EP0053555A1 - Mobile crane for operation in cold regions - Google Patents

Abstract

Mobile crane driven by one or more diesel engines and intended for operation in an ambient temperature which can fall to below -30 DEG C. Each diesel engine (2) is equipped with a hot-air heating device comprising a centrifugal fan (21) and a tube (16) containing heating resistors (17, 18). The assembly is fixed permanently on the engine and can be connected, by flexible pipes (22, 27), to an inlet point (23) and an outlet point (28) of the diesel engine. <IMAGE>

Description

The present invention relates to a mobile crane powered by one or more diesel engines and intended to operate in regions where the ambient temperature can drop below -30 ° C, to reach temperatures of the order of -40 ° C at -50 ° C for example.

It is known that starting diesel engines with an ambient temperature below -30 ° C requires prior warming of the entire engine and of the components necessary for starting it, that is to say the accumulator batteries and the diesel tank.

It is currently known to start diesel engines for such temperatures when these are stationary. For this, we generally use a device for heating by electrical resistances with regard to the batteries and the tank, and, with regard to the diesel engine, a device for heating consisting of a hot air generator operating on gas. -oil and blowing hot air in a sealed and removable insulated enclosure surrounding the diesel engine.

The use of an insulated enclosure is however not possible on rolling stock, such as a mobile crane, for obvious reasons of space and accessibility. Furthermore, the most powerful diesel hot air generators known to date have far too large dimensions for the space available on a mobile crane and also require regular and delicate maintenance, which is therefore costly. In addition, their design is such that they do not allow recycling of hot air, so that their use results in a warm-up time of the diesel engine greatly exceeding the hour for ambient temperatures of the order of -40 ° C. Finally, the use of two different energy sources to heat the engine on the one hand and its starting members on the other hand would lead to complications which could advantageously be avoided by the use of a single source. of energy.

• - d'utiliser une seule et même source d'énergie, l'électricité, pour le réchauffage du moteur diesel et de ses accessoires de démarrage;
• - d'utiliser un appareil de réchauffage du moteur léger et peu encombrant, pouvant rester à demeure sur le moteur;
• - d'augmenter le rendement de l'ensemble de réchauffage de façon à obtenir un temps de démarrage de l'ordre d'une demi-heure pour une température ambiante de -40°C.

The mobile crane of the invention can operate in. cold countries thanks to a heating device for its diesel engine (or its diesel engines) allowing:

• - to use a single energy source, electricity, for heating the diesel engine and its starting accessories;
• - to use a light and space-saving engine heater, which can remain permanently on the engine;
• - to increase the efficiency of the reheating assembly so as to obtain a start-up time of the order of half an hour for an ambient temperature of -40 ° C.

The mobile crane of the invention is of the type comprising at least one diesel engine, the tank and the batteries of which are provided with a device for heating by electrical resistances, and is ca = characterized in that said diesel engine is provided with a closed circuit heating device comprising a hot air generator with electrical resistances and centrifugal electric fan.

According to another characteristic of the invention, said hot air generator comprises an air inlet connected to an outlet socket of said diesel engine on the one hand and to the suction inlet of the centrifugal fan on the other hand, as well as a tube-shaped casing containing electrical resistances, and whose upstream air inlet is connected to the discharge outlet of the centrifugal fan, while its downstream air outlet is connected to an inlet socket said diesel engine.

• - la figure 1 est une vue d'ensemble schématique de la grue de l'invention;
• - les figures 2 et 3 représentent schématiquement le dispositif de réchauffage équipant chaque moteur diesel de la grue de l'invention, la figure 2 étant une coupe transversale de l'ensemble selon la direction ab de la figure 3 et la figure 3 étant une vue selon la direction f de la figure 2;
• - la figure 4 représente schématiquement le détail de la prise d'entrée d'air chaud sur le moteur ;
• - la figure 5 représente schématiquement le détail de la prise de sortie d'air du moteur;
• - la figure 6 est une vue arrière de la plaque à bornes associée aux résistances électriques équipant le dispositif de réchauffage de la figure 2.

