NO116407B

NO116407B -

Info

Publication number: NO116407B
Application number: NO160705A
Authority: NO
Inventors: A Schwartzkopf
Original assignee: Windmoeller & Hoelscher
Priority date: 1964-11-30
Filing date: 1965-11-30
Publication date: 1969-03-17
Also published as: FI52310C; FR1455621A; DK108447C; DE1486724B1; FI52310B; GB1131063A; SE326401B; US3352411A

Description

Betjeningsmekanisme for ekshaustbremseapparater for motorkjøretøyer. Operating mechanism for exhaust brake devices for motor vehicles.

Foreliggende oppfinnelse angår ekshaustbremseapparater for motorkjøretøyer, The present invention relates to exhaust brake devices for motor vehicles,

dvs. apparater som nedsetter hastigheten i.e. devices that reduce speed

av et kjøretøy ved å hemme avløpet av of a vehicle by obstructing the drain of

ekshaustgassen fra motoren. Dette utføres the exhaust gas from the engine. This is carried out

ved hjelp av en strupeventil eller et annet by means of a choke valve or another

stengeorgan, som anbringes i ekshaustledningen og som er innrettet slik at den helt closing device, which is placed in the exhaust line and which is designed so that it completely

eller delvis kan stenge for ekshaustavløpet, or can partially block the exhaust outlet,

så at det i dette dannes et mottrykk slik so that in this a counter pressure is formed like this

at motorens hastighet nedsettes og vognen that the speed of the engine is reduced and the carriage

derved bremses av gjennom transmisjonen. thereby slowing down through the transmission.

Oppfinnelsen angår særlig ekshaustbremseapparater av den type som anven-der et roterende stengeorgan, som er anbragt i ekshaustrøret og betjenes av en The invention particularly relates to exhaust brake devices of the type that use a rotating closing device, which is placed in the exhaust pipe and is operated by a

mekanisme utenfor ekshaustrøret ved hjelp mechanism outside the exhaust pipe using

av en overføringsaksel, som er dreibart lagret i ekshaustrørets vegg og raker utenfor of a transmission shaft, which is rotatably stored in the wall of the exhaust pipe and rakes outside

denne for forbindelse med betjeningsan-ordningen. this for connection with the operating device.

Oppfinnelsens hensikt er å tilveie-bringe en forbedret betjeningsanordning The purpose of the invention is to provide an improved operating device

for slike apparater. for such devices.

Ifølge oppfinnelsen omfatter betjen-ingsmekanismen for et ekshaustbremse-apparat av nevnte art en fjæranordning, According to the invention, the operating mechanism for an exhaust brake device of the aforementioned type comprises a spring device,

som normalt holder stengeorganet i fullt which normally keeps the closure in full

åpen stilling, samt en elektromagnetisk open position, as well as an electromagnetic one

anordning, som når den tilføres strøm virker til å overvinne fjæranordningens mot-kraft så at stengeanordningen helt eller device, which when supplied with current acts to overcome the spring device's counter force so that the rod device completely or

delvis stenges. Det hovedsakelig karakter-istiske ved oppfinnelsen er at fjæranordningens spesifikke fjærkraft tiltar under partially closed. The main characteristic of the invention is that the spring device's specific spring force increases below

stengeorganets bevegelse mot stengestilling. the closing member's movement towards the closing position.

Det kan også benyttes anordninger til Devices can also be used for

å sikre at tilstrekkelig mengde gass kan to ensure that a sufficient amount of gas can

unnslippe når ekshaustbremsen er i arbeidsstilling, slik at motoren ikke stopper. escape when the exhaust brake is in working position, so that the engine does not stop.

Dette kan oppnåes ved at stengeorganet er This can be achieved by the closing member being

anordnet slik at det aldri er helt lukket. Al-ternativt kan dette oppnås ved å anordne organer, som påvirkes avtrykket på den mot gasstrømmen vendende side av stengeorganet, så at stengeorganet åpnes i hvert fall delvis når trykket faller til en forutbestemt verdi. Ved et tredje arrangement anordnes organer) som er avhengig av motorens hastighet og som bevirker at stengeorganet åpnes i hvert fall delvis før motorens hastighet avtar til tomgangshastighet. arranged so that it is never completely closed. Alternatively, this can be achieved by arranging organs, which are affected by the pressure on the side of the closing member facing the gas flow, so that the closing member is at least partially opened when the pressure falls to a predetermined value. In a third arrangement, means are arranged) which are dependent on the engine's speed and which cause the closing means to be opened at least partially before the engine's speed decreases to idling speed.

Oppfinnelsen skal beskrives i det føl-gende under henvisning til hosstående teg-ninger. Fig. 1 viser en utførelsesform av oppfinnelsen sett fra siden. Fig. 2 viser samme utførelsesform sett The invention shall be described in the following with reference to the accompanying drawings. Fig. 1 shows an embodiment of the invention seen from the side. Fig. 2 shows the same embodiment seen

fra høyre ende i fig. 1. from the right end in fig. 1.

Fig. 3 og 4 viser detaljer, som illustrerer to alternative metoder for betjening av mekanismen. Fig. 5 er en skjematisk fremstilling av anordninger til fastlåsing av stengeorganet i dets stengestilling. Fig. 6, 7 og 8 er skjematiske fremstil-linger av tre alternative anordninger som bevirker at stengeanordningen automatisk åpnes, hvis det er fare for at motoren skal stoppe når den er kommet ned på tomgang som følge av en påvirkning av stengeorganet. Fig. 9 illustrerer skjematisk ytterligere Figs 3 and 4 show details, which illustrate two alternative methods of operating the mechanism. Fig. 5 is a schematic representation of devices for locking the closing member in its closing position. Fig. 6, 7 and 8 are schematic representations of three alternative devices which cause the closing device to automatically open, if there is a danger that the engine will stop when it has reached idle as a result of an influence on the closing device. Fig. 9 schematically illustrates further

en utførelsesform av oppfinnelsen. an embodiment of the invention.

