Electric vehicle charging device

Abstract

An electric vehicle charging device (1) includes a device body (2), comprising a housing (3) and charging circuitry (5) controllable to selectively supply power to an electric vehicle. The charging circuitry (5) is contained within the housing (3). An outer surface of the housing (3) comprises a heat sink structure (6). The electric vehicle charging device (1) further comprises a cover (4), connected to the housing (3) so as to be positioned over the heat sink structure (6) and to be spaced apart from the heat sink structure (6) so as to create an air gap (40) therebetween.

Description

[0001] 410.173452 / 01

[0002] Electric Vehicle Charging Device

[0003] BACKGROUND OF THE INVENTION

[0004] This invention relates to an electric vehicle charging device.

[0005] Electric vehicle charging devices are known for charging electric vehicles. They may be installed at domestic or commercial properties or dedicated charging facilities (e.g. charging stations). They are generally mounted outdoors and are therefore exposed to the elements, including solar radiation.

[0006] Heat from the external environment, including solar radiation, as well as internally generated heat (e.g. by circuitry within the electric vehicle charging device) can cause the temperature within the device to rise above the safe operating temperature.

[0007] Overheating of the device can be dangerous. Furthermore, in case of overheating the operation of the device may have to be compromised, e.g. by reducing the charging power that is output, or may even have to be shut off altogether until the device cools to a safe temperature. This compromises performance of the device.

[0008] The present invention seeks to address at least some of these shortcomings.

[0009] SUMMARY OF THE INVENTION

[0010] From a first aspect, the invention provides an electric vehicle charging device comprising:

[0011] a device body, comprising:

[0012] a housing; and,

[0013] charging circuitry controllable to selectively supply power to an electric vehicle, the charging circuitry contained within the housing;

[0014] wherein an outer surface of the housing comprises a heat sink structure;

[0015] the electric vehicle charging device further comprising a cover, connected to the housing so as to be positioned over the heat sink structure and to be spaced apart from the heat sink structure so as to create an air gap therebetween.Thus it will be seen that, in accordance with the invention, by providing a heat sink structure on the surface of the housing of the device body, an area with increased surface area is provided (as is understood by the term heat sink structure) which thereby has increased heat dissipation into the air adjacent the surface. Furthermore, the spacing between the heat sink structure and the cover creates an air gap through which air is able to flow, passing over the heat sink structure and carrying away the air over the heat dissipation structure which has been heated by the heat dissipated there from the device body, e.g. the charging circuitry. The cover is furthermore advantageous to the cooling function of the heat sink structure since it may partially or fully shield the heat sink structure from solar radiation, which may help to prevent the solar radiation from further heating the heat sink structure, and therefore compromising its effectiveness.

[0016] These cooling effects are advantageous since they reduce the likelihood of the electric vehicle charging device (e.g. in particular the charging circuitry) overheating, i.e. going above its highest safe operating temperature. If the charging device does exceed its safe operating temperature (or a maximum temperature limit set to prevent the true safe highest temperature from being reached) then the power output of the charging circuitry will need to be reduced or possibly even shut off altogether for a period of time, until the temperature drops, in order to prevent overheating. This reduction in output power is known as throttling, and it is undesirable for a user since the rate of charging for their vehicle will be reduced when the power output is throttled, potentially inconveniencing them. The improved cooling of the claimed electric vehicle charging device helps to avoid such throttling.

[0017] The housing comprises a heat sink structure. By this it will be understood that a part of the housing is shaped so as to provide a passive heat exchanger (i.e. by increasing its surface area), for example comprising at least one (optionally a series) of indents and / or protrusions. The heat sink structure is for cooling the device body, e.g. both the part of the housing itself and also internal components within the device body, e.g. the charging circuitry.

[0018] In some embodiments, the housing may comprise a first region, comprising the heat sink structure, wherein the housing is convex in the first region, and wherein the heat sink structure is concave. For example, the heat sink structure may comprise concaveindentations and / or grooves. Thus the heat sink structure may be formed by one or more recesses in the surface of an otherwise convex area of the housing.

[0019] In some embodiments, the heat sink structure comprises (e.g. forms) an airflow channel, i.e. at least one airflow channel. The heat sink structure may comprise more than one (optionally three or more than three) airflow channels. The airflow channel(s) may also be referred to as airflow groove(s). By this it will be understood that the heat sink structure forms a hollow (i.e. a furrow) through or along which, in use, air travels. The airflow channel(s) thus allow or encourage air circulation across the heat sink structure, and therefore further helps to cool the device body by encouraging air flow over the heat-dissipating surfaces of the heat sink structure (in addition to simply dissipating heat at its surface). Thus the heat sink structure is optionally shaped (i.e. formed) both to dissipate heat and to encourage air flow over its heat dissipating surfaces, i.e. without needing separate active airflow, e.g. by a fan.

