DK158014B

DK158014B - ELECTROTHERMIC SETTING BODY

Info

Publication number: DK158014B
Application number: DK584083A
Authority: DK
Inventors: Hans Michael Mayer
Original assignee: Elektrowatt Ag
Priority date: 1982-12-20
Filing date: 1983-12-19
Publication date: 1990-03-12
Also published as: SE8305803D0; FR2538045B1; FR2538045A1; NL189978C; GB2133544A; SE458053B; NL8303791A; DE3340548C2; NL189978B; GB8333739D0; DK584083D0; DE3340548A1; DK158014C; GB2133544B; CH659858A5; SE8305803L; DK584083A

Description

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Opfindelsen angår et elektrotermisk indstillingsorgan af den i krav l's indledning angivne art.The invention relates to an electrothermal adjusting means of the kind specified in the preamble of claim 1.

Et sådant indstillingsorgan er kendt fra De offentliggørelsesskrift nr. 3 028 532. Det tjener til vedvarende 5 omstilling af et indstillingsled, eksempelvis en ventil eller en luftklap, i afhængighed af en vedvarende regulators indstillingssignal. Ved hjælp af indstillingssignalet bliver fordampningsrummet opvarmet mere eller mindre ved hjælp af et elektrisk varmeelement for at 10 opnå en til den tilførte elektriske varmeydelse svarende indstilling af det med stødstangen forbundne indstillingsled. Hvis der nu ved reduktion af den elektriske varmeydelse strømmer kold væske tilbage i fordampnings-rummet, kan dejtte_jjjdXøse en-piudsel.ig kondensation af 15 den J^QtM-arnp'ede væske, begunstiget af virkningen af den ρΊ fordampningsrummet indvirkende kantraf'jed'er. ~~En deri ved betinget pludselig tilbagestilling er dog uønsket, — _fordi den drager en vedvarende regulering i tvivl.Such an adjusting member is known from Deed of Publication No. 3 028 532. It serves to continuously adjust an adjustment link, for example a valve or air valve, depending on the setting signal of a continuous controller. By means of the setting signal, the evaporation space is heated more or less by means of an electric heating element in order to obtain an adjustment of the adjustment link connected to the thrust bar corresponding to the supplied electric heat output. If, by reducing the electric heat output, cold liquid flows back into the evaporation room, the condensed single-ply condensation of the J ^ QtM-annealed liquid, favored by the effect of the ρΊ evaporation space, can affect is. ~~ A conditional sudden reset therein, however, is undesirable, - because it doubts persistent regulation.

For at undgå et sådant fænomen har e1r fFa'Df^S-S ^Q-28-20 532 kendt indstillingsorgan et fortrængningslegeme med ^ en stempelring, som tætner fordampningsrummet fra det øvrige med fordampningsvæske fyldte rum. Det i afhængighed af fordampningen forskydelige fortrængningslegeme forhindrer ganske vist en væskeudveksling imellem 25 fordampningsrummet og de øvrige rum, men stempelringen forårsager imidlertid som følge af gnidning ved cylindervæggen en hysterese eller gør denne større.In order to avoid such a phenomenon, the adjusting member of the prior art has a displacement body with a piston ring which seals the evaporation chamber from the rest of the vapor-filled compartment. The displaceable displaceable body, depending on the evaporation, although prevents a fluid exchange between the evaporation chamber and the other compartments, however, due to rubbing at the cylinder wall, the piston ring causes a hysteresis or increases it.

