CN209498594U - A kind of low temperature smoking set in parallel being layered heat radiating structure and its application - Google Patents

Abstract

The utility model discloses a kind of layering heat radiating structure in parallel and its low temperature smoking sets of application, parallel connection layering heat radiating structure includes base layer and overlays on Electrothermic wire in the base layer, the Electrothermic wire is divided at least two hot zones in matrix layer surface, and the electrode that the Electrothermic wire and corresponding Electrothermic wire connect is located at two different surfaces of base layer；It include the main Electrothermic wire for controlling the hot zone and realizing fever in each hot zone, it is mixed with other hot zones at least one hot zone and extends the secondary Electrothermic wire to come, form mixing hot zone, it insulate and is distributed between the pair Electrothermic wire and the main Electrothermic wire mixed in hot zone, be parallel relationship between the main Electrothermic wire in the pair Electrothermic wire and extension starting hot zone.The low temperature smoking set of the utility model solves the influence that smoke medium is heated in electrode fever, and combines the Electrothermic wire of parallel arrangement, reduces the superheating phenomenon in mixing hot zone, improves the experience sense of low temperature smoking set.

Description

A kind of low temperature smoking set in parallel being layered heat radiating structure and its application

Technical field

The utility model relates to a kind of layering heat radiating structure in parallel and its low temperature smoking sets of application.

Background technique

The electric heating power of low temperature smoking set is constant, is evenly arranged in the heat of heating wire sending on heater surface in difference The heat issued in the heating region of area is the same, and is existed in this way on the heater surface using Segmented heating as follows Problem:

Shown in the heater of Segmented heating up and down as shown in figure 1, sub-fraction is provided in upper and lower two heating zones In addition the area of the heating wire in hot zone, part heating wire fever is smaller, all to be connected to electricity when heating wire once being powered The electric current that the heating wire of road passes through is the same, and the heating wire in part facets product will generate biggish heat in this way Amount, excessively heats the fraction smoke medium in the fraction heating region, causes smoke temperature is excessively high to occur scalding mouth, And since heating is uneven, it is easy to appear the phenomenon that part smoke medium is charred.

In addition, since the mode of segmentally heating is unlike the mode that integrally heats, no matter two hot zones in Fig. 1 how cloth It sets, it is necessary to the heating wire connection electrode to vacate a part of region on the surface of heater to be arranged in two hot zones, and And since electrode includes the public electrode shared there are two the fever electrode inside hot zone, either which hot zone work When making, the electrode of corresponding hot zone can conductive exothermal, especially public electrode when two hot zones works all can conduction, it is right The corresponding smoke medium in electrode region carries out continuous heating, can equally generate caused by smoke medium excessively heats and be charred Taste, and cause the bad user experience of low temperature smoking set.

Utility model content

The technical issues of the utility model solves is: office is easy existing for the segmented heater for existing low temperature smoking set Portion's overheat generates the defect for being charred phenomenon, provides a kind of novel low temperature smoking set in parallel for being layered heat radiating structure and its application.

The utility model adopts the following technical solution realizes:

Parallel connection layering heat radiating structure, including base layer and overlays on Electrothermic wire in the base layer, the electricity fever Silk is divided into the electrode difference position of at least two hot zones, the Electrothermic wire and corresponding Electrothermic wire connection in matrix layer surface In two different surfaces of base layer；

It include the main Electrothermic wire for controlling the hot zone and realizing fever, at least one fever in each hot zone The main Electrothermic wire that other hot zones are mixed in area extends the secondary Electrothermic wire to come, forms mixing hot zone, the mixing hair It insulate and is distributed between secondary Electrothermic wire and main Electrothermic wire in hot-zone, the main Electrothermic wire and its pair electricity extended are sent out Heated filament is in parallel.

Further, all hot zones are distributed along the length segmentation of heat radiating structure, and in the circumferential direction of heat radiating structure Head and the tail connect cyclization.

Further, the main Electrothermic wire distribution area in the mixing hot zone is greater than secondary Electrothermic wire distribution area.

In the layering heat radiating structure in parallel of the utility model, the main Electrothermic wire includes the fever of several parallel arrangements Resistance wire.

Further, the Electrothermic wire overlays on a side surface of the base layer close to heating region, and the electrode overlays on base Another side surface of the body layer far from heating region, the base layer are equipped with to form electricity for being in electrical contact electrode and Electrothermic wire The through hole in road circuit.