[0020] Features described below in relation to a particular airflow channel may be present in all (i.e. each) of the airflow channels, where the heat sink structure includes multiple airflow channels, or they may be present in only some of the airflow channels (e.g. a subset).

[0021] The airflow channel(s) may be elongate. In some embodiments the airflow channel(s) are (substantially) vertical in use, i.e. they extend (i.e. along their elongate direction) along the vertical direction. Thus the direction of fluid flowing through the channel is vertical. The vertical direction in use will be understood to refer to the direction extending vertically (i.e. along the direction of gravity) when the electric vehicle charging device is in the intended orientation for proper use. Thus, in use, air is encouraged along the vertical direction due to the airflow channel(s). Since hot air rises, and the heat sink structure generally acts to heat air adjacent to it as it dissipates heat from the device body, the air adjacent the heat structure is caused to rise as so to flow upwards.

[0022] In some embodiments, the heat sink structure comprises at least two parallel airflow channels. The heat sink structure may comprise a series of (e.g. three) parallel airflow channels. Thus, the outer surface of the housing (i.e. at the heat sink structure) may be corrugated.It will be understood that the heat sink structure may therefore define respective (optionally elongate) teeth, formed between adjacent parallel airflow channels. The teeth may be level with the surrounding housing structure (i.e. they do not protrude beyond the main surface of the housing), although nonetheless they protrude further than the recessed channels, so as to define the channels. In some embodiments, the one or more teeth may be hollow or solid, i.e. such that they do not form a structure in which components of the device body may be housed, rather their only purpose may be to facilitate cooling.

[0023] In some embodiments, a depth of the airflow channel (optionally of each airflow channel) varies gradually at a lower end of the airflow channel (e.g. at a low gradient). The depth will be understood as the extent in a direction perpendicular to the face of the housing. The lower end will be understood as the end which is lower, in use (i.e. relative to the vertical direction of the electric vehicle charging device when positioned in its intended orientation for use). The more sharply the depth varies the deeper the corner formed at the lower end of the airflow channel and therefore the greater the risk of low or no air circulation occurring within that sharp corner. The lower end of the airflow channel may be defined by an end portion (e.g. a planar end portion) of the airflow channel and a (e.g. planar) base portion of the airflow channel, wherein the end portion and the base portion meet at (i.e. are arranged relative to each other at) an angle of more than 90 degrees (i.e. at an obtuse angle), optionally of more than 120 degrees.

[0024] In some embodiments, the airflow channel(s) (optionally each airflow channel) has a smooth internal profile along its length (e.g. throughout its whole length). By this is meant that the angle of the wall or walls defining the channel along the lengthwise direction (e.g. its end walls, rather than its side walls) do not vary sharply, e.g. with angles of less than 90 degrees, optionally of less than 120 degrees, such that air is able to flow smoothly through the channel and the risk of dead spaces in which air circulates only minimally (or not at all) is reduced. Thus, in some embodiments, the airflow channel(s) has an internal profile along its length direction in which all angles of the internal profile are obtuse or straight.The airflow channel(s) may be defined by the (lower) end portion, the base portion, and two opposing side portions. The side portions may extend substantially parallel to each other and may each be arranged (to extend) perpendicular to the base portion. Thus, the airflow channel(s) may have sharply angled sides, such as to help keep the air flowing within them, since minimal air may be flowing across the channels (i.e. horizontally), and therefore contacting the sharply angled side portions, but the channel may have a gently angled base portion so as to allow smooth flowing of air along the primary air flow direction (which is vertical).

[0025] In some embodiments, an upper end of the airflow channel(s) may be open, i.e. such that there is no end portion at the upper end of the channel). Thus the depth of the channel may reduce (e.g. gradually) along its length until it is zero, i.e. such that at its upper end the height of the side portions reduces to zero and the base portion opens directly out of the channel. The surface of the housing may be angled, and the base portion of the channel may extend vertically, in order to achieve a gradual reduction in depth to give an open upper end. This may be the case for all or only some of the airflow channels, where more than one airflow channel is present.

[0026] In some embodiments, the airflow channel(s) have a constant width (i.e. along its length). Thus, the two side portions (i.e. first and second side portions) may be a constant distance away from each other. This ensures that a constant air flow is possible along the whole length of the channel and avoids interfering with the air flow by constraining it at a certain point along the length of the channel. The width of the airflow channels may all be the same. One, some or all of the airflow channel(s) may have a width of at least (or approximately) 1cm, optionally at least (or approximately) 2cm. This may refer to a minimum width, or where the width is constant to the constant width. One, some or all of the airflow channel(s) may have a width of less than (or approximately) 5cm, optionally less than (or approximately) 3cm. The width direction will be understood as the direction across the channel, i.e. perpendicular to the length direction e.g. the elongate direction. This may refer to a maximum width, or where the width is constant to the constant width. The width direction may be the horizontal direction when the electric vehicle charging device is arranged, in use, in its intended orientation.In some embodiments in which more than one airflow channel is present, the airflow channels may be positioned equidistantly from each other (i.e. each is the same distance from its closest adjacent airflow channel(s)). In some embodiments, a separation distance between adjacent airflow channels may be substantially equal to the width of the airflow channels. Thus the width of the teeth may be substantially equal to the width of the airflow channels. This advantageously provides a good balance for both sufficient heat dissipation, primarily from the teeth, and sufficient air flow through the channels between the teeth for cooling.

