WO2015137871A1

WO2015137871A1 - Arrangement for fastening of a radiator in an air duct

Info

Publication number: WO2015137871A1
Application number: PCT/SE2015/050273
Authority: WO
Inventors: Dan Pettersson; Magnus Kolasa
Original assignee: Scania Cv Ab
Priority date: 2014-03-12
Filing date: 2015-03-11
Publication date: 2015-09-17
Also published as: DE112015000854T5; SE539006C2; SE1450276A1

Abstract

The present invention relates to an arrangement for attachment of a radiator (7) in an air duct. The arrangement comprises a first channel unit (8), comprising a first channel section of the air duct (8a₁, which leads air to the radiator (7), and a second channel unit (9), comprising a second channel section (9a₁ of the air duct, which receives the air after it has passed through the radiator (7). The arrangement comprises a first sealing element (13), arranged between the first channel unit (8) and the radiator (7), a second sealing element (14), arranged between the second channel unit (9) and the radiator (7), and fastening elements (12), which are adapted to connect the first channel unit (8) and the second channel unit (9) with each other in an assembly position, wherein said channel units (8, 9) exert a pressure against the radiator's (7) opposite side surfaces (7f, 7g) via sealing elements (13, 14), so that the sealing elements (13, 14) hold the radiator (7) in an attachment position in the air duct at a distance from the channel units (8, 9).

Description

Arrangement for fastening of a radiator in an air duct BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention relates to an arrangement for attachment of a radiator in an air duct according to the preamble of claim 1. Hybrid vehicles fuelled with electricity in combination with some other form of fuel, may be equipped with an electrical machine, which alternatingly operates as a motor and as a generator. A hybrid vehicle usually comprises a hybrid battery for storage of electric power, and power electronics to control the flow of electric power between the hybrid battery and the electrical machine. The hybrid battery and the power electronics are heated during operation. In order for the hybrid battery and the power electronics to function in a desired manner, they should in applicable cases be cooled, which may be carried out with the assistance of a cooling system, suitably applied in connection with the hybrid battery and the power electronics. The cooling system may comprise a radiator, where a circulating coolant is cooled by air before it is led to the hybrid battery and the power electronics. The radiator may in this case be arranged inside an air duct through which a cooling air flow passes. A fan may be arranged in the air duct to secure the air flow through the radiator. The air duct is advantageously formed by a plate shaped metal material, such as for example stainless steel, which has good durability characteristics and a good ability of withstanding corrosion.

Radiators are made of metal materials with good heat transfer characteristics, such as for example aluminium. A radiator is usually fixed in an air duct with the help of fastening elements made of metal, such as screws, bolts and similar. When the radiator, the fastening elements and the air duct are made of metals of different types, and when they are in contact with each other in an environment where there is access to humidity and oxygen, there is an obvious risk of galvanic corrosion. The least precious metal accordingly obtains an oxidation in connection with the contact surfaces. In this case, there is a risk of corrosion of the radiator made of aluminium, which a less precious metal than stainless steel. SUMMARY OF THE INVENTION

The objective of the present invention is to provide an arrangement for fastening of a radiator in an air duct, in a manner which eliminates the galvanic corrosion problem. Another objective is to provide such an arrangement with a small number of component parts, which may be assembled quickly and easily.

The above mentioned objectives are achieved with the arrangement according to the characterising portion of claim 1. The arrangement thus comprises a first channel unit leading air to the radiator, and a second channel unit receiving the air after it has passed through the radiator. The first channel unit may receive air with an ambient temperature, and the second channel unit may lead the air back to the environment after it has been used to cool, for example, a coolant in the radiator. Radiators are advantageously made of a metal material with good heat transfer characteristics, such as aluminium, and the channel units are advantageously made of a more robust and durable material, such as stainless steel. According to the invention, a first sealing element is arranged between a surface of the first channel unit and a first side surface of the radiator, and a second sealing element is arranged between a surface of the second channel unit and an opposite second side surface of the radiator. Thus, said surfaces of the channel units are in contact with the radiator solely via the sealing elements. Said surfaces of the channel units are adapted, in an assembly position, to create a pressure against the radiator's opposite side surfaces via the sealing elements. Thus, a stable attachment of the radiator may be obtained inside the air duct.

Accordingly, the arrangement may comprise a radiator of a relatively non-precious metal, such as aluminium, and channel units made of a more precious metal, such as stainless steel, without any risk of galvanic corrosion appearing. The arrangement above comprises few component parts, facilitating a quick and simple assembly.