Further, the temperature control through hole for detecting Electrothermic wire temperature is additionally provided in the base layer.

In the layering heat radiating structure in parallel of the utility model, the Electrothermic wire is the resistance for being printed on matrix layer surface Pulp layer, the electrode are the conductive coating for being printed on another surface of base layer.

Further, the electrode includes several heating electrics that the main Electrothermic wire in different heat area is separately connected The common electrode that main Electrothermic wire and secondary Electrothermic wire in pole and all hot zones are connected in parallel jointly.

Further, the Electrothermic wire is in connect along base layer length direction and/or circumferential direction in corresponding hot zone Continuous bending distribution.

Further, the base layer for being covered with Electrothermic wire and electrode is wound into the tubulose fever that heating is surrounded to smoke medium Body, or it is wound into the hollow rodlike or hollow sheet-shaped heating element that insertion smoke media interior carries out center heating.

Further, the tubulose heater further includes having metal tube, is covered with the base layer volume of Electrothermic wire and electrode Insulated substrate is arranged on metal tube in packet between Electrothermic wire and metal tube.

The invention also discloses a kind of low temperature smoking set, the low temperature smoking set is using above-mentioned layering heat radiating structure conduct in parallel The heater of low temperature smoking set.

The utility model by between the main Electrothermic wire and secondary Electrothermic wire in hot zone using being connected in parallel by the way of, it is sharp The characteristics of with parallel circuit, reduces logical so that the secondary Electrothermic wire in mixing hot zone can control in relatively small resistance value Cross the electric current of secondary Electrothermic wire, it is ensured that the calorific value in the region can be received, and small area in mixing hot zone is avoided Phenomenon is charred caused by the calorific value of secondary Electrothermic wire is excessive；In addition, also using multistage parallel way cloth between main Electrothermic wire It sets, so that the distribution of resistance controllability on Electrothermic wire is higher, the resistance of control corresponding site that can be more accurate, and The normal use for not influencing heater avoids the occurrence of the problems such as heater is burned by cigarette and smog scalds mouth.

The utility model by heat radiating structure Electrothermic wire and electrode be arranged in two of base layer not ipsilaterals, And electrode is located remotely from heating region setting, eliminates electrode to the occupancy of hot zone, increases hot zone area, hot zone All controlled by Electrothermic wire, heating effect of the electrode heating power to smoke medium is reduced to it is minimum, in this way can be effective It avoids because electrode, which is persistently powered, is charred phenomenon to the smoke medium continuous heating generation in heating region；It is applied using printing is conductive The mode of layer and resistance slurry realizes the solidification of Electrothermic wire and electrode on base layer, and production technology is more convenient, Gu It is reliable to change effect；Hot zone subsection setup, in corresponding heating region operational heat, low-temperature airflow can not covered from its heating zone Other area cirulatings of lid can effectively reduce the temperature of produced smog after the heating of smoke medium, greatly solve low Warm smoking set smog existing for heating initial stage scalds the problem of mouth.

In conclusion the utility model is solved by the way that Electrothermic wire and electrode are carried out hierarchical design with respect to base layer The influence that smoke medium is heated in electrode fever, and the Electrothermic wire of parallel arrangement is combined, it reduces in mixing hot zone Superheating phenomenon improves the experience sense of low temperature smoking set.

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

Detailed description of the invention

Fig. 1 is the Electrothermic wire schematic diagram after the low temperature smoking set heater expansion of the prior art.

Fig. 2 is the decomposition diagram of the layering heat radiating structure in parallel in embodiment.

Fig. 3 is the arrangement schematic diagram of Electrothermic wire after the heating layer of the layering heat radiating structure in parallel in embodiment is unfolded.

Fig. 4 is the schematic diagram after the base layer expansion of the layering heat radiating structure in parallel in embodiment.

Fig. 5 is the schematic diagram after the electrode layer expansion of the layering heat radiating structure in parallel in embodiment.

Fig. 6 is the base layer in embodiment and the schematic diagram after heating layer overlapping.

Fig. 7 is the base layer in embodiment and the schematic diagram after electrode layer overlapping.

Fig. 8 is the parallel circuit schematic diagram of the Electrothermic wire on the heating layer in embodiment.

