Vehicle lighting devices and vehicle lamps

Abstract

The objective is to provide a vehicle lighting device and a vehicle lamp that can efficiently transfer the heat generated in the light-emitting module to the socket. [Solution] The vehicle lighting device according to the embodiment comprises: a socket; a light-emitting module having a light-emitting element, provided on one end side of the socket; and a heat transfer section provided between the socket and the light-emitting module. When viewed from a direction along the central axis of the vehicle lighting device, the contour of the heat transfer section includes an outwardly projecting arc, and the portion of the heat transfer section including the arc is located outside the light-emitting module.

Description

Technical Field

[0001] Embodiments of the present invention relate to a vehicle lighting device and a vehicle lamp.

Background Art

[0002] From the viewpoints of energy saving and long life, instead of a vehicle lighting device including a lamp having a filament, a vehicle lighting device including a light emitting element such as a light emitting diode has been increasingly popularized. Such a vehicle lighting device includes a socket and a light emitting module provided on one end side of the socket and having a light emitting element.

[0003] Here, when an electric current flows through the light emitting element, light is irradiated from the light emitting element and heat is generated. Due to the generated heat, for example, if the temperature of the light emitting element exceeds the maximum junction temperature, the life of the light emitting element may be shortened, the light emitting element may malfunction, or the luminous flux irradiated from the light emitting element may decrease.

[0004] Therefore, a technique of providing a heat transfer part containing a metal between the light emitting module and the socket has been proposed. If the heat transfer part is provided, it becomes easier to transfer the heat generated in the light emitting module to the socket. For example, it is possible to suppress the temperature of the light emitting element from exceeding the maximum junction temperature.

[0005] However, in recent years, an increase in luminous flux has been desired. Therefore, the current flowing through the light emitting element increases, and the generated heat tends to increase.

[0006] Therefore, the development of a technique that can efficiently transfer the heat generated in the light emitting module to the socket has been desired.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

[0008] The problem that this invention aims to solve is to provide a vehicle lighting device and a vehicle lamp that can efficiently transfer the heat generated in the light-emitting module to the socket. [Means for solving the problem]

[0009] The vehicle lighting device according to the embodiment comprises: a socket; a light-emitting module having a light-emitting element, provided on one end side of the socket; and a heat transfer section provided between the socket and the light-emitting module. When viewed from a direction along the central axis of the vehicle lighting device, the contour of the heat transfer section includes an outwardly projecting arc, and the portion of the heat transfer section including the arc is located outside the light-emitting module. [Effects of the Invention]

[0010] According to embodiments of the present invention, it is possible to provide a vehicle lighting device and a vehicle lamp that can efficiently transfer heat generated in a light-emitting module to a socket. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic exploded view illustrating a vehicle lighting device according to this embodiment. [Figure 2] This is a cross-sectional view of the vehicle lighting device shown in Figure 1, along line AA. [Figure 3] This is a schematic perspective view illustrating the heat transfer section. [Figure 4] This is a schematic plan view illustrating a heat transfer section according to another embodiment. [Figure 5] This is a schematic plan view illustrating a heat transfer section according to another embodiment. [Figure 6] (a) and (b) are schematic perspective views illustrating heat transfer sections according to other embodiments. [Figure 7] It is a schematic cross-sectional view for exemplifying a vehicle lighting device provided with a heat transfer part. [Figure 8] It is a schematic partial cross-sectional view for exemplifying a vehicle lamp.

Embodiments for Carrying out the Invention

[0012] Hereinafter, embodiments will be exemplified while referring to the drawings. In each drawing, the same components are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0013] (Vehicle Lighting Device) The vehicle lighting device 1 according to the present embodiment can be provided, for example, in an automobile or a railway vehicle. Examples of the vehicle lighting device 1 provided in an automobile include, for example, a front combination lamp (for example, a combination of a daytime running lamp (DRL), a position lamp, a turn signal lamp, etc. as appropriate), a rear combination lamp (for example, a combination of a stop lamp, a tail lamp, a turn signal lamp, a back lamp, a fog lamp, etc. as appropriate), etc. However, the use of the vehicle lighting device 1 is not limited to these.

[0014] FIG. 1 is a schematic exploded view for exemplifying the vehicle lighting device 1 according to the present embodiment. FIG. 2 is a cross-sectional view taken along line A-A of the vehicle lighting device 1 in FIG. 1. As shown in FIGS. 1 and 2, the vehicle lighting device 1 is provided with, for example, a socket 10, a light emitting module 20, a power supply part 30, and a heat transfer part 40.

[0015] The socket 10 has, for example, a mounting part 11, a bayonet 12, a flange 13, heat dissipation fins 14, and a connector holder 15.

[0016] The mounting portion 11 is provided on one surface side of the flange 13. The outer shape of the mounting portion 11 is, for example, substantially cylindrical. The mounting portion 11 has, for example, a recess 11a that opens at an end opposite to the flange 13 side.

[0017] The bayonet 12 is provided, for example, on the side portion of the mounting portion 11. The bayonet 12 protrudes outward from the vehicle lighting device 1. The bayonet 12 faces the flange 13. A plurality of bayonets 12 can be provided. The bayonet 12 is used when mounting the vehicle lighting device 1, for example, to the housing 101 of the vehicle lamp 100 described later. The bayonet 12 can be used for a twist lock.

