EP2952746B1 - Hot air device - Google Patents

Description

The present invention relates to a hot air device according to the preamble of the main claim. Such a device is known from EP-A-0170974 known.

A hot air device is well known in the art and, also in a typical designation as a "hot air blower", is used for a variety of industrial and residential applications. Such, typically manually manageable (and accordingly having an elongated or pistol grip) device is not only suitable for all applications in which short-term and flexible a several hundred ° C warm air jet, discharged from the hot air outlet to be brought to a workspace.

In order to achieve the desired heating of the air flow, the heating unit has electrically operated heating means, for example realized by means of resistance conductor material, which are held in suitable carrier structures through which the air to be heated flows. Such a heating unit is then charged in an otherwise known manner from the end facing away from the hot air outlet with an air flow generated by the fan rotor driven by the fan motor.

Often, such as generically presupposed and well-known hot air devices have temperature controls, such that provided at the hot air outlet heat sensor allow control of the temperature of outflowing air to a setpoint; suitable for this purpose, the electrical control power for the heating unit changed.

However, since, in the sense of a thermal equilibrium, the air flow promoted by the fan rotor alike causes a cooling of the heating unit, then, if at high electrical heating power and - for example defect - Reduce the air flow or even a failure of the fan motor, a thermally unstable situation arise (which is particularly serious in unregulated hot air devices). In this case, a continuous electrical heat application of the heating unit, without or at significantly reduced flow with the air flow, lead to overheating, which then in particular also surrounding (usually realized from a plastic material) housing components, such as housing shells of the hot air device impaired. In an extreme case, such an overheating state (which may also have been deliberately brought about in the context of electrical approval and testing methods) may cause plastic housing sections which are in thermal contact with the heating unit to melt or otherwise impair their holding and strength properties be, and in particular in constructive implementation of hot air devices, in which such housing components make the (mechanical) connection between the heating unit and upstream airflow components fan rotor and fan motor, come to damage the entire device and the associated hazards. By way of example, a state to be avoided is conceivable in which, for example, a (pistol-shaped) hot air device is damaged in a horizontal installation position and in the case of the described overheating such that the (typically peripherally having a metal jacket) heating unit tilts out of the softening plastic housing or a device-destroying pivoting experiences.

Since hot air devices of the generic type are often designed for potentially multi-year periods of use and - age-related - failure or power reduction of the engine function can not be excluded especially with such long useful life, there is a need to reduce the risk described potential largely.

It is therefore an object of the present invention to provide a generic hot air device with regard to its safety properties, in particular its mechanical behavior under thermal overloading of the heating unit improve, in particular to ensure that a described overheating of the heating unit in case of failing or insufficient air flow through the heating unit to no significant deformation, in particular to no destruction of the heating unit mechanically connected to the upstream units (plastic) housing leads.

The object is achieved by the hot air device with the features of the main claim. Advantageous developments of the invention are described in the subclaims.

In accordance with the invention advantageously, the clip-shaped, metallic connecting means ensure that the heating unit with corresponding heat-resistant support means (in the form of connecting means) is held on the blower motor, so far therefore even a thermal stability impairment of the (plastic) housing no falling apart or no adverse tilting or Pivoting the heating unit relative to the blower motor can cause more. Rather, the heating unit is held in its (typically aligned along the axial air flow direction) relative position to the fan motor including fan rotor by the connecting means.

In a preferred embodiment of the invention, it has proved to be particularly advantageous in terms of design and manufacturing when the connecting means according to the invention overlap on the outside or on the shell side a plastic shell which encloses the fan space. In the sense of a modular concept, the involved components can thus be connected structurally simple and favorable in terms of production technology.

It is particularly preferred to realize the connecting means as a clasp of a wire, which is then formed into a corresponding contour. Such, according to the invention preferred wire clasp has at both ends mounting portions in order to realize the connection effect, namely on the one hand the clasp on the heating device - preferred here is the setting on a fan side flange section -, and on the other hand to provide the fan motor.

While a variant of the invention provides for the connection partners (ie end section of the heating device or the blower motor) to be provided with suitable screws or the same elongated-pin-shaped assemblies which, according to training, extend parallel to the longitudinal axis and are dimensioned for cooperation with the wire of the connection means, However, it is also possible within the scope of the invention, to use the (wire) clip (s) in suitable formations, grooves or undercuts of the connection partners, to allow extent, further education using a spring action of the clip, a reliable engagement and secure connection ,

In a preferred embodiment of the invention is provided, the (advantageously realized by wire) connecting means in such a way that around the cylindrical or circular circumference of the fan space around a plurality of clasps, which are offset from each other along the circumference or spaced. In this way, the securing effect according to the invention is realized not only in a loading direction, but potentially for any mechanical force application.