Figure label: 1- metal tube, 2- insulated substrate, 3- heating layer, the first hot zone 301-, 302- second generate heat Area, the main Electrothermic wire of 31- first, the main Electrothermic wire of 32- second, the secondary Electrothermic wire of 33- first, the secondary Electrothermic wire of 34- second, 4- Base layer, the main Electrothermic wire through hole of 41- first, the main Electrothermic wire through hole of 42- second, 43- share through hole, 44- second Secondary Electrothermic wire through hole, the secondary Electrothermic wire through hole of 45- first, 46- the first temperature control through hole, 47- the second temperature control through hole, 5- electrode layer, the fever electrode of 51- first, the fever electrode of 52- second, 53- common electrode.

Specific embodiment

Embodiment

Referring to fig. 2, the layering heat radiating structure in parallel in diagram be the tubulose heater in illustrating, in the tubulose heater The intracavitary heating region for heat radiating structure of blank pipe, smoke media filler enter in the hollow lumen of the tubulose heater, pass through Electrothermic wire on tubulose heater carries out encirclement heating to smoke medium.The tubulose heater include metal tube 1 and according to The secondary insulated substrate 2 surrounded on metal tube 1, heating layer 3, base layer 4 and electrode layer 5, wherein heat radiating structure includes matrix Layer 4 and the heating layer 3 for overlaying on 4 surface of base layer, heating layer 3 includes the Electrothermic wire for overlaying on 4 inner surface of base layer, fixed The electrode layer 5 on 4 outer surface of base layer is overlayed on for external control circuit and Electrothermic wire circuit connection, insulated substrate 2 will Insulation separates between heating layer 3 and metal tube 1, and the heat that heating layer 3 issues is by the conduction of metal tube 1 to intraluminal Smoke medium is heated.

Base layer 4 is made of aluminium oxide or other isolation materials, in base layer 4 close to the inner surface of metal tube 1 Upper fixation is covered with several Electrothermic wires shown in Fig. 3, which forms the heating layer 3 for being covered in 4 inner wall of base layer, tool Body is as shown in figure 3, the Electrothermic wire of heating layer 3 includes the first main Electrothermic wire 31, the second secondary electricity hair of main Electrothermic wire 32, first Heated filament 33 and the second secondary Electrothermic wire 34, by the above Electrothermic wire in the arrangement of 4 inner surface of base layer, formation is whole to include The first hot zone 301 and the second hot zone 302 of the above Electrothermic wire.Wherein the first hot zone 301 is located at the upper half of base layer 4 Portion, including the first main Electrothermic wire 31 and the second secondary Electrothermic wire 34, wherein the first main Electrothermic wire 31 is distributed in the first fever Most of region in area 301, the second secondary Electrothermic wire 34 are distributed in the remaining partial region of the first hot zone 301；Second fever Area 302 is located at the lower half of body layer 4, including the second main Electrothermic wire 32 and the first secondary Electrothermic wire 33, wherein the second main electricity Heating wire 32 is distributed in most of region of the second hot zone 302, and the first secondary Electrothermic wire 33 is distributed in the second hot zone 302 Remaining partial region.The first hot zone 301 may be implemented respectively by the first main Electrothermic wire 31 and the second main Electrothermic wire 32 Main fever with the second hot zone 302 controls, and the first secondary Electrothermic wire 33 and the second secondary Electrothermic wire 34 then respectively can be right The control that first hot zone 301 and the second hot zone 302 are preheated and kept the temperature.

The fever of the first hot zone 301 and the second hot zone 302 in Fig. 3 is real by the power control of Electrothermic wire Existing, electrode layer 5 is arranged in the other side surface of base layer 4, largely avoids influence of the electrode heating power to heating layer.