[0018] The flange 13 is in a plate shape. The side portion of the flange 13 is located outside the vehicle lighting device 1 more than the side portion of the bayonet 12.

[0019] The heat dissipation fin 14 is provided on the side of the flange 13 opposite to the mounting portion 11 side. At least one heat dissipation fin 14 can be provided. For example, when providing a plurality of heat dissipation fins 14, as shown in FIGS. 1 and 2, the plurality of heat dissipation fins 14 can be arranged side by side in a predetermined direction. The heat dissipation fin 14 is, for example, in a plate shape or a cylindrical shape.

[0020] The connector holder 15 is provided on the side of the flange 13 opposite to the mounting portion 11 side. The connector holder 15 can be provided side by side with the heat dissipation fin 14. The connector holder 15 is in a cylindrical shape, and a connector 105 having a seal member 105a inside is inserted therein.

[0021] The socket 10 has the function of holding the light-emitting module 20 and the power supply unit 30, and the function of transferring heat generated in the light-emitting module 20 to the outside. For this reason, the socket 10 is made of a material with high thermal conductivity. In recent years, there has been a desire to lighten the vehicle lighting device 1, and consequently the socket 10. For this reason, it is preferable to make the socket 10 from, for example, a highly thermally conductive resin. A highly thermally conductive resin includes, for example, a resin and a filler using an inorganic material. A highly thermally conductive resin is, for example, a resin such as PET (Polyethylene terephthalate) or nylon mixed with a filler using carbon or aluminum oxide.

[0022] The light-emitting module 20 (substrate 21) is provided on one end of the socket 10. For example, the light-emitting module 20 is provided on the end 40a1 of the heat transfer section 40 that is exposed from the socket 10. The light-emitting module 20 includes, for example, a substrate 21, a light-emitting element 22, a frame portion 23, a sealing portion 24, and a circuit element 25.

[0023] The substrate 21 is bonded, for example, to the end portion 40a1 of the heat transfer section 40. In this case, it is preferable to use an adhesive with high thermal conductivity. For example, the adhesive can be an adhesive mixed with an inorganic material filler.

[0024] The substrate 21 is plate-shaped. The planar shape of the substrate 21 (shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) is, for example, approximately rectangular. The substrate 21 can be formed from, for example, inorganic materials such as ceramics (e.g., aluminum oxide or aluminum nitride), organic materials such as paper phenol or glass epoxy. The substrate 21 may also be a metal core substrate in which the surface of a metal plate is coated with an insulating material. When the light-emitting element 22 generates a large amount of heat, it is preferable to form the substrate 21 using a material with high thermal conductivity from the viewpoint of heat dissipation. Examples of materials with high thermal conductivity include ceramics such as aluminum oxide or aluminum nitride, high thermal conductivity resins, and metal core substrates. The substrate 21 may also have a single-layer structure or a multilayer structure.

[0025] Furthermore, a wiring pattern 21a is provided on the surface of the substrate 21. The wiring pattern 21a is formed from, for example, a material mainly composed of silver or a material mainly composed of copper. A covering portion can also be provided to cover the wiring pattern 21a and film-like resistors, which will be described later. The covering portion may include, for example, a glass material.

[0026] The light-emitting element 22 is located on the substrate 21 (on the side of the substrate 21 opposite to the heat transfer section 40). The light-emitting element 22 is electrically connected to the wiring pattern 21a.

[0027] At least one light-emitting element 22 can be provided. If multiple light-emitting elements 22 are provided, they can be connected in series. The light-emitting element 22 can be, for example, a light-emitting diode, an organic light-emitting diode, a laser diode, or the like.

[0028] The light-emitting element 22 can be a chip-shaped light-emitting element, a surface-mount type such as a PLCC (Plastic Leaded Chip Carrier), or a leaded light-emitting element such as a bullet-shaped element. The light-emitting element 22 illustrated in Figures 1 and 2 is a chip-shaped light-emitting element. In this case, considering the miniaturization of the light-emitting module 20 and, consequently, the vehicle lighting device 1, it is preferable to use a chip-shaped light-emitting element. In the following, as an example, the case in which the light-emitting element 22 is a chip-shaped light-emitting element will be described.

[0029] The chip-shaped light-emitting element 22 can be mounted on the wiring pattern 21a using COB (Chip On Board). The chip-shaped light-emitting element 22 may be an upper electrode type light-emitting element, an upper and lower electrode type light-emitting element, or a flip-chip type light-emitting element.

[0030] The frame portion 23 is provided on the substrate 21. The frame portion 23 is bonded to the substrate 21. The frame portion 23 has a frame shape and surrounds the light-emitting element 22. The frame portion 23 can be formed from, for example, a thermoplastic resin.

[0031] The frame portion 23 can have the function of defining the formation range of the sealing portion 24 and the function of a reflector. Therefore, the frame portion 23 may contain titanium dioxide particles or a white resin in order to improve reflectivity.

