CS268529B2 - Unit for electric current production - Google Patents

Abstract

The equipment carried on a two-wheeled chassis (1) with a prop (3) and steering handle (4), includes a petrol engine (5) coupled to a 380V 50 Hz three-phase generator (6). This is partly covered by a housing (7) which contains a power converter (8) and a multi-output panel (9) with current supply sockets. The converter is a motor-generator set producing 42V 200 Hz when supplied from the generator via a thermal circuit-breaker (15) and switch (14). The main generator output is available at a three-phase socket (16) and a single-phase socket (17). From 10% to 35% of its power is provided at the higher frequency from the converter output sockets (13).

Description

The present invention relates to an on-site power generating unit comprising a frame carrying a power generator and an internal combustion or explosive engine for driving a generator which is driven to generate alternating single-phase or three-phase current at voltage and frequency Local Area Networks ·

On the construction site, in addition to machines intended for supplying three-phase · or single-phase · electric · local power, there are some machines, such as vibratory needles or vibrators for compacting concrete, hammering etc., which must be supplied with a special current, usually single-phase or 42 V and 200 Hz three-phase current · To provide this extra current, construction companies rely on another power generation unit containing a gasoline or heavy oil engine and a power generator to generate this current.

SUMMARY OF THE INVENTION The object of the present invention is to reduce material investment and to make it as easy to use as possible, particularly in concrete work, while allowing the use of various machines such as vibration needles, trowels, vibrating rulers, mixers, lighting fixtures etc. according to the invention, it comprises a frame carrying an electric generator and an internal combustion engine or an explosive motor for driving a generator which is driven to generate an alternating single-phase or three-phase current at a voltage and frequency corresponding to the local network. at least One generator output A three-phase electric motor of the frequency converter is connected via a switch whose current generator has a frequency output higher than the mains frequency.

The advantages of the invention are that the device makes it possible to create a single mobile power source for various construction appliances, such as lighting, agitator, vibrator or jackhammer, which according to the prior art require different power supplies.

As specific advantages of the invention over the use of a conventional building compressor to power a jack or drill, the following numbers may be mentioned.

The compressor unit weighs approximately 650 kg and will need a power input of about 12.4 W to produce 30 l / sec of 6 At compressed air. A concrete breaker or pneumatic drill weighing 30 kg requires an air input of 29 l / sec of 6 At, ie a minimum engine power of 12.10 kw.

A unit of the type of the invention weighing about 250 kg with a 9.2 kw motor produces an electrical output of 7.4 kw with an efficiency of 0.8. A 30 kg concrete jack or drill absorbs 2,200 W, ie a 3.9 kW power. Thus, when using a compressor, a weight of 52 kg / kW is required to achieve 1 kw of power, while using a device of the type of the invention is 27.2 kg.

Moreover, the possibilities of connecting different tools to the unit according to the invention are more varied than to the compressed air outlet.

Thus, the invention makes it possible to obtain a source of high-frequency current needed to efficiently supply shock-generating appliances such as drills, jacks and vibrators # without the need for compressed air. At the same time it allows to supply appliances with normal increased voltage, such as building lighting. With low weight, high efficiency and operational safety, enabling vibrators and jacks to be powered by a safe voltage from the same main power source, ie the unit according to the invention, which powers the lighting and motor circuits with increased voltage energy using an easy mobile unit.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in greater detail below with reference to the accompanying drawing, in which: Figure 1 shows a side view of the power generating unit according to the invention; Figure 2 shows an end view of the unit;

CS 268529 82, as shown in FIGS. 1 and 2, the power generating unit is mounted on a frame 1 having two knees 2, a support 3 and a displacement handle. Frame 1 carries a gasoline engine 5 coupled to a generator 6 driven to produce a three-phase current of 380 V and 50 Hz. Of course, the motor includes a rotation speed control device to maintain the frequency of the 50 Hz generator 6 within the usual tolerances. This control device is not described in further detail since it is a device known in the art which does not form part of the invention.

Generator 6 It is partially covered by a housing 7 comprising an inverter 8 and a switchboard 9 with power sockets to the 220 and 380 V power supply mechanisms. 200 Hz. General Inverters of this type, the electric motor and generator are mounted on the same shaft and are housed in the same housing.

□ as shown in Fig. 2, in which the switchboard 9 has been removed for displaying the transducer 8, the transducer 8 is hinged by means of resilient elements 20 on the top wall 10 of the cover 7. Under the transducer 8 passes a cover pro. The cover 7 has openings 17 and 18 at its upper side for the ventilation air passage of the transducer 8. The advantage of this transverse ventilation is that the intake of air that served to vent the generator is avoided as much as possible.

Cover 7 is reinforced by posts 12, one of which carries two sockets for a 200 Hz, 42V current. The other post carries a switch 14 and a thermal breaker 15, which is reclosable. On the one hand, the cover 7 carries a tubular sleeve 19 provided with a clamping knob 20 for the possibility of attaching a type lamp holder.

As shown in FIG. 3, the generator 6 has an output 23. The input of the converter 8 is coupled to the three-phase current provided by the generator 6 from the output 23 via a switch 14 and a thermal breaker 15. The converter 8 comprises a three-phase electric motor 25 and a current generator 26. The current generator 26 has a socket outlet 13 at a frequency higher than the grid frequency. In addition, the three-phase current provided by the generator 6 is fed to the socket, while one phase of the current is fed to the socket 17.

The power required to vibrate the concrete Compaction needles is considerably less than the power needed to drive the three-phase engines of construction machines needed during concreting, such as mixers, trowels, vibrating rulers, lighting fixtures, etc. Generally, a power of 1 to 3 kw is required for one or two concrete vibrators, while about 5 to 7 kw are required to power the other construction machines.

It is expedient to oversize the generator 6 so as to be able to provide a power of about 6 to 10 kw, which allows to simultaneously feed the concrete mixing plant, lighting lamp and one or more concrete vibrators without overloading the power generating unit.

it is of course possible to envisage various embodiments, particularly with respect to the location of the transducer 8, which can also be adapted to provide a three-phase current, if necessary. This converter 8 can furthermore comprise outputs for currents of 200 Hz in single-phase and three-phase form.

Finally, the power generating unit can be mounted simply on a frame in the form of a carriage intended for transport on a towing truck from which it is folded at the construction site. Other accessories that are required on the construction site, such as a water pump or electric welding generator, can be attached to the frame.

Of course, one or more transducers providing higher frequencies than 200 Hz, for example 400 to 600 Hz, may also be used.

Claims (1)

A low voltage site power generating unit comprising a frame carrying a power generator and an internal combustion engine or an explosive motor for driving a generator which is driven to generate an alternating single phase or three-phase current at a voltage and frequency corresponding to the local network. the output (23) of the generator (6) is connected via a switch (14) to a three-phase electric motor (25) of the current frequency converter (8) whose current generator (26) has a frequency output (13) higher than the mains frequency.