Desuden kendes fra CH-PS 479 809 et indstillingsorgan, hvis elektrisk opvarmede fordampningsrum ved hjælp af 30 et åbent forbindelsesrør er forbundet med arbejdsrum met, som har en foldebælg. Ved dette kendte indstillings-organ er der tilvejebragt et andet elektrisk varmelegeme, ved hjælp af hvilket arbejdsrummet hele tiden bliver opvarmet med konstant ydelse. Derved skal et sammen- 2Furthermore, from CH-PS 479 809 there is known an adjusting means whose electrically heated evaporation space is connected by means of an open connecting pipe to the working space having a folding bellows. By this known adjusting means another electric heater is provided, by means of which the working space is constantly heated at constant output. Thereby, a con- 2

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brud af dampfasen være umulig. Ulempen ved et sådant indstillingsorgan er på den ene side den større udgift til fremstilling og på den anden side det yderligere vedvarende forbrug af elektrisk energi.fracture of the vapor phase be impossible. The disadvantage of such an adjusting device is, on the one hand, the greater cost of manufacturing and, on the other, the further renewable consumption of electrical energy.

5 Opfindelsen har til formål at tilvejebringe et elektro- termisk indstillingsorgan, som ved en enkelt opbygning ikke blot forhindrer en pludselig kondensation, men også en ved friktion forårsaget hysterese.The invention has for its object to provide an electrothermal adjusting means which, in a single construction, prevents not only a sudden condensation but also a friction caused by friction.

Dette formål opnås ifølge opfindelsen ved, at det ind-10 ledningsvis angivne elektrotermiske indstillingsorgan er ejensdaBimmeligt ved det i krav l's kendetegnende del angivne. ___^This object is achieved according to the invention in that the electrothermal adjusting means, which is stated at the beginning, is not distinguishable by the characteristic part of claim 1. ___ ^

Ved anbringelsen af det radiale mellemrum^ilTv&r^den — - .indtil det sted bestående friktion imellem fortrærigp-15 ningslegemet og indervæggen af den dåseagtige del i praksis ophævet. Den kapillaragtige dimensionerrritpir'F"^"'' mellemrummet f^rhJ^adrlfrF-i" vidtgående grad en uønsket a'rwé'vek"sTing imellem fordampningsrummet og arbejdsrummet. Tilslutningffi'm af den .yderligere d åsæra g t i g e del, 20 stim omslutter foldebælgen, ved den 'førstnævnte dåseag tige del muliggør en kompakt konstruktion af indstillingsorganet med et mindst muligt og derfor inertifattigt væskevolumen, da såvel fordampningsrummet som arbejdsrummet kan slutte sig umiddelbart til det radiale 25 mellemrum. Foldebælgens levetid er større, da denne bliver trykpåvirket udefra i stedet for indefra. Ved en anordning, ved hvilken foldebælgen bliver trykpåvirket udefra, kan fyldningsmængden med fordampningsvæske desuden gøres mindre, da den dåseagtige del, som omslut-30 ter foldebælgen, kan anbringes i umiddelbar nærhed af bælgens udad rettede folder. Det kapillaragtige radiale mellemrum har desuden den fordel, at indstillingsorganet arbejder stillingsuafhængigt, da en ufuldstændigUpon application of the radial space, the transverse friction between the pre-opening body and the inner wall of the can-like portion is effectively lifted. The capillary-like dimensions of the space between the evaporation space and the working space are largely undesirable. Connection of the additional portion, 20 shoals, encloses the fold bellows, at the first mentioned portion allows a compact construction of the adjusting means with a minimum possible and therefore inert liquid volume, since both the evaporation chamber and the working space can immediately join it. radial 25 spaces. The life of the folding bellows is greater as it is pressurized from the outside rather than from the inside. In addition, by a device in which the folding bellows are exerted by pressure, the filling quantity of evaporating liquid can be reduced, since the can-like part which encloses the folding bellows can be placed in the immediate vicinity of the outwardly directed folds of the bellows. The capillary-like radial gap also has the advantage that the adjusting means operates independently, since an incomplete

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3 forskydning af fordampningsvæsken forhindres som følge af tyngdekraftens virkning.3 displacement of the evaporating fluid is prevented due to the effect of gravity.