Fig. 10 er en horisontalprojeksjon av en modifikasjon av den i fig. 1 og 2 viste utførelsesform, og Fig. 11 og 12 viser, sett fra siden, nok en utførelsesform av oppfinnelsen i to al-ternativer. Fig. 10 is a horizontal projection of a modification of that in fig. 1 and 2 showed an embodiment, and Fig. 11 and 12 show, seen from the side, another embodiment of the invention in two alternatives.

Ved den viste utførelsesform er eks-haustbremsens ventilanordning av kjent type og består av et dreibart stengeorgan (ikke vist) av spjeldtypen fritt lagret i et rørformet hus 1, som er innskutt i eks-haustrøret 2 foran lyddemperen. Husets ender har flenser som antydet ved 3, som passer sammen med flenser 4 på de til-støtende ender av ekshaustrøret. Mellom flensene er anbragt asbestpakninger, og huset holdes på plass ved boltene 5. Spjeld-ventilen betjenes fra betjeningsmekanis-men, som er montert utenfor ekshaustkanalen, ved hjelp av en aksel 6, som er lagret i og raker gjennom ventilhusets vegg og strekker seg gjennom veggen av huset på ventilens lavtrykkside samt er mekanisk forbundet med ventilen således at ventilen stenges eller åpnes når akselen dreies i den ene eller den annen retning ved hjelp av betj eningsmekanismen. In the embodiment shown, the valve arrangement of the exhaust brake is of a known type and consists of a rotatable closing member (not shown) of the damper type freely stored in a tubular housing 1, which is inserted into the exhaust pipe 2 in front of the silencer. The ends of the housing have flanges as indicated at 3, which mate with flanges 4 on the adjacent ends of the exhaust pipe. Asbestos gaskets are placed between the flanges, and the housing is held in place by bolts 5. The flap valve is operated from the operating mechanism, which is mounted outside the exhaust duct, by means of a shaft 6, which is stored in and rakes through the wall of the valve housing and extends through the wall of the housing on the valve's low-pressure side and is mechanically connected to the valve so that the valve is closed or opened when the shaft is turned in one direction or the other by means of the operating mechanism.

Ventilen kan anordnes dreibart om en diametral akse, i hvilket tilfelle den er avbalansert i forhold til ekshaustgasstrykket, som virker på den når den er lukket, eller om en ikke diametral akse, således at ekshaustgasstrykket vil søke å åpne ventilen. Dette trykk er størst når ventilen er helt lukket og avtar etterhvert som ventilen åpnes og når et minimum når ventilen gir full åpning. The valve can be arranged rotatably about a diametrical axis, in which case it is unbalanced in relation to the exhaust gas pressure, which acts on it when it is closed, or about a non-diametrical axis, so that the exhaust gas pressure will seek to open the valve. This pressure is greatest when the valve is fully closed and decreases as the valve opens and reaches a minimum when the valve opens fully.

I den utførelsesform som er vist i fig. 1 og 2 bevirkes ventilens stengning ved hjelp av en solenoid 7, som er festet paral-lelt med ekshaustrøret ved hjelp av en plate 8, som er fastklemt mellom flensen i den ene ende av ventilhuset og den nær-liggende flens på ekshaustrøret. Bevegel-sene av solenoidens kjerne 9 overføres til ventilakselen 6 ved hjelp av en stang 10, som i den ene ende er svingbart forbundet med den ytre ende av kjernen 9 og i den annen ende med en vektarm 11 festet til akselen 6 utenfor ventilhuset 1. Vektarmen 11 er sikret til akselen ved hjelp av en oppsplittet rund klemme 12, som tillater en vinkeljustering av vektarmen i forhold til ventilen. In the embodiment shown in fig. 1 and 2, the closing of the valve is effected by means of a solenoid 7, which is attached parallel to the exhaust pipe by means of a plate 8, which is clamped between the flange at one end of the valve housing and the nearby flange on the exhaust pipe. The movements of the solenoid's core 9 are transferred to the valve shaft 6 by means of a rod 10, which at one end is pivotally connected to the outer end of the core 9 and at the other end with a weight arm 11 attached to the shaft 6 outside the valve housing 1. The weight arm 11 is secured to the shaft by means of a split round clamp 12, which allows an angular adjustment of the weight arm in relation to the valve.

Fra den innerste ende av solenoidens kjerne raker det frem en koaksial stang 13, som er ført gjennom trykkfjæren 14, anbragt i en forlengelse 15 av solenoidens hus. Fjæren holdes fast mellom enden av sitt hus og en krave 16 på stangen 13, således at den utøver en kraft gjennom kjernen 9, stangen 10, vektarmen 11 og akselen 6 og derved beveger ventilen til åpen stilling. I den nedenfor beskrevne hensikt er fjæren av det slag hvis spesifikke fjærkraft øker ved sammenpresning. Alterna-tivt kan det anordnes nok en fjær 17, som fortrinnsvis er stivere enn den første, idet den annen fjær er anordnet slik at den kun er i funksjon når ventilen begynner å åpnes. From the innermost end of the solenoid's core, a coaxial rod 13 protrudes, which is guided through the compression spring 14, placed in an extension 15 of the solenoid's housing. The spring is held between the end of its housing and a collar 16 on the rod 13, so that it exerts a force through the core 9, the rod 10, the weight arm 11 and the shaft 6 and thereby moves the valve to the open position. In the purpose described below, the spring is of the kind whose specific spring force increases when compressed. Alternatively, another spring 17 can be arranged, which is preferably stiffer than the first, the second spring being arranged so that it is only in function when the valve begins to open.