[0027] In some embodiments, the heat sink structure comprises three airflow channels (which may each have any of the features described above), i.e. comprises exactly three. This has been found to achieve a particularly good compromise between the effectiveness of the cooling achieved for the electric vehicle charging device and the ease of manufacture of the housing containing such a heat sink structure.

[0028] In some embodiments, the heat sink structure is positioned on a front surface of the housing, the housing comprising a rear surface, on an opposite side of the housing to the front surface, wherein the rear surface is suitable for mounting the electric vehicle charging device in use (e.g. to a wall).

[0029] The device body comprises a housing which contains the charging circuitry. The device body will therefore be understood as the main body of the electric vehicle charging device, i.e. the most important to the charging function carried out by the device, since it contains the circuitry needed to achieve charging.

[0030] The housing contains the charging circuitry within it. By this it will be understood that the housing substantially surrounds the charging circuitry, i.e. surrounds the majority of the charging circuitry, e.g. 75% or more, optionally 90% or more. It will be understood however that not entirely all of the charging circuitry may be contained inside the housing, some, for example a charging socket, may be exposed through an opening in the housing, which may be necessary in order for it to achieve its function.

[0031] Thus, in some embodiments, the housing further comprises a socket opening, and the device body (e.g. the charging circuitry) further comprises a charging socket, the socket opening arranged over the charging socket.The cover may be configured to extend over the socket opening. The cover may comprise a cover opening, wherein when the cover is connected to the housing, the cover opening is arranged over (e.g. in alignment with) the socket opening. The cover opening may be at least as large as the socket opening (and may have a corresponding shape).

[0032] The housing may be sealed, e.g. it may be weatherproof and / or watertight. This advantageously provides the environmental protection needed for the electric vehicle charging device to the device body, and therefore avoids a need to rely on the cover to provide any environmental protection. This allows more flexibility in how the cover may be installed and what it may be made of.

[0033] The housing may comprise or consist of a plastics material, i.e. be formed from plastic. The plastics material may include one or more additives. These may be used to give the plastics material more desirable properties.

[0034] The charging circuitry may comprise a circuit board. The circuit board may be located within the housing behind the heat sink structure (i.e. close to the inside surface of the part of the housing in which the corresponding outside surface includes the heat sink structure). This helps to cool the charging circuitry effectively since the circuit board is a component producing a large amount of the heat that is created by the charging circuitry. For example, the copper tracks on the circuit board hold and release heat. In some embodiments, the charging circuitry comprises wiring, and / or terminals, and / or socket(s). These are also key contributors to heat generation, and one or more of these may be located within the housing behind the heat sink structure.

[0035] In some embodiments, the housing and the cover are configured such that with the cover connected to the housing, at least one upper air flow opening and at least one lower airflow opening are formed in the electric vehicle charging device, the air gap extending to both the upper air flow opening(s) and the lower airflow opening(s). This advantageously provides a good flow or air into and away from the air gap, helping to draw heat away from the heat sink structure, and in particular enables an upwards flow of air over the heat sink structure by allowing cool air to be drawn in through the lower airflow opening(s) and then hot air, heated by the heat sink structure, to rise and flowout of the upper airflow opening(s). Thus, the upper airflow opening(s) and lower airflow opening(s) enable convection cooling of the heat sink structure. The upper airflow opening(s) may be positioned at a top of the housing, and the lower airflow opening(s) may be positioned at a bottom of the housing. This helps to maximise the distance that the cooling air flows over the surface of the housing, by allowing the air to flow over the whole length of the housing.

[0036] In some embodiments, the housing comprises a flange extending from the housing, the flange comprising one or more airflow apertures, wherein the cover is connected to the housing at a position outside of the airflow apertures, i.e. such that the apertures allow air to flow into the air gap between the cover and at least a part of the housing. The flange may extend from a side surface of the housing e.g. extending from a side surface positioned between the front surface and the rear surface, and / or the flange may extend from an upper surface of the housing. The airflow apertures may therefore be located at a top part of the housing and / or at one or both sides of the housing.

[0037] The airflow apertures may provide the upper airflow opening(s).

[0038] The airflow apertures may also provide side airflow opening(s). This advantageously allows a secondary flow of air horizontally, i.e. out of the side openings.

[0039] The cover is connected to the housing so as to be positioned over the heat sink structure. By this it will be understood that the cover covers (i.e. extends over, shields) at least the heat sink structure of the housing, and that it may also be positioned over (i.e. covering) other parts of the housing. For example, as described above, the cover may also be positioned over a socket opening of the housing (optionally with a cover opening aligned with the socket opening to allow access to the socket opening).