[0032] Furthermore, the frame portion 23 can be omitted. However, if the frame portion 23 is provided, the utilization efficiency of the light emitted from the light-emitting element 22 can be improved. In addition, since the area in which the sealing portion 24 is formed can be reduced, the light-emitting module 20 can be miniaturized, and consequently the vehicle lighting device 1 can be miniaturized.

[0033] The sealing portion 24 is provided inside the frame portion 23. The sealing portion 24 is provided so as to cover the area enclosed by the frame portion 23. The sealing portion 24 is provided so as to cover the light-emitting element 22. The sealing portion 24 contains a light-transmitting resin. The resin is, for example, a silicone resin. The sealing portion 24 may also contain a phosphor.

[0034] If the frame portion 23 is omitted, for example, a dome-shaped sealing portion 24 is formed on the substrate 21. Furthermore, if the light-emitting element 22 is a surface-mount type light-emitting element, or if the light-emitting element 22 is a bullet-shaped or other type of light-emitting element with lead wires, the frame portion 23 and the sealing portion 24 can be omitted.

[0035] The circuit element 25 can be a passive or active element used to constitute a light-emitting circuit having a light-emitting element 22. The circuit element 25 is provided, for example, around the frame portion 23 and electrically connected to the wiring pattern 21a.

[0036] The circuit elements 25 can be, for example, a resistor 25a, a protection element 25b, and a control element 25c. However, the types of circuit elements 25 are not limited to those exemplified, and can be appropriately changed depending on the configuration of the light-emitting circuit having the light-emitting element 22. For example, in addition to those mentioned above, the circuit elements 25 may also be capacitors, positive characteristic thermistors, negative characteristic thermistors, inductors, surge absorbers, varistors, transistors, integrated circuits, computing elements, etc.

[0037] The resistor 25a is mounted on the substrate 21. The resistor 25a is electrically connected to the wiring pattern 21a. The resistor 25a can be, for example, a surface-mount resistor, a resistor with lead wires (metal oxide film resistor), or a film-type resistor formed using a screen printing method. The resistor 25a shown in Figure 1 is a film-type resistor. The material of the film-type resistor is, for example, ruthenium oxide (RuO2). Film-type resistors are formed, for example, using a screen printing method and a firing method.

[0038] The resistor 25a is provided to reduce variations in the brightness (luminous flux, luminance, luminous intensity, illuminance) of the light emitted from the light-emitting element 22, which are caused by variations in the forward voltage characteristics of the light-emitting element 22. In this case, by changing the resistance value of the resistor 25a connected in series with the light-emitting element 22, the value of the current flowing through the light-emitting element 22 is made to fall within a predetermined range.

[0039] If resistor 25a is a surface-mount type resistor or a resistor with leads, select a resistor 25a with an appropriate resistance value according to the forward voltage characteristics of the light-emitting element 22. If resistor 25a is a film-type resistor, the resistance value can be increased by removing a portion of resistor 25a. For example, a portion of the film-type resistor can be easily removed by irradiating it with laser light. Furthermore, the resistor 25a can also have the function of preventing excessive current from flowing through the light-emitting element 22.

[0040] The protection element 25b is provided on the substrate 21. The protection element 25b is electrically connected to the wiring pattern 21a. The protection element 25b is provided, for example, to prevent reverse voltage from being applied to the light-emitting element 22 and to prevent pulse noise from being applied to the light-emitting element 22 from the reverse direction. The protection element 25b can be, for example, a diode or a field-effect transistor. The protection element 25b illustrated in Figure 1 is a surface-mount type diode.

[0041] The control element 25c is provided on the substrate 21. The control element 25c is electrically connected to the wiring pattern 21a. The control element 25c changes the number of light-emitting elements 22 to be lit according to the voltage (input voltage) applied to the vehicle lighting device 1. The control element 25c may also, for example, switch the voltage applied to the light-emitting elements 22 or perform temperature derating.

[0042] In addition, optical elements may be provided as needed. These optical elements can be provided, for example, on the sealing portion 24. Examples of optical elements include convex lenses, concave lenses, and light guides.

[0043] The power supply unit 30 has, for example, a plurality of power supply terminals 31 and a holding unit 32. The multiple power supply terminals 31 can be rod-shaped. The multiple power supply terminals 31 can be arranged in a line in one direction, for example. One end of the multiple power supply terminals 31 protrudes from the bottom surface 11a1 of the recess 11a. One end of the multiple power supply terminals 31 is soldered to a wiring pattern 21a provided on the substrate 21. The multiple power supply terminals 31 are electrically connected to the light-emitting element 22 and the circuit element 25 via the wiring pattern 21a. The other end of the multiple power supply terminals 31 is exposed inside the hole of the connector holder 15. The connector 105 is fitted to the multiple power supply terminals 31 exposed inside the hole of the connector holder 15. The multiple power supply terminals 31 can be formed from a metal such as a copper alloy, for example.