In the context of favorable developments of this inventive concept, it is on the one hand cheap and preferred to provide a plurality of (realized from a wire) individual braces, which are each individually and separately at the partners to be connected heating unit or blower motor set, alternatively and according to a structurally elegant development However, according to the invention it is also possible, in the manner of a double or multiple clasp, to connect clasp-like wire sections - more preferably in one piece - through a connecting section and thus to realize the connection task with only one module as connecting means by means of a single, three-dimensionally more complex clamping unit.

As a result, in a surprisingly simple and effective manner, the present invention makes it possible to overcome the stability and mechanical disadvantages of a plastic housing of the hot air device associated with inadvertent overheating of the heating unit, particularly with regard to disadvantageous pivoting, tilting or other destructive deformation the associated risk potential for users effectively prevented or at least mitigated. In this case, an additional, constructive assembly effort is low, so that it can be assumed that a large number of future hot air blowers (hot air devices) should be provided with the security technology according to the invention.

Fig. 1

eine Seitenansicht funktionswesentlicher Komponenten der erfindungsgemäßen Heißluftvorrichtung gemäß einem ersten Ausführungsbeispiel der Erfindung, bestehend aus Gebläsemotor, Lüfterraum und Heizungseinheit, wobei die erfindungsgemäßen Verbindungsmittel eine Doppelspange realisieren;

Fig. 2

eine teilweise aufgeschnittene Schrägansicht des Ausführungsbeispiels der Fig. 1 mit aufsitzenden Verbindungsmitteln;

Fig. 3

eine schräg-perspektivische Rückansicht des Ausführungsbeispiels der Fig. 1, 2;

Fig. 4

eine Detailansicht der als Draht-Einzelspange realisierten Verbindungsmittel und

Fig. 5

eine Detailansicht der als Draht-Doppelspange realisierten Verbindungsmittel gemäß einem weiteren Ausführungsbeispiel der Erfindung.

Further advantages, features and details of the invention will become apparent in the following description of preferred embodiments and with reference to the drawings; these show in

Fig. 1

a side view of functionally essential components of the hot air device according to the invention according to a first embodiment of the invention, consisting of blower motor, fan room and heating unit, wherein the connecting means according to the invention realize a double clasp;

Fig. 2

a partially cutaway perspective view of the embodiment of the Fig. 1 with seated connecting means;

Fig. 3

an oblique-perspective rear view of the embodiment of Fig. 1, 2 ;

Fig. 4

a detailed view of realized as a wire single clip connecting means and

Fig. 5

a detailed view of realized as a wire double clasp connecting means according to another embodiment of the invention.

The Fig. 1 illustrates how along an axial direction (horizontal direction in the image plane, so far according to the air flow direction to the right), a blower motor 10 ansitzenden connecting lines 12 via a rotor housing (Leitschaufelkasten) 14 merges into an elongated, cylindrical heating unit 16, which ends a in Diameter tapered hot air outlet 18 forms.

The partial sectional view of Fig. 2 illustrates how in the region of the fan chamber 14, a plastic shell assembly 15 encloses a driven by the fan motor 10 fan rotor 20 and so far defines the fan chamber. The subsequent heating unit 16 has at its end opposite the hot air outlet 18 flat flange portions 22 which are overlapped or enclosed by the plastic shells 15, so that in the arrangement shown, the plastic shells 15 a mechanical coupling between the heating unit 16 and the fan motor 10 effect; the illustrations illustrate how a motor housing 17, which engages integrally with the housing shells 15 by means of webs, encloses the actual electric motor 11 of the fan motor unit 10. The reference numeral 21 additionally illustrates supply or control lines for the heating unit or therein provided (not shown) thermocouples or similar units.

In addition, the clarify Fig. 1 to 3 , how - in the Fig. 4 or 5 in detail and enlarged shown - wire clips for the realization of the connecting means according to the invention an additional mechanical connection between the flange end 22 of the heating unit on the one hand and the blower motor on the other hand produce. For this purpose, a first, loop-shaped bent end 24 of an individual clip 26 (FIG. 6) engages over a fastening pin realized as a screw 28 in the flange 22 of the heating unit. At the other end, a hook portion 30 of the single clip 26 is formed so that it is in an undercut Opening or groove ( Fig. 3 ) of the motor formwork 17 can intervene. A pair of single braces 26, mounted in the in the Fig. 1 to 3 shown manner around the circumference of the fan chamber 14 around, thus allowing a stable even with greater heat, mechanical connection between the heating unit 16 and blower motor 10, even if, for example by failure or loss of power of the fan motor 10, no or only a significantly reduced air flow to the heating unit 16 flows through and accordingly, in the absence of sufficient contribution to the cooling of the same, an unintentional overheating is effected. Namely, even if then a correspondingly overheated flange portion 22 softens or melts the material of the surrounding plastic shell 15, there is no change in the axial relative orientation between the motor unit 10 and the heating unit. Rather, the thermally stable wire clips provide a reliable hold, even with thermally unstable plastic shell.