According to one embodiment of the present invention, the first channel unit comprises a section directed radially inwards, comprising said contact surface, which is in contact with the first sealing element. Such a contact surface may be located in the air duct at a distance from an internal wall surface, which defines the air duct. Accordingly, the radiator may be kept in a fixed position at a distance from the internal wall surface. Direct contact between the radiator and the internal wall surface may thus be avoided in connection with the first channel unit. Such a section directed radially inwards may comprise a contact surface, having a parallel extension with the radiator' s side surface. Thus, the transfer of the above mentioned pressure from said contact surface of the first channel unit to the first side surface of the radiator, via the first sealing element, is facilitated.

According to one embodiment of the present invention, the first sealing element is fixedly connected with said surface of the first channel unit. By attaching the sealing element in a correct position on said contact surface of the first channel unit, the channel unit and the first sealing element may be mounted as one unit. The first sealing element is advantageously attached on said contact surface of the first channel unit with an adhesive, such as glue. Alternatively, the sealing element may be attached on the first side surface of the radiator. According to an additional alternative, the first sealing element is applied as a separate unit, which is held between the contact surface of the first channel unit and the first side surface of the radiator with only a pressure force. According to one embodiment of the present invention, the second channel unit also comprises a section directed radially inwards, comprising a contact surface that is in contact with the second sealing element. Such a section directed radially inwards may comprise a contact surface, which advantageously has a parallel extension with the opposite second side surface of the radiator. This facilitates the transfer of the above mentioned pressure from said contact surface of the second channel unit to the second side surface of the radiator, via the second sealing element. The second sealing element may be fixedly connected with said contact surface of the second channel unit. In this case, the second channel unit and the second sealing element may be mounted as one unit. The second sealing element is advantageously fixed with an adhesive, such as a glue, on said contact surface of the second channel unit. Alternatively, the second sealing element may be fixed on the second side surface of the radiator. According to an additional alternative, the second sealing element is applied as a separate unit, held between said contact surface of the second channel unit and the second side surface of the radiator with only a pressure force. According to one embodiment of the present invention, the first channel unit comprises a radially outwards directed section, and the second channel unit comprises a radially outwards directed section, so that said radially outwards directed sections are adapted to be connected with each other in the assembly position, with the assistance of said fastening elements. The outwards directed sections may be adapted as flanges, which are attached to each other with screw elements in the form of bolts or similar. Thus, the channel units may be assembled in a simple manner.

According to one embodiment of the present invention, at least one of the sealing elements has elastic characteristics. In order for the sealing elements to achieve a good sealing, while providing a stable attachment of the radiator, it is an advantage if they have elastic characteristics. They may, for example, be made of a suitable rubber material According to the invention, at least one of the sealing elements is annular. Thus, it is able to extend around the entire air duct, and provide a good sealing between the radiator and the connecting channel unit. Such an annular sealing element provides contact with the channel unit and a connecting side surface of the radiator over a large area, and in a symmetrical manner. With an annular sealing element, a stable attachment of the radiator in the air duct is facilitated. Said side surfaces of the radiator are advantageously substantially plane. Accordingly, the transfer of a uniform pressure from said contact surfaces of the channel units, via the respective sealing elements, to the radiator' s side surfaces is facilitated. According to one embodiment of the present invention, the first channel unit comprises a channel, leading the air in a first flow direction towards the radiator, and the second channel unit comprises a channel leading the air in a second flow direction from the radiator, so that the first flow direction and the second flow direction have an angle in relation to each other. The air duct has, in this case, at least one curved section. In many installations, it is not possible or suitable to apply a radiator in a completely straight air duct. The first channel unit may, for example, comprise a channel leading a vertical air flow in towards the radiator, and the second channel unit may comprise a channel leading a horizontal air flow. In this case, a curved section is provided, where the air flow must provide a directional change of 90°. According to one embodiment of the present invention, the radiator is fitted in an inclined position inside the air duct, so that the air which flows through the radiator obtains a flow direction differing from the first flow direction and the second flow direction. In this case, the air flow may provide a first directional change in the radiator, and a remaining directional change in the second channel unit. With such an arrangement the air's flow direction does not need to be changed abruptly between the first and the second flow directions. The flow resistance in the air duct may thus be reduced. According to one embodiment of the present invention, one of said channel units contains a fan. The fan may be arranged in the first channel unit and press air through the radiator. Alternatively, the fan may be arranged in the second channel unit and suck air through the radiator. BRIEF DESCRIPTION OF THE DRAWINGS