[0040] In some embodiments, the cover is positioned (i.e. when connected to the housing) over the majority of the front surface of the housing, optionally over substantially all of the front surface of the housing. Since the front surface is opposite to the rear surface (i.e. used for mounting the device) the front surface of the housing is the most likely to be exposed, in use, to sunlight and possibly other external heat sources. Covering most of the front surface of the housing thus advantageously allows the cover to shield the housing from external heating, thereby further improving cooling of the device.In some embodiments, the cover is spaced apart from the majority (optionally substantially all) of the front surface of the housing, for examples at least 50% by area, optionally at least 60%, further optionally at least 75%. Thus the air gap may extend over at least 50% by area of the front surface of the housing, optionally at least 60%, further optionally at least 75%

[0041] In some embodiments, the cover is connected to (only) a side surface, or the side surfaces, of the housing. By connected to it will be understood that there is a structural link between the two parts at the connection, beyond simply the housing and the cover being in contact. Thus, there may (or may not) be contact between the front surface and the cover, even if the cover is connected to only the side surface.

[0042] Thus, the cover may be connected to the housing at one or more connection points, wherein the connection point(s) may be located on a side surface of the housing. The cover may be connected to the housing at a first connection point, on a first side surface of the housing, and at a second connection point on a second, opposite side of the housing. Optionally all of the connection points may be positioned on side surfaces of the housing.

[0043] In some embodiments, the cover is removably connected to the housing. By this it will be understood that the cover is configured to be reversibly detachable from the housing (i.e. without the use of excessive force or causing permanent damage). This allows the cover to be easily removed, e.g. if maintenance is required of the cover or for easier access to the housing for maintenance, and allows the cover to be changed whilst the same device body is maintained, for example if the cover has become too worn due to exposure to solar radiation and needs to be replaced with a new cover, or if a user desires a different look for the product and so replaces the cover with an interchangeable one having a different aesthetic appearance.

[0044] In some embodiments, the cover is connected to the housing by one or more clips. Thus, the connection point(s) may be provided by clips. This provides a particularly effective and reliable means of removable attachment.In some embodiments, the cover is connected to the housing at cover connection points positioned around the outer edge of the cover. This avoids there being connection points in the central part of the cover which could interfere with air flow under the cover.

[0045] In some embodiments, the cover comprises an opaque portion. The cover may be entirely opaque, or the cover may comprise a transparent portion. The device body may comprise a display, positioned behind or arranged on the transparent portion, e.g. an illuminated logo, or an information display. The transparent portion may thus be used for functional and / or aesthetic purposes. In some embodiments, the majority of the cover is opaque, e.g. over 50%, optionally over 75%, further optionally over 90% (by area). An opaque cover is advantageous because it offers improved protection to the housing from solar radiation and heating, and it also hides the (covered portions of) the housing from a user’s view, which may be desirable. The cover may be predominantly (or entirely) white and / or reflective. This helps to optimise the reflection of solar radiation and therefore keep the device cool, particularly in the event that it is mounted in direct sunlight. A reflective material may be a material, e.g. a plastic, to which is added one or more coating(s), additive(s), and / or surface treatment(s), which are such as to enhance specular reflection. A reflective cover may be a cover made of (e.g. comprising or consisting of) such a reflective material. In some embodiments, the cover may comprise a high-reflectivity plastic or a specular-reflective plastic. In some embodiments, the cover may be predominantly (or entirely) black.

[0046] In some embodiments the cover comprises (or consists of) a plastics material. The opaque portion may be made of (i.e. consist of) a plastics material. Plastics materials are readily available and low cost, and can also be easily tailored to give the desired material properties to the cover. The plastics material may include one or more additives. These may be used to give the plastics material more desirable properties. Possible materials for the cover and / or the housing are polycarbonate (PC), acrylonitrile styrene acrylate (ASA) or a combination of these materials.

[0047] In some embodiments the cover comprises (or consists of) a material resistant to ultraviolet (UV) radiation. It will be understood that UV resistance refers to UV resistance refers to a material which substantially (or entirely) does not degrade as a result of absorption of UV radiation, i.e. it has low degradation due to UV exposure. Forexample, the material of the cover may comprise an additive (or additives) for enhancing its resistance to UV radiation. This advantageously extends the lifetime of the cover even if the electric vehicle charging device is mounted in a location in which it is exposed to sunlight. A material being resistant to ultra-violet radiation may be understood as a material which is scored as having “excellent” or “good” UV resistance in accordance with recognised testing techniques, such as SAE J2412, SAE J2527, ASTM G 155, and / or ISO 4892-2.

[0048] In some embodiments, the cover is made of a different material to the material of the housing. This may allow the material of each to be selected as a particularly suitable material. The cover and the housing may each comprise a plastics material (possibly the same plastic) but including different additives.

