WO2017016946A1

WO2017016946A1 - Device for performing open-loop and/or closed-loop control of a fan motor

Info

Publication number: WO2017016946A1
Application number: PCT/EP2016/067248
Authority: WO
Inventors: Johannes RISTELHUBER; Heiko Reiss; Frank Adam
Original assignee: Valeo Klimasysteme Gmbh
Priority date: 2015-07-30
Filing date: 2016-07-20
Publication date: 2017-02-02
Also published as: EP3329754A1; CN108029223B; DE102015112446A1; CN108029223A

Abstract

A device for performing open-loop and/or closed-loop control of a fan motor in a module for heating, ventilating and/or air-conditioning a passenger cell of a motor vehicle has a circuit board (16) with electric components (32) for performing open-loop and/or closed- loop control of the fan motor, an electric connecting structure (18) for electrically connecting the circuit board (16) and/or the electric components (32) to a vehicle-side power supply, a heat-discharging device (26) for transmitting heat from the electric components (32) to a heat sink (28), in particular the surroundings, and a housing (12) which surrounds the device (10) and has a housing wall (14). The electric connecting structure (18) and/or the heat discharging device (26) is at least partially integrated into the housing wall (14).

Description

Device for performing open-loop and/or closed-loop control of a fan motor

The invention concerns a device for performing open- loop and/or closed-loop control of a fan motor in a module for heating, ventilating and/or air-conditioning a passenger cell of a motor vehicle, having a circuit board with electric components for performing open-loop and/or closed-loop control of the fan motor, an electric connecting structure for electrically connecting the circuit board and/or the electric components to a vehicle-side power supply, a heat- discharging device for transmitting heat from the electric components to a heat sink, in particular the surroundings, and a housing which surrounds the device and has a housing wall.

Such devices are used to influence the flow of air in a module for heating, ventilating and/or air-conditioning a vehicle (English: heating, ventilation and air conditioning unit, HVAC) , in that the speed of a fan motor which can be, in particular, a brushless DC motor or a DC motor with brushes, is subjected to open-loop or closed-loop control by means of a pulse-width- modulated output signal of the control device.

Known control devices are usually composed of a circuit board which is equipped with electric components, a heat sink (commonly made of a metal alloy) , a thermal interface, an electric connecting structure, for example in the form of a male multipoint connector, and a housing in which all the components are accommodated. The power supply is provided via a vehicle-side cable harness which is connected to connections of the male multipoint connector and therefore supplies the circuit board and the components arranged thereon. The waste heat which occurs at the electric components is conducted via the thermal interface to the heat sink, which is, for example, cooled by a flow of air. A device of the generic type is known, for example, from KR 2003-0030437 A. An object of the invention is to make available a device for performing open-loop and/or closed-loop control of a fan motor, which device is distinguished by simpler assembly and lower manufacturing costs. According to the invention, this is achieved in a device of the type mentioned at the beginning in that the electric connecting structure and/or the heat discharging device are at least partially integrated into the housing wall. This means that the electric connecting structure which comprises, for example, a multipoint male connector and/or a busbar, and/or the heat discharging device is/are connected to the housing wall in such a way that these components cannot be disconnected from one another without destroying the parts. The device according to the invention is suitable, particularly, for performing power regulation of a brushless DC motor for a fan in a module for heating, ventilating and/or air-conditioning the passenger cell of a motor vehicle. In particular in such motors, owing to the high engine efficiency, the waste heat which is output by the power transistors becomes ever smaller, which means that the high number of parts required which are known from the prior art is hardly still justified. Owing to the combination of up to three parts (housing, connecting structure and heat discharging device) to form a single component, into which only the circuit board with the electric components has yet to be inserted, the device according to the invention is characterized by significantly shortened assembly time and a small overall size, allowing the manufacturing costs to be reduced. According to one preferred embodiment, the housing wall is made of plastic, and the electric connecting structure is embedded at least partially in the plastic of the housing wall, in particular by encapsulation or covering by means of injection moulding in an injection moulding process. This process is one which is simple in terms of fabrication technology and has the purpose of providing a combined component. A further reduction in the required components can be achieved when the electric connecting structure simultaneously forms at least partially the heat discharging device and extends, in particular, to the outside of the housing.

The electric conducting structure therefore also serves to transmit heat from the electric components to a heat sink, wherein this can take place directly or the heat can first be transmitted to the housing, which in turn outputs the heat to the surroundings. For this purpose, for example a flow of air for the purpose of cooling is applied to the outside of the housing. The heat discharging device consequently does not necessarily extend as far as the outside of the housing; it is also possible for a section of the housing wall to be located between the heat discharging device formed by the electric connecting structure and the surroundings.