The second secondary Electrothermic wire 34 in the first hot zone 301 is from the main electricity fever of second in the second hot zone 302 The extension of 32 electrical connection of silk, between the in the first hot zone 301 second secondary Electrothermic wire 34 and the first main Electrothermic wire 31 Insulation distribution, and the area that is distributed of the first main Electrothermic wire 31 is much larger than the area that the second secondary Electrothermic wire 34 is distributed, second Secondary Electrothermic wire 34 is then parallel relationship between the second main Electrothermic wire 32；Likewise, first in the second hot zone 302 Secondary Electrothermic wire 33 is then from the extension that the first main Electrothermic wire 31 in the first hot zone 301 is electrically connected, in the second hair Insulate between first secondary Electrothermic wire 33 and the second main Electrothermic wire 32 distribution, and the second main Electrothermic wire 32 in hot-zone 302 The area of distribution much larger than the area that the first secondary Electrothermic wire 33 is distributed, the first secondary Electrothermic wire 33 then with the first main Electrothermic wire It is parallel relationship between 31.Reduced by parallel circuit carried out in the first hot zone 301 and the second hot zone 302 preheating and The electric current passed through on correspondence Electrothermic wire when heat preservation, thereby reduces the heat in preheating and insulating process, effectively avoids Should during heat it is excessive.

In the present embodiment, the first hot zone 301 and the second hot zone 302 are the mixing for including two parts Electrothermic wire Hot zone.In practical applications, greater number of hot zone can also be set according to the actual demand of heat radiating structure, can also incites somebody to action Some hot zone therein is arranged to the complete hot zone fully controlled by single Electrothermic wire, another hot zone is arranged to Mixing hot zone including two parts Electrothermic wire.

Electrothermic wire on either the first hot zone 301 or the second hot zone 302 is along the length on 4 surface of base layer Direction and circumferential direction are in that Curved Continuous splits cloth, and the fever for improving corresponding hot zone by the snakelike distribution continuously bent is uniform Property, after heat radiating structure volume is wrapped onto metal tube, the heating layer 3 that Electrothermic wire is formed connects from beginning to end around the circumferential direction of metal tube 1 It is connected into ring, realizes and the full encirclement of lumen heating region is evenly heated.The Electrothermic wire on the heater surface in practical application Arrangement can carry out adaptation adjustment, and the present embodiment will not repeat them here.

Electrothermic wire in Fig. 3 overlays on lumen side inner surface of the base layer 4 close to metal tube 1, the electrode layer in Fig. 5 5 overlay on lumen one side external surface of the base layer 4 far from metal tube 1, electrode layer 5 be respectively set the first fever electrode 51, Second fever electrode 52 and common electrode 53, the present embodiment generate heat the main electricity in an end of the first main Electrothermic wire 31 and second The first fever electrode 51 of setting connection and the second fever electrode 52 are individually drawn in one end of silk 32, then main by first Another end of Electrothermic wire 31 and another end of the second main Electrothermic wire 32 draw and are connected to common electrode 53, and By the first main Electrothermic wire 31 and the second main Electrothermic wire 32 the first secondary Electrothermic wire 33 in parallel extended and the second secondary electricity fever The end of silk 34 is drawn and is connected in common electrode 53, can be realized in this way by three electrodes to being distributed in two hot zones Two groups of Electrothermic wires control effectively.Pairing in relation to electrode and Electrothermic wire is set as can refer on existing low temperature smoking set It is segmented heater.

As shown in figure 4, on base layer 4 be equipped with for make electrode and Electrothermic wire be in electrical contact to be formed circuit loop electricity hair Heated filament through hole and the temperature control through hole that Electrothermic wire is touched for external temperature element.Specifically as shown in figure 4, in matrix The first main Electrothermic wire through hole 41 is provided on layer 4, the second main Electrothermic wire through hole 42 shares through hole 43, and second is secondary Electrothermic wire through hole 44, the first secondary Electrothermic wire through hole 45, the first temperature control through hole 46 and the second temperature control through hole 47, root According to the arrangement contact position of the Electrothermic wire in the electrode and heating layer 3 in electrode layer 5, wherein the first main Electrothermic wire through hole 41 for penetrating contact, the second main Electrothermic wire through hole between the first fever electrode 51 and the end of the first main Electrothermic wire 31 42, for penetrating contact between the second fever electrode 52 and the end of the second main Electrothermic wire 32, share through hole 43 for sharing Electrode 53 is penetrated jointly with the other end of the first main Electrothermic wire 31 and the second main Electrothermic wire 32 and is contacted, the second secondary electricity fever Silk through hole 44 is worn for penetrating contact, the first secondary Electrothermic wire between common electrode 53 and the end of the second secondary Electrothermic wire 34 Open-work 45 is for penetrating contact between common electrode 53 and the end of the first secondary Electrothermic wire 33.Since the needs of common electrode 53 cover The position of three through holes of lid, and each electrode is set to the same end of heat radiating structure, is set by fixed on base layer It sets pad to connect with external circuit, therefore the present embodiment penetrates hole site printing conduction what matrix layer surface covered as required Coating is formed electrode layer 5.In addition, it is main to respectively correspond first for setting on base layer 4 in order to be monitored to the temperature of fever The the first temperature control through hole 46 and the second temperature control through hole 47 of Electrothermic wire 31 and the second main Electrothermic wire 32, outside heat radiating structure The temperature-controlled members such as thermistor can penetrate base layer 4 and the main Electrothermic wire of corresponding hot zone is physically contacted, to measure the The temperature of one hot zone and the second hot zone.

