Vehicle lamp, in particular motor vehicle headlamp

Abstract

Vehicle light (1), in particular a motor vehicle headlight (6), comprising a number of light sources (2), a circuit carrier (3) with a front (3a) and a rear (3b), wherein the light sources (2) are arranged on the front (3a) of the circuit carrier (3), a heat sink (4), wherein the heat sink (4) is attached over a surface to the rear (3b) of the circuit carrier (3), and a fan (5) attached to the heat sink (4), wherein the heat sink (4) has a base body (4a) for surface contact with the rear (3b) of the circuit carrier (3), a flange (4b) for receiving the fan (5), and an air duct (4c), wherein the flange (4b) encloses an air inlet opening (4d) opening into the air duct (4c), which is designed to receive an airflow (L) generated by the fan (5), wherein the air duct (4c) extends to an air outlet opening (4e). extendswherein the heat sink (4) is formed in one piece from 3D printed material.

Description

[0001] The invention relates to a vehicle light, in particular a motor vehicle headlight, comprising a number of light sources, a circuit carrier with a front and a back, wherein the light sources are arranged on the front of the circuit carrier, a heat sink, wherein the heat sink is attached flat to the back of the circuit carrier, and a fan attached to the heat sink.

[0002] Numerous vehicle lights are known from the prior art that feature active cooling comprising a heat sink and a fan attached to it. An object of the invention is to create a vehicle light that offers more optimized cooling performance, particularly in situations with limited installation space and / or a restricted design geometry.

[0003] This problem is solved by a vehicle light of the type mentioned above, in which, according to the invention, the heat sink has a base body for planar contacting of the back of the circuit carrier, a flange for receiving the fan, and an air duct, wherein the flange encloses an air inlet opening opening into the air duct, which is designed to receive an airflow generated by the fan, wherein the air duct extends to an air outlet opening, and wherein the heat sink is formed in one piece from 3D printed material.

[0004] The number of light sources can preferably be at least 4, 8, 10, or more. The base body, or a part thereof, should not be a prefabricated substrate but rather 3D printed from scratch. A one-piece construction is therefore understood to be a design free of non-destructively detachable connections. The invention allows for space-optimized manufacturing of the vehicle light. The shape of the heat sink can be determined by a simulation based on artificial intelligence, so that abstract, irregular shapes of the heat sink or its surface are conceivable. Optimized airflow within the heat sink allows the heated air to be directed into the housing. A weight saving compared to conventional vehicle lights is estimated at approximately 10%. For 3D printing, the "Desktop Metal P50" 3D printer, for example, can be used. The heat sink can be printed and subsequently sintered.

[0005] In particular, the air outlet opening can be designed such that the flow direction of the air exiting the air outlet opening is inclined at an angle α of no more than 45° relative to the angle of attack of the air entering through the air inlet opening. This allows for efficient maintenance of the airflow, a high flow velocity, and low dynamic pressure on the outlet side.

[0006] Furthermore, the air duct can be designed such that it tapers continuously from the air inlet opening to the air outlet opening in the direction of the base body, with the cross-section of the air duct decreasing continuously from the air inlet opening to the air outlet opening. This means that the width parallel to the base body decreases less than its depth measured in the normal direction to the base body. The width can be constant or taper accordingly. A tapered duct increases the flow velocity within the duct. In this way, the cooling capacity at the end of the duct can be increased and / or dehumidification at or near the end of the duct can be made more efficient. For example, downstream components such as a cover plate can be dehumidified more efficiently.

[0007] In particular, it can be provided that an inner housing engages the air outlet opening, holding a projection lens downstream of the circuit carrier for manipulating the light distribution emitted by the light sources, wherein the inner housing is enclosed by an outer housing, the outer housing having a translucent cover plate downstream of the projection lens, and the inner housing having an internal air duct configured to direct an airflow drawn in through the air outlet opening towards the cover plate. This can serve to dehumidify the cover plate and / or defrost it.

