approximately 2.48 GHz.

[0063] If conventional bending slots 114 are included in the simulation, the attenuation minimum shifts by more than 100 MHz, as shown in attenuation curve K2. Such a deviation results in a noticeably increased leakage rate, assuming a microwave frequency of approximately 2.48 GHz in the microwave treatment chamber. The leakage rate is then typically increased by a factor of approximately 10.

[0064] By inserting even just one web 5 into the bending slots 4, the attenuation minimum closely approximates the case without bending slots, for example, at approximately 2.46 GHz in attenuation curve K3. This frequency corresponds to a desired target operating frequency for the example shown. This effectively reduces the leakage rate.

[0065] By inserting two webs 5 into the bending slots 10, the damping minimum is brought even closer to the case without bending slots (see damping curve K4).

[0066] The above simulations were performed for a typical microwave frequency range of approximately 2.46 GHz ± 20 MHz. The specific target frequency range depends on the specific properties of the cooking appliance and the microwave generator. Similar results were obtained for an operating range between 902 MHz and 928 MHz.

[0067] Of course, the present invention is not limited to the embodiment shown.

[0068] The teeth can also have different shapes, for example, L-shaped or straight in cross-section. Furthermore, they can have a non-rectangular shape transverse to the bending lines, e.g., wavy or conical, etc.

[0069] In general, "a", "an", etc., can be understood as a singular or a plural, in particular in the sense of "at least one" or "one or more", etc., unless this is explicitly excluded, e.g. by the expression "exactly one", etc.

[0070] A numerical value may also include the exact number stated as well as a usual tolerance range, as long as this is not explicitly excluded. Bezugszeichenliste

[0071] 1Microwave cooking appliance 2Microwave trap 3Sheet metal part 4Bending slot / microwave trap 5Web 6aFirst slot section 6bSecond slot section 7Microwave cooking appliance 8Microwave trap 9Sheet metal part 10Bending slot 11aFirst slot section 11bSecond slot section 11cThird slot section 101Microwave cooking appliance 102Cooking chamber 103Loading opening 104Door 105Flange 106Microwave trap 107Cover 108Microwave generator 109Rotating antenna 110Sheet metal part 111Free edge 112Recess 113Tooth 114Bending slot fMicrowave frequency B1-B3Bending lines K1-K4Attenuation curves L1Length of the bending slot 4 L1-1Length of the first Slot section L1-2Length of the second slot section L1-3Length of the third slot section L2Length of the tooth L3Length of the recess L4Length of the web RRedge area S21Microwave transmission TSDeep-drawn step xLongitudinal extension

Claims

1. Household microwave appliance (1; 7), having a microwave treatment chamber (102), the loading opening (103) of which can be closed by means of a door (104) of the household microwave appliance (1; 7), and at least one microwave trap (2; 8) for preventing microwaves escaping when the door (104) is closed, wherein - the microwave trap (2; 8) is a bent sheet-metal component (3; 9) with a main bending edge (B3), which is adjoined by a row of teeth (113) at a distance, - a row of bending slots (4; 10) is present in the main bending edge (B3), characterised in that - the bending slots (4; 10) are arranged parallel to the teeth (113) and - the bending slots (4; 10) are each interrupted by at least one web (5).

2. Household microwave appliance (1) according to one of the preceding claims, wherein a length (L1-1, L1-2, L1-3) of the slot sections (6a, 6b; 11a, 11b, 11c) separated by the at least one web (5) is not greater than 1 cm, in particular not greater than 0.9 cm, in particular not greater than 0.8 cm.

3. Household microwave appliance (1) according to one of the preceding claims, wherein at least one of the bending slots (4) is interrupted by precisely one web (5).

4. Household microwave appliance (1) according to claim 3, wherein the web (5) traverses the associated bending slot (4) centrally.

5. Household microwave appliance according to claim 3, wherein the web (5) traverses the associated bending slot (4) eccentrically.

6. Household microwave appliance (7) according to one of the preceding claims, wherein at least one of the bending slots (10) is interrupted by multiple webs (5).

7. Household microwave appliance (7) according to claim 6, wherein the webs (5) traverse the associated bending slot (10) equidistantly.

8. Household microwave appliance (7) according to claim 6, wherein the webs (5) traverse the associated bending slot (10) non-equidistantly.

9. Household microwave appliance (1; 7) according to one of the preceding claims, wherein the at least one web (5) has a length in each case of at least approximately 2 mm.

10. Household microwave appliance (1; 7) according to one of the preceding claims, wherein a bending slot (4; 10) is arranged completely inside a longitudinal section of a tooth (113) arranged in parallel thereto.

11. Method for the production of a microwave trap (2; 8) of a household microwave appliance (1; 7) from a sheet-metal component (3; 9), in which - bending slots (4; 10), each provided with at least one web (5), are made in the sheet-metal component (3; 9) along an intended main bending edge (B1) at a distance from a row of teeth (113) arranged on the remote edge and - the sheet-metal component (3; 9) is bent at the main bending edge (B3).

12. Method according to claim 11, in which the sheet-metal component (3; 9) is additionally reshaped by deep drawing.

13. Method according to one of claims 11 to 12, in which the slot sections (6a, 6b; 11a, 11b, 11c) separated by the at least one web (5) with a length (L1-1, L1-2, L1-3) along the main bending edge (B3) of not more than 0.9 cm, in particular of not more than 0.8 cm, are made in the sheet-metal component (3; 9).