[0044] As mentioned above, it is preferable that the socket 10 be made from a material with high thermal conductivity. However, materials with high thermal conductivity may also be electrically conductive. For example, a highly thermally conductive resin containing a carbon filler is electrically conductive. Therefore, the retaining portion 32 is provided to insulate the multiple power supply terminals 31 from the conductive socket 10. The retaining portion 32 also has the function of holding the multiple power supply terminals 31. Note that if the socket 10 is made from a highly thermally conductive resin with insulating properties (for example, a highly thermally conductive resin containing an aluminum oxide filler), the retaining portion 32 can be omitted. In this case, the socket 10 holds the multiple power supply terminals 31. The retaining portion 32 is made from, for example, a resin with insulating properties. The retaining portion 32 can be, for example, press-fitted into a hole provided in the socket 10 or bonded to the inner wall of the hole.

[0045] The heat transfer unit 40 is located between the socket 10 and the light-emitting module 20. Figure 3 is a schematic perspective view illustrating the heat transfer section 40. As shown in Figures 1 to 3, the heat transfer section 40 is plate-shaped. The thickness of the heat transfer section 40 (dimension along the central axis 1a of the vehicle lighting device 1) can be, for example, 5 mm or more and 30 mm or less. The heat transfer section 40 is formed from a material with a higher thermal conductivity than a high thermal conductivity resin. The heat transfer section 40 can be formed from a metal such as aluminum, aluminum alloy, copper, or copper alloy. Since the plate-shaped heat transfer section 40 can be formed by, for example, press working, manufacturing costs can be reduced.

[0046] The heat transfer section 40 is provided on one end side of the socket 10. One end 40a1 of the heat transfer section 40 is exposed from one end of the socket 10. For example, the end 40a1 of the heat transfer section 40 can be a flat surface substantially perpendicular to the central axis 1a of the vehicle lighting device 1.

[0047] The heat transfer section 40 can be embedded in the bottom surface 11a1 of the recess 11a, for example, as shown in Figure 2. Alternatively, the heat transfer section 40 can be provided on the bottom surface 11a1 of the recess 11a, or on the top surface of a protrusion provided on the bottom surface 11a1 of the recess 11a.

[0048] As mentioned above, the light-emitting module 20 (substrate 21) is bonded to the end portion 40a1 of the heat transfer portion 40. Therefore, it is preferable that the end portion 40a1 of the heat transfer portion 40 be positioned so as to protrude from the bottom surface 11a1 of the recess 11a. If the end portion 40a1 of the heat transfer portion 40 protrudes from the bottom surface 11a1 of the recess 11a, it is possible to suppress the adhesive from spreading onto the light-emitting module 20.

[0049] The heat transfer unit 40 can be bonded to one end of the socket 10, attached to one end of the socket 10 via thermal conductive grease (heat dissipation grease), or embedded in one end of the socket 10 by insert molding. In this case, it is preferable to use an adhesive with high thermal conductivity. For example, the adhesive can be the same as the adhesive used to bond the substrate 21 and the heat transfer unit 40 as described above. For example, the thermal conductive grease can be a mixture of modified silicone and an inorganic material filler. The thermal conductivity of the thermal conductive grease is, for example, 1 W / (m·K) or more and 5 W / (m·K) or less.

[0050] Furthermore, as shown in Figures 1 and 3, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, the contour of the heat transfer section 40 includes an outwardly projecting arc. Also, as shown in Figure 3, the portion of the heat transfer section 40 including the arc is located outside the light-emitting module 20 (substrate 21). In this way, the heat transfer area between the heat transfer section 40 and the socket 10 can be increased, thereby improving the heat dissipation performance of the heat transfer section 40.

[0051] For example, the contour of the heat transfer section 40 includes an arc, a pair of straight lines with one end connected to each of the endpoints of the arc, and a straight line connecting the ends of the pair of straight lines opposite to the arc. For example, the contour of the heat transfer section 40 can be a shape in which one side of a rectangle is changed to an arc. The central angle of the arc can be, for example, 180° or more and 330° or less.

[0052] Furthermore, as mentioned above, if the outer shape of the mounting portion 11 is substantially cylindrical, when the heat transfer portion 40 is provided on one end of the socket 10, the center of the arc of the contour can be made to coincide with the central axis 10a of the socket 10. In this way, for example, it becomes easy to provide the heat transfer portion 40 in the recess 11a of the mounting portion 11. Furthermore, the central axis 10a of the socket 10 is also the central axis 1a of the vehicle lighting device 1.

[0053] Figure 4 is a schematic plan view illustrating a heat transfer section 41 according to another embodiment. Figure 4 is a schematic plan view of the heat transfer section 41 as seen from a direction along the central axis 1a of the vehicle lighting device 1.

[0054] As shown in Figure 4, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, the contour of the heat transfer section 41 includes an outwardly projecting arc. Also, as shown in Figure 4, the portion of the heat transfer section 41 including the arc is located outside the light-emitting module 20 (substrate 21). This increases the heat transfer area between the heat transfer section 41 and the socket 10, thereby improving the heat dissipation performance of the heat transfer section 41. For example, the contour of the heat transfer section 41 includes an arc and a chord connecting the two endpoints of the arc. The central angle of the arc can be, for example, 180° or more and 330° or less. For example, the only difference between the heat transfer section 41 and the heat transfer section 40 described above is the contour when viewed from a direction along the central axis 1a of the vehicle lighting device 1.

