GB2033073A

GB2033073A - Air conditioning device for vehicles

Info

Publication number: GB2033073A
Application number: GB7929877A
Authority: GB
Original assignee: Compagnie Electro Mecanique SA
Current assignee: Compagnie Electro Mecanique SA
Priority date: 1978-08-29
Filing date: 1979-08-29
Publication date: 1980-05-14
Also published as: DE2934501C2; FR2434722B1; DE2934501A1; BE878469A; FR2434722A1; GB2033073B

Abstract

A modular air-conditioning device for vehicles comprises a duct (1) adapted to be fitted transversely beneath the vehicle roof with inlets (4) at each end for fresh air from outside the vehicle and inlets (3) along its length for air from inside the vehicle. Filters (5) and shutters (12) are associated with each fresh air inlet (4), the shutters (12) being coupled to an actuator (15) for adjustment of their positions. A central aperture (6) admits air into the vehicle and has associated with it a diffuser (7) and a fan impeller (8). Temperature sensitive probes (23) and (24) are associated with one of each of the external and internal air inlets respectively. A controller (22) is responsive to the probes to adjust heating elements (10) and cooling elements (11) as appropriate and also to adjust actuator (15) which is pneumatically powered from a main air line (18) of the vehicle. A valve (26) is arranged to connect the actuator (15) to atmosphere in response to a sudden fall in the outside air temperature so that the shutters (12) rapidly close. <IMAGE>

Description

SPECIFICATION Air-conditioning devices for vehicles The invention relates to prefabricated modular air-conditioning devices for vehicles, particularly though not exclusively for vehicles adapted for urban or suburban traffic, in which ventilation ducts are disposed transversely under the roof of the cars.

Surburban cars or cars for urban traffic have been known in which ventilation ducts are disposed transversely under the car roofs, external air inlets are provided consisting of lateral ears, apertures for recycled air are disposed in the duct, and the admission of the ventilation air is effected via a central circular aperture in which a fan is disposed. It is likewise known to provide heating devices disposed in plinths formed between the doors, at the base of the side walls of the cars.

Such a known arrangment has the disadvantage of distributing hot air very badly inside the cars and not permitting proper regulation of the air-conditioning of the vehicle. In particular, when the cars pass from a hot zone (tunnel) to a cold outside zone, it is practically impossible to prevent a sudden cooling of the upper portion of the cars while the lower portion remains relatively hot.

An object of the invention is to overcome or at least substantially reduce the disadvantages abovementioned, to enable regulation of the heating of the vehicle to be effected, and consequently to enable an economy in energy to be obtained.

The air-conditioning device proposed in accordance with the invention comprises one or more prefabricated modules adapted to be disposed transversely under the roof of a vehicle and each comprising a ventilation duct provided with one or more inlet apertures for fresh air at one or both ends and with one or more air inlets distributed over the lateral faces of the duct, the blowing of the mixed air into the vehicle being effected through an aperture with which there is associated a vertical fan provided with a diffuser. The or each fresh air inlet aperture is provided with a shutter which can be adjusted to enable the proportion of fresh air to be mixed with the air taken into the vehicle again, which is thus recycled, to be controlled.

The system above defined can be enhanced by the installation of heating elements and, as desired, cooling elements, inside the ducts, at each side of and upstream of the fan.

The shutters can be arranged to be controlled automatically in dependence upon the temperature of the inside air and the outside temperature by means of a pneumatic or other servo-mechanism for example which by actuating a control linkage can obtain the immediate or substantially immediate closure of the shutters to prevent the admission of fresh air in response to a sudden lowering in the temperature of the fresh or outside air.

The invention will be better understood from consideration of the following description of a non-limiting embodiment of the invention which is illustrated in the accompanying draw ing the single figure of which shows a prefab ricated air-conditioning module together with its control systems.

In the figure, one of the ventilation ducts 1 which can be dismounted, is disposed under the vehicle roof 2, transversely with respect to the vehicle.

Air admission apertures 3 formed on the lateral faces of the duct enable the internal air of the vehicle to be recycled, while lateral apertures 4, which may be equipped with filters 5, enable the fresh outside air to be adnÇitted .

An aperture 6 is situated in the centre of the duct and equipped with a diffuser 7 and has associated with it a fan 8 driven by a motor 9 which permits the blowing of the mixed fresh and recirculated air inside the vehicle.

Heating elements 10, for example resistors, are disposed in the duct 1 upstream of the fan. Cooling elements 11 are likewise placed upstream of the fan.