[0008] Furthermore, it may be provided that cooling structure elements are provided within the air duct, extending from an inner wall of the duct and / or the base body within the air duct.

[0009] In particular, the cooling structure elements may be designed to be cooling fins extending parallel to a longitudinal dimension of the air duct and / or cooling pins.

[0010] Furthermore, the cooling structure elements can be designed asymmetrical and irregularly arranged. These structures can be flow-optimized using AI despite their irregular shape. A combination with the aforementioned cooling fins or cooling pins is also conceivable.

[0011] In particular, the base body can be designed to have a flat area, with the flange being configured such that a fan mounted flat on the flange is inclined relative to the flat area of ​​the base body. Inclined means that the angle is, for example, between 20° and 70°, and in particular between 30° and 60°. In this way, the required installation space can be reduced.

[0012] Furthermore, the position of the air inlet opening and the inclination of the fan relative to the base body can be chosen such that, after entering the air inlet opening, the airflow, without additional deflection, strikes at least a section of the base body or of any protruding cooling elements that is directly opposite the light sources. This means that the back of the circuit carrier makes direct contact with the heat sink, and the relevant cooling elements lie within an imaginary normal projection onto a contact plane thus configured, opposite the light sources.

[0013] In particular, this area can be designed to encompass the centroid of a polygon formed by the outermost LEDs. Preferably, all LEDs can also be detected "thermally".

[0014] In particular, it may be provided that the section in question encompasses the area directly opposite the highest concentration of light sources. The three latter features can be combined to particular advantage.

[0015] Furthermore, it can be provided that the light sources are distributed over the front of the circuit carrier, with the heat sink being arranged on the opposite surface of the back of the circuit carrier, such that a normal projection of the base body onto the front of the circuit carrier covers at least 70%, preferably at least 80% of the area formed by a virtual polygon whose vertices are formed by light sources, such that all light sources that do not form vertices of the polygon lie within the polygon.

[0016] In particular, it may be provided that, in order to increase heat transfer from the front to the back of the circuit carrier, heat transfer means are provided which penetrate the circuit carrier from its front to its back.

[0017] Furthermore, it can be provided that at least some of the heat transfer means are designed as vias, which are preferably filled with thermally conductive material and are particularly preferably arranged in the immediate vicinity of the light sources.

[0018] A VIA stands for "vertical interconnect access". Typically, a VIA is located in close proximity to the light sources. This is defined as a distance of less than 5 mm to the nearest light source.

[0019] In particular, the heat sink may be made of an aluminum alloy. Suitable materials include, for example, aluminum alloys such as AlSi10Mg or alloy 6061. The shape of the heat sink, including its fins, pins, and / or irregular structures, can be finalized, for example, using a laser sintering process.

[0020] Furthermore, it may be provided that the base body has integrally molded fastening means that are prepared for detachable connection with the circuit carrier or a housing that engages the circuit carrier.

[0021] Furthermore, the invention relates to a motor vehicle headlight, comprising a vehicle light according to the invention.

[0022] Further optional aspects of the invention are described below: The fan can be designed as an axial fan. The 3D-printed heat sink can consist of an air duct and the base surface, with the body being manufactured as a single piece. The fan is mounted directly on the air duct. Starting from the base surface, the optimized cooling geometry extends through the air duct, focusing on the specified heat sources and an optimal airflow. Depending on the primary cooling function, the airflow can be precisely directed, for example, towards the end plate for efficient further use.

[0023] The 3D printing process allows for optimization of cooling performance, airflow, and weight / installation size. The fan can be mounted directly onto the flange of the air duct's air inlet opening. The air duct's exhaust opening can extend beyond the base body on at least one of its four sides and features integrated connecting elements for a detachable, direct connection to the fan (screw eyes, clips, etc.). The air duct's intake opening seals almost completely airtight against the fan housing (no air leakage). The air duct encloses heat-dissipating, air-guiding structures located within it, extending away from the base heat sink. The base of these structures is positioned directly opposite the light sources. The structures are integrally manufactured with the air duct and / or base body. The structures have symmetrical, regular (e.g.,Ribs or pins) geometry and / or asymmetrical irregular free-form geometry.

