EP2131111B1 - Method for manufacturing a hob and hob - Google Patents

Description

The invention relates to a method for producing a hob according to the preamble of claim 1.

In the production of hobs made of metal or plastic functional or design elements manufacturing technology with the simple z. B. bonded glass ceramic plate glued. It is known that in such non-porous materials, a silicone adhesive can be used, which can also act as a sealant with good adhesion in a dual function.

In a generic method for producing a hob, the functional or design element is glued to the hob plate by means of a first, heat-resistant adhesive in a gluing process.

A further processing of the cooktop panel after the bonding process can only be done after the heat-resistant adhesive has cured and thus the functional or design element is secured in place in its installed position. The curing phase can be up to two days in the case of a silicone adhesive, resulting in overall cycle times in the manufacturing process.

WO 2007/023183 A1 relates to a method of assembling a ceramic hob in an oven, comprising: a) providing a frame having a recess for the ceramic hob, the recess having a periphery and a bearing surface within the recess; b) comprising providing a dam on the support surface which extends continuously around the support surface at a height such that the hob has a spaced relationship between the lower surface of the hob and at least a portion of the support surface; c) positioning the hob within the recess in the frame, wherein the edge of the hob is spaced from the side walls of the frame; d) introducing a flowable, hardenable silicone between the side walls of the frame and the edge of the hob, allowing the silicone to sit down to provide a visible level seal between the frame and the hob.

DE 33 41 194 A1 relates to a method of making a cooktop, an apparatus for carrying out the method and a cooktop produced by the method. Such cooktops consist of a circulating, z. B. metallic frame and from an inserted into this frame and glued, or sealed at the joints cooking plate, z. B. glass ceramic hotplate. The gluing or sealing of the hotplate requires many operations, which must be carried out largely by hand, in particular with regard to the smoothing of the sealant at the upper edge of the joint. at DE 33 41 194 A1 At the joint area between frame and plate, a cavity closed at the upper edge of the joint by an elastic sealing bag is created, into which a flowable sealing material, eg by spraying, is introduced, which sealing material is subsequently solidified, eg by the action of heat.

DE 10 2006 037 241 A1 relates to a cooking appliance with at least one cooking plate and a frame member for supporting on a worktop, which is in contact with an upper surface of the cooking plate, wherein in the area of the plant a food-safe seal is arranged.

DE 198 54 229 A1 relates to a hob with a two-part frame, namely a mounting frame and an associated decorative frame, between which a hob plate, in particular made of glass ceramic is supported. In order to achieve a high positional accuracy of the hob plate relative to the frame during assembly of the hob, an elastic spacing means is arranged and compressed between the underside of the hob plate and a shoulder parallel to the mounting frame. In a side wall oriented perpendicular to the shoulder of one of the two frames openings are also provided in the respective lobes of the likewise oriented perpendicular to the shoulder side wall of the other of the two frames, whereby the target frame due to the bias of the elastic spacing means circumferentially substantially gap-free the hob plate is applied.

The object of the invention is to provide a method for producing a hob and a hob, which can be manufactured in a reduced cycle time.

The object is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the subclaims.

According to the characterizing part of claim 1, a second, in comparison to the first adhesive fast-curing hot melt adhesive is used in addition to the first adhesive. The second, fast-curing adhesive may preferably be during the curing phase secure the functional or design element stationary in its installed position of the first adhesive. In this way, after the not yet cured first, heat-resistant adhesive is applied, carried out immediately further processing of the hob plate. A time-consuming intermediate storage of the hob until the end of the Aushärtphase the first, heat-resistant adhesive is therefore eliminated.

The first heat-resistant adhesive may preferably be a silicone adhesive. This is known to have a good fatigue strength under compressive or tensile loads and good adhesion to non-porous materials such as glass, metal or plastic. Another advantage of the silicone adhesive is its great elasticity, so that it can be used in a double function as a sealant between the functional and design element and the hob plate. However, the curing phase of a silicone adhesive may be up to 48 hours.

According to the invention, in contrast to such a silicone adhesive, the second, in comparison to the first adhesive fast-curing adhesive is a hot melt adhesive which is solid at room temperature and can be processed by melting. The hot adhesive melt is applied to the part to be bonded and immediately joined with a second part. Immediately after cooling and solidification of the hot melt adhesive, the compound is solid and functional. Such hot melt adhesives are often referred to as "hotmelts". The curing phase of such a hotmelt adhesive is limited to a few seconds, within which period of time the hot melt adhesive between the joined parts cools down again.

