EP2984406B1

EP2984406B1 - Heat sink for illuminating device and illuminating device

Info

Publication number: EP2984406B1
Application number: EP14728878.1A
Authority: EP
Inventors: Tingbiao LAN; MingTao WANG; Yonggang XIAO; Qihui Zhang
Original assignee: Ledvance GmbH
Current assignee: Ledvance GmbH
Priority date: 2013-06-17
Filing date: 2014-05-28
Publication date: 2018-08-22
Anticipated expiration: 2034-05-28
Also published as: WO2014202360A1; EP2984406A1; CN104235795A

Description

Technical Field

The present invention relates to a heat sink for an illuminating device and an illuminating device having the heat sink.

Background Art

In the manufacturing process of modern electronic device, especially LED illuminating device, the die casting or extrusion process is used more and more for manufacturing the heat sink for heat dissipation of the illuminating device. Such heat sink, for instance, can be directly configured as a cup-shaped body, and then, on one hand, it can be used as an accommodation part to receive therein heating parts of the illuminating device such as light engine, and on the other hand, it effectively dissipates heat of the heating parts.
A heat dissipating body with a lot of individual air guiding cavities on the outer circumferential wall can be made through the die casting process, but the heat dissipating body manufactured thereby has a high cost. A heat dissipating body with a lot of fins on the outer circumferential wall can be made through the extrusion process, while such heat dissipating body consumes a lot of machining time and produces a high defective rate during the manufacture.
Therefore, the existing heat sink of the illuminating device should be improved to enable it to be manufactured simply and precisely with characteristics of high thermal conductivity and low cost.
US 2012/044680 A1 shows an illuminating device with light emitting diodes. US 2012/170262 A1 provides a lighting device having at least one heat sink for cooling at least one light source, a method for producing a heat sink of the lighting device and a method for producing the lighting device. US 2009/170361 A1 discloses a connector and connector assemblies for use with miniature high power electrical components, and specifically with miniature LEDs. WO 2013/020773 A2 relates to a LED lightning assembly.

Summary of the Invention

Therefore, the object of the present invention lies in providing a heat sink for an illuminating device and an illuminating device having the heat sink.
Specifically, the present invention provides a heat sink for an illuminating device, characterized in that the heat sink comprises a first housing and a second housing, the first housing is a first metal stamping part, and the second housing is a second metal stamping part, and the first metal stamping part and the second metal stamping part are removably assembled together. The heat sink according to the present invention gives up the one-piece manufacturing method in the prior art, and configures the heat sink in two parts, thereby, the first and second housings can be firstly simply manufactured, and then the two parts are assembled together to form a complete heat sink. Thus, the defective rate of the heat sink during the manufacture can be reduced, and the assembled heat sink can be ensured to have good thermal conductivity.
According to the present invention, the first housing is in thermal contact with a first part of the illuminating device at one side, and defines, together with the second housing, a first space at the other side, and the first space is in air communication with the outside. The first housing, on one hand, can directly dissipate heat for the first part, and also can further indirectly guide, via the first space, the heat generated by the first part to the outside of the heat sink. Consequently, two heat dissipation paths for the illuminating device, especially the first part which generates heat, are formed.
According to the present invention, the first housing comprises a recessed region which support the first part and an air guiding region, the air guiding region extends radially outwardly from the recessed region at one side away from the second housing, and a flow path enabling communication of the first space with the outside is formed in the air guiding region. The first housing herein is configured in, for instance, a basin structure with one end closed, and the air guiding region as an extending part, extends outwardly laterally from an open end of the recessed region.
According to a preferred solution of the present invention, the first space surrounds the recessed region. Since the first part of the illuminating device which generates heat can be installed in the recessed region, the first space provided surrounding the recessed region can form a convection region in the whole circumferential direction so as to perform highly effective heat dissipation.
According to a preferred solution of the present invention, at least one air guiding hole forming the flow path is opened in the air guiding region. The air guiding hole can ensure air communication of the first space with the outside; thereby the convective effect can be realized for heat dissipation.
According to the present invention, the second housing comprises an annular second bottom region, and a second central region and a second side wall which respectively extend from two sides of the second bottom region to the first housing, wherein the second central region is in thermal contact and mechanical connection with the recessed region. In order to guarantee that the first space can surround the recessed region at an area as big as possible, a height of the second central region is smaller than that of the second side wall.
According to a preferred solution of the present invention, the second central region is configured as a protrusion, and a top surface of the protrusion is in thermal contact with a bottom surface of the recessed region. The top surface of the protrusion is preferably in form-fitted thermal contact with the bottom surface of the recessed region. The two surfaces can be configured as, for instance, planes.
According to the present invention, a removable joint structure is present between the second central region and the recessed region. With the help of the joint structure, the first housing and the second housing can be simply and reliably fixed together.
According to the present invention, the joint structure comprises at least one assembling hole opened in the bottom surface of the recessed region and at least one fastener extending from the second central region to run through the at least one assembling hole.
According to the present invention, in an assembling state of the heat sink, a free end of the fastener exerts a pressure onto the first housing at one side of the first housing supporting the first part. The free end of the fastener, passing through the assembling hole, penetrates into the space defined by the first housing itself for fixing together the first and second housings.
According to the present invention, the free end is bent to an angle relative to a central axis of the heat sink, and the recessed region is sandwiched between the free end and the second central region. According to a preferred solution of the present invention, the fastener is a bendable tablet. When the first and second housings are assembled together, the free end of the fastener can be bent with an external force so that it is ensured that the free end can be used as a stop part fixed in the first housing, and further presses the bottom surface of the first housing to the second central region of the second housing.
According to a preferred solution of the present invention, the second central region defines a second space at one side facing away from the first part for receiving a second part equipped for the illuminating device. The second part can be, for instance, a driver or the like for supplying power to the first part of the illuminating device.
According to a preferred solution of the present invention, a plurality of the air guiding holes distributed uniformly in a circumferential direction are opened in the air guiding region. The number and shape of the air guiding holes can be varied according to practical demand, and then the convective effect of the first space with the outside can be improved.
According to a preferred solution of the present invention, via holes for the first part and fittings of the first part are opened respectively in the second central region and the recessed region. Connectors such as wires or pins for electrically connecting the first part and the second part can run through these via holes.
In addition, the present invention further relates to an illuminating device, comprising a light engine configured as the first part, a driver configured as the second part and a lens. The illuminating device according to the present invention further comprises the above heat sink. The light engine configured as the first part will generate a lot of heat during operation.
According to a preferred solution of the present invention, the first part is located in the recessed region of the first housing, and the second part is located in the second space defined by the second housing. In order to radiate heat of the light engine, the light engine is fixed in the recessed region, and the light engine is controlled by the driver located in the second space.
According to a preferred solution of the present invention, a support is further comprised. The support has one end fixing the first part on the first housing of the heat sink, and the other end in fixed connection with the lens.
According to a preferred solution of the present invention, the support is located in the recessed region of the first housing, and the lens and the support define a sealed cavity receiving the first part. With the aid of the lens, the first part configured as the light engine can be protected, and the optical efficiency of the illuminating device is improved.
It shall be understood that both the above general description and the following detailed description are for illustrative and explanative purposes in order to provide further description of the claimed present invention.