Solenoiden er innkoblet i en strøm-krets 18 gjennom vognens batteri 19 eller dynamo og en bryter 20, som kan være montert på dashbordet eller styrestangen og betjenes av kjøreren ved behov. The solenoid is connected in a power circuit 18 through the carriage's battery 19 or dynamo and a switch 20, which can be mounted on the dashboard or steering column and operated by the driver when necessary.

Fig. 3 og 4 illustrerer to alternative metoder for styring av solenoidens funksjon. Ved den ene (fig. 3) settes solenoiden automatisk i funksjon ved at vognens gass-pedal slippes opp. Dette oppnåes ved hjelp av en bryter 21, som er montert like ved pedalen 22 og betjenes ved hjelp av en trykknapp 23, som er bestemt til å presses ned av gasspedalen slik at bryteren sluttes når pedalen slippes (som vist med prikkede linjer i fig. 3). Ved den metode som er vist i fig. 4 kontrolleres solenoiden av en bryter 24, som er montert på vognens bremsepedal, idet arrangementet er slik at ekshaustventilen settes i funksjon før hjulbremsene. Bryteren betjenes ved hjelp av en trykknapp 25, som er anordnet til å presses ned ved hjelp av en hengslet plate 26 når kjøreren plaserer foten på gasspedalen, idet nedtrykningen av trykknappen lukker bryteren. Fig. 3 and 4 illustrate two alternative methods for controlling the function of the solenoid. With one (fig. 3), the solenoid is automatically activated by releasing the vehicle's gas pedal. This is achieved by means of a switch 21, which is mounted close to the pedal 22 and is operated by means of a push button 23, which is intended to be pressed down by the gas pedal so that the switch closes when the pedal is released (as shown by dotted lines in fig. 3). By the method shown in fig. 4, the solenoid is controlled by a switch 24, which is mounted on the carriage's brake pedal, the arrangement being such that the exhaust valve is activated before the wheel brakes. The switch is operated by means of a push button 25, which is arranged to be pressed down by means of a hinged plate 26 when the driver places his foot on the gas pedal, as pressing the push button closes the switch.

Hvis solenoiden betjenes fra gasspedalen eller bremsepedalen, er det fortrinnsvis anbragt en hovedbryter i strømkretsen 18, slik at kjøreren kan sette mekanismen ut av funksjon ved behov. If the solenoid is operated from the gas pedal or the brake pedal, a main switch is preferably placed in the circuit 18, so that the driver can put the mechanism out of action if necessary.

Når mekanismen betjenes vil kontrollbryteren slutte strømkretsen 18, så at solenoiden blir strømførende. Kjernen 9 trekkes inn i spolen under motstand fra fjæren 14 og eventuelt den annen fjær 17, hvor sådan benyttes, og gjennom bolten 10 og vektarmen 11 vil kjernen dreie akselen 6 så ventilen stenges. Vektarmens 11 stilling når ventilen er helt lukket er vist med prikkede linjer i fig. 1. Når bryteren åpnes igjen, blir solenoiden strømløs, således at fjæren eller fjærene gjennom kjernen 9, stangen 10, vektarmen 11 og akselen 6 atter åpner ventilen. When the mechanism is operated, the control switch will close the circuit 18, so that the solenoid will be energized. The core 9 is drawn into the coil under resistance from the spring 14 and possibly the other spring 17, where such is used, and through the bolt 10 and the weight arm 11 the core will turn the shaft 6 so that the valve is closed. The position of the weight arm 11 when the valve is fully closed is shown with dotted lines in fig. 1. When the switch is opened again, the solenoid is de-energized, so that the spring or springs through the core 9, the rod 10, the weight arm 11 and the shaft 6 open the valve again.