In a first step of the joining process, both the first and the second adhesive are applied to at least one of the contact surfaces of the functional or design element and the hob plate. When using a hot melt adhesive as the second adhesive, it is applied to the respective contact surface at correspondingly high processing temperatures. Subsequently, the contact surfaces of the functional or design element and the hob plate are joined together, that is, if necessary, pressed together under pressure load in abutment. After just a few seconds, the fast-curing second adhesive secures the functional or design element stationary in its installed position, while the first, slow-curing and heat-resistant adhesive still hardens and still provides a reduced adhesive strength.

Preferably, the first and second adhesives are applied to juxtaposed splices of the respective contact surface of the functional or design element or the hob plate. The application of the two adhesives on the contact surface can be done in a joint step.

Mixing of the applied first and second adhesives may possibly impair their heat resistance, curing time or adhesive strength properties. Preferably, therefore, provided on at least one contact surface first and second splices for each of the first and second adhesive over a molding threshold or over a free distance can be separated from each other to avoid mixing of both adhesives largely.

The form threshold acts as a separator, which may be a separate component or integrated in the functional or design element. In terms of manufacturing technology, it is preferred if the forming threshold is integrated in the same way as the material and / or in one piece in the contact surface of, in particular, the functional and design element. Such a shape threshold can be easily realized in particular in the design of the functional and design element as a sheet metal bent part. In this case, the forming threshold can be, for example, a gradation or bending edge provided between the splices. Notwithstanding this, the forming threshold may be any irregularity in the contact surface which hinders mixing of the two adhesives.

During the joining process, it is important that in particular the first, heat-resistant adhesive is arranged after the joining process with a predetermined material thickness between the functional or design element and the hob plate. Against this background, the adhesive patch associated with the first adhesive, such as by virtue of the stepping threshold, may be set back by a height difference above the second adhesive patch to which the second, fast curing adhesive is applied. By means of this height difference, the material thickness of the second adhesive can be determined.

In a special embodiment, the functional or design element can be a frame strip which can be glued as edge protection on the side edges of the hob plate. In particular, in this case, the first adhesive may be strip-shaped, introduced as a sealing strip between the functional and design element and the hob plate. In contrast, the second, fast-curing adhesive can be applied with reduced material costs in separate adhesive points. These may extend along the strip-like applied first adhesive. In this case, the first, heat-resistant adhesive may preferably be arranged between an outer edge region of the functional and design element and the second, fast-curing adhesive.

Such an adhesive arrangement is particularly advantageous when using a hot melt adhesive as a second, fast-curing adhesive. Namely, such a hot-melt adhesive behaves reversibly, that is, the adhesive melts at temperature increases during the hob operation. In the case mentioned above, the first, heat-resistant adhesive acts as a further molding threshold, which prevents the reversible hot-melt adhesive from flowing off.

Hereinafter, an embodiment of the invention with reference to the accompanying figures will be described.

Fig. 1

in einer perspektivischen Ansicht von unten eine Kochfeldplatte für ein Kochfeld mit daran verklebten Funktions- und Designelementen;

Fig. 2

in einer perspektivischen Darstellung als Funktions- oder Designelement eine mit der Unterseite der Kochfeldplatte verklebbare Haltekonsole; und

Fig. 3

in einer schematischen Perspektivdarstellung ein Funktions- und Designelement als eine mit dem Rand der Kochfeldplatte verklebte Rahmenleiste.

Show it:

Fig. 1

in a perspective view from below a hob plate for a hob with glued functional and design elements;

Fig. 2

in a perspective view as a functional or design element a glued to the underside of the hob plate holding bracket; and

Fig. 3

in a schematic perspective view of a functional and design element as a glued to the edge of the hob frame strip.

In the Fig. 1 a hob plate 1 is shown in a view from below, which may be here by way of example a glass ceramic plate or a hard glass plate for a gas hob.

The hob plate 1 therefore has mounting holes for carrying not shown gas burner and / or control knob. With the hob plate 1 also different functional and design elements are glued. Thus, the hob plate 1 on its underside 3 distributed holding brackets 5. These protrude in the installed state in a housing interior of the hob and can be bolted by means of a clamping bolt with a hob base to brace the hob plate 1 with the hob bottom.