Adjustable shutters 1 2 enable the admission of fresh air to be regulated between total opening and closure. The closed position is arranged still to permit the passage of a flow of fresh air corresponding to a minimum renewal of air by virtue of the provision of a stud 27 serving as a stop for the shutter.The figure shows the control device for the shutters 1 2. A transmission device, represented diagrammatically by the broken line, controlled by a push-rod actuated by a pneumatic control actuator 1 5 enables the intake of fresh air to be closed or opened by manipulation of the shutters 1 2. The actuator 1 5 comprises a piston loaded on one side by a calibrated spring and subject at the other side to a compressed air pressure originating from a circuit which comprises a conduit 1 7 branched off of a main pneumatic conduit 18.

A pressure reducer 1 9 enables the pressure in the conduit 1 7 to be lowered and the pressure which it transmits to the feed conduit 20 of the actuator to be maintained constant by means of an electropneumatic transducer 21 which regulates the pressure at the actuator 1 5 in dependence upon a corresponding control signal from regulator 22. The regulator 22 is arranged to be responsive to probes 23 and 24 which are located in the duct and are responsive respectively to the fresh air and the internal air. The signals from the probes can be processed in the regulator in accordance with whatever control strategy is desired to be followed and is programmed into the regulator.

For example, the regulator can be arranged for the regulation of the average heating level by control of a switching device 25 controlling either the heating elements or the cooling elements at a greater or lesser frequency depending on the temperature of the inside air. Additionally, beyond a certain external temperature threshold the regulator can be arranged to transmit information to the transducer 21 to control the position of the shutters 12 by the progressive regulation of the pressure in the actuator 1 5. Finally the regulator 22 can be arranged to control an electrically operated valve 26 in order to connect the conduit 1 6 to atmosphere in the event of a sudden appearance of cold air in the duct, for example on leaving a tunnel.For this purpose, the regulator 22 comprises a function sensitive to the derivative of the temperature indicated by the probe 23. The connection of the conduit 1 6 to atmosphere leads to the rapid closing of the shutters 12. A delay device is incorporated in the regulator to cause, at the end of a given period of time, the closing of the valve 26 in order to reestablish the regulation.

In order to facilitate mounting, reduce cost, and facilitate checking before placing in position, it is preferred that the assembly consisting of the duct equipped with its ventilation, heating, cooling and regulation components should be prefabricated so as to constitute a homogeneous block, premounted and prewired, immediately available for integration into the vehicle.

Such devices may be placed in railway vehicles as well as in road vehicles such as trolley-buses, buses or other transport devices for passengers.

It is to be understood that the invention is not limited to the example described but that the elements may be modified without departing from the scope of the invention. For example, an electrical or hydraulic control of the shutters may be considered instead of the pneumatic control described.

Claims

1. An air-conditioning device for vehicles, particularly for communal transport vehicles, which comprises temperature control elements and a ventilation system, and in which the whole of the device is housed in a prefabricated module which is adapted to be disposed transversely under the roof of the vehicle and comprises at least one inlet for outside air controlled by an adjustable shutter.

2. A device as claimed in claim 1, wherein complete closure of the shutter(s) is prevented so as even when the shutter(s) are closed to permit a flow of outside air into the device corresponding to a minimum renewal of air inside the vehicle.

3. A device as claimed in claim 1 or 2, wherein the prefabricated module comprises at least one inlet for the admission of internal air of the vehicle to be mixed with the outside air; two temperature probes, responsive respectively to the inside air and the outside air; and control means responsive to the probes for controlling the temperature control elements and, through an actuator, the position of said adjustable shutter.

4. A device as claimed in claim 3, wherein the actuator for controlling the shutters consists of a jack the piston of which is subject at one side to the pressure of a calibrated spring and at the other side to a fluid pressure the variation in which causes displacement of the piston in the cylinder of the jack, compressed fluid being supplied to the actuator from a pressurised fluid circuit of the vehicle.

5. A device as claimed in claim 4, wherein compressed fluid is transmitted to the jack by means of a pressure reducer and an electrically operated transducer which adjusts the pressure supplied to the jack depending on a signal emitted by the control means.

6. A device as claimed in claim 5, wherein the control means receives the signals supplied by the probe for the outside air temperature and the probe for the inside air temperature, and after transformation in accordance with a set internal law, delivers a signal for controlling the temperature control elements and a signal for operating the transducer.

7. A device as claimed in claim 5 or 6, wherein a valve is interposed between the transducer and the jack for venting the jack to atmospheric pressure, the operation of said valve being controlled by a signal from the said control means in order to cause the substantially instantaneous closure of the shutters in response to a second sudden lowering of the temperature of the outside air.

8. A device as claimed in any of claims 4 to 7, wherein the actuator is arranged to be operated by air pressure from a main pneumatic line of the vehicle.

9. A device as claimed in any of the preceding claims wherein said temperature control elements comprise heating elements and cooling elements.

10. An air-conditioning device for vehicles which is substantially as herein described with reference to the accompanying drawing.