[0055] Similar to the case of the heat transfer section 40 described above, when the heat transfer section 41 is provided on one end of the socket 10, the center of the arc of the contour can be made to coincide with the central axis 10a of the socket 10. In this way, for example, it becomes easy to provide the heat transfer section 41 in the recess 11a of the mounting section 11. Furthermore, since the heat transfer area between the heat transfer unit 41 and the socket 10 can be made larger than the heat transfer area between the heat transfer unit 40 and the socket 10, the heat dissipation performance of the heat transfer unit 41 will be higher than that of the heat transfer unit 40.

[0056] Figure 5 is a schematic plan view illustrating a heat transfer section 42 according to another embodiment. Figure 5 is a schematic plan view of the heat transfer section 42 as seen from a direction along the central axis 1a of the vehicle lighting device 1.

[0057] As shown in Figure 5, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, the contour of the heat transfer section 42 includes an outwardly projecting arc. Also, as shown in Figure 5, the portion of the heat transfer section 42 including the arc is located outside the light-emitting module 20 (substrate 21). This increases the heat transfer area between the heat transfer section 42 and the socket 10, thereby improving the heat dissipation performance of the heat transfer section 42. For example, the contour of the heat transfer section 42 includes a shape in which a part of a circle is cut out. For example, only the contour of the heat transfer section 42 when viewed from a direction along the central axis 1a of the vehicle lighting device 1 differs from that of the heat transfer sections 40 and 41 described above.

[0058] As shown in Figure 1, multiple power supply terminals 31 are exposed on one end of the socket 10. In the case of the contours of the heat transfer parts 40 and 41 described above, a straight portion can be provided that faces the multiple power supply terminals 31, so that the heat transfer parts 40 and 41 do not come into contact with the multiple power supply terminals 31. If the contour of the heat transfer part 42 is made circular and the heat transfer part 42 does not come into contact with the multiple power supply terminals 31, the area of ​​the heat transfer part 42 may become too small, making it difficult to install the light-emitting module 20 on the heat transfer part 42, or the heat dissipation performance of the heat transfer part 42 may decrease.

[0059] Therefore, as shown in Figure 5, the heat transfer section 42 is provided with a notch 42a. The notch 42a penetrates the heat transfer section 42 in the thickness direction and opens at the periphery of the heat transfer section 42. Similar to the heat transfer section 40 described above, when the heat transfer section 42 is provided on one end side of the socket 10, the center of the circle of the outline can be made to coincide with the central axis 10a of the socket 10. In this case, the multiple power supply terminals 31 can be positioned inside the notch 42a. As a result, the heat transfer area between the heat transfer section 42 and the socket 10 can be increased, and contact between the heat transfer section 42 and the multiple power supply terminals 31 can be suppressed. Note that the heat transfer area between the heat transfer section 42 and the socket 10 can be made larger than the heat transfer area between the heat transfer sections 40, 41 and the socket 10.

[0060] Here, if the portion of the light-emitting module 20 (substrate 21) that includes an arc located on the outside is larger, the heat transfer area between it and the socket 10 will increase, thus improving heat dissipation. However, since the light-emitting module 20 is bonded to the heat transfer sections 40-42, if the portion of the light-emitting module 20 that includes an arc located on the outside is larger, the adhesive will be more likely to spread onto the light-emitting module 20. If the adhesive spreads onto the light-emitting module 20, the aesthetic appearance will be compromised, and the product's value may decrease. Therefore, if the portion of the light-emitting module 20 that includes an arc located on the outside is larger, the amount of adhesive and the application position of the adhesive will need to be strictly controlled when bonding the light-emitting module 20 to the heat transfer sections 40-42.

[0061] Therefore, considering the amount of heat generated in the light-emitting module 20, the shape of one end of the socket 10 (for example, the planar shape of the inner wall of the recess 11a), and the productivity in the bonding process, a heat transfer section with an appropriate contour can be appropriately selected. Furthermore, if a step 43a2, described later, is provided outside the area of ​​the heat transfer section 40-42 where the light-emitting module 20 is installed, it is possible to suppress the adhesive from creeping up onto the light-emitting module 20.

[0062] Furthermore, although plate-shaped heat transfer sections 40-42 have been illustrated above, the heat transfer sections 40-42 may also have at least one fin extending inside the socket 10. If a fin extending inside the socket 10 is provided, the heat transfer area between the socket 10 and the heat transfer section can be further increased, thereby further improving heat dissipation.

[0063] Figures 6(a) and 6(b) are schematic perspective views illustrating the heat transfer section 43 according to another embodiment. Figure 7 is a schematic cross-sectional view illustrating a vehicle lighting device 1b equipped with a heat transfer section 43.

[0064] As shown in Figure 7, the heat transfer unit 43 is provided between the socket 10 and the light-emitting module 20. The heat transfer unit 43 can be bonded to one end of the socket 10, attached to one end of the socket 10 via thermal conductive grease (heat dissipation grease), or embedded in one end of the socket 10 by insert molding.