I det tilfelle hvor ventilen er avbalansert om sin svingeakse med henblikk på ekshaustgasspresset, som virker på ventilen når den er lukket, er den kraft, som er nød-vendig for å motvirke dette press og sette igang ventilens åpningsbevegelse, større enn den kraft som trenges til å fullføre åpningsbevegelsen. Den nødvendige ekstra kraft frembringes på ovennevnte måte ved anvendelse av en enkelt fjær, hvis spesifikke fjærkraft øker under ventilens bevegelse henimot stengestillingen, eller en kombinasjon av to fjærer anordnet således at fjærkombinasjonens spesifikke fjærkraft øker under den siste del av ventilens stengebevegelse. Dette muliggjør bruken av en mindre kraftig solenoid og derfor en svakere betjeningsstrøm enn hva som ville kreves om det ble brukt en tilstrekkelig sterk enkelt fjær med konstant spesifikk fjærkraft. Ved anvendelse av to fjærer eller en enkelt fjær med varierende spesifikk fjærkraft vil motstanden mot den elektromagnetiske trekkraft på solenoidens kjerne når denne trekkraft er svakest, dvs. ved begynnelsen av solenoidens virksomhet, være meget mindre enn om det ble anvendt en enkelt fjær med konstant spesifikk fjærkraft avpasset til å gi samme begyn-nende ventilåpningskraft. Bruken av to fjærer eller en enkelt fjær med varierende spesifikk fjærkraft bevirker naturligvis en viss «stivhet» i motstanden mot stengningen av ventilen, men dette motvirkes av den økede magnetiske tiltrekningskraft på kjernen ettersom denne trekkes lenger inn i spolen. Denne stivhet i fjærmotstanden har den fordel at den hindrer solenoiden i å stenge ventilen med et slag. In the case where the valve is unbalanced about its axis of rotation with regard to the exhaust gas pressure, which acts on the valve when it is closed, the force which is necessary to counteract this pressure and initiate the opening movement of the valve is greater than the force required to complete the opening movement. The necessary additional force is produced in the above-mentioned manner by using a single spring, whose specific spring force increases during the movement of the valve towards the closing position, or a combination of two springs arranged so that the specific spring force of the spring combination increases during the last part of the closing movement of the valve. This enables the use of a less powerful solenoid and therefore a weaker operating current than would be required if a sufficiently strong single spring with constant specific spring force were used. When using two springs or a single spring with varying specific spring force, the resistance to the electromagnetic pulling force on the solenoid's core when this pulling force is weakest, i.e. at the start of the solenoid's operation, will be much less than if a single spring with constant specific force was used spring force adjusted to give the same initial valve opening force. The use of two springs or a single spring with varying specific spring force naturally causes a certain "stiffness" in the resistance to the closing of the valve, but this is counteracted by the increased magnetic attraction force on the core as it is drawn further into the coil. This stiffness in the spring resistance has the advantage of preventing the solenoid from slamming the valve shut.

For å redusere kraftforbruket når ap-paratet skal være i funksjon uavbrutt i et lengre tidsrom, som f. eks. når vognen kjø-rer utfor en lengre bakke, er det anordnet midler til mekanisk fastlåsing av ventilen i stengt stilling. Ved en utførelsesform som vist skjematisk i fig. 5, består disse midler av en tapp 27, som kan komme i inngrep med et sirkulært spor eller en stopper 28 i solenoidkjernens 9 forlengelsesstang 13, når kjernen befinner seg i inntrukket eller arbeidsstilling inne i solenoiden, dvs. når ekshaustbremseventilen er stengt. Tappen, som presses mot stangen 13 ved hjelp av en fjær 29, bærer den bevegelige kontakt 30 på en bryter 31, som er innskutt i strøm-kretsen 18. Når kjernen 9 er ute av funksjon, som vist i fig. 5, dvs. når ekshaustbremseventilen er åpen, holdes bryteren 31 lukket ved anslag av tappen 27 mot stangen 13 slik at strømkretsen 18 er klar til å sluttes av hovedkontrollbryteren 20. For å stenge ventilen blir den bevegelige kontakt 32 på bryteren 20 bragt i kontakt med en fast kontakt 33 i samme bryter så at strømkretsen 18 sluttes og solenoiden 7 til-føres strøm. Når kjernen 9 når sin arbeidsstilling og ventilen er stengt, vil tappen 27 gripe inn i sporet 28 i stangen 13, hvorved kjernen og derfor også ventilen låses fast i sine arbeidsstillinger, samtidig som bryteren 31 bryter strømkretsen 18 så at energiforbruket opphører. Den bevegelige kontakt 32 i bryteren kan så føres tilbake til nullstilling. Det kan anordnes fjærende organer for å tvinge kontakten tilbake til nullstilling. To reduce power consumption when the device must be in operation continuously for a longer period of time, such as e.g. when the carriage drives down a long hill, means are provided for mechanically locking the valve in the closed position. In an embodiment as shown schematically in fig. 5, these means consist of a pin 27, which can engage with a circular groove or a stop 28 in the solenoid core 9 extension rod 13, when the core is in the retracted or working position inside the solenoid, i.e. when the exhaust brake valve is closed. The pin, which is pressed against the rod 13 by means of a spring 29, carries the movable contact 30 on a switch 31, which is inserted into the current circuit 18. When the core 9 is out of order, as shown in fig. 5, i.e. when the exhaust brake valve is open, the switch 31 is held closed by the impact of the pin 27 against the rod 13 so that the current circuit 18 is ready to be closed by the main control switch 20. To close the valve, the movable contact 32 on the switch 20 is brought into contact with a fixed contact 33 in the same switch so that the current circuit 18 is closed and the solenoid 7 is supplied with current. When the core 9 reaches its working position and the valve is closed, the pin 27 will engage in the groove 28 in the rod 13, whereby the core and therefore also the valve is locked in its working positions, at the same time that the switch 31 breaks the current circuit 18 so that the energy consumption ceases. The movable contact 32 in the switch can then be returned to the zero position. Resilient means may be provided to force the contact back to the zero position.

For påny å åpne ventilen blir kontakten 32 bragt i kontakt med en fast kontakt 34 så at det sluttes en strømkrets 35 gjennom en solenoid 36, som virker på tappen 27. Denne solenoids magnetiske felt bevirker at tappen trekkes ut"av sporet 28, slik at kjernen 9 blir frigjort for bevegelse tilbake til sin utgangsstilling under påvirkning av fjæren 14, hvorved ventilen åpnes samtidig som brytérén 31 sluttes for å forberede strømkretsen 18 for videre påvirkning av ventilen'. Kontakten 32 kan så føres tilbake til nullstilling så at strømkretsen gjennom solenoiden 36 brytes, idet bryteren 31 holdes lukket ved anslag av tappen 27 mqt stangen 13. To open the valve again, the contact 32 is brought into contact with a fixed contact 34 so that a current circuit 35 is closed through a solenoid 36, which acts on the pin 27. This solenoid's magnetic field causes the pin to be pulled out of the slot 28, so that the core 9 is freed for movement back to its original position under the action of the spring 14, whereby the valve is opened at the same time that the switch 31 is closed to prepare the circuit 18 for further actuation of the valve'. The contact 32 can then be brought back to the zero position so that the circuit through the solenoid 36 is broken, as the switch 31 is kept closed when the pin 27 hits the rod 13.

