WO2003054366A1

WO2003054366A1 - Jalousie for a cooler

Info

Publication number: WO2003054366A1
Application number: PCT/SE2002/002265
Authority: WO
Inventors: Hans WIKSTRÖM
Original assignee: Scania Cv Ab (Publ)
Priority date: 2001-12-13
Filing date: 2002-12-10
Publication date: 2003-07-03
Also published as: SE518588C2; DE10297534B4; SE0104194D0; DE10297534T5; SE0104194L; AU2002359104A1

Abstract

The invention relates to an air-cooled cooler (1) which has air channels (7) formed between a system of tubes (6). By means of a crank mechanism (22) with crankshafts (26, 26'), a control device (30) and spring means (34), a shutter (14) with slats (20) is manoeuvrable between a first position in which the air channels (7) are open and a second position in which the air channels (7) are closed.

Description

Jalousie for a cooler

The invention relates to an improvement to an air-cooled cooling arrangement which comprises two or more coolers/radiators (e.g. water radiator, charge air cooler and oil cooler), is arranged in box form and preferably incorporates a radial fan, and in which at least one cooler/radiator incorporates a system of pipes which have fins arranged between them. At least the charge air cooler is equipped with a movable shutter for regulating the air flow through the charge air cooler.

A cooling arrangement of this kind already known from DE-A1 197 24728 makes it possible to effect rapid adaptation of the cooling arrangement to different operating circumstances. This characteristic is of great importance for vehicles which use for their operation a relatively large amount of hydraulic oil, e.g. trucks, construction machines and the like. Such cases often involve operating situations in which the hydraulic oil cooling capacity has to be increased suddenly. The cooling arrangement is particularly suitable for this and similar operating situations in that the movable shutter of the charge air cooler can be closed, which leads to a large proportion of the air flow pushed through the cooling arrangement by the fan being utilised by the oil cooler, thereby increasing the latter' s cooling capacity.

One object of the present invention is to provide an improved cooling arrangement of the kind described in the introduction which can be adapted to different load situations easily and reliably and more efficiently than hitherto. This is possible with a cooling arrangement which has the characterising features according to claim 1. Further objects, further developments and improvements of the invention are indicated in the description and the dependent claims.

The invention is applicable with particular advantage to the charge air cooler of a cooling arrangement of the kind indicated but is of course also

^ applicable to other coolers/radiators which form part of the arrangement or to a separately arranged air-cooled cooler/radiator in cases where it is desired to regular the air flow through the latter. Alternatively, for example, a charge air cooler may be placed in series with one or more other coolers/radiators, and/or some of the coolers/radiators may be mutually

. „ displaced sideways so that parallel flows of cooling air occur. Where applicable, it is then possible to utilise a larger proportion of the total air flow in any cooler/radiator which temporarily needs a higher performance, by shutting off the air flow through the charge air cooler.

15 The invention is described below in more detail with reference to the attached schematic drawings. Fig. 1 is a plan view depicting a cooler/radiator provided with a shutter device according to the invention in a closed position, Fig. 2 is a perspective view on a larger scale depicting a cutaway portion of the cooler/radiator, with the shutter device in an open 2_Q position, Fig. 3 is a detail cutaway view of Fig. 2 showing individual slats of the shutter device, and Figs. 4 and 5 are detail views similar to Fig. 3 but with the individual slats in a closed position, for different designs of tube edges.

,-,.- A cooler/radiator, e.g. a charge air cooler 1, is provided with a first gathering box 2 and a second gathering box 4 which have extending between them a system of tubes 6 and, in air channels 7 formed between the latter, cooling flanges 8. The charge air is supplied via an inlet 10 and the cooled charge air is drawn off via an outlet 12. As in the cooling fl arrangement described in the introduction, a shutter 14 is used for regulating the air flow through the cooler 1 in cooperation with the edges 18 of the tubes 6 which face towards the inlet side or outlet side of the cooler, which shutter may also be configured correspondingly.

Thus the shutter 14 takes the form of a sheet with the short sides 16 bent to a right angle. The sheet incorporates apertures or slits adapted to the edges 18 of the tubes 6 in such a way that evenly distributed slats 20 are formed at mutual spacing corresponding to the distance between the tubes 6. In practice this spacing may amount to 5-20 mm and correspond also to the width of each tube edge 18.

The shutter described in the introduction is movable in a rectilinear manner by means of slide rails between open and closed positions in its own plane parallel to the tube system and situated at a substantially constant distance from the tube system.

The shutter 14 according to the invention, however, does not move in its own plane but is caused by means of a crank mechanism 22 to perform a cyclic circular-arc motion from an open first position to a closed second position. In the open first position depicted in Figs. 2 and 3, each slat 20 is situated centrally to its tube 6, and in the closed second position depicted in Figs. 1 and 4 each slat 20 has its longitudinal edges 24 abutting against opposite portions of adjacent tube edges 18. This means that, starting from the first position, the plane of the shutter 14 will first, at the beginning of a movement cycle, move away from the tubes 6 in the tube system and then move transversely relative to the tubes 6 while continuing to move away from the tube system past the top of the movement path. Thereafter the movement decreases successively while at the same time the shutter 14 comes closer to the tube system in order to assume the second position. The curved arrows in Fig. 3 are intended to illustrate the movement path of each individual slat edge 24.