Ved de i krav 2 og 3 angivne udførelsesformer opnås en høj styrke af fortrængningslegemet med ringe mate-5 rialebehov. Som følge af det ringe materialebehov op nås også en lille termisk træghed.In the embodiments set out in claims 2 and 3, a high strength of the displacement body with low material demand is obtained. Due to the low material demand, a small thermal inertia is also achieved.

Udførelses formerne i krav A og 5 bidrager til, at friktionen mellem fortrængningslegemet og den dåseagtige del holdes mindst mulig.The embodiments of claims A and 5 help to keep the friction between the displacement body and the can-like part as small as possible.

10 Ved en i krav 6 angiven udførelsesform kan det elektri ske varmelegeme være udformet således, at det omfatter fordampningsrummets længde ved den første vandring af stødorganet og det dermed forbundne fortrængningslegeme.In an embodiment as claimed in claim 6, the electric heater may be designed to comprise the length of the evaporation chamber at the first travel of the impactor and the associated displacement body.

Ved den i krav 7 angivne udformning af det radiale mel-15 lemrum udviser dette en tilstrækkelig lang strækning til at opnå en optimal termisk adskillelse imellem fordampningsrummet og arbejdsrummet.In the design of the radial gap space according to claim 7, this exhibits a sufficiently long distance to achieve an optimal thermal separation between the evaporation chamber and the working space.

Den ved en udførelsesform ifølge krav 8 opnåede styrke betinger desuden et så ringe materialeforbrug som muligt, 20 for at forøge indstillingsorganets reaktionshastighed.In addition, the strength obtained in one embodiment according to claim 8 conditions as little material consumption as possible, 20 to increase the reaction rate of the adjusting member.

Opfindelsen skal i det følgende nærmere beskrives med henvisning til tegningen, som viser et elektrotermisk indstillingsorgan i længdesnit.BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the drawing which shows an electrothermal adjusting member in longitudinal section.

Det i et hus 10 anbragte indstillingsorgan har en gen-25 nem en befæstigelsesflange 12 forløbende stødstang 14.The adjusting means arranged in a housing 10 has a thrust bar 14 extending through a fastening flange 12.

Den indre ende af stødstangen 14 er forbundet med en plade 16, imellem hvilken og beholderflangen 12 en foldebælg 18, som omslutter stødstangen 14, strækker sig.The inner end of the thrust bar 14 is connected to a plate 16, between which and the container flange 12 a folding bellows 18 which surrounds the thrust bar 14 extend.

En tilbageføringsfjeder 20 er ved den ene ende under-A return spring 20 is provided at one end underneath.

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4 støttet ved pladen 16 og ved den anden ende på befæ-stigelsesflangen 12.4 supported at the plate 16 and at the other end of the mounting flange 12.

I den modsat foldebælgen 12 liggende side af pladen 16 er der med denne forbundet et cylindrisk, som hul-5 legeme udformet fortrængningslegeme 22, hvis længst fra pladen 16 vendende overside 24 er hvælvet udad. Fortrængningslegemet 22 består af et materiale med ringe varmeledningsevne, eksempelvis af chrom-nikkel-stål. Fortrængningslegemet 22 og foldebælgen 18 er indsat 10 i en dåse, hvis første del 26 omgiver fortrængningsle gemet 22, og hvis anden del 28 omgiver foldebælgen 18.In the opposite side of the folding bellows 12, the side 16 of the plate 16 is connected with a cylindrical, like hollow body, displacement body 22, the outermost surface 24 of which extends farthest from the plate 16. The displacement body 22 consists of a material with low thermal conductivity, for example of chromium-nickel steel. The displacement body 22 and the folding bellows 18 are inserted 10 in a can whose first part 26 surrounds the displacement body 22 and whose second part 28 surrounds the folding bellows 18.