Below, as an example, a preferred embodiment of the invention is described with reference to the enclosed drawings, on which: Fig. 1 shows a hybrid bus comprising a number of hybrid components,

Fig. 2 shows an arrangement for attachment of a radiator in an air duct,

Fig. 3 shows a separate view of the first channel unit in Fig. 2,

Fig. 4 shows a separate view of the radiator in Fig. 2,

Fig. 5 shows a separate view of the second channel unit in Fig. 2 and

Fig. 6 shows a cross section in a vertical plane of the arrangement in Fig. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Fig. 1 shows a bus 1, in the form of a hybrid vehicle operated by a schematically displayed combustion engine 2, and an electrical machine 3. Since the electrical machine 3 operates as a motor, it operates the bus 1 with or without the assistance of the combustion engine 2. The electrical machine 3 operates as a generator on the occasions when the bus 1 brakes. The electrical machine 3 may provide braking of the bus 1 up to a certain braking effect. Where a higher braking effect is required, the braking process is complemented by the vehicle's ordinary brakes. The bus 1 is, on the roof, equipped with hybrid components necessary for the operation of the electrical machine 3. The hybrid components are fitted as three units. A first unit 4 comprises a hybrid battery, a second unit 5 comprises power electronics, controlling the flow of electric power between the hybrid battery 4 and the electrical machine 3, and a third unit 6 comprises primarily parts of a cooling system for cooling of the hybrid battery 4 and the power electronics 5. The third unit 6 comprises a part of a cooling system, comprising a non-displayed line circuit with a circulating coolant. The coolant is cooled in an air-cooled radiator 7, before it is led to the hybrid battery 4 and the power electronics 5.

Fig. 2 shows the air-cooled radiator 7 in the third unit 6. The radiator 7 is arranged in an air duct, defined by a first channel unit 8 and a second channel unit 9. The first channel unit 8 comprises a pipe-shaped wall 8a, forming a vertical channel part 8ai of the air duct 8. The pipe-shaped wall 8a may have any suitable external shape. It may, for example, be round or square. The first channel unit 8 comprises a fan 10 that sucks in air from an environment 11, and presses air in a vertical flow direction di downwards towards the radiator 7, which is arranged at a lower end of the first channel unit 8. With the help of the fan 10, a required cooling air flow may be led to the radiator 7 during substantially all operating modes of the bus 1. The first channel unit 8 comprises, at the lower end, a section 8b, extending radially outwards from the pipe- shaped wall 8a. The radially outwards directed section 8b extends around the whole first channel unit 8. The first channel unit 8 comprises a first opening 8d and a second opening 8e in the wall 8a. An inlet conduit 7a, which leads coolant to the radiator 7, extends through the first opening 8d in the wall 8a, and an outlet conduit 7b, which leads coolant out from the radiator 7, extends through the second opening 8e in the wall 8a.

The second channel unit 9 comprises a pipe-shaped wall 9a that forms a horizontal channel part 9ai of said air duct. The pipe-shaped wall 9a may have any suitable external shape. It may, for example be round or square. The second unit 9 receives air from the radiator 7, and leads it in a primarily horizontal flow direction d₂back to the environment 11. The second channel unit 9 comprises a section 9b, extending radially outwards from the pipe- shaped wall 9a. The radially outwards directed section 9b extends around the whole second channel unit 9. The radially outwards directed section 9b of the second channel unit 9 has a shape complementing the radially outwards directed section 8b of the first channel unit 8. Fastening elements in the form of screw elements 12 have been arranged to hold together the two outwards directed sections 8b, 9b. Accordingly, a stable connection is created between the first channel unit 8 and the second channel unit 9. Fig. 3 shows the first channel unit 8 in a separate view from below. The radially outwards directed section 8b is equipped with several holes 8b i, which are arranged at a substantially constant distance. The first channel unit 8 also comprises a section 8c, extending radially inwards from the pipe-shaped wall 8a. The radially inwards directed section 8c is arranged at a higher level than the radially outwards directed section 8b. The radially inwards directed section 8c extends around the whole vertical channel 8ai of the inlet channel. A first annular sealing element 13 is attached on a lower contact surface 8ci of the radially inwards directed section 8c. The sealing element 13 is advantageously attached with an adhesive means, such as a suitable glue. The first channel unit 8 is made of a metal material, which may be a stainless steel.