Referring again to Fig. 3, Fig. 6, Fig. 7 and Fig. 8, the main Electrothermic wire 31 of the first of the present embodiment and the second main Electrothermic wire 32 It include three groups of heating resistance wires in parallel.

It is in parallel with Ra1 and Ra2 after wherein Ra1 and Ra2 parallel connection in the first main Electrothermic wire 31, Ra3-1 and Ra3-2a series connection, Ra3-2b is in parallel with Ra3-2a as the first secondary Electrothermic wire 33, in an end position matrix of corresponding Ra1, Ra2 and Ra3-1 parallel connection The first main Electrothermic wire through hole 41 is correspondingly arranged on layer 4, the first fever electrode 51 in 4 other side face of base layer passes through first Main Electrothermic wire through hole 41 and the first main Electrothermic wire 31 realize electrical contact, extend to the second hot zone in corresponding Ra3-2b The first secondary Electrothermic wire through hole 45, the common electrode in 4 other side face of base layer are correspondingly arranged on the base layer 4 of distal end 53 realize electrical contact by the first secondary Electrothermic wire through hole 45 and Ra3-2b；In parallel in corresponding Ra1, Ra2 and Ra3-2a Shared through hole 43 is correspondingly arranged on one end position base layer 4, the common electrode 53 in 4 other side face of base layer is worn by sharing Open-work 43 and the first main Electrothermic wire 31 realize electrical contact.

, Rb3- in parallel with Rb1 and Rb2 after Rb1 and Rb2 parallel connection in second main Electrothermic wire 32, Rb3-1 and Rb3-2b series connection 2b is in parallel with Rb3-2a as the second secondary Electrothermic wire 34, in an end position base layer 4 of corresponding Rb1, Rb2 and Rb3-1 parallel connection On be correspondingly arranged the second main Electrothermic wire through hole 42, the second fever electrode 52 in 4 other side face of base layer is main by second Electrothermic wire through hole 42 and the second main Electrothermic wire 32 realize electrical contact, and it is remote to extend to the first hot zone in corresponding Rb3-2b It holds and is correspondingly arranged the second secondary Electrothermic wire through hole 44, the common electrode 53 in 4 other side face of base layer on the base layer 4 of end Electrical contact is realized by the second secondary Electrothermic wire through hole 44 and Rb3-2b；The one of corresponding Rb1, Rb2 and Rb3-2a parallel connection End position extends to base layer 4 and shares at through hole 43, and the common electrode 53 in 4 other side face of base layer is by sharing through hole First main Electrothermic wire 31 and the second main Electrothermic wire 32 are realized electrical contact by 43 together.

In the above heating circuit, the Ra3- of Rb3-2b and the second hot zone 302 for the first hot zone of heater 301 2b, separately as an access, can reach in such a way that it is in parallel with main Electrothermic wire in corresponding extension starting hot zone The purpose of the resistance sizes of itself is flexibly controlled, thus the part calorific value more in flexible control mixing hot zone, Avoid or reduce occur in technical background be charred problem.