The electric connecting structure preferably has at least one heat discharging region which has a heat transfer resistance with respect to the heat sink, in particular the surroundings, which is lower by at least a factor of 2 than the housing wall. The heat discharging region or the heat discharging regions is/are preferably connected to contact regions which are in direct thermal contact with the components to be cooled . In order to achieve good thermal transfer, a housing section which is provided between the at least one heat discharging region and the heat sink has a thickness of a maximum of 1 mm. The heat discharging region or the heat discharging regions is/are therefore consequently covered merely with a thin electrically insulating plastic layer on the outside of the housing.

In one development of the invention, the at least one heat discharging region of the electric connecting structure is arranged at least partially on an outside of the housing wall and, in particular, terminates flush with the adjoining outside. That is to say the plastic material of the housing wall has a cutout for the heat discharging region, with the result that the latter is in direct contact with the surrounding air. In this way, a particularly good transfer of heat can be achieved. A heat discharging region, in particular made of metal, is preferably provided on 10% to 80%, in particular 20% to 40% of the outer surface of the housing. Said heat discharging region is preferably exposed on the outside of the housing but can alternatively be implemented with a thin plastic layer over the heat discharging region or the heat discharging regions for the purpose of electrical insulation.

It is advantageous for a large portion of the outer surface of the housing to be used as a heat discharging region, since a low heat flow density to the heat sink is then sufficient. Owing to the low heat flow density, it is possible to implement an indirect heat transfer through a thin plastic layer, and the heat discharging region or the heat discharging regions of the electric connecting structure is/are provided in a sufficiently large region of the outer surface of the housing. The temperature gradient in insulating plastic material can be kept in the range from 1 to 5 K here. Furthermore, it is not absolutely necessary to enlarge the surface region by means of fins or the like. However, if it is necessary to optimize the heat discharging regions on the application side, the connecting structure and the structure of the housing can be easily adapted or modified .

The electric connecting structure being made of metal, in particular aluminium or copper, which is defined by low electrical and thermal resistance is advantageous.

The electric connecting structure is preferably fabricated from a metallic plate material by stamping and/or punching. The manufacture in a stamping or punching process is defined by low manufacturing costs, since they can be carried out using mass production. In particular, in comparison with the aluminium heat sinks which are known from the prior art and which are fabricated by extrusion or pressure die casting, the manufacture of an electric connecting structure made of a metallic plate material with a progressive tool in a punching process is significantly more cost-effective. In addition, since the wall thickness or material thickness can be adapted to the electrical and thermal requirements, a particularly low material thickness can be achieved, which is not possible, for example, in a pressure die casting process. The electric connecting structure preferably has a material thickness of 0.1 mm to 1.0 mm, as a result of which a low weight is achieved.

According to one development of the invention, a heat discharging region of the electric connecting structure, which is in direct contact with the surroundings serves simultaneously as an earthing contact. A heat discharging region which projects outward through the housing is therefore at earth potential, which additionally reduces the number of parts . The electric components and/or conductor tracks of the circuit board are preferably in electrical and thermal contact with the electric connecting structure by crimping, clamping and/or press-fit connecting pins. Such connections can be implemented in a gas-tight and simple fashion, which facilitates the mounting of the circuit board with the electric components in the combined housing. Solder connections are alternatively also conceivable. In the device according to the invention and its developments which are specified in the dependent claims, the heat sink which is known from the prior art and is made of an aluminium alloy is replaced by a plastic housing into which an electric connecting structure, which serves simultaneously as a heat discharging region, is already integrated.

The electric connecting structure is connected to a vehicle-side power supply and supplies the electric components of the circuit board (power components such as MOSFETs, chemical capacitors and coils) by means of which the open-loop and/or closed-loop control of the fan motor is carried out. The connection between the electric connecting structure and the electric components is achieved by means of soldering or a mechanical connection, for example clamping.

The male multipoint connector or busbar which is integrated into the plastic housing simultaneously makes available the cooling function of the module and, depending on the required cooling power, is either in direct contact with a flow of air outside the housing or is covered with a thin plastic layer. Advantages compared to the prior art are a reduced weight, a smaller number of parts and a shortened assembly time.