Brief Description of the Drawings

The accompanying drawings constitute a part of the present Description and are used to provide further understanding of the present invention. Such accompanying drawings illustrate the embodiments of the present invention and are used to describe the principles of the present invention together with the Description. In the accompanying drawings the same components are represented by the same reference numbers. As shown in the drawings:

Fig. 1 shows a 3D exploded view of a first embodiment of a heat sink according to the present invention;
Fig. 2 shows a 3D view of the heat sink as shown in Fig. 1 during assembling;
Fig. 3 shows a 3D view of the heat sink as shown in Fig. 1 after assembling;
Fig. 4 is a sectional view of a first embodiment of the heat sink according to the present invention;
Fig. 5 is a 3D exploded view of a first embodiment of an illuminating device according to the present invention; and
Fig. 6 shows a sectional view of the illuminating device as shown in Fig. 5.

Detailed Description of the Embodiments

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top", "bottom", "inner", "outer", is used in reference to the orientation of the figures being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise.
Fig. 1 shows a 3D exploded view of a first embodiment of a heat sink according to the present invention. A heat sink 10 according to the present invention is configured for an illuminating device, and has a first housing 11 shown in the upper part of the figure and a second housing 12 shown in the lower part. In the present invention, the first housing 11 is a first metal stamping part, and the second housing 12 is a second metal stamping part also formed through a stamping process. By manufacturing the heat sink 10 in two parts, the yield of the whole heat sink can be improved during the manufacturing process. If a defective product, e.g. the first housing, appears during the manufacture, only this unqualified part needs to be re-manufactured for compensation. Thus, the yield is improved when manufacturing the heat sink and the cost is reduced.
The first housing 11 is configured in a basin structure, and comprises a recessed region 11.1 located in the center and an air guiding region 11.2 extending radially outwardly from a free end of the recessed region 11.1, i.e. in a horizontal direction in the figure. Since the recessed region 11.1 itself defines an accommodation space, a bottom surface of the recessed region 11.1 can support part of components of the illuminating device, and can radiate heat of the components received in this accommodation space.
The air guiding region 11.2 in the present embodiment is configured as an annular, horizontally extending section, and extends horizontally, radially, outwardly starting from an upper end of the recessed region 11.1. The air guiding region 11.2 is opened with a plurality of air guiding holes 11.3, which air guiding holes are uniformly distributed such that air above and below the air guiding region 11.2 can exchange and flow.
The second housing 12 in the lower part of the figure can be taken as a base to be installed together with the first housing 11 used as a top cover. The second housing 12 comprises: a second side wall 12.3 as an outer circumferential wall, a second bottom region 12.1 extending inwardly from a bottom end of the second side wall 12.3, and a second central region 12.2 extending inwardly and upwardly from the second bottom region 12.1. The second central region 12.2 is configured as a protrusion, and has a plane in the center and a side wall connecting the plane and the second bottom region 12.1 together. The side wall can be used as an inner circumferential wall and in opposite arrangement to the second side wall 12.3.
A removable joint structure is present between the second central region 12.2 and the recessed region 11.1. The joint structure comprises assembling holes 11.4 opened in the bottom surface of the recessed region 11.1 and fasteners 12.4 extending upwardly from the plane of the second central region 12.2. Quantities and shapes of the fasteners 12.4 and the assembling holes 11.4 match, respectively.
The second central region 12.2 defines a second space R2 (see Fig. 4) at one side facing away from a first part 1, i.e. in the lower part shown in the figure. A second part equipped for the illuminating device, such as driver or the like, can be received in the second space R2. Besides, a plurality of via holes are also provided in the second central region 12.2 and the recessed region 11.1 so that fittings of the illuminating device such as wires can run through the via holes.