[0049] As explained above, the housing and the cover together encourage air flow over and through the heat sink structure, to draw heat away from the heat sink structure and thereby cool the electric vehicle charging device. The electric vehicle charging device is therefore cooled without any active air circulation, i.e. without a fan, rather only by passive convection cooling.

[0050] The improved cooling of the described electric vehicle charging device is particularly advantageous where the electric vehicle charging device is small, since the risk of overheating is particularly high in small devices, where components must be placed closer together.

[0051] The electric vehicle charging device (and / or the housing) may have a length of less than 60cm, optionally less than 50cm, further optionally less than 40cm. The electric vehicle charging device may be approximately 40cm long. The length will be understood as the extent along the vertical direction, in use, (e.g. parallel to the elongate airflow channels).

[0052] The electric vehicle charging device may have a width of less than 40cm, optionally less than 30cm. The electric vehicle charging device may have a depth (i.e. perpendicular to the width direction, the extent from the rearmost part of the rear surface to the frontmost part of the front surface) of less than 40cm, optionally lessthan 30cm. It will be appreciated that this is considerably smaller than most known electric vehicle charging devices.

[0053] Features of any aspect or embodiment described herein may, wherever appropriate, be applied to any other aspect or embodiment described herein. Where reference is made to different embodiments or sets of embodiments, it should be understood that these are not necessarily distinct but may overlap.

[0054] BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Certain preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0056] Figure 1 is a perspective view showing a device body of an electric vehicle charging device according to an embodiment of the present invention;

[0057] Figure 2 is a perspective view showing the electric vehicle charging device; Figure 3 is a front-on view of the device body of Figure 1;

[0058] Figure 4 is a front-on view of the electric vehicle charging device of Figure 2; Figure 5 is a cross-sectional view of the electric vehicle charging device of Figures 2 and 4, taken along the line A-A shown in Figure 4;

[0059] Figure 6 is a cross-sectional view of the electric vehicle charging device of Figures 2 and 4, taken along then line B-B shown in Figure 4, intersecting a side wall of a side channel;

[0060] Figure 7 is a cross-sectional view of the electric vehicle charging device of Figures 2 and 4, taken along then line C-C shown in Figure 4;

[0061] Figure 8 is rear view of the device body shown in Figure 1 ; and

[0062] Figure 9 is an exploded view of the electric vehicle charging device of Figure 2.

[0063] DETAILED DESCRIPTION

[0064] Figure 1 is a perspective view showing a device body 2 of an electric vehicle charging device 1, which is seen in a perspective view in Figure 2. In addition to the device body 2, the electric vehicle charging device 1 further includes a cover 4, which is arranged over the device body 2, in the position shown in Figure 2.

[0065] Figures 3 and 4 show front-on views of the components of Figures 1 and 2, respectively.The device body 2 includes a housing 3 which contains within it charging circuitry 5, some of which is shown in Figure 9. In addition to the charging circuitry 5 which is accommodated within the housing 3, the device body 2 also includes a charging socket 7 which extends through the housing (i.e. to be partially exposed), as seen in Figures 1 and 3 and in cross-section in Figure 5. In particular, the charging socket 7 is accessible through a socket opening in the housing 3. The charging socket 7 is suitable for receiving a plug of an electric vehicle charging cable - this plug may be received permanently in the socket (in the case of a tethered charger) or may be selectively removable from the charging socket 7 as desired (in the case of an untethered charger). In order for the charging socket 7 to be accessible in use even when the cover 4 is placed over the device body 2, the cover 4 includes a cover opening 9, which is larger than the exposed area of the charger socket 7 and is aligned over the charger socket 7 so that the cover 4 does not obscure the charger socket 7.

[0066] The housing 3 includes a heat sink structure 6. The heat sink structure 6 in this embodiment includes three elongate grooves 8a, 8b, 8c, which extend parallel to each other, along the vertical direction 10, as seen in Figure 3.

[0067] The shape of the heat sink structure 6 is advantageous in two ways - firstly, it has a larger surface area compared to if the surface of the housing was just smooth and flat in that area, and also the grooves of the heat sink structure 6 are shaped to enable and encourage air flow through them, to encourage circulation of air passing over and through the heat sink structure 6, to improve heat exchange from the surface and therefore improve cooling. Thus each of the elongate grooves 8a, 8b, 8c may also be referred to as an airflow channel.

[0068] Considering first the structure of the airflow channels 8a, 8b, 8c, it can be seen that each channel is linear and elongate, and extends vertically upwards (parallel to the length direction 10). The grooves each have a base portion 12a, a lower end portion 12b, and two side portions 12c, 12d. These are described in greater detail below with reference to the later Figures.