According to an embodiment depicted in Fig. 1, the crank mechanism 22 comprises a first crankshaft 26 and a second crankshaft 26' which have their respective ends suspended for rotation in bearing devices 28 arranged firmly on the cooler 1. The shutter 14 is itself suspended on crank portions of the crankshafts 26, 26' via bearing devices 29 on its short sides 16. The bearing devices 28 and 29 are of a conventional kind, e.g. plain bearings made of metal, plastic material or the like.

By rotating one or both of the crankshafts 26, 26' through an experimentally predetermined angle of rotation α of approximately 180° by means of a control device 30, e.g. an actuator, solenoid etc., or manually, it is therefore possible to effect the circular-arc movement for moving the shutter 14 from the first position to the second and vice versa. In cases where the control device 30 is only arranged on the first crankshaft 26, the rotation movement may be transmitted to the second crankshaft 26' by an undepicted crank arm or the like.

Alternatively, the second crankshaft may be entrained by the movement of the shutter 14 generated by the first crankshaft, in which case it is also possible to replace the second crankshaft 26' by a hinge device, e.g. a link arm 32, the length of which will correspond to the movement of the crank portion relative to the rotation portion of the first crankshaft 26.

The control device 30 may be activated by an undepicted control unit programmed to evaluate signals from a likewise undepicted temperature sensor situated, where applicable, in one or more of the coolers/radiators, e.g. in the oil cooler of the system. When the shutter 14 is in its first position, a temperature rise beyond a predetermined threshold in the oil cooler will cause the control unit to activate the control device 30 which will, via the crank mechanism 22, move the shutter 14 to the closed second position.

As best illustrated in Figs. 3-5, the crank mechanism 22 may in addition be provided with spring means 34, e.g. a leaf spring, spring wire, coil spring, rubber shock-absorber or the like, acting between parts of the crank portion of each crankshaft 26, 26' and the cooler package 1. The spring force of each spring means 34 will then endeavour to urge the respective part of each crank portion towards the cooler package 1, thereby also preventing the crank portion from moving transversely relative to the tubes 6. The control device 30 can be used to overcome the action of the spring means 34 so that the crank portion can slide towards the respective spring means 34 during its transverse movement relative to the tubes 6.

The shutter 14 may then be held, by the crank mechanism 22, in both its open first position and its closed second position with a force F of predeterminable magnitude directed towards the tube edges 18 of the system. The magnitude of the force F depends on the degree of activation of the control device 30 and/or the force of the spring device 34. Thus in the second position each slat 20 will be pressed against the opposite portions of the adjacent tube edges 18 with sufficient force dF to provide an effective seal between these latter and the edges 24 of the slats. Any leakage is thus reduced to a minimum, thereby not only resulting in improved operation but also effectively preventing the occurrence of sounds and noise which might otherwise be caused by undesired air movements.

The tubes 6 depicted in Figs. 3 and 4 have a substantially rectangular cross- section, i.e. the tube edges 18 are substantially planar. Fig. 5 depicts another commonly occurring version of tubes 6' with tube edges 18' which are semi-cylindrical in shape. Experiments have shown that this design makes it easier to achieve an accurate match between the tube edges 18' and mutually opposite edges 24 of two adjacent slats 20. This is only possible by the slat edges 24 being pushed by the crank mechanism 22 to contact with the curved tube edges 18'.

A further advantage of the cyclic pattern of movement of the shutter 14 is that it makes it possible to apply seals of conventional kinds (seal strips made of rubber, plastic etc.) either to the slats 20 or to the tube edges 18 without the seals being worn away by operation of the shutter.

Although the embodiment described of the crank mechanism is provided with two crankshafts, more than two crankshafts are of course also possible, e.g. for the operation of shutters for coolers/radiators for extremely large vehicles or machines.

Claims

1. An air-cooled arrangement (1), e.g. a water radiator, charge air cooler or oil cooler, which incorporates a system, intended for the relevant medium, of tubes (6) with cooling flanges (8) and, formed between the latter, channels (7) through which a cooling air flow adjustable by means of a shutter (14) with slats (20) is caused to flow, characterised in that the shutter (14) is manoeuvrable, by means of a crank mechanism (22), between a first position in which each slat (20) is situated centrally to its respective tube (6) and a second position in which each slat (20) abuts against adjacent edges (18) of adjacent tubes (6) and thereby blocks its respective air channel (7).

2. An air-cooled arrangement according to claim 1, characterised in that the crank mechanism (22) has at least one crankshaft (26, 26') which is suspended in bearing devices (28) on the cooler (1) and which is connected to bearing devices (29) arranged on the shutter (14) in such a way that the shutter (14) can be moved from the first position to the second position by the crankshaft being caused to rotate through an angle α.

3. An air-cooled arrangement according to claims 1 or 2, characterised in that the crank mechanism (22) has first and second crankshafts (26 and 26' respectively) by means of which, when the shutter (14) has assumed its second position under the influence of a control device (30), longitudinal edges (24) of the slats (20) are pressed tightly against the adjacent tube edges (18).

4. An air-cooled arrangement according to claim 3, characterised in that each crankshaft (26, 26') is under the influence of at least one spring means (34) acting between the respective crank portion and the cooler (1) so that the crank portion is urged towards the cooler.

5. An air-cooled arrangement according to any one of the previous claims, characterised in that each tube (6) is provided with planar tube edges (18).

6. An air-cooled arrangement according to any one of claims 1-4, characterised in that each tube (6) is provided with curved tube edges (18).