On the edge side, the hob plate 1 as edge protection in each case frame strips 7, which are also glued to the hob plate 1 as the holding brackets 5. In addition, in the depth direction y rear provided retaining strip 9 is glued to the underside 3 of the hob plate 1.

In the production of the hob, the functional or design elements 5, 7, 9 to be glued are first of all pre-positioned in the correct position in a mounting device, not shown, in a joining process.

According to the invention, the functional and design elements 5, 7, 9 thus prepositioned are adhesively bonded to the cooktop panel 1 by means of second adhesives 11, 13 having different properties Fig. 2 is applied as a strip-shaped adhesive layers on the holding bracket 5. By way of example, here is the first adhesive 11, a heat-resistant silicone adhesive, which has good elasticity with high elasticity, but is slow-curing, that is, only after a long Aushärtphase reaches its final adhesion. The second adhesive 13, in contrast, is a fast-curing hot melt adhesive, which is also known by the name "hotmelt". The hotmelt adhesive 13 is solid at room temperature and can only be processed by melting at high processing temperatures. The hot-melt adhesive 13, in contrast to the silicone adhesive, although solid and functional immediately after its cooling, but only to a limited extent heat-resistant. That is, in a subsequent cooktop operation, the hot melt adhesive 13 would soften again during temperature increases, so that in this case it has only limited adhesion.

Subsequently, the joining process will first be explained with reference to the retaining brackets 5, of which a retaining bracket 5 of the Fig. 2 shown in isolation. The retaining bracket 5 is a known strip-shaped sheet metal blank having a U-shaped profile. The holding bracket 5 is formed with a, a passage opening 15 having support base 17, which is spaced in the installed position of the hob plate 1 and are pulled up from the two side walls 19. At the upper free ends of the side walls 19 outwardly angled mounting flanges 21 are provided, the tops of each form contact surfaces 23 which are glued to the bottom 3 of the hob plate 1. In the installed position of the retaining bracket 5, a clamping bolt, not shown, may be guided through the passage opening 15 of the retaining bracket 5, the bolt head is supported on the support base 17. The hob plate 1 can thus be screwed on the clamping bolt with the hob bottom.

Like from the Fig. 2 It can also be seen that in the mounting flanges 21 of the holding brackets 5 are each a gradation 25 formed, which divides the contact surfaces 23 each in an outer first splice 27 for the silicone adhesive 11 and an inner second splice 29 for the hot melt adhesive 13. The gradation 25 acts here as a forming threshold, which largely prevents mixing of the two adhesives after application of the two adhesives 11, 13 to the associated splices 27, 29.

The two first, outer splices 27 of the holding bracket 5 are reset by means of the gradation 25 over a height difference .DELTA.h relative to the second splice 29.

During the joining process, the in the Fig. 2 shown retaining bracket 5 inserted into the mounting device and pre-positioned therein. Thereafter, the silicone adhesive 11 is applied to its associated splice 27 in a first step. In the same way, the hot-melt adhesive 13 is applied to its associated second splices 29. In a subsequent step, the hob plate 1 is pressed with the bottom 3 in pressure system with the contact surfaces 23 of the holding bracket 5. The pressure force is released again after 20 to 30 seconds. Both the duration and the magnitude of the compressive force can vary depending on the geometry of the parts to be bonded.

Due to the height difference Δh between the first and second splices 27, 29, the material thickness of the silicone adhesive 11 is fixed to the sum of the material thickness of the second adhesive 13 and the height difference Δh of the gradation. If the contact surface 23 is in direct contact with the cooktop plate 1 after the printing system, the material thickness of the silicone adhesive 11 is set to Δh.

Parallel to the pre-positioning of the retaining brackets 5 and the frame strips 7 and the retaining strip 9 are pre-positioned in the mounting device. Is exemplary in the Fig. 3 in an enlarged partial view already glued to the hob plate 1 frame strip 7 shown. The frame strip 7 is made as a metal part with an angular profile and glued here by way of example with a mounting leg 31 with the bottom 3 of the hob plate 1. The adhesive points for the silicone adhesive 11 and for the hot melt adhesive 13 are not separated by a forming threshold, but over a free distance a from each other, which largely prevents mixing of the two adhesives 11, 13.