[0069] In this example, the channels 8a, 8b, 8c each have a constant width 14, as is shown in Figure 3 - thus the side walls 12c, 12d of each groove are a constant distance apart.The side walls of each groove are connected with those of the adjacent groove, to form teeth 16a, 16b, 16c, 16d between the grooves and to the outside of each of the outer grooves. The teeth likewise have a constant width 18 along their vertical length. Furthermore in this example, all the grooves 8a, 8b, 8c have the same width, all the teeth 16a, 16b, 16c, 16d have the same width as each other, and the grooves are approximately the same width as the teeth.

[0070] In this example, there are three airflow channels 8a, 8b, 8c. This has been found to provide a particularly advantageous heat sink structure 6, since it is straightforward to manufacture reliably using low-cost and easily available techniques, but also provides a good cooling effect.

[0071] The cover 4 enhances the cooling effect by shielding the device body 2 from solar radiation (in use). The cover 4 includes an opaque portion 24a and a transparent portion 24b. The transparent portion 24b is relatively small and allows a lit-up display 22 (seen in Figure 3) to be seen by the user through the transparent portion 24b. This may be used to display a logo or other decorative effect, e.g. as shown in Figure 3, or may be used to display information, e.g. on an LCD screen. For example, the lit-up display 22 may be a light pipe or other shaped portion, formed into the shape of a logo or emblem, through which light is projected to display the logo through the cover.

[0072] The opaque portion 24a makes up the majority of the cover, as can be seen in Figures 2 and 4. The opaque portion 24a blocks solar radiation from reaching the device body 2 which is covered by it, thereby keeping it cooler. In this example the opaque portion 24a is formed from a UV resistant material, which allows it to endure the solar radiation with relatively low degradation of the material.

[0073] In this embodiment, advantageously, the device body 2 itself is a fully sealed, waterproof and weatherproof unit, which is suitable for operation without the cover 4 being present. This allows more flexibility in the configuration of the cover since the cover is not required to provide any weatherproofing function of the unit, rather it can be adapted entirely for the purpose of solar shielding and also encouraging air circulation.The cover 4 is removably connected to the housing 3 by means of clips 26, which are arranged around the outer side edge of the housing 3, and which connect with clips arranged in corresponding positions around the edge of the cover 4 (not shown). The cover 4 and the housing 3 are shaped so that when the cover 4 is connected to the housing by these clips 26 there is a gap between most of the front surface of the housing 3 and the inner surface of the cover 4, as is seen in the Figures described below. This provides a layer of air over the housing to be circulated across the heat sink structure 6 to provide cooling.

[0074] In order to allow air to flow into and out of the air gap between the housing 3 and the cover 4 airflow apertures 28a, 28b are provided in a flange 30 which extends around the side of the housing 3 (extending from the side portion or surface 31 , where the front and rear portions meet, as described further below).

[0075] These and other details of the electric vehicle charging device 1 can be seen in the cross-sectional views of Figures 5, 6 and 7. Figure 5 is a cross-sectional view of the electric vehicle charging device 1 taken along the line A-A shown in Figure 4, Figure 6 is a cross-sectional view taken along the line B-B, and Figure 7 is a cross-sectional view taken along the line C-C.

[0076] In Figure 5, the location of the charging circuitry 5 is shown schematically. It can be seen that the charging circuitry 5 is located close to the heat sink structure 6, i.e. behind the portion of the housing 3 which contains the heat sink structure 6, thus allowing the heat sink structure 6 to cool the charging circuitry 5 quite directly. This charging circuitry 5 may include, for example, a circuit board.

[0077] The housing 3 has a front surface 32a, facing towards the left in Figure 5, and a rear surface 32b, facing towards the right. The heat sink structure 6 is formed on the front surface 32a. In use, the rear surface 32b is mounted to a mount structure, such as the wall of a property, or a mounting post. The electric vehicle charging device 1 has a depth 34 which is the greatest extent along the depth direction between the front surface 32a and the rear surface 32b. In this example the housing is made up of a front housing part 3a and a rear housing part 3b, which can be seen more clearly in Figure 9, in which they are shown exploded apart.The profile shape of the central groove 8b can be seen in Figure 5, and a crosssection through a side wall at one edge of one of the side grooves 8a (particularly the left-hand side groove according to the view of Figure 3) can be seen in Figure 6. It can be seen that for all of the grooves the end portion 12b of the groove, at its lower end, is sloped, i.e. such that the depth of the groove increases gradually from its lower end and so that it has a relatively smooth profile. This avoids there being a “dead” area in the lower end of the groove, where minimal air flow occurs as would be the case if the lower end of the groove had a sharp corner profile. In this example, the angle of the corner 36 of the lower end of the channels 8a, 8b, 8c is approximately 120 degrees.