Imellem den første cylindriske dåsedel 26 og fortrængningslegemet 22 er der dannet et kapillaragtigt, radialt mellemrum 30. Den anden cylindriske dåseagtige del 15 28 har en større diameter end den første dåseagtige del 26, da foldebælgen 18 er således beregnet, at dens virksomme tværsnitsflade svarer til fortrængningslegemets 22 tværsnitsflade.Between the first cylindrical can portion 26 and the displacement body 22, a capillary-like radial space 30 is formed. The second cylindrical can-like portion 28 has a larger diameter than the first can-like portion 26, since the folding bellows 18 are designed to correspond to its effective cross-sectional surface. the cross-sectional surface of the displacement body 22.

Imellem fortrængningslegemets 22 hvælvede overside 24 20 og den ligeledes hvælvede overside 32 af den første dåsedel 26 findes et fordampningsrum 34. Rumindholdet af fordampningsrummet 34 er variabel, da fortrængnings-legemet 22 og dermed skiven 16 Samt foldebælgen 18 er forskydelige mod virkningen af fjederen 20 indtil en 25 stilling, i hvilken den hvælvede overside 24 befinder sig i stillingen 24'. I sin største udvidelse strækker fordampningsrummet 34 sig derfor over det med 34' viste område. På cylinderoverfladen af den første dåseagtige del 26 er fordampningsrummet 34' omgivet af 30 et elektrisk varmelegeme 36.Between the vaulted top surface 24 of the displacement body 22 and the also vaulted upper surface 32 of the first can portion 26, there is an evaporation compartment 34. The compartment content of the evaporative compartment 34 is variable, since the displacement body 22 and thus the disc 16 and the folding bellows 18 are displaceable against the action of the spring 20 until a position in which the vaulted top 24 is in position 24 '. In its largest expansion, therefore, the evaporation compartment 34 extends over the region shown by 34 '. On the cylinder surface of the first can-like portion 26, the evaporation compartment 34 'is surrounded by an electric heater 36.

Fordampningsrummet 34, det kapillaragtige radiale mellemrum 30 og et mellem foldebælgens 18 cylinder flade og den anden dåseagtige del 28 dannede arbejdsrum 38The evaporation compartment 34, the capillary radial gap 30, and a working space 38 formed between the cylinder surface of the folding bellows 18 and the second canister-like portion 28

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5 er fyldt med en fordampningsvæske 40. Den af delstykkerne 26 og 28 bestående dåse er ved en sømkant 42 tæt loddet eller svejset med befæstigelsesflangen 12. Desuden er foldebælgen 18 ved sømstedet 42 ligeledes tæt 5 loddet eller svejset med befæstigelsesflangen 12 eller den anden dåseagtige del 28. Fortrængningslegemet 22 og foldebælgen 18 er ligeledes tæt loddet eller svejset med pladen 16 ved sømsteder 44. Ved de angivne forbindelser er fordampningsrummet 34, arbejdsrummet 38 og 10 det kapillaragtige radiale mellemrum 30, som forbinder de to nævnte rum med hinanden, fra alle sider lukket udadtil.5 is filled with an evaporating liquid 40. The can of the parts 26 and 28 is tightly welded or welded at the seam edge 42 to the fastening flange 12. Furthermore, the folding bellows 18 at the seaming point 42 is also tightly welded or welded to the fastening flange 12 or the other can-like part. 28. The displacement body 22 and folding bellows 18 are also tightly soldered or welded to the plate 16 at seams 44. At the indicated connections, the evaporation compartment 34, the working compartment 38 and 10 are the capillary radial spaces 30 connecting the two mentioned compartments to each other from all sides. closed outwards.

En isoleringszone, med hvilken fordampningsrummet 34 eller 34' er termisk isolerede fra arbejdsrummet 38, 15 er vist med henvisningstallet 46. Det som hulrum udformede fortrængningslegeme 22 samt i det mindste den første dåseagtige del 46 har en meget ringe vægtykkelse, således at der over disse dele også kun kan forekomme en meget ringe varmestrømning gennem isolerings-20 zonen 46.An insulation zone with which the evaporation compartment 34 or 34 'is thermally insulated from the working compartment 38, 15 is shown with reference numeral 46. The displacement body 22 formed as a cavity and at least the first can-like part 46 has a very small wall thickness, so that over these parts may also only have very little heat flow through the insulation zone 46.