Da motoren har lett for å stanse hvis ekshaustbremseventilen holdes stengt når motoren er kommet ned på tomgangshastighet etter at ;bremseventilen har vært i funksjon, anvendes en anordning som automatisk åpner ventilen hvis det oppstår fare for motorstopp. Ved en utførelses-form, som er illustrert skjematisk i fig. 6, består denne anordning av en bryter 37, som er innskutt i strømkretsen 18 og betjenes av en sentrifugalanordning 38 på-virket av motorens hastighet. Når motorhastigheten er over en bestemt verdi, som kan være tomgangshastighet eller like over, vil sentrifugalanordningen tillate at bryteren forblir lukket f. eks. ved hjelp av As the engine is easy to stop if the exhaust brake valve is kept closed when the engine has come down to idle speed after the brake valve has been in operation, a device is used that automatically opens the valve if there is a risk of engine stalling. In an embodiment, which is illustrated schematically in fig. 6, this device consists of a switch 37, which is inserted into the current circuit 18 and is operated by a centrifugal device 38 affected by the speed of the engine. When the engine speed is above a certain value, which may be idle speed or just above, the centrifugal device will allow the switch to remain closed, e.g. using

en fjær 39, slik at strømkretsen 18 er klar a spring 39, so that the current circuit 18 is ready

til å sluttes ved anvendelse av hovedbry-teren 20 når det blir nødvendig å betjene ventilen. Når motorhastigheten som et resultat av bruken av ventilen avtar til den to be closed by using the main switch 20 when it becomes necessary to operate the valve. When the engine speed as a result of the use of the valve decreases to it

forutbestemte verdi, vil sentrifugalanordningen fjerne den bevegelige kontakt 40 i bryteren 37 fra dennes faste kontakt 41, predetermined value, the centrifugal device will remove the movable contact 40 in the switch 37 from its fixed contact 41,

hvorved strømkretsen 18 gjennom solenoiden 7 brytes og ventilen åpnes igjen. whereby the current circuit 18 through the solenoid 7 is broken and the valve is opened again.

En annen utførelsesform er vist i fig. 7, hvor anordningen for automatisk gjenåpning av ventilen når motorhastigheten avtar til tomgangshastighet består av en bryter 42, som er innskutt i strømkretsen 18 og betjenes av en solenoid 43. Denne Another embodiment is shown in fig. 7, where the device for automatically reopening the valve when the engine speed decreases to idle speed consists of a switch 42, which is inserted into the circuit 18 and is operated by a solenoid 43. This

solenoid tilføres strøm fra vognens dynamo solenoid is supplied with power from the vehicle's dynamo

44 gjennom den normale bryter 45, som er 44 through the normal switch 45, which is

plasert mellom dynamoen og batteriet. Ved normalt turtall, når bryteren 45 forblir lukket, tilføres solenoiden 43 strøm for å holde bryteren 42 lukket, så at strømkret-sen 18 er klar til å sluttes av kontrollbryteren 20 når det blir nødvendig å bruke ventilen. Når motoren som følge av bruken av ventilen er bragt ned på tomgangshastighet, vil bryteren 45 åpnes i vanlig placed between the alternator and the battery. At normal speed, when the switch 45 remains closed, current is supplied to the solenoid 43 to keep the switch 42 closed, so that the circuit 18 is ready to be closed by the control switch 20 when it becomes necessary to use the valve. When, as a result of the use of the valve, the engine has been brought down to idling speed, the switch 45 will be opened in normal

tur og orden så at solenoiden 43 blir strøm-løs. Bryteren 42 blir følgelig åpnet, f. eks. ved en fjær 46, hvorved strømkretsen 18 brytes så at solenoiden 7 blir strømløs og ventilen atter åpnes. turn and order so that the solenoid 43 becomes de-energized. The switch 42 is consequently opened, e.g. by a spring 46, whereby the current circuit 18 is broken so that the solenoid 7 becomes de-energized and the valve opens again.