[0065] As shown in Figures 6(a) and (b), the heat transfer section 43 has a base 43a and a plurality of fins 43b. The base 43a and the plurality of fins 43b can be formed integrally. The heat transfer section 43 is formed from a material with a higher thermal conductivity than a high thermal conductivity resin. The heat transfer section 43 can be formed from a metal such as aluminum, aluminum alloy, copper, or copper alloy.

[0066] The base portion 43a is, for example, plate-shaped. The thickness of the base portion 43a (dimension along the central axis 1ba of the vehicle lighting device 1b) can be, for example, 2 mm or more and 30 mm or less. The contour of the base portion 43a, when viewed from the direction along the central axis 1ba of the vehicle lighting device 1b, can be a shape that includes an arc. For example, as shown in Figures 6(a) and (b), the contour of the base portion 43a includes an arc and a chord connecting the two endpoints of the arc. The central angle of the arc can be 180° or more and 330° or less.

[0067] Furthermore, as shown in Figure 7, the base portion 43a can be embedded in the bottom surface 11a1 of the recess 11a. Alternatively, the base portion 43a can be provided on the bottom surface 11a1 of the recess 11a, or on the top surface of a protrusion provided on the bottom surface 11a1 of the recess 11a. For example, the end portion 43a1 of the base portion 43a is exposed from the bottom surface 11a1 of the recess 11a. For example, the end portion 43a1 of the base portion 43a can be a flat surface substantially perpendicular to the central axis 1ba of the vehicle lighting device 1b.

[0068] When viewed from a direction along the central axis 1ba of the vehicle lighting device 1b, the contour of the end portion 43a1 includes an outwardly projecting arc. For example, as shown in Figures 6(a) and (b), the contour of the end portion 43a1 includes an arc extending along the circumferential edge of the base portion 43a, a pair of straight lines with one end connected to each of the endpoints of the arc, and a straight line connecting the ends of the pair of straight lines opposite to the arc side. For example, the contour of the end portion 43a1 can be a shape in which one side of a rectangle is replaced with an arc. The central angle of the arc can be between 180° and 330°.

[0069] The end portion 43a1 of the base portion 43a is bonded to the light-emitting module 20 (substrate 21). Therefore, it is preferable that the end portion 43a1 of the base portion 43a is positioned to protrude from the bottom surface 11a1 of the recess 11a. If the end portion 43a1 of the base portion 43a protrudes from the bottom surface 11a1 of the recess 11a, it is possible to suppress the adhesive from spreading onto the light-emitting module 20.

[0070] A step 43a2 can be provided on the periphery of the end portion 43a1 of the base portion 43a. The step 43a2 can be provided outside the area of ​​the heat transfer portion 43 in which the light-emitting module 20 is provided. The step 43a2 opens, for example, at the end portion 43a1 of the base portion 43a and at the circumferential end of the base portion 43a. The distance between the end portion 43a1 of the base portion 43a and the bottom portion 43a2a of the step 43a2 (the depth of the step 43a2) can be, for example, about 1 mm. The maximum distance between the circumferential end of the base portion 43a and the circumferential end of the end portion 43a1 when viewed from a direction along the central axis 1ba of the vehicle lighting device 1b (the maximum width of the step 43a2) can be, for example, about 10 mm.

[0071] The step 43a2 can be omitted. However, if the step 43a2 is provided, it can be embedded inside the socket 10 (mounting part 11) as shown in Figure 7. As a result, the heat transfer area between the base 43a and the socket 10 can be increased by the depth of the embedded step 43a2, thereby further improving the heat dissipation of the heat transfer part 43. In addition, the bonding strength between the heat transfer part 43 and the socket 10 can be increased, so even if vibrations due to driving are applied to the vehicle lighting device 1b, or thermal stress is generated when the light-emitting element 22 is turned on and off, it is possible to suppress the heat transfer part 43 from falling off the socket 10 or the position of the heat transfer part 43 from shifting, which would prevent the predetermined light distribution characteristics from being obtained.

[0072] Multiple fins 43b are provided on the end 43a3 of the base 43a, opposite the end 43a1. Multiple fins 43b extend inside the socket 10. Multiple fins 43b extend, for example, along the central axis 1ba of the vehicle lighting device 1b. The tips of the multiple fins 43b (the ends opposite to the end 43a3 side) are provided inside the socket 10.

[0073] In this case, if the distance between the tip of the fin 43b and the heat dissipation fin 14 is shortened, the heat generated in the light-emitting module 20 can be efficiently transferred to the heat dissipation fin 14 via the heat transfer section 43. Therefore, the heat dissipation performance of the light-emitting module 20 can be improved. For example, it is preferable that the tip of the fin 43b be located inside the flange 13, and even more preferable that it be located inside the heat dissipation fin 14.

[0074] The shape of the fin 43b can be, for example, plate-shaped or columnar. The shape of the fin 43b illustrated in Figures 6(a), 6(b), and 7 is plate-shaped.

[0075] For example, multiple fins 43b can be arranged in one direction with spacing between them. The heat transfer section 43 illustrated in Figures 6(a), 6(b), and 7 is provided with multiple fins 43b, namely fins 43b1 and fins 43b2. For example, at least one fin 43b2 can be provided between a pair of opposing fins 43b1 in a direction intersecting the central axis 1ba of the vehicle lighting device 1b. The heat transfer section 43 illustrated in Figures 6(a), 6(b), and 7 is provided with three fins 43b2. For example, fins 43b1 and fins 43b2 can be arranged so that they are substantially parallel to each other.