Fordampningsrummet 34 er således udformet, at den deri indeholdte væskemængde lige netop er tilstrækkelig til i dampformig tilstand at sikre stødstangens 14 fulde udstrækning. Fortrængningslegemets 22 cylinderflade 25 er forsynet med et gildelag for at gøre en mulig friktion imellem fortrængningslegemet 22 og den første dåseagtige del 26 så lille som mulig. Det er desuden mu ligt at anbringe små, ikke viste fremspring på fortrængningslegemets 22 cylinderflade for at begrænse friktio-30 nen på disse fremspring. Indstillingsorganets virkemå de skal forklares i det følgende: Det elektriske varmelegeme 36 bliver tilført en hele tiden foranderlig elektrisk effekt med en vedvarende regulator. Ved opvarmningen fordampes fordampningsvæsken i fordampningsrum-The evaporation compartment 34 is designed such that the amount of liquid contained therein is just sufficient to ensure, in the vapor state, the full extent of the thrust bar 14. The cylinder surface 25 of the displacement body 22 is provided with a guide layer to make possible friction between the displacement body 22 and the first can-like part 26 as small as possible. Furthermore, it is possible to place small projections not shown on the cylinder surface of the displacement body 22 to limit the friction on these projections. The operation of the adjusting means must be explained in the following: The electric heater 36 is supplied with a constantly changing electric power with a continuous regulator. Upon heating, the evaporating liquid is evaporated in the evaporation chamber.

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6 met 34, således at der på fortrængningslegemet 22 og på foldebælgen 18 udøves et tryk, ved hjælp af hvilket fortrængningslegemet samt foldebælgen 18 og den dertil fastgjorte stødstang 14 bliver bevæget i retning af 5 stillingen 14' eller 24' mod virkningen fra fjederen 20, indtil der indstiller sig en ligevægtstilstand mellem det i fordampningsrummet 34 opbyggede tryk og virkningen af fjederen 20. Indstillingen af stødstangen 14 er derfor afhængig af den til det elektriske varme-10 legeme 36 tilførte elektriske effekt.6 with 34, so that a pressure is exerted on the displacement body 22 and on the folding bellows 18 by means of which the displacement body and the folding bellows 18 and the supporting rod 14 attached thereto are moved in the direction of the position 14 'or 24' against the action of the spring 20, until an equilibrium state is established between the pressure built up in the evaporative space 34 and the action of the spring 20. The adjustment of the thrust bar 14 is therefore dependent on the electrical power applied to the electric heating body 36.

Da foldebælgen 18's virksomme tværsnit stemmer overens med det virksomme tværsnit af fortrængningslegemet 22, bliver der ved en fortrængning ingen væskeforskydning imellem fordampningsrummet 34 og arbejdsrummet 38 gen-15 nem den kapillaragtige ringspalte 30. Som følge af en sådan udformnijiug sikres det, at der som ffnal-ge af en tilbagestilling som følge af reduceret varmeydelse ikke kan komme kold fordampningsvæske ind i fordampnings-rummet 34. Desuden sikrer isoleringszonen 46, at varme-20 tabet fra fordampningsrummet 34 eller 34' i retning mod arbejdsrummet 38 er meget ringe. Som fordampningsvæske anvendes fortrinsvis enten vand eller trichlor-fluormethan.Since the effective cross-section of the folding bellows 18 corresponds to the effective cross-section of the displacement body 22, no displacement of fluid between the evaporation chamber 34 and the working space 38 through the capillary annular gap 30. In such a configuration, it is ensured that Because of a reduced heat output, cold evaporation fluid cannot enter the evaporation compartment 34. Furthermore, the insulation zone 46 ensures that the heat loss from evaporation compartment 34 or 34 'towards the working compartment 38 is very low. Preferably, either water or trichlorofluoromethane are used as the evaporating liquid.