The Fig. 5 shows as a variant, in particular to a multiple arrangement of individual braces 26 of Fig. 4 a one-piece double clasp 34; this consists of free legs 32 and 38 which are interconnected by an integral archwire section 40 and each corresponding to an individual clip 26 (FIG. Fig. 4 ) are contoured. Again at the end hook portions 30 are provided for holding engagement in the blower motor 10, while at the other end (with respect to the legs) hook portions 42 are formed and the fastening screws 28 (FIG. Fig. 1 to 3 ) are formed for holding the heating unit 16.

Accordingly, the double clasp of Fig. 5 , As a variant of the above-described embodiment, two individual braces 26 of Fig. 4 replace, only in the form of a single component, since realized in one piece from the spring wire used here.

The present invention is not limited to the described embodiments; so it is particularly possible and encompassed by the invention, the connecting means according to the invention in other ways, such as in the form of flatter Metal bands to realize and select alternative material to the exemplary selected wire. Also, depending on an intended backup purpose, the clasp shape and the number of clasps can be realized. Also, the present invention is in principle for any hot air device, regardless of a configuration of further, not shown in the figures housing and handle components; For example, it is both possible to associate a pistol grip (for example in the area of the blower motor 10) with the described exemplary embodiments, as well as to elongate a handling handle and to form it in the direction of the blower and air flow axis.

LIST OF REFERENCE NUMBERS

10

Blower motor / blower motor unit / motor unit

11

electric motor

12

connecting cables

14

Rotor housing / Leitschaufelkasten / fan room

15

Plastic cup assembly / plastic cups / housing shells

16

Heating unit

17

Motor housing / motor formwork

18

hot air outlet

20

fan rotor

21

Supply or control lines

22

Flange portions / flange / flange

24

eye-shaped bent end / flange section

26

individual clips

28

Screw / fixing screws

30

hook portions

32

free thigh

34

double clasp

38

free thigh

40

Wire arc section

42

hook portions

Claims (10)

1. Hot air apparatus with
   a blower motor (10) driving a ventilator rotor (20), a heating unit (16), arranged downstream of the ventilator rotor related to an air flow generated thereby and electrically driven and providing at the end a hot air outlet (18),
   and a housing (15), made at least in sections of a plastic material, at least surrounding the ventilator rotor in order to form a ventilator chamber and connecting the blower motor to the heating unit,
   characterised in that
   the blower motor and the heating unit are additionally mechanically connected by a connecting means (26; 34) in the form of a buckle, made of a metallic material, and the heating unit is held by the connecting means at the blower motor, in such a way that the connecting means prevent or make difficult any tipping and/or pivoting of the heating unit relative to the blower motor in the event of the housing (15) being rendered unstable due to heat.
2. Device according to claim 1, characterised in that the blower motor, the ventilator rotor, and the longitudinally extended heating are aligned with one another along a common axis, corresponding to an air guide path.
3. Device according to claim 1 or 2, characterised in that the connecting means engage over a plastic shell (15) which at least in sections surrounds the ventilator chamber, on the casing side and/or on the outside.
4. Device according to any one of claims 1 to 3, characterised in that the connecting means are provided as a buckle (26; 34), formed from a wire, which comprises at both ends securing sections (24, 30; 30, 42) for connecting to an end section, in particular an end-side flange section (22), of the heating apparatus or the blower motor respectively.
5. Device according to claim 4, characterised in that the buckle comprises two buckle sections (36, 38) provided in a circumferential direction of the ventilator chamber, offset to one another, which in each case engage over the ventilator space.
6. Device according to claim 5, characterised in that the buckle sections are connected at one end by a bow section (40), in particular being of one piece.
7. Device according to any one of claims 4 to 6, characterised in that the securing sections are formed in particular as suitably shaped wire sections (24, 42), for interacting with screws (28) and/or pin-shaped securing bodies provided at the end section of the heating device and/or at the blower motor.
8. Device according to any one of claims 4 to 7, characterised in that the securing sections are formed in particular as suitably shaped wire sections (30), for interacting with grooves (32), undercuts, and/or mouldings, provided at the end section of the heating device and/or at the blower motor, such as allow for the fixing of the connecting means.
9. Device according to any one of claims 1 to 8, characterised in that a wire buckle (26) forming the connecting means is configured as being of one piece and/or from a spring-loaded wire material.
10. Device according to any one of claims 1 to 9, characterised in that the connecting means comprise a plurality of wire buckles (26) arranged offset to one another in a circumferential direction of the ventilator chamber.

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