[0076] The side of fin 43b1 facing the adjacent fin 43b2 can be tilted. The tilt angle of the side of fin 43b1 with respect to the central axis 1ba of the vehicle lighting device 1b can be, for example, about 1°. The side of fin 43b2 facing the adjacent fin 43b2, or the side of fin 43b2 facing the adjacent fin 43b1, can be tilted. The tilt angle of the side of fin 43b2 with respect to the central axis 1ba of the vehicle lighting device 1b can be, for example, about 1°.

[0077] In the heat transfer section 43 illustrated in Figures 6(a), 6(b), and 7, the sides of fin 43b1 and fin 43b2 are inclined in a direction that decreases the cross-sectional area in the direction intersecting the central axis 1ba of the vehicle lighting device 1b as they approach the tip. Alternatively, the sides of fin 43b1 and fin 43b2 may be inclined in a direction that increases the cross-sectional area in the direction intersecting the central axis 1ba of the vehicle lighting device 1b as they approach the tip.

[0078] If the sides of fin 43b1 and fin 43b2 are inclined, the heat transfer area between fin 43b and socket 10 can be increased, thereby further improving the heat dissipation performance of the heat transfer section 43.

[0079] Furthermore, as shown in Figures 6(a), 6(b), and 7, the side portion 43b1a of the fin 43b1 opposite to the fin 43b2 side can be a curved surface that protrudes outward. For example, the side portion 43b1a of the fin 43b1 can be a curved surface that curves along the peripheral end of the base portion 43a. If the side portion 43b1a of the fin 43b1 is a curved surface, the heat transfer area between the side portion 43b1a of the fin 43b1 and the socket 10 can be increased, thereby further improving the heat dissipation performance of the heat transfer portion 43.

[0080] Here, since fin 43b2 is provided between fins 43b1 and fin 43b1, heat released from one fin 43b1 and heat released from the other fin 43b1 are incident on fin 43b2. If multiple fins 43b2 are provided, heat released from adjacent fins 43b2 and heat released from adjacent fins 43b1 are incident on fin 43b2. As a result, thermal interference between fins 43b1 and fin 43b2 increases, which may suppress heat dissipation from fin 43b2.

[0081] In contrast, in the case of fin 43b1, only the heat emitted from the adjacent fin 43b2 is incident. Therefore, thermal interference between fin 43b1 and fin 43b2 is reduced. Furthermore, the heat emitted from fin 43b1 propagates through the inside of the socket 10 and is released to the outside through the mounting portion 11, flange 13, and heat dissipation fin 14. Therefore, the heat dissipation performance of fin 43b1 is higher than that of fin 43b2.

[0082] In this case, if the cross-sectional area of ​​fin 43b1 in the direction in which the pair of fins 43b1 and fin 43b2 are aligned is made larger than the cross-sectional area of ​​fin 43b2, the surface area of ​​fin 43b1 can be made larger than the surface area of ​​fin 43b2, or the thermal resistance of fin 43b1 can be made smaller than the thermal resistance of fin 43b2. Therefore, the heat dissipation performance of fin 43b1 can be further improved.

[0083] Improving the heat dissipation of the fins 43b1 allows the heat generated in the light-emitting module 20 to be transferred to the socket 10 more efficiently. This effectively prevents the temperature of the light-emitting element 22 and the circuit element 25 from becoming too high.

[0084] For example, as shown in Figure 6(b), the maximum dimension T1 (mm) of fin 43b1 in the direction in which the pair of fins 43b1 and fin 43b2 are aligned may be made larger than the maximum dimension T2 (mm) of fin 43b2.

[0085] For example, the maximum dimension T1 (mm) of fin 43b1 and the maximum dimension T2 (mm) of fin 43b2 are given by the "maximum cross-sectional area (mm) of fin 43b1". 2 ) / Maximum cross-sectional area of ​​fin 43b2 (mm 2 The value of ) can be made to be 1.5 or higher.

[0086] Furthermore, if multiple fins 43b2 are provided, the maximum distance between fin 43b1 and fin 43b2 can be made larger than the maximum distance between fins 43b2 themselves. In this way, thermal interference between fin 43b1 and fin 43b2 can be suppressed, thereby further improving the heat dissipation performance of fin 43b1.

[0087] (Vehicle lighting fixtures) In one embodiment of the present invention, a vehicle lighting fixture 100 equipped with a vehicle lighting device 1 can be provided. The above-described vehicle lighting device 1, and variations of the vehicle lighting device 1 (for example, vehicle lighting device 1b, or those in which components are added, deleted, or redesigned as appropriate by those skilled in the art, and which possess the features of the present invention) can all be applied to the vehicle lighting fixture 100.

[0088] In the following explanation, we will use the example that the vehicle lighting fixture 100 is a front combination light installed on an automobile. However, the vehicle lighting fixture 100 is not limited to a front combination light installed on an automobile. The vehicle lighting fixture 100 can be any vehicle lighting fixture installed on an automobile, railway vehicle, etc.