Den beskrevne konstruktion har ialt et meget ringe rum-25 indhold for fordampningsvæsken, hvorved indstillingsor ganets termiske inerti er reduceret til et minimum. Reaktionshastigheden af det beskrevne indstillingsorgan når ligeledes en minimal værdi.The construction described has a very low volume content of the evaporating liquid, thereby reducing the thermal inertia of the adjusting member to a minimum. The reaction rate of the described adjusting member also reaches a minimal value.

Det særlige ved denne konstruktion består i, at der 30 imellem fordampningsrummet 34 og arbejdsrummet 38 ikke kræves nogen tætning, og at der alligevel i praksis ikke finder nogen væskeforskydning sted imellem disse to rum, når fortrængningslegemet 22 og foldebælgen 18The special feature of this construction consists in the fact that between the evaporative compartment 34 and the working compartment 38 no sealing is required and that, in practice, no liquid displacement takes place between these two compartments when the displacement body 22 and the folding bellows 18

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7 bliver forskudt.7 will be displaced.

Skønt oversiden 24 af fortrængningslegemet 22 ved det viste udførelseseksempel er hvælvet udad, er det også muligt at hvælve dette indad. Det er i hvert tilfælde 5 af betydning, at såvel oversiden 24 af fortrængnings- legemet 22 som af overfladen 32 af den dåseagtige del 26 er hvælvet ensartet for at opnå et relativt smalt fordampningsrum 34.Although the upper side 24 of the displacement body 22 is vaulted outwardly in the illustrated embodiment, it is also possible to vault this inwardly. In each case 5, it is important that both the top surface 24 of the displacement body 22 and of the surface 32 of the can-like portion 26 are vaulted uniformly to obtain a relatively narrow evaporative space 34.

Claims

An electrothermal adjusting means having a heatable evaporative compartment (34) of variable volume content filled with an evaporative liquid located between the upper side (32) of a cylindrical can-like portion (26) and the upper side (24) of a displaceable cylindrical displacement body ( 22) of a thermally inferior conductive material, wherein the displacement body (22) at a junction (44) is mechanically connected to a folding bellows (18) defining a work space (38) filled with evaporative liquid (38) to which fastened a thrust bar (14) which is actuated by a reset spring (20) and wherein the cross-sectional surface of the displacement body (22) is as large as the effective cross-sectional surface of the folding bellows (18), characterized by part (26) and the displacement body (22), there is a capillary-like radial gap (30) which connects the evaporation chamber (34) to the working space (38) located between 20 the outside of the folding bellows (18) and a further can-like portion (28) which joins the first-mentioned can-like portion (26).

Adjusting device according to claim 1, characterized in that the displacement body (22) is a hollow.

Adjusting device according to claim 2, characterized in that the displacement body (22) and / or at least the first mentioned can-like part (26) surrounding the displacement body consists of a metal with low thermal conductivity such as e.g. chromium-nickel-steel.

Adjusting means according to any one of the preceding claims, characterized in that the displaceable bearing surface (22) of the cylinder (22) of the blade (22) is provided with a guard layer.

Adjusting means according to claim 4, characterized in that projections are provided on the cylinder surface of the displacement body (22).

Adjusting device according to any one of the preceding claims, characterized in that an electric heater (36) is arranged at the region adjacent the upper side (32) of the cylinder surface of the first mentioned can-like part (26).

Adjusting means according to any one of the preceding claims, characterized in that the capillary radial space (30) is longer than the largest dimension of the evaporation chamber (34 ').

Adjusting means according to any one of claims 1-7, 15, characterized in that the displacement body (22) and the first mentioned can-like part (26) are vaulted uniformly on the upper side.