[0078] It can furthermore be seen in Figure 6 that at least some of the airflow channels 8a, 8b, 8c (in particular the side channels, positioned either side of the central channel) are open-ended at their upper end 38 (i.e. across as least part, optionally all, of their width). By this it is meant that there is no separate end face at that vertically upper end of the channel 8a, 8c. Instead, as can be seen in the side profile of Figure 6 (showing a cross-section along the line of the side channel side wall 12d of Figure 7), the depth of the channel gradually decreases moving upwards along the length of the channel, until it opens out at its upper end. This allows air to flow more smoothly out of the upper end of the channel. The hatched area in Figure 6 represents the side wall 12d of the side channel. Although not illustrated, the other side channel 8c has substantially the same cross-sectional profile in this example. The side channels do not include any protruding display part 22 (seen in Figure 5) and therefore the side channels have a fully open profile.

[0079] In contrast, the central channel includes a display part 22, seen in side view in Figure 5 and front view in Figure 3. This displays a logo or other visual marker to a user. As a result of this display part, the central channel has an upper end portion 12e which is angled sharply (e.g. at 90° or less) compared to the base portion of the central channel. This angled upper end portion may extend across the entire width of the central channel, or only across part of its width.

[0080] Where a sharply angled upper end portion is present in a channel (e.g. the central channel) this is likely to cause direct impact of air rising through the channel with the angled upper end surface 12e (i.e. with the lower part of the protruding display part 22). This may, in some cases, be beneficial by enhancing thermal transfer betweenthe air and the housing as the air exits the channel. It will be understood that in some examples this may be omitted, such that all of the channels could be open at their upper ends.

[0081] The airflow around the device body 2 is illustrated in Figure 6 (cross-sectional side view) and Figure 7 (cross-sectional view from below).

[0082] It can be seen in Figure 6 that the cover 4 is spaced apart from the front housing part 3a, so as to form an air gap 40 therebetween.

[0083] The cover 4, the housing 3 and their connection are configured so that air gaps between the two allow air to flow into and out of the air gap 40. In this example, the lower part of the cover is spaced apart from the lower part of the housing, creating a lower airflow opening 42, seen in Figure 6. Although not visible at the position at which the cross-sectional view of Figure 6 is located, it will be understood that elsewhere in the width of the device, the lower airflow opening 42 connects to the air gap 40 that is visible in Figure 6. In this example, the connection is made by airflow pathways which extend to either side (i.e. left and right in Figure 4) of the charger socket 7, to pass around it and join to the air gap 40.

[0084] The flange 30, includes airflow apertures spaced around it at various positions to enable air flow. These airflow apertures include upper airflow apertures 28a located towards the top of the device body to provide upper airflow openings, and side airflow apertures 28b, located on each side of the device body to provide side airflow openings. In this example, airflow through these top and side apertures 28a, 28b is predominantly in the direction out of the air gap 40.

[0085] These airflow apertures 28a, 28b can be seen more clearly in Figure 8 which is a rear view of the housing 3, i.e. showing the rear surface 32b of the rear housing part 3b. As can be seen in Figure 1 , the front housing part 3a connects to the rear housing part 3b inside of the flange 30, such that the flange 30 extends or protrudes outwards from the edge of the housing 3. The cover 4 then connects over the front housing part 3a including covering the flange 30 as seen in Figure 2, such that the flange 30 then extends between the housing main body and the cover 4, allowing air flow into the air gap 40 between the two.The mounting holes 44 are visible in the rear housing part 3b, by means of which the electric vehicle charging device 1 is mounted for use.

[0086] Upwards arrows 46 shown in Figure 6 represent the heat generated by the charging circuitry 5 contained within the housing 3. The heat output by the charging circuitry 5 heats the air adjacent to the circuitry, and any other components nearby, including the housing 3 and in particular the heat sink structure 6. This heat is absorbed by air in the air gap 40 (which has been drawn in through the lower airflow opening 42), and in particular is absorbed very effectively by air travelling upwards through the airflow channels 8a, 8b, 8c. This causes the air in the air gap 40 to be heated, and therefore to move upwards, and ultimately to travel out of the upper airflow openings 28a, as represented by the arrow 48 shown in Figure 6. This out-flow in turn draws in more air through the lower airflow opening 42.

[0087] Although the primary airflow path is vertically upwards, as illustrated in Figure 6, there also may be some secondary cooling air flow out of the side airflow openings 28b, as illustrated in Figure 7.

[0088] Again the heat 46 generated by the internal circuitry components is illustrated by arrows, heating up the heat sink structure 6. Air within the airflow channels 8a, 8b, 8c is heated up and then may move laterally (possibly in addition to moving upwards) so as to leave the channels 8a, 8b, 8c over their side walls (rather than out of their upper end) and to travel out from the air gap 40 through one of the side airflow openings 28b, as illustrated by the airflow arrows 50a, 50b. It will be understood that the volume of cooling airflow following this path is likely to be significantly lower compared to the volume of airflow following the predominantly upwards flow path illustrated in Figure 6.