[0089] Figure 8 is a schematic partial cross-sectional view illustrating a vehicle lighting fixture 100. As shown in Figure 8, the vehicle lighting fixture 100 includes, for example, a vehicle lighting device 1(1b), a housing 101, a cover 102, an optical element 103, a sealing member 104, and a connector 105.

[0090] A vehicle lighting device 1(1b) is mounted on the housing 101. The housing 101 holds the mounting portion 11. The housing 101 has a box shape with one end open. The housing 101 is made of, for example, a resin that does not transmit light. A mounting hole 101a is provided on the bottom surface of the housing 101 into which the portion of the mounting portion 11 with the bayonet 12 is inserted. A recess is provided around the periphery of the mounting hole 101a into which the bayonet 12 provided on the mounting portion 11 is inserted. Although the example shows the mounting hole 101a being directly provided on the housing 101, a mounting member having the mounting hole 101a may also be provided on the housing 101.

[0091] When attaching the vehicle lighting device 1(1b) to the vehicle lamp 100, the portion of the mounting part 11 with the bayonet 12 is inserted into the mounting hole 101a, and the vehicle lighting device 1(1b) is rotated. Then, for example, the bayonet 12 is held in place by a fitting portion provided on the periphery of the mounting hole 101a. This type of mounting method is called a twist lock.

[0092] The cover 102 is provided to close the opening of the housing 101. The cover 102 is made of a light-transmitting resin or the like. The cover 102 may also have functions such as a lens.

[0093] Light emitted from the vehicle lighting device 1(1b) is incident on the optical element 103. The optical element 103 performs functions such as reflection, diffusion, guidance, focusing, and formation of a predetermined light distribution pattern of the light emitted from the vehicle lighting device 1(1b). For example, the optical element 103 illustrated in Figure 8 is a reflector. In this case, the optical element 103 reflects the light emitted from the vehicle lighting device 1(1b) to form a predetermined light distribution pattern.

[0094] The sealing member 104 is provided between the flange 13 and the housing 101. The sealing member 104 is annular in shape and is made of an elastic material such as rubber or silicone resin.

[0095] When the vehicle lighting device 1(1b) is attached to the vehicle lamp 100, the sealing member 104 is sandwiched between the flange 13 and the housing 101. Therefore, the sealing member 104 can seal the internal space of the housing 101. In addition, the elastic force of the sealing member 104 presses the bayonet 12 against the housing 101. Therefore, it is possible to prevent the vehicle lighting device 1(1b) from detaching from the housing 101.

[0096] The connector 105 is fitted onto the ends of the multiple power supply terminals 31 that are exposed inside the connector holder 15. The connector 105 is electrically connected to a lighting circuit and the like, which are located outside the vehicle lighting fixture 100. Therefore, by fitting the connector 105 onto the ends of the multiple power supply terminals 31, the lighting circuit and the light-emitting element 22 can be electrically connected.

[0097] Furthermore, the connector 105 is provided with a sealing member 105a. When the connector 105 having the sealing member 105a is inserted into the connector holder 15, the inside of the connector holder 15 is sealed to be watertight.

[0098] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other.

[0099] The following are additional notes regarding the embodiments described above.

[0100] (Note 1) Socket and; A light-emitting module having a light-emitting element is provided on one end side of the socket; A heat transfer unit provided between the socket and the light-emitting module; It is equipped with, A vehicle lighting device in which, when viewed from a direction along the central axis of the vehicle lighting device, the contour of the heat transfer portion includes an outwardly projecting arc, and the portion of the heat transfer portion including the arc is located outside the light-emitting module.

[0101] (Note 2) The vehicle lighting device according to Appendix 1, wherein the contour of the heat transfer section includes the arc, a pair of straight lines whose one end is connected to each of the endpoints of the arc, and a straight line connecting the ends of the pair of straight lines opposite to the arc side.

[0102] (Note 3) The vehicle lighting device according to Appendix 1, wherein the contour of the heat transfer section includes the arc and a chord connecting the two endpoints of the arc.

[0103] (Note 4) The vehicle lighting device according to Appendix 1, wherein the contour of the heat transfer section includes a shape in which a part of a circle is cut out.

[0104] (Note 5) The vehicle lighting device according to any one of appendices 1 to 4, wherein the heat transfer section further comprises at least one fin extending inside the socket.

[0105] (Note 6) A vehicle lighting device according to any one of the appendices 1 to 5, wherein a step is provided outside the area of ​​the heat transfer section in which the light-emitting module is provided.

[0106] (Note 7) A vehicle lighting device as described in any one of the appendices 1 to 6; The housing on which the aforementioned vehicle lighting device is mounted; A vehicle lighting fixture equipped with the following features. [Explanation of Symbols]

[0107] 1 Vehicle lighting device, 1a central shaft, 1b Vehicle lighting device, 1ba central shaft, 10 socket, 10a central shaft, 11 mounting part, 20 light-emitting module, 21 substrate, 22 light-emitting element, 40-43 heat transfer part, 43a2 step, 43b fin, 100 vehicle lamp, 101 housing

Claims

1. Socket and; A light-emitting