[0024] The invention is explained in more detail below with reference to an exemplary and non-limiting embodiment, which is illustrated in the figures. These show Figure 1 is a perspective view of a vehicle light according to the invention, Figure 2 is a perspective view of a heat sink including a fan according to the invention. Fig. 1 Figure 3a shows a view of the top of the heat sink excluding the fan. Fig. 2 Figure 3a2 shows an indication of a section through the Fig. 3a , Figure 3 legs sectional view according to the indicated section according to Fig. 3a2 Figure 4 shows a view of the top of the heat sink including the fan; Figure 5 shows an oblique view of the vehicle light according to Fig. 1 including an inner housing 7, Figure 6 an oblique view of the vehicle light according to Fig. 5including a projection lens, Figure 7 a side view of the vehicle light according to Fig. 6 integrated into an outer housing including a translucent cover plate, so that a vehicle headlight is retained, and Figures 8 to 10 show details of exemplary designs of cooling pins and structures.

[0025] In the following figures, unless otherwise stated, the same reference symbols denote the same features.

[0026] Fig. 1 Figure 1 shows a perspective view of a vehicle light 1 according to the invention. The vehicle light 1 can be used as part of a motor vehicle headlight 6 (see Figure 1). Fig. 7) shall be designed and shall comprise a number of light sources 2, a circuit carrier 3 with a front 3a and a back 3b, wherein the light sources 2 are arranged on the front 3a of the circuit carrier 3, a heat sink 4, wherein the heat sink 4 is attached over a flat surface to the back 3b of the circuit carrier 3, and a fan 5 attached to the heat sink 4.

[0027] With regard to Fig. 2 As mentioned in Figures 3a, 3a2, and 3b, the heat sink 4 comprises a base body 4a for surface contact with the rear surface 3b of the circuit carrier 3, a flange 4b ​​for mounting the fan 5, and an air duct 4c. The flange 4b ​​encloses an air inlet opening 4d that opens into the air duct 4c and is designed to receive an airflow L generated by the fan 5. The air duct 4c extends to an air outlet opening 4e, and the heat sink 4 is formed in one piece from 3D-printed material.

[0028] The air duct 4c can be designed such that it tapers continuously from the air inlet opening 4d towards the air outlet opening 4e in the direction of the base body 4a, in particular it is provided that the cross-section of the air duct 4c decreases continuously from the air inlet opening 4d towards the air outlet opening 4e.

[0029] Cooling structure elements 10 are provided within the air duct 4c, extending from an inner duct wall 4c' and / or the base body 4a within the air duct 4c. Figures 3a to 3b Cooling structure elements 10 in the form of cooling fins 10a are shown as examples, extending parallel to a longitudinal extension of the air duct 4c. Figures 8 to 10 In contrast, pencils 10b and asymmetrical, irregularly arranged structures 10c show.

[0030] With regard to Fig. 1It should be noted that the air outlet opening 4e is designed such that the flow direction of the air La flowing out through the air outlet opening 4e is inclined at an angle α of a maximum of 45° with respect to the angle of attack of the air Le flowing in through the air inlet opening 4d. The base body 4a preferably has a planar region 4a', wherein the flange 4b ​​of the heat sink 4 is designed such that a fan 5 mounted flat on the flange 4b ​​is inclined at an angle with respect to the planar region 4a' of the base body 4a.

[0031] The position of the air inlet opening 4d and the inclination of the fan 5 with respect to the base body 4a can be selected such that an airflow L, after entering the air inlet opening 4d, without additional deflection, impinges at least on a section of that area of ​​the base body 4a or of cooling structure elements 10 projecting therefrom that is directly opposite the light sources 2. In particular, it can be provided that this area includes a centroid of a polygon formed by the outermost LEDs. Preferably, all LEDs can also be thermally controlled. Furthermore, it can be provided that said section includes the area directly opposite the highest concentration of light sources 2.