Further features and advantages can be found in the following description of a plurality of preferred embodiments on the basis of the appended drawing, in which :

Figure la shows a plan view of a device according a first embodiment of the invention;

- Figure lb shows a longitudinal section view of the device from Figure la; - Figure lc shows a front view of the device from

Figure la;

Figure 2 shows a longitudinal section view of a device according to a second embodiment of the invention;

Figure 3 shows a longitudinal section view of a device according to a third embodiment of the invention;

Figure 4 shows a longitudinal section view of a device according to a fourth embodiment of the invention;

Figure 5 shows a longitudinal section view of a device according to a fifth embodiment of the invention;

- Figure 6 shows a longitudinal section view of a device according to a sixth embodiment of the invention; and - Figure 7 shows a sectional view through a device according to the invention which explains the connection of the electric components. Figures la to lc show a first embodiment of a device 10 for performing open-loop and/or closed-loop control of a fan motor (not illustrated in the figures) in a module for heating, ventilating and/or air conditioning a passenger cell of a motor vehicle.

The device 10 has a preferably water-tight housing 12 with a pot-shaped housing wall 14 in which a circuit board 16 is accommodated, said circuit board 16 having a plurality of electric components (not shown in Figures la to lc) for performing open-loop and/or closed-loop control of the fan motor.

In order to connect the circuit board 16 or the electric components arranged on it to a vehicle-side power supply, an electric connecting structure 18 is provided which has a busbar 20 which is connected to the circuit board 16 via a connection 21. Furthermore, the electric connecting structure 18 comprises two connecting terminals 24 which are held in a connecting socket 22 and project outwards from the housing 12 and are connected to a vehicle-side cable harness. In this context, the connecting socket 22 is formed in one piece with the housing wall 14, for example in an injection moulding process.

The electric connecting structure 18, composed of the busbar 20 and the connecting terminals 24 which are formed in one piece therewith, is made of metal, in particular aluminium or copper, and is fabricated from a metallic plate material with a material thickness of preferably 0.1 mm to 1.0 mm by stamping or punching. The housing 12 or the housing wall 14 has on the side which is the lower one in Figure lb, a heat discharging device 26 which is embodied in one piece with the housing wall 14 and is almost in contact with the circuit board 16 and serves to transmit heat from the electric components to a heat sink 28, here the surroundings. The heat discharging device 26 is a plate-shaped projection which projects juts forward with respect to the circuit board 16 and runs parallel to the circuit board 16.

In this context, the heat discharging device 26, like the housing wall 14, is manufactured from plastic in an injection moulding process. Since a very large region of the housing wall 14 is embodied as a heat discharging device 26, the relatively low heat flow density made available as a result of the plastic is sufficient to cool the circuit board 16 and the electric components adequately and to conduct away waste heat to the surroundings.

In the device 10 according to the invention, the electric connecting structure 18 and the heat discharging device 26 are therefore at least partially integrated into the housing wall 14, in particular by encapsulation or covering by injection moulding, for which reason the device 10 is defined by a low weight, a low number of individual components and a short assembly time.

Figure 2 shows a device 10 according to a second embodiment of the invention, wherein details are given below only on the differences from the first embodiment in Figures la to lc. In particular, it is to be noted that in the device 10 according to Figure 2 the front view of the narrow side which has the electric connecting socket 22 is identical to Figure lc. In the device 10 according to Figure 2, the connection 21 of the busbar 20 to the circuit board 16 is provided on the side of the housing 12 lying opposite with respect to the connecting socket 22, as a result of which the busbar 20 or the electric connecting structure 18 extends under virtually the entire circuit board 16. In this context, the part of the busbar 20 which extends under the circuit board 16, parallel thereto, is embedded completely in the plastic of the housing wall 14, again by encapsulation or covering by injection moulding in an injection moulding process. The metal of the connecting structure 18 or of the busbar 20 serves here as a heat discharging device 26 from which the waste heat of the electric components is firstly transmitted to the housing wall 14 and from there to the heat sink 28.

Figure 3 shows a device 10 according to a third embodiment of the invention, wherein details are in turn given only on the differences from the previously described embodiments.

In the device 10 according to Figure 3, the electric connecting structure 18 or, in particular, the busbar 20 serves again simultaneously as a heat discharging device 26 and for this purpose has contact regions 30 which are stamped into the plate material and which make contact with the electric components 32 directly or via a thermal interface. The waste heat which is discharged by the components 32 in this way is firstly output to the housing wall 14 via the sections of the electric connecting structure 18 which are embedded in the housing wall 14 and serve as heat discharging regions 34, and is output from said housing wall 14 to the heat sink 28 in the form of the surroundings.

The device 10 (illustrated in Figure 4) according to a fourth embodiment of the invention differs from that in Figure 3 only in that the housing sections 36 which are provided between the heat discharging regions 34 of the electric connecting structure 18 and the heat sink 28 have a significantly smaller thickness of at maximum 1 mm.

In addition, cooling fins 38, which amplify the cooling effect further, are provided on the outside of the housing .