Fig. 2 shows a 3D view of the heat sink as shown in Fig. 1 during assembling. In this state, two fasteners 12.4 formed on the second housing 12, running through two assembling holes 11.4 equipped, respectively, extend into the space defined by the recessed region 11.1. Thus, the first housing 11 and the second housing 12 can be ensured to be fixed in position to each other.
Fig. 3 shows a 3D view of the heat sink as shown in Fig. 1 after assembling. The first housing 11 and the second housing 12 are removably assembled together with the aid of the fasteners 12.4. In this state, a free end of each fastener 12.4 exerts a pressure on the first housing 11, especially the recessed region 11.1, in the space defined by the recessed region 11.1. The free ends are bent to an angle, preferably 90°, relative to a central axis of the heat sink 10; consequently, the recessed region 11.1 of the first housing 11 is sandwiched between the free end of the second housing 12 and the second central region 12.2. In the present embodiment, the fasteners 12.4 preferably are configured as bendable tablets.
In a second embodiment not shown, positions of the fasteners and the assembling holes equipped therefor can be three or more. Besides, the fastener also can be configured as positioning column or the like deformable under an external force.
Fig. 4 shows a sectional view of a first embodiment of the heat sink according to the present invention. The first housing 11 provides, at one side facing upwardly, the recessed region 11.1 that can be in thermal contact with the first part of the illuminating device, and at the other side, it defines, together with the second housing 12, the first space R1 for heat dissipation, therefore, the first space R1 is in air communication with the outside by means of the plurality of air guiding holes 11.3 opened in the air guiding region 11.2. The second housing 12 has a cross section resembling "W", and then, it can be ensured that the first space R1 surrounds the recessed region 11.1 which is in direct contact with a heat source so as to improve the heat dissipation effect of the heat sink 10. Particularly advantageously, the second central region 12.2 is in thermal contact and mechanical connection with the recessed region 11.1, that is to say, the top surface in the center of the second central region 12.2 and the bottom surface of the recessed region 11.1 are in thermal contact at an area as big as possible.
In a third embodiment not shown, the top surface in the center of the second central region, i.e. the top surface of the protrusion, viewed from the cross section, can be configured in a wave shape or other shapes, correspondingly, the bottom surface of the recessed region is also configured in a shape corresponding to the profile of the top surface in the cross section, such that direct good thermal contact of the first and second housings is realized.
Fig. 5 shows a 3D exploded view of a first embodiment of an illuminating device according to the present invention. An illuminating device 20 according to the present invention comprises a light engine 1, a driver 2, a lens 3, a support 4 and the heat sink 10 as shown in Figs. 1-4. Herein, the light engine 1 generates heat during operation and therefore can be regarded as the first part 1 of the illuminating device 20, and the driver 2 supplies power to the light engine 1 and therefore can be taken as the second part 2 of the illuminating device 20. In the present embodiment, the driver 2, the heat sink 10, the light engine 1, the support 4 and the lens 3 are assembled together in turn so as to constitute a complete illuminating device 20. Therefore, the support 4 is particularly configured as a joint piece, which, at one end, fixes the light engine 1 on the first housing 1 of the heat sink 10, and at the other end, can be in fixed connection with the lens 3. In addition, a thermal conductive gasket 5 is further provided between the light engine 1 and the first housing 11.
Fig. 6 shows a sectional view of the illuminating device as shown in Fig. 5. The light engine 1, i.e. the first part, is located in the recessed region 11.1 of the first housing 11, and the driver 2, i.e. the second part 2, is located in the second space R2 defined by the second housing 12 itself. The support 4 is installed in the recessed region 11.1 of the first housing 11, and the lens 3 and the support 4 define a sealed cavity accommodating the first part 1.
The above is merely preferred embodiments of the present invention but not to limit the present invention. For the person skilled in the art, the present invention may have various alterations and changes.