[0089] As described above, the cover 4 further helps to keep the device body 2 (and in particular the charging circuitry 5) cool since it blocks solar radiation 52 from reaching the housing 3. It acts to provide a physical barrier to the solar radiation 52, and furthermore since it is spaced from the housing 3 across most of its area (i.e. largely not in contact with the housing 3) forming an air gap between them, any heat which is absorbed by the cover 4, due to the solar radiation 52 or other sources, is less easily transferred to the device body 2 and in particular the charging circuitry 5.In Figure 9, the front housing part 3a and the rear housing part 3b can be seen more clearly. In this view the cavity 90 formed within the housing is seen more clearly. As described above, this cavity 90 accommodates components of the charging circuitry 5 (e.g. the circuit board), and their position behind the heat sink structure 6 helps heat from the charging circuitry 5 to be dissipated more effectively out of the heat sink structure 6.

[0090] It will be appreciated by those skilled in the art that the invention has been illustrated by describing one or more specific embodiments thereof, but is not limited to these embodiments; many variations and modifications are possible, within the scope of the accompanying claims.

Claims

Claims1. An electric vehicle charging device comprising:a device body, comprising:a housing; and,charging circuitry controllable to selectively supply power to an electric vehicle, the charging circuitry contained within the housing;wherein an outer surface of the housing comprises a heat sink structure;the electric vehicle charging device further comprising a cover, connected to the housing so as to be positioned over the heat sink structure and to be spaced apart from the heat sink structure so as to create an air gap therebetween.

2. The electric vehicle charging device of claim 1 , wherein the heat sink structure comprises an airflow channel.

3. The electric vehicle charging device of claim 2, wherein the airflow channel is elongate, and wherein the airflow channel extends along the vertical direction in use.

4. The electric vehicle charging device of claim 2 or 3, wherein a depth of the airflow channel varies gradually at a lower end of the airflow channel.

5. The electric vehicle charging device of any of claims 2 to 4, wherein a lower end of the airflow channel is defined by an end portion of the airflow channel and a base portion of the airflow channel, wherein the end portion and the base portion meet at an angle of more than 90 degrees..

6. The electric vehicle charging device of any of claims 2 to 5, wherein an upper end of the airflow channel is open.

7. The electric vehicle charging device of any of claims 2 to 6, wherein the airflow channel has a constant width.

8. The electric vehicle charging device of any of claims 2 to 7, wherein the airflow channel has a minimum width of approximately 1 cm.

9. The electric vehicle charging device of any of claims 2 to 8, wherein the heat sink structure comprises at least two parallel airflow channels.

10. The electric vehicle charging device of claim 9, wherein the at least two parallel airflow channels are positioned equidistantly from each other, and wherein a separation distance between adjacent airflow channels is substantially equal to the width of the airflow channels.

11. The electric vehicle charging device of claim 9 or 10, wherein the heat sink structure comprises three airflow channels.

12. The electric vehicle charging device of any preceding claim, wherein the housing comprises a first region, comprising the heat sink structure, wherein the housing is convex in the first region, and wherein the heat sink structure is concave.

13. The electric vehicle charging device of any preceding claim, wherein the heat sink structure is positioned on a front surface of the housing, the housing comprising a rear surface, on an opposite side of the housing to the front surface, wherein the rear surface is suitable for mounting the electric vehicle charging device in use.

14. The electric vehicle charging device of any preceding claim, wherein the housing is sealed.

15. The electric vehicle charging device of any preceding claim, wherein the housing is formed from plastic.

16. The electric vehicle charging device of any preceding claim, wherein the charging circuitry comprises a circuit board, and wherein the circuit board is located within the housing behind the heat sink structure.

17. The electric vehicle charging device of any preceding claim, wherein the housing and the cover are configured such that with the cover connected to the housing, at least one upper air flow opening and at least one lower airflow opening are formed in the electric vehicle charging device, the air gap extending to both the at least one upper air flow opening and the at least one lower airflow opening.

18. The electric vehicle charging device of any preceding claim, wherein the housing comprises a flange extending from the housing, the flange comprising one or more airflow apertures, wherein the cover is connected to the housing at a position outside of the airflow apertures.

19. The electric vehicle charging device of any preceding claim, wherein the cover is spaced apart from the majority of a front surface of the housing.

20. The electric vehicle charging device of any preceding claim, wherein the cover is connected to the housing at a first connection point, on a first side surface of the housing, and at a second connection point on a second, opposite side of the housing.

21. The electric vehicle charging device of claim 20, wherein the cover is connected to the housing at cover connection points positioned around the outer edge of the cover.

22. The electric vehicle charging device of any preceding claim, wherein the cover is removably connected to the housing.

23. The electric vehicle charging device of any preceding claim, wherein the cover comprises a material resistant to ultra-violet radiation.

24. The electric vehicle charging device of any preceding claim, wherein the cover is made of a different material to the material of the housing.

25. The electric vehicle charging device of any preceding claim, wherein the housing has a length of less than 60cm, a width of less than 40 cm and a depth of less than 40 cm.

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