Ved den tredje utførelsesform, som er vist i fig. 8, består nevnte anordning av en trykkbryter 47, som påvirkes av gasstryk-ket i ekshaustrøret 2 på ventilens opp-strømsside, hvilken bryter er innskutt i en strømkrets 48 som er koblet sammen med hovedstrømkretsen 18 gjennom hovedkontrollbryteren 20. Sistnevnte har en bevegelig kontakt 49, som en fjær 50 søker å holde i bruddstilling, og to overlappende bue- eller segmentformede faste kontakter 51 og 52 i strømkretsen 18 henholdsvis 18. For å stenge ventilen bringes den bevegelige kontakt 49 i kontakt med den faste kontakt 51 i hovedstrømkretsen 18, hvorved denne strømkrets sluttes og solenoiden 7 blir strømførende. Kontakten 49 beveges så videre til kontakt med kontakten 52 i strømkretsen 48, dog uten at berøringen med kontakten 51 i hovedstrømkretsen avbrytes. Imidlertid vil det trykk, som bygges opp i ekshaustgassen på ventilens opp-strømsside som resultat av ventilens virkning, virke på bryteren 47. Når trykket overskrider en forutbestemt verdi, ved hvilken denne bryter skal tre i funksjon og som kan opptre når motoren befinner seg under tomgangsforhold, vil trykket lukke bryteren så at strømkretsen 48 sluttes. Solenoiden blir nu tilført strøm gjennom begge strømkretser 18 og 48. Kontakten 49 beveges så videre forbi kontakten 51, så at hovedstrømkretsen 18 brytes og solenoiden 7 bare påvirkes gjennom strøm-kretsen 48. Kontakten 49 holdes i denne endestilling av en elektromagnet 53, som magnetiseres gjennom strømkretsen 48. Ettersom motorens hastighet reduseres som følge av bruken av ventilen, avtar trykket i ekshaustgassen på ventilens opp-strømsside tilsvarende, og når trykket når den nevnte forutbestemte verdi åpnes bryteren 47 og bryter strømkretsen 48, så at solenoiden 7 blir strømløs og ventilen åpnes igjen. Brytingen av kretsen 48 bevirker også brytning av strømmen i elektromag-neten 53 med det resultat at den bevegelige kontakt 49 i kontrollbryteren 20 frigis for bevegelse tilbake til nullstilling ved hjelp av fjæren 50. In the third embodiment, which is shown in fig. 8, said device consists of a pressure switch 47, which is affected by the gas pressure in the exhaust pipe 2 on the valve's upstream side, which switch is inserted into a current circuit 48 which is connected to the main current circuit 18 through the main control switch 20. The latter has a movable contact 49 , which a spring 50 seeks to hold in the broken position, and two overlapping arc or segment-shaped fixed contacts 51 and 52 in the current circuit 18 and 18 respectively. To close the valve, the movable contact 49 is brought into contact with the fixed contact 51 in the main current circuit 18, whereby this circuit is closed and the solenoid 7 becomes live. The contact 49 is then moved further into contact with the contact 52 in the current circuit 48, however without the contact with the contact 51 in the main current circuit being interrupted. However, the pressure which builds up in the exhaust gas on the upstream side of the valve as a result of the action of the valve will act on the switch 47. When the pressure exceeds a predetermined value, at which this switch shall operate and which may occur when the engine is under idle conditions, the pressure will close the switch so that the current circuit 48 is closed. The solenoid is now supplied with current through both current circuits 18 and 48. The contact 49 is then moved further past the contact 51, so that the main current circuit 18 is broken and the solenoid 7 is only affected through the current circuit 48. The contact 49 is held in this end position by an electromagnet 53, which is magnetized through the circuit 48. As the speed of the engine is reduced as a result of the use of the valve, the pressure in the exhaust gas on the upstream side of the valve decreases accordingly, and when the pressure reaches the aforementioned predetermined value, the switch 47 opens and breaks the circuit 48, so that the solenoid 7 becomes de-energized and the valve opens again. The breaking of the circuit 48 also causes the breaking of the current in the electromagnet 53 with the result that the movable contact 49 in the control switch 20 is released for movement back to the zero position by means of the spring 50.

Den faste kontakt 52 i strømkretsen 48 overlapper kontakten 51 i hovedstrømkret-sen 18 tilstrekkelig til å sikre at, hvis kontakten 49 beveges fra nullstilling til den endelige arbeidsstilling i en sammenhen-gende bevegelse, vil ekshaustgasstrykket lukke bryteren 47 så at strømkretsen 48 sluttes før kontakten 49 forlater kontakten 51 for å bryte strømkretsen 18. The fixed contact 52 in the current circuit 48 overlaps the contact 51 in the main current circuit 18 sufficiently to ensure that, if the contact 49 is moved from the zero position to the final working position in one continuous movement, the exhaust gas pressure will close the switch 47 so that the current circuit 48 is closed before the contact 49 leaves the contact 51 to break the circuit 18.

I den utførelsesform av oppfinnelsen, som er vist skjematisk i fig. 9, har ventilens stengesolenoid 7 to separate spoler 54 og 55, så at ventilen kan stenges enten delvis eller helt etter behov. Solenoidkjernen 9 er som vist delt for å passe til antallet spoler. De sistnevnte er innkoblet i strømkretsen 18 gjennom kontrollbryteren 20, som har en bevegelig kontakt 56 og to overlappende bue- eller segmentformede faste kontakter 57 og 58 forbundet med spolene 54 henholdsvis 55. Hvis det ønskes å foreta en delvis stengning av ekshaustavløpet, bringes kontakten 56 i kontakt med kontakten 57, således at bare den første spole blir strøm-førende. Hvis man ønsker full stengning, beveges kontakten 56 videre så at den be-rører kontakten 58, hvorved den annen spole 55 trer i funksjon. Kontakten 58, som kontrollerer den annen spole, kan forlen-ges utenfor kontakten 57 som vist på teg-ningen, således at kontakten 56 kan frigis fra kontakten 57 mens den fremdeles er i berøring med kontakten 58, hvorved den første spole 54 blir strømløs og bare den annen spole fortsatt er i funksjon for å holde ventilen i helt stengt stilling. In the embodiment of the invention, which is shown schematically in fig. 9, the valve's closing solenoid 7 has two separate coils 54 and 55, so that the valve can be closed either partially or completely as required. As shown, the solenoid core 9 is divided to fit the number of coils. The latter are connected to the current circuit 18 through the control switch 20, which has a movable contact 56 and two overlapping arched or segment-shaped fixed contacts 57 and 58 connected to the coils 54 and 55 respectively. If it is desired to make a partial closure of the exhaust outlet, the contact 56 is brought in contact with contact 57, so that only the first coil becomes current-carrying. If full closure is desired, the contact 56 is moved further so that it touches the contact 58, whereby the second coil 55 comes into operation. The contact 58, which controls the second coil, can be extended beyond the contact 57 as shown in the drawing, so that the contact 56 can be released from the contact 57 while it is still in contact with the contact 58, whereby the first coil 54 becomes de-energized and only the second coil is still in operation to keep the valve in the fully closed position.