List of reference signs

1: first part/light engine
2: second part/driver
3: lens
4: support
5: thermal conductive gasket
10: heat sink
11: first housing
11.1: recessed region
11.2: air guiding region
11.3: air guiding hole
11.4: assembling hole
12: second housing
12.1: second bottom region
12.2: second central region
12.3: second side wall
12.4: fastener
20: illuminating device
R1: first space
R2: second space

Claims

A heat sink (10) for illuminating device (20), wherein the heat sink (10) comprises a first housing (11) and a second housing (12), the first housing (11) is a first metal stamping part, the second housing (12) is a second metal stamping part, and the first metal stamping part and the second metal stamping part are removably assembled together, wherein the first housing (11) is in thermal contact with a first part (1) of the illuminating device (20) at one side, and defines, together with the second housing (12), a first space (R1) at the other side, and the first space (R1) is in air communication with outside, wherein the first housing (11) comprises a recessed region (11.1) which supports the first part (1) and an air guiding region (11.2), the air guiding region (11.2) extends radially outwardly from the recessed region (11.1) at one side away from the second housing (12), and a flow path enabling communication of the first space (R1) with outside is formed in the air guiding region (11.2), wherein the second housing (12) comprises a second bottom region (12.1) which is annular, and a second central region (12.2) and a second side wall (12.3) which respectively extend from two sides of the second bottom region (12.1) to the first housing (11), wherein the second central region (12.2) is in thermal contact and mechanical connection with the recessed region (11.1), wherein a removable joint structure is present between the second central region (12.2) and the recessed region (11.1), wherein the joint structure comprises at least one assembling hole (11.4) opened in the bottom surface of the recessed region (11.1) and at least one fastener (12.4) extending from the second central region (12.2) to run through the at least one assembling hole (11.4), wherein in an assembling state of the heat sink (10), a free end of the fastener (12.4) exerts a pressure onto the first housing (11) at one side of the first housing (11) supporting the first part (1), characterized in that the free end is bent to an angle relative to a central axis of the heat sink (10), and the recessed region (11.1) is sandwiched between the free end and the second central region (12.2).
The heat sink (10) according to claim 1, characterized in that the first space (R1) surrounds the recessed region (11.1).
The heat sink (10) according to claim 2, characterized in that at least one air guiding hole (11.3) forming the flow path is opened in the air guiding region (11.2) .
The heat sink (10) according to claim 1, characterized in that the second central region (12.2) is configured as a protrusion, and a top surface of the protrusion is in thermal contact with a bottom surface of the recessed region (11.1).
The heat sink (10) according to claim 1, characterized in that the fastener (12.4) is a bendable tablet.
The heat sink (10) according to any one of claims 1-4, characterized in that the second central region (12.2) defines a second space (R2) at one side facing away from the first part (1) for receiving a second part (2) equipped for the illuminating device (20).
The heat sink (10) according to claim 3, characterized in that a plurality of the air guiding holes (11.3) distributed uniformly in a circumferential direction are opened in the air guiding region (11.2).
The heat sink (10) according to claim 1, characterized in that via holes for the first part (1) and fittings of the first part (1) are opened respectively in the second central region (12.2) and the recessed region (11.1).
An illuminating device (20), comprising a light engine configured as a first part (1), a driver configured as a second part (2) and a lens, characterized by further comprising the heat sink (10) according to any one of claims 1-8.
The illuminating device (20) according to claim 9,
characterized in that the first part (1) is located in a recessed region (11.1) of the first housing (11), and the second part (2) is located in a second space (R2) defined by the second housing (12).
The illuminating device (20) according to claim 10,
characterized by further comprising a support (4), of which one end fixes the first part (1) on the first housing (11) of the heat sink (10), and the other end is in fixed connection with the lens (3).
The illuminating device (20) according to claim 11,
characterized in that the support (4) is located in the recessed region (11.1) of the first housing (11), and the lens (3) and the support (4) define a sealed cavity receiving the first part (1).