[0032] Preferably, the light sources 2 are distributed over the front surface 3a of the circuit carrier 3, wherein the heat sink 4 is arranged on the opposite surface of the back surface 3b of the circuit carrier 3, such that a normal projection of the base body 4 onto the front surface 3a covers at least 70%, preferably at least 80% of the area formed by a virtual polygon whose vertices are formed by light sources 2, such that all light sources 2 that do not form vertices of the polygon lie within the polygon.

[0033] To increase heat transfer from the front 3a to the back 3b of the circuit carrier 3, heat transfer means 11 can be provided, which penetrate the circuit carrier 3 from its front 3a to its back 3b. At least some of the heat transfer means 11 can be designed as vias 11a, which are preferably filled with thermally conductive material and are particularly preferably arranged in the immediate vicinity of the light sources 2.

[0034] Figure 4 Figure 1 shows a view of the top of the heat sink 4 including the fan 5. It can be seen that the base body 4a may have integrally molded fastening means 4f, which are prepared for detachable connection with the circuit carrier 3 or a housing 7 that engages the circuit carrier 3.

[0035] Figure 5 shows an oblique view of the vehicle light 1 according to Fig. 1 including an inner housing 7. Figure 6shows an oblique view of the vehicle light 1 according to Fig. 5 including a projection lens 8.

[0036] Figure 7 shows a side view of the vehicle light according to Fig. 6 Integrated into an outer housing including a translucent cover, thus creating a vehicle headlight. An inner housing 7 engages the air outlet opening 4e and holds a projection lens 8 downstream of the circuit carrier 3 for manipulating the light distribution emitted by the light sources 2. The inner housing 7 is enclosed by an outer housing 9. This outer housing has a translucent cover 9a downstream of the projection lens 8, and the inner housing 7 has an internal air duct 7a designed to direct an airflow L drawn in through the air outlet opening 4e towards the cover 9a.

[0037] Figures 8 to 10show details of exemplary designs of cooling pins 10b and cooling structures 10c.

[0038] The cooling element 5 is preferably made of an aluminum alloy.

[0039] The invention is not limited to the embodiments shown, but is defined by the entire scope of protection of the claims. Individual aspects of the invention or the embodiments may also be adopted and combined. Any reference numerals in the claims are exemplary and serve only to improve the readability of the claims, without limiting them. Reference sign

[0040] 1 Vehicle light 2 Light source 3 Circuit carrier 3a Front of circuit carrier 3b Rear of circuit carrier 4 Heat sink 4a Base heat sink 4b Flange heat sink 4c Air duct 4d Air inlet 4e Air outlet 4f Fastening element 5 Fan 6 Vehicle headlight 7 Inner housing 8 Projection lens 9 Outer housing 9a Translucent cover 10 Cooling structure elements 10a Cooling fins (cooling structure elements) 10b Pins (cooling structure elements) 10 Asymmetrical, irregularly arranged protrusions (cooling structure elements) 11 Heat transfer medium 11a VIAS (heat transfer medium) L Airflow L Outflowing air L Inflowing air α Angle inflowing / outflowing air

Claims

1. Vehicle light (1), in particular motor vehicle headlight (6), comprising: - a number of light sources (2), - a circuit carrier (3) with a front (3a) and a back (3b), wherein the light sources (2) are arranged on the front (3a) of the circuit carrier (3), - a heat sink (4), wherein the heat sink (4) is attached over a flat surface to the back (3b) of the circuit carrier (3), and - a fan (5) attached to the heat sink (4). characterized by the fact thatthe heat sink (4) *a base body (4a) for planar contacting of the rear side (3b) of the circuit carrier (3), *a flange (4b) for receiving the fan (5), *and an air duct (4c), wherein the flange (4b) encloses an air inlet opening (4d) opening into the air duct (4c), which is designed to receive an airflow (L) generated by the fan (5), wherein the air duct (4c) extends to an air outlet opening (4e), wherein the heat sink (4) is formed in one piece from 3D printed material.