Ved den utførelsesform som er vist i fig. 10, er solenoiden 7 anordnet koaksialt med ventilakselen 6. Solenoider bæres av en ramme 74, som er fastspent mellom flensene 3 i endene av ventilhuset og flenser 4 på ekshaustledningen. Solenoidens kjerne In the embodiment shown in fig. 10, the solenoid 7 is arranged coaxially with the valve shaft 6. Solenoids are carried by a frame 74, which is clamped between the flanges 3 at the ends of the valve housing and flanges 4 on the exhaust line. The core of the solenoid

9 har en aksial boring, som glidbart opptar 9 has an axial bore, which slideably accommodates

en stang 75. Denne er forbundet med akselen 6 og danner en koaksial forlengelse av denne..1 overflaten av stangen 75 er utformet et spiralformet spor 76, med hvilket en tapp 77, som er montert på kjernen 9, står i inngrep. Når solenoiden er i funksjon vil den aksiale bevegelse av kjernen 9 for-årsake en roterende bevegelse av stangen 75 og akselen 6 på grunn av at tappen 27 a rod 75. This is connected to the shaft 6 and forms a coaxial extension thereof..1 the surface of the rod 75 is formed a helical groove 76, with which a pin 77, which is mounted on the core 9, engages. When the solenoid is in operation, the axial movement of the core 9 will cause a rotary movement of the rod 75 and the shaft 6 due to the pin 27

beveges i sporet 76. Kjernen 9 kan kun foreta aksial bevegelse og er sikret mot ro-tasjon av et utspring 78, som er anbragt på solenoidhuset og griper inn i et langsgående spor 79 i kjernens ytre overflate. Fjæren eller fjærene for tilbakeføring av kjernen og gjenåpning av ventilen er anbragt inne i forlengelsen 15 på solenoidhuset og har lig-nende spesifikk fjærkraft som fjæranordningen ifølge fig. 1. Om ønskes kan tappen 77 være anbragt på stangen 75 og sporet 76 utformet i kjernen. moves in the groove 76. The core 9 can only make axial movement and is secured against rotation by a projection 78, which is placed on the solenoid housing and engages in a longitudinal groove 79 in the outer surface of the core. The spring or springs for returning the core and reopening the valve are placed inside the extension 15 of the solenoid housing and have a similar specific spring force as the spring device according to fig. 1. If desired, the pin 77 can be placed on the rod 75 and the groove 76 formed in the core.

Som vist i fig. 11 og 12 kan det iste-denfor en solenoid benyttes en dreibar magnet 80 for betjening av ventilen, idet magnetens anker enten er koblet direkte til ventilakselen 6 (fig. 11) eller hengslet til vektarmen 11 på akselen (fig. 12). For å bringe ventilen til åpen stilling finnes fjær-anordninger (ikke vist) med spesifikk fjærkraft i likhet med hvad som ovenfor er be-skrevet. As shown in fig. 11 and 12, instead of a solenoid, a rotatable magnet 80 can be used to operate the valve, the magnet's armature being either connected directly to the valve shaft 6 (fig. 11) or hinged to the weight arm 11 on the shaft (fig. 12). In order to bring the valve to the open position, there are spring devices (not shown) with specific spring force similar to what has been described above.

Claims

1. Operating mechanism for exhaust brake devices for motor vehicles, where a closing device rotatably arranged in the engine's exhaust duct can be influenced by means of an operating mechanism connected to said body's pivot shaft and situated outside the duct to completely or partially close the duct, and where there is a spring device, which normally seeks to bring the closing device into a fully open position, as well as an electromagnetic device, which, when supplied with power, can be brought to overcome the opposite force of the spring device and move the closing device to the closed position, characterized in that the spring device (14) is designed in such a way that its specific spring force increases during the movement of the closing device towards the closed position .

2. Operating mechanism according to claim 1, characterized in that the spring device (14) consists of a compression spring, the specific spring force of which increases with the compression of the spring.

3. Operating mechanism according to claim 1, characterized in that the spring device (14) consists of two springs, one of which is arranged to be active during the closing movement of the closing member.

4. Operating mechanism according to claim 1, 2 or 3, characterized in that the electromagnetic device consists of a solenoid (7) arranged to influence the shaft (6) of the closing member via a weight arm (11) attached to it and radially projecting from one end thereof outside the channel (2), as the force of the spring device (14) is also transferred to the shaft (6) via the weight arm (11).

5. Operating mechanism according to claim 1. 2 or 3. characterized in that the electromagnetic device consists of a solenoid (7) arranged coaxially with the shaft (6) of the closing member, whose core (9) has an axial hole for receiving the shaft's (6) projecting part (75), and that the core (9) and the projecting part (75) have a screw-shaped groove (76) or an intervening projection (77) or vice versa, whereby an axially directed movement of the core (9) is converted into a turning movement of the shaft (6).

6. Operating mechanism according to claim 4 or 5, characterized in that the solenoid (7) comprises a number of separate coils (54, 55), each of which can be activated by means of a switching device (20) in such a way that the closing device can be made to assume different working positions so that more or less complete closure of the exhaust duct (2) can be effected.