Fig. 4 shows the radiator 7 in a separate state. The radiator 7 comprises an inlet tank 7c, equipped with a connection 7ci for connecting the inlet conduit 7a that leads coolant to the radiator 7, and an outlet tank 7d equipped with a connection 7di for connecting the outlet conduit 7b. The radiator 7 comprises a cooling section 7e, which is arranged between the inlet tank 7c and the outlet tank 7d. The cooling section 7e comprises several parallel conduits 7e_l5 leading the coolant from the inlet tank 7c to the outlet tank 7d. The coolant is cooled by air flowing through the slot shaped flow passages, formed between the parallel conduits 7ei. In order to increase the heat transfer surface between the air and the coolant, the slot shaped flow passages 7ei comprise heat transfer elements 7e₂. The radiator's 7 component parts are made of a material with good heat transfer characteristics, such as aluminium.

Fig. 5 shows the second channel unit 9 in a separate state, seen from above. The second channel unit 9 thus comprises a horizontal channel section 9ai of air duct. It is clear that the radially outwards directed section 9b is equipped with holes 9b i, arranged at substantially constant distances around the whole radially outwards directed section 9b, and in places corresponding to the holes 8bi of the radially outwards directed section 8b in the first channel unit 8. The second channel unit 9 comprises a section 9c that extends radially inwards from the pipe- shaped wall 9a. A second annular sealing element 14 is attached on an upper contact surface 9c i of the radially inwards directed section 9c. The sealing element 14 may be attached with an adhesive means, such as a glue. The second channel unit 9 is advantageously made of the same material as the first channel unit 8. It may thus be made of stainless steel.

Fig. 6 shows a cross section of the radiator 7 in the air duct. The radially inwards directed section 8c of the first channel unit 8 has a downward facing contact surface 8ci with the first sealing element 13. The radially inwards directed section 9c of the second channel unit 9 has an upward facing contact surface 9ci with the first sealing element 13. The distance between said contact surfaces 8ci, 9ci is dimensioned in such a way that, in an assembly state, the first sealing element 13 is pressed against an upper side surface 7f of the radiator 7 by the radially inwards directed section 8c of the first channel unit 8, and in such a way that the second sealing element 14 is pressed against a lower side surface 7g of the radiator 7 by the radially inwards directed section 9c of the second channel unit 9. The sealing elements 13, 14 are made of an elastic material, so that they are deformed elastically when pressed against the radiator's side surfaces 7f, 7g. The radiator's side surfaces 7f, 7g are substantially plane, as are the contact surfaces 8ci, 9c . The first sealing element 13 creates a sealed transition of the air duct, between the first channel unit 8 and the radiator 7. The second sealing element 14 creates a sealed transition of the air duct, between the radiator 7 and the second channel unit 9. The pressure which the sealing elements 13, 14 exert on the radiator's side surfaces 7f, 7g are of a dimension causing the sealing elements 13, 14 to keep the radiator 7 attached in a stable manner, without causing any damage to the component parts. The radiator 7 is, in the attached position, in contact only with the sealing elements 13, 14. The radiator is thus attached at a distance from the pipe-shaped wall 8a of the first channel unit 8, and the pipe-shaped wall 9a of the second channel unit 9. Thus, no part of the radiator 7 obtains direct contact with any of the channel units 8, 9. With such an attachment, the radiator 7 and the channel units 8, 9 may be made of different materials, such as aluminium and stainless steel, without any risk of galvanic corrosion arising. The air led in the first channel unit 8, in the direction towards the radiator 7, has a substantially vertical flow direction di. The contact surfaces 8ci, 9ci of the radially inwards directed sections 8c, 9c are inclined in relation to a horizontal plane. The radially inwards directed sections 8c, 9c thus keep the radiator 7 attached in a corresponding inclined position in the air duct. The air flow thus provides a change of direction when it is led through the radiator 7. The air flow is led through the radiator 7 in the direction d_r. The air flow that leaves the radiator 7 changes direction in the second channel unit 2, to a substantially horizontal flow direction d_2. Since the radiator 7 is inclined, the air flow leaving the radiator 7 obtains a horizontal component, which facilitates the subsequent air flow through the second channel unit 9. The flow resistance in the air duct may thus be reduced.