2. Vehicle light (1) according to claim 1, wherein the air outlet opening (4e) is designed such that the flow direction of the air (La) flowing out through the air outlet opening (4e) is inclined at an angle (α) of a maximum of 45° with respect to an angle of attack of the air (Le) flowing in through the air inlet opening (4d).

3. Vehicle light (1) according to claim 1 or 2, wherein the air duct (4c) is designed such that it tapers continuously from the air inlet opening (4d) to the air outlet opening (4e) in the direction of the base body (4a), wherein it is particularly provided that the cross-section of the air duct (4c) decreases continuously from the air inlet opening (4d) to the air outlet opening (4e).

4. Vehicle light (1) according to one of the preceding claims, wherein an inner housing (7) engages the air outlet opening (4e), which holds a projection lens (8) downstream of the circuit carrier (3) for manipulating the light distribution emitted by the light sources (2), wherein the inner housing (7) is enclosed by an outer housing (9), wherein the outer housing (9) has a light-transmitting cover plate (9a) downstream of the projection lens (8), and wherein the inner housing (7) has an inner housing air channel (7a) which is configured to direct an airflow (L) received through the air outlet opening (4e) towards the cover plate (9a).

5. Vehicle light (1) according to one of the preceding claims, wherein cooling structure elements (10) are provided within the air duct (4c) which extend from an inner wall of the duct (4c') and / or the base body (4a) within the air duct (4c).

6. Vehicle light (1) according to claim 5, wherein the cooling structure elements (10, 10a, 10b, 10c) are * cooling fins (10a) extending parallel to a longitudinal extension of the air duct (4c), and / or * pins (10b).

7. Vehicle light (1) according to claim 5, wherein the cooling structure elements (10, 10a, 10b, 10c) are asymmetrical, irregularly arranged structures (10c).

8. Vehicle light (1) according to one of the preceding claims, wherein the base body (4a) has a planar area (4a'), wherein the flange (4b) of the heat sink (4) is designed such that a fan (5) mounted flat on the flange (4b) is inclined at an angle with respect to the planar area (4a') of the base body (4a).

9. Vehicle light (1) according to one of the preceding claims, wherein the position of the air inlet opening (4d) and the inclination of the fan (5) in relation to the base body (4a) is selected such that an airflow (L) after entering the air inlet opening (4d) without additional deflection impinges at least on a section of that area of ​​the base body (4a) or of cooling structure elements (10) projecting therefrom which is directly opposite the light sources (2).

10. Vehicle light (1) according to claim 9, wherein said section comprises the area directly opposite the highest concentration of light sources (2).

11. Vehicle light (1) according to one of the preceding claims, wherein the light sources (2) are distributed over a surface on the front (3a) of the circuit carrier (3), wherein the heat sink (4) is arranged on the opposite surface of the back (3b) of the circuit carrier (3), such that a normal projection of the base body (4) onto the front (3a) covers at least 70%, preferably at least 80% of the area formed by a virtual polygon whose vertices are formed by light sources (2), such that all light sources (2) that do not form vertices of the polygon lie within the polygon.

12. Vehicle light (1) according to one of the preceding claims, wherein, to increase the heat transfer from the front (3a) to the rear (3b) of the circuit carrier (3), heat transfer means (11) are provided which penetrate the circuit carrier (3) from its front (3a) to its rear (3b).

13. Vehicle light (1) according to claim 12, wherein at least some of the heat transfer means (11) are designed as VIAS (11a) which are preferably filled with thermally conductive material and are particularly preferably arranged in the immediate vicinity of the light sources (2).

14. Vehicle light (1) according to one of the preceding claims, wherein the cooling element (5) is made of an aluminum alloy.

15. Vehicle light (1) according to one of the preceding claims, wherein the base body (4a) has integrally molded fastening means (4f) which are prepared for detachable connection with the circuit carrier (3) or a housing (7) engaging the circuit carrier (3).

16. Motor vehicle headlight (6), comprising a vehicle light (1) according to one of the preceding claims.

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