7. Operating mechanism according to claim 1, characterized in that the electromagnetic device consists of a rotatable magnet (80), whose armature is connected directly to the shaft (6) of the closing member or by means of a link connected to a , radially projecting weight arm (11) outside the exhaust duct (2).

8. Operating mechanism according to any of the preceding claims, characterized by a locking device (27, 28, 29) to maintain the closing device in the closed position, in which position the power supply to the electromagnetic device (7), which causes the closing, can be interrupted and the energy consumption is thereby reduced.

9. Operating mechanism according to claim 8, characterized in that the locking device includes a locking device (27) arranged to cooperate under the influence of a spring with an element (13) participating in the movement of the closing device, which locking device (27) is arranged to automatically engage in a locking connection with the element (13), when this reaches a position corresponding to the closing position of the closing element, where a solenoid (36) is arranged, which, when supplied with power, releases the locking element (27) from the element (13), so that the closing element can move freely return to open position.

10. Operating mechanism according to claim 9, characterized in that the locking device (27) is arranged to actuate a switch (31), which is inserted into a circuit (18) through which current is supplied to the electromagnetic device (7) for closing the locking device , which locking means (27) is arranged when not in locking engagement with the element (13) to keep the switch (31) closed to prepare the current circuit (18) for completion by means of another switch (20), which is under the driver's control, which locking device also when it comes into locking engagement with the element (13) can be automatically influenced to open the first switch (31) so that said current circuit (18) is broken and thereby the power supply to said electromagnetic device (7 ) ceases.

11. Operating mechanism according to any of the claims 1-7, characterized in that there is a device for causing the closing member to reopen automatically to prevent the machine from stopping in the event that it is brought to idle after a work shift of the closing device.

12. Operating mechanism according to claim 11, characterized in that said device consists of a switch (37), which is inserted into a current circuit (18) through which current is supplied to the electromagnetic device (7) for closing the closing device, and which normally is kept closed to prepare the circuit (18) for closing by means of another switch (20), which is under the driver's control, and a device (38), which is affected by the speed of the machine and, in the event that said speed decreases to a predetermined value due to the action of the closing device, can act automatically to open the first switch (37) so that said current circuit is broken and thereby said electromagnetic device becomes de-energized and causes the opening of the closing device.

13. Operating mechanism according to claim 12, characterized in that said device consists of a switch (37), which is inserted into a current circuit (18) through which current is supplied to the electromagnetic device (7) for closing the closing device, and which is normally held closed to prepare said circuit for closing by means of another switch (20), which is under the control of the driver by means of another electromagnetic device (43), which is supplied with current from the vehicle's alternator (44) through a relay (45) , which is arranged in such a way that, in the event that the machine is brought to idle after an operation of the closing device, it switches off and breaks the current through said second electromagnetic device (43) and causes the first switch (42) to open so that said current circuit (18) is broken and thereby puts the electromagnetic device (7), which closes the closing device, out of function, whereby the closing device opens again.

14. Operating mechanism according to claim 11, characterized in that said device consists of a pressure-dependent switch (47), which reacts to the pressure that builds up in the exhaust pipe due to the action of the closing device, which switch when said pressure drops below a predetermined following the operation of the closing device a low value causes the breaking of a current circuit (48), through which current is supplied to the electromagnetic device (7) for closing the closing device, whereby the current supply to said device ceases so that the closing device opens again.

15. ' Operating mechanism according to claim 14, characterized in that the pressure-dependent switch is kept closed by the pressure when it is above a predetermined value, and is arranged to, when closed, cut off current through an electromagnetic device (53), which can be brought to the effect of a spring device (50) to keep another switch (20) in the closed position, which switch (20) is controlled by the driver and is inserted into the circuit (48) which carries current to the electromagnetic device (7) for closing of the closing member, the arrangement being such that when said pressure drops below the predetermined value following an operation of the closing member, the pressure-actuated switch (47) is opened and causes a power failure in the electromagnetic device (53) which holds said second switch (20), so that this is released to be moved by the spring device (50) to an open position, in which it breaks the current circuit (48) and thereby produces a power failure in the electromagnetic device (7) which st narrows the closing member.

16. Operating mechanism according to claim 15, characterized in that the electromagnetic device (7), which causes closing of the closing member, is connected to a current source (19) through a first current circuit (18), in which said second switch (20) is inserted , and through another circuit (48), in which said other switch (20), the electromagnetic device (53) for retaining the other switch (20) in said closed position and the pressure-dependent switch (47) are inserted, which other switch (20) can be set first to close the first current circuit (18) so that current is sent through the electromagnetic device (7) for closing the closing device to thereby bring the closing device into operation, and then, when the pressure-dependent switch'(47 ) is closed by the pressure in the exhaust line (2) to close the second current circuit (48), so that the current through the electromagnetic device (7), which closes the closing device, is maintained through said second current circuit (48), whereby the t jerk-dependent switch (47), when the pressure drops below the predetermined value, is opened so that the current through both electromagnetic devices (17, 53) is broken and causes both the closing device and said second switch (20) to open again.

17. Operating mechanism according to any of the preceding claims, characterized in that the function of the mechanism is controlled by means of a switch (21, 22, 23) arranged to be affected by the vehicle's accelerator pedal, so that the mechanism is automatically put into operation upon release of said pedal.

18. Operating mechanism according to any of the preceding claims, characterized in that the function of the mechanism is controlled by means of a switch (24, 25, 26) mounted on the carriage's brake pedal, which switch is affected by a device, which is arranged to be pressed down by the driver's foot when the latter is placed on the pedal, so that the mechanism is brought into operation before the application of the carriage's wheel brakes.