According to the Fig. 3 the silicone adhesive 11 is provided in the manner of a sealing strip between an outer edge 33 of the frame strip 7 and the hob plate 1. The silicone adhesive 13 additionally serves as a sealant, which seals a joint between the hob plate 1 and the frame strip 7.

In contrast to the continuously applied silicone adhesive 11, the hot-melt adhesive 13 is applied intermittently on the contact surface of the fastening flange 31 in separate adhesive points.

Between the hot melt adhesive 13 and the outer edge 33 of the frame strip 7 is according to the Fig. 3 the silicone adhesive 11 is arranged. The silicone adhesive 11 serves as an additional form of threshold, which prevents, for example, in hob operation at elevated temperatures, a flow of the hot melt adhesive 13 from the joint between the frame strip 7 and the hob plate 1.

LIST OF REFERENCE NUMBERS

1

Hotplate

3

Bottom of the hob plate 1

5

retaining bracket

7

frame strip

9

retaining strip

11

first adhesive, silicone adhesive

13

second adhesive, hot melt adhesive

15

Through opening

17

support base

19

side walls

21

mounting flanges

23

contact surfaces

25

gradation

27

first splices

29

second splices

31

fastening leg

33

Outer edge region

a

free distance

.delta.h

height difference

y

Bautiefenrichtung

Claims (12)

1. Method for manufacturing a hob, in which in a joining process at least one function or design element (5, 7, 9) is glued to a hob plate (1) by means of a first, heat-resistant adhesive (11), wherein in addition to the first adhesive (11) a second adhesive (13) is used, which sets more quickly than the first adhesive (11), and the second fast-setting adhesive (13) positionally secures the function or design element (5, 7, 9) in its mounting position at least during a setting phase of the first adhesive (11), characterised in that in a first work step both the first and the second adhesive (11, 13) are applied to at least one of the contact surfaces (23) of the function or design element (5, 7, 9) and of the hob plate (1), and in a second work step the contact surfaces (23) are pressed so as to lie against one another.
2. Method according to claim 1, characterised in that the first, heat-resistant adhesive (11) is a silicone adhesive.
3. Method according to claim 1 or 2, characterised in that the second, fast-setting adhesive (13) is a hot-melt adhesive.
4. Method according to one of the preceding claims, characterised in that the first and second adhesives (11, 13) are applied to adjacently arranged bonding surfaces (27, 29) of the respective contact surface (23) of the function or design element (5, 7, 9) or of the hob plate (1).
5. Method according to one of the preceding claims, characterised in that the first bonding surface (27) provided for the first adhesive (11) and the second bonding surface (29) provided for the second adhesive (13) are separated from one another by a free distance (a).
6. Method according to one of claims 1 to 4, characterised in that the first bonding surface (27) provided for the first adhesive (11) and the second bonding surface (29) provided for the second adhesive (13) are separated from one another by a moulded threshold (25).
7. Method according to claim 6, characterised in that the moulded threshold (25) is integrated into the contact surface (23) of in particular the function and design element (5, 7, 9) by being composed of a single material and/or by being formed integrally.
8. Method according to claim 6 or 7, characterised in that the moulded threshold (25) is a graduation, bending edge or the like provided between the bonding surfaces (27, 29).
9. Method according to one of the preceding claims, characterised in that the bonding surface (27) associated with the first adhesive (11), for example by means of the graduation (25), is recessed by a height difference (Δh) compared to the bonding surface (29) associated with the second adhesive (13), said height difference (Δh) essentially determining a material strength of the second adhesive (13).
10. Method according to one of the preceding claims, characterised in that the first adhesive (13) is introduced in the form of a strip, in particular as a sealing strip, between the function or design element formed in particular as a frame strip (7) and the hob plate (1).
11. Method according to claim 10, characterised in that the second adhesive (13) is applied discontinuously in bonding points separate from one another which extend along the first adhesive (11) applied in the form of a strip.
12. Method according to one of the preceding claims, characterised in that the first, heat-resistant adhesive (11) is applied between an outer edge (33) of the function and design element (5, 7, 9) and the second, fast-setting adhesive (13) recessed in respect of the outer edge (33).

Images