Figure 5 shows a device 10 according to a fifth embodiment of the invention, in which device 10 the heat discharging regions 34 of the electric connecting structure 18 are arranged on an outside of the housing wall 14 and terminate flush with the adjoining outside. That is to say the plastic material of the housing wall 14 has cutouts here, as a result of which the heat discharging regions 34 make direct contact with the heat sink 28, specifically the surroundings. As a result, particularly good transfer of heat is achieved, especially since the heat discharging regions 34 have a heat transfer resistance with respect to the heat sink 28 which is lower by at least a factor of 2 than the housing wall 14.

In addition, in the case of the device 10 according to Figure 5, the heat discharging regions 34 of the electric connecting structure 18 serve simultaneously as an earthing contact, since here the metal of the connecting structure 18 is in direct contact with the surroundings .

All the embodiments have in common the fact that a heat discharging device 26 or heat discharging regions 34 is/are provided in a relatively large part of the outer surface of the housing 12, in particular 10% to 80%, preferably 20% to 40%, said heat discharging device 26 or heat discharging regions 34 being, in particular, made of metal which can, however, also be covered toward the outside by a (thin) plastic layer.

Figure 6 shows a further embodiment of the device 10 which differs from the previously described ones merely in respect of having a somewhat different architecture and having differently configured connecting terminals 24. Figure 7 illustrates a possible attachment of the electric components 32 to the electric connecting structure 18 or the busbar 20. This attachment can be implemented by (gas-tight) cutting in of the busbar 20 and clamping of the components 32 (here a capacitor and a coil) .

Alternatively, the components 32 can be soldered to the electric connecting structure 18 or the busbar 20. Crimping is also possible or a connection by means of press-fit connecting pins in order to ensure the electrical and thermal contact with the electric connecting structure 18.

Claims

Paten claims

1. Device for performing open-loop and/or closed-loop control of a fan motor in a module for heating, ventilating and/or air-conditioning a passenger cell of a motor vehicle, having a circuit board (16) with electric components (32) for performing open-loop and/or closed-loop control of the fan motor, an electric connecting structure (18) for electrically connecting the circuit board (16) and/or the electric components (32) to a vehicle-side power supply, a heat-discharging device (26) for transmitting heat from the electric components (32) to a heat sink (28), in particular the surroundings, and a housing (12) which surrounds the device (10) and has a housing wall (14), characterized in that the electric connecting structure (18) and/or the heat discharging device (26) is at least partially integrated into the housing wall (14) .

2. Device according to Claim 1, characterized in that the housing wall (14) is made of plastic, and the electric connecting structure (18) is embedded at least partially in the plastic of the housing wall (14), in particular by encapsulation or covering by means of injection moulding in an injection moulding process.

3. Device according to Claim 1 or 2, characterized in that the electric connecting structure (18) simultaneously forms at least partially the heat discharging device (26) and extends, in particular, to the outside of the housing.

4. Device according to one of the preceding claims, characterized in that the electric connecting structure

(18) has at least one heat discharging region (34) which has a heat transfer resistance with respect to the heat sink (28), in particular the surroundings, which is lower by at least a factor of 2 than the housing wall (14) .

5. Device according to Claim 4, characterized in that a housing section (36) which is provided between the at least one heat discharging region (34) and the heat sink (28) has a thickness of a maximum of 1 mm.

6. Device according to Claim 4 or 5, characterized in that the at least one heat discharging region (34) of the electric connecting structure (18) is arranged at least partially on an outside of the housing wall (14) and, in particular, terminates flush with the adjoining outside .

7. Device according to one of Claims 4 to 6, characterized in that a heat discharging region (34), in particular made of metal, is provided on 10% to 80%, in particular 20% to 40%, of the outer surface of the housing ( 12 ) .

8. Device according to one of the preceding claims, characterized in that the electric connecting structure (18) is made of metal, in particular aluminium or copper .

9. Device according to one of the preceding claims, characterized in that the electric connecting structure (18) is fabricated from a metallic plate material by stamping and/or punching.

10. Device according to one of the preceding claims, characterized in that the electric connecting structure (18) has a material thickness of 0.1 mm to 1.0 mm.

11. Device according to one of Claims 4 to 10, insofar as referred back to Claim 4, characterized in that a heat discharging region (34) of the electric connecting structure (18) which is in direct contact with the surroundings serves simultaneously as an earthing contact .

12. Device according to one of the preceding claims, characterized in that the electric components (32) and/or conductor tracks of the circuit board (16) are in electrical and thermal contact with the electric connecting structure (18) by crimping, clamping and/or press-fit connecting pins.