The arrangement consists of few parts, namely a first channel unit 8, which is equipped with a pre-glued first sealing element 13, and a second channel unit 9, which is equipped with a pre-glued second sealing element 13. During assembly of the arrangement, the second channel unit 9 is initially anchored on the roof of the bus in a suitable manner. The first channel unit 8 is then applied in an assembly position on the second channel unit 9. Screw elements 12 are applied in the holes 8b i, 9b i of the radially protruding sections 8b, 9b in the respective channel units 8, 9. When the screw elements 12 are tightened, the channel units 8, 9 are pulled towards each other, until they reach the assembly position, wherein the protruding sections 8b, 9b in the channel units 8, 9 are in a fully joined state. In the assembly position, the contact surfaces 8ci, 9ci of the channel units 8, 9 exert a pressure against the radiator's 7 opposite side surfaces 7f, 7g via the sealing elements 13, 14, so that the sealing elements 13, 14 hold the radiator 7 in a predetermined attachment position, in which it is located at a distance from all the surfaces of the channel units 8, 9. The assembly of the

arrangement is simple, and may be completed within a short period of time.

The invention is in no way limited to the embodiment described in the drawing, but may be varied freely within the scope of the patent claims. The arrangement as described above does not need to be arranged on a roof, but may be arranged in substantially any suitable place. The radiator may be of substantially any suitable type and need not be comprised in a cooling system that cools hybrid components in a vehicle.

Claims

1. Arrangement for attachment of a radiator (7) in an air duct, wherein the arrangement comprises a first channel unit (8), comprising a first channel section of the air duct (8a , leading air to the radiator (7), and a second channel unit (9), comprising a second channel section (9a of the air duct, receiving the air after it has passed through the radiator (7), characterised in that the arrangement comprises a first sealing element (13), arranged between a contact surface (8ci) of the first channel unit (8) and a first side surface (7f) of the radiator (7), so that the air duct obtains a sealed passage in a transition area between the first channel unit (8) and the radiator (7), a second sealing element (14), arranged between a contact surface (9ci) of the second channel unit (9) and an opposite second side surface (7g) of the radiator (7), so that the air duct obtains a sealed passage in a transition area between the radiator (7) and the second channel unit (9), and fastening elements (12), adapted to connect the first channel unit (8) and the second channel unit (9) with each other in an assembly position, in which said contact surfaces (8ci, 9ci) of the channel units (8, 9) exert a pressure against the radiator's (7) opposite side surfaces (7f, 7g), via the sealing elements (13, 14), so that the sealing elements (13, 14)) hold the radiator (7) in a fastening position in the air duct at a distance from the channel units (8, 9), wherein at least one of the sealing elements (13, 14) is annular.

2. Arrangement according to claim 1, characterised in that the first channel unit (8) comprises a radially inwards directed section (8c), comprising said contact surface (8ci), which is in contact with the first sealing element (13).

3. Arrangement according to claim 1 or 2, characterised in that the first sealing element (13) is fixedly connected with said contact surface (8ci) of the first channel unit (8).

4. Arrangement according to any of the previous claims, characterised in that the second channel unit (9) comprises a radially inwards directed section (9c), comprising said contact surface (8ci), which is in contact with the second sealing element (14).

5. Arrangement according to any of the previous claims, characterised in that the second sealing element (14) is fixedly connected with said contact surface (9c i) of the second channel unit (9).

6. Arrangement according to any of the previous claims, characterised in that the first channel unit (8) comprises a radially outwards directed section (8b), and in that the second channel unit (9) comprises a radially outwards directed section (9b), wherein said radially outwards directed sections (8b, 9b) are adapted to be connected with each other in said assembly position, with the help of said fastening elements (12).

7. Arrangement according to any of the previous claims, characterised in that at least one of the sealing elements (13, 14) has elastic characteristics.

8. Arrangement according to any of the previous claims, characterised in that said side surfaces (7f, 7g) of the radiator (7) are substantially plane.

9. Arrangement according to any of the previous claims, characterised in that the first channel unit (8) comprises a channel (8a), leading the air in a first flow direction (di) towards the radiator (7), and that the second channel unit (9) comprises a channel (9a), leading the air in a second flow direction (d₂) from the radiator (7), wherein the first flow direction (di) and the second flow direction (d₂) have an angle in relation to each other.

10. Arrangement according to claim 9, characterised in that the radiator is fitted in an inclined position inside the air duct, so that the air which flows through the radiator (7) obtains a flow direction (d_r) that differs from the first flow direction (di) and the second flow direction (d₂).

11. Arrangement according to any of the previous claims, characterised in that one of said channel units (8, 9) comprises a fan (10).