The invention will be better understood using the following description of an example of application to a mobile handling crane equipped with a first diesel engine to drive the carrier and a second diesel engine to drive the proper movements. of the crane, with reference to the accompanying drawings in which:

• - Figure 1 is a schematic overview of the crane of the invention;
• - Figures 2 and 3 schematically represent the heating device fitted to each diesel engine of the crane of the invention, Figure 2 being a cross section of the assembly in the direction ab of Figure 3 and Figure 3 being a view in the direction f of Figure 2;
• - Figure 4 schematically shows the detail of the hot air intake on the engine;
• - Figure 5 shows schematically the detail of the engine air outlet;
• FIG. 6 is a rear view of the terminal plate associated with the electrical resistances equipping the heating device of FIG. 2.

We recognize in Figure 1 a mobile crane composed of a carrier 1 driven by a diesel engine 2, which also distinguishes the diesel tank 4 and starter batteries 3, and a crane part 5. Conventionally, the crane part 5 can rotate around an axis 6 and is itself driven by another diesel engine 7 also equipped with starter batteries 8 and a diesel tank 9. In a very usual, the batteries (3.8) and the tanks (4.9) are each placed in an enclosure which can be heated by electrical resistances, said enclosures not having been detailed in the figure.

According to the invention, each diesel engine (2.7) is permanently associated with a heating device (respectively 13 and 15) with circulation of hot air heated by electrical resistances, the hot air being sent inside. of each of the motors (2,7) and being recycled into the hot air generator, the latter being equipped with a centrifugal fan (respectively 16 and 17).

_. The carrier 1 is equipped with a socket 14 which can be supplied with electrical energy either by an external socket, such as a site service socket, or by a generator 12 on board the vehicle and operating for example using a small gasoline engine. The socket 14 is associated with a conventional switch 11 which makes it possible, according to the chosen switching, to supply electrical energy either with the electrical resistances and fan intended for heating the motor 2 of the carrier and its accessories (3,4), or, by means of a rotary electrical collector 10 of conventional type, supplying electrical energy to the corresponding heating elements (8, 9, 15) of the engine 7 equipping the crane part 5.

We will now refer to all of Figures 2 to 5 which show in more detail one of the two devices (13 for example) for heating a diesel engine (2 for example) fitted to the crane of the invention.

The heating device shown diagrammatically in FIGS. 2 and 3 consists of a casing 16 in the form of an elongated tube of square section (the square or rectangular section having been found more advantageous than the circular section) and containing two heating resistors (17, 18) of three kilowatts each supplied with electrical energy by means of a terminal plate 19 which is also used for fixing said resistors to the casing 16. The two resistors 17 and 18 are standard armored electrical resistors of wide distribution and are placed at right angles as shown in the drawing.

The casing 16 is provided with an upstream inlet orifice 20 connected to the discharge outlet of a turbine 21 constituted by a centrifugal fan driven by an electric motor 42 surrounded by an electric preheating resistor not shown. It will be noted that the use of a centrifugal fan is essential for the implementation of the invention, because only this type of fan allows, without costly artifices, the use of an electric drive motor 42 which does not not found in the jet of hot air which, as will be seen below, allows operation of the assembly in a closed circuit.

As can be seen in the drawings, the downstream outlet orifice 41 of the casing is connected, via a flexible pipe 22, to an inlet orifice 23 in the motor 2, normally closed by a plug 24 held attached to the motor by a chain 25, the seal being made by a seal 26. Similarly, the suction inlet of the centrifugal fan 21 is connected, via a flexible pipe 27, to a socket 28 of output of motor 2, also normally closed by a plug 29 retained by a chain 30.