Electrothermic wire in the present embodiment forms heating layer 3 in 4 inner surface printed resistor slurry of base layer, and electrode is in base 4 outer surface of body layer prints conductive coating and forms electrode layer 5, alumina base of the base layer 4 using insulation, resistance slurry extruding It is contacted in the through hole being filled into base layer 4 with electrode layer 5.Layering heat radiating structure in the present embodiment uses metal tube 1 As carrying, insulated substrate 2 is coated on metal tube 1, then the layering that heating layer 3, base layer 4 and electrode layer 5 are formed is sent out Heat structure in insulated substrate 2, can form the tubulose heater in the present embodiment in order.It, can also in practical application Layering heat radiating structure is directly rolled into tubulose heater, then in base layer using the tubulose heater of integrated sinter molding Print the medial surface sintering protection glaze layer of heating layer.Heater can also be wound into insertion smoke media interior progress center to add The arrangement and this reality of the hollow rodlike or hollow sheet-shaped heating element of heat, specific layered structure and Electrothermic wire and electrode Apply that example is identical, unlike Electrothermic wire be arranged in the outer surface of fever base, rodlike heater or sheet-shaped heating element are inserted The smoke medium entered is heated.

Therefore, the heat radiating structure in the present embodiment can be used for all kinds of use encirclement heating or the low of smoke medium is heated at center In warm smoking set.

The above is only specific embodiment of the present utility model, the protection scope of the utility model is not limited merely to above-mentioned Embodiment, technical solution belonging to the idea of the present invention belong to the protection scope of the utility model.It should be pointed out that pair For those skilled in the art, several improvements and modifications without departing from the principle of the utility model, These improvements and modifications also should be regarded as the protection scope of the utility model.

Claims (12)

1. parallel connection layering heat radiating structure, including base layer and overlays on Electrothermic wire in the base layer, it is characterised in that: institute State the electricity that Electrothermic wire is divided at least two hot zones, the Electrothermic wire and corresponding Electrothermic wire connection in matrix layer surface Pole is located at two different surfaces of base layer；

It include the main Electrothermic wire for controlling the hot zone and realizing fever in each hot zone, at least one hot zone The main Electrothermic wire for being mixed with other hot zones extends the secondary Electrothermic wire to come, forms mixing hot zone, the mixing hot zone Insulate distribution, the main Electrothermic wire and its secondary Electrothermic wire extended between interior secondary Electrothermic wire and main Electrothermic wire It is in parallel.

2. layering heat radiating structure in parallel according to claim 1, all hot zones are along the length segmentation of heat radiating structure Distribution, and cyclization is connected in the circumferential head and the tail of heat radiating structure.

3. layering heat radiating structure in parallel according to claim 1, the main Electrothermic wire mixed in hot zone are distributed face Product is greater than secondary Electrothermic wire distribution area.

4. layering heat radiating structure in parallel according to any one of claim 1-3, if the main Electrothermic wire includes dry doubling Join the heating resistance wire of arrangement.

5. layering heat radiating structure in parallel according to claim 1, the Electrothermic wire overlay on base layer close to heating region A side surface, the electrode overlays on another side surface of the base layer far from heating region, and the base layer is equipped with for making Electrode and Electrothermic wire are in electrical contact the through hole to form circuit loop.

6. parallel connection according to claim 5 is layered heat radiating structure, it is additionally provided in the base layer for detecting Electrothermic wire The temperature control through hole of temperature.

7. layering heat radiating structure in parallel according to claim 5 or 6, the Electrothermic wire is to be printed on matrix layer surface Resistance slurry layer, the electrode are the conductive coating for being printed on another surface of base layer.

8. layering heat radiating structure in parallel according to claim 1, the electrode includes the main electricity fever in different heat area Several main Electrothermic wires to generate heat in electrodes and all hot zones that silk is separately connected and secondary Electrothermic wire are jointly in parallel to be connected The common electrode connect.

9. layering heat radiating structure in parallel according to claim 1, the Electrothermic wire is in corresponding hot zone along base layer Length direction and/or circumferential direction are in that Curved Continuous splits cloth.

10. layering heat radiating structure in parallel according to claim 1, the base layer for being covered with Electrothermic wire and electrode is wound into pair Smoke medium surrounds the tubulose heater of heating, or be wound into insertion smoke media interior carry out center heating hollow rodlike or Hollow sheet-shaped heating element.

11. layering heat radiating structure in parallel according to claim 10, the tubulose heater further includes having metal tube, is covered There is the base layer of Electrothermic wire and electrode volume packet on metal tube, and the setting insulation base between Electrothermic wire and metal tube Layer.

12. low temperature smoking set, it is characterised in that: using layering heat radiating structure conduct in parallel of any of claims 1-11 The heater of low temperature smoking set.