The assembly constituted by the casing 16 and the turbine 21 is fixed to the motor 2 by means of supports 31. Furthermore, the installation can optionally be equipped with relay thermocouples (32, 33) placed respectively at the outlet 41 of the casing 16 and at the air outlet 28 of the engine 2, and being able for example to allow an automatic control of the heating device, the thermocouples 32 and 33 measuring the temperature of the heating air at the inlet and at the outlet of the engine and acting for example on electrical contactors controlling the starting or stopping of reheating.

The inlet 23 and outlet 28 ports are chosen by the user so as to allow circulation of hot air in the engine. Their choice is simple to make depending on the engine used, and Figures 4 and 5 only give an indication of a non-limiting example which is not in itself part of the invention.

In the example of Figure 4, the inlet 23 is taken on the line 34 comprising the oil filling inlet 35 and the outlet 36 of the oil vapors to the breather.

In the example of FIG. 5, the air outlet 28 is taken on a manhole 37 normally fitted to a shaft socket 38 closed by a cover 39.

Figure 6 shows the terminal plate 19 seen in the direction f of Figure 2, the diagram shown, very conventional, corresponding to the parallel supply of the two resistors.

• - les bouchons 24 et 29 étant retirés, on branche le tuyau flexible 22 sur l'orifice 23 et le tuyau flexible 27 sur l'orifice 28, et l'on alimente en énergie électrique le moteur électrique 22 du ventilateur 21 et les résistances chauffantes 17 et 18. L'air chauffé par les résistances 17 et 18 suit le tuyau flexible 22 dans le sens indiqué par la flèche sur les figures 2 et 3,et ressort apxès avoir traversé le moteur 2, par l'orifice 28 dans le tuyau flexible 27 dans le sens également indiqué par la flèche. Le tuyau flexible 27 étant relié directement à l'orifice d'aspiration axial du ventilateur 21, l'air est alors repris directement par le ventilateur, ce qui est possible car ce dernier n'a pas son moteur électrique dans le circuit d'air : le circuit fonctionne donc en circuit fermé ce qui permet le maximum d'efficacité et de rendement dans les échanges thermiques air-moteur et air-résistances. L'arrêt et la mise en route peuvent être effectuées soit par commande manuelle à l'aide du commutateur 11 par exemple, soit par commande automatique avec régulation à l'aide des contacteurs à thermocouples 32 et 33 par exemple.

The operation of the heating device according to FIGS. 2 and 3 is as follows:

• - the plugs 24 and 29 being removed, the flexible hose 22 is connected to the orifice 23 and the flexible hose 27 to the orifice 28, and the electric motor 22 of the fan 21 and the heating resistors are supplied with electrical energy 17 and 18. The air heated by the resistors 17 and 18 follows the flexible pipe 22 in the direction indicated by the arrow in FIGS. 2 and 3, and exits after passing through the motor 2, through the orifice 28 in the pipe flexible 27 in the direction also indicated by the arrow. The flexible hose 27 being connected directly to the axial suction port of the fan 21, the air is then taken up directly by the fan, which is possible because the latter does not have its electric motor in the air circuit : the circuit therefore operates in a closed circuit which allows maximum efficiency and yield in air-motor and air-resistance heat exchanges. Stopping and starting can be carried out either by manual control using the switch 11 for example, or by automatic control with regulation using the thermocouple contactors 32 and 33 for example.

Claims (2)

1.- Mobile crane powered by at least one diesel engine (2.7), the tank (4.9) and batteries (3.8) of which are provided with a device for heating by electrical resistances, characterized in that said or said diesel engines is (are) provided with a closed circuit heating device (13,15) comprising a hot air generator with electrical resistance (s) (17,18) and electric fan centrifugal (21). 2.- mobile crane according to claim 1, characterized in that said hot air generator comprises an air inlet connected to an outlet socket (28) of said diesel engine on the one hand and to the suction inlet the centrifugal fan on the other hand, and a casing (16) in the form of a tube containing electrical resistances (17,18), the upstream air inlet (20) of which is connected to the discharge outlet of the centrifugal fan, and the downstream air outlet (41) of which is connected to an inlet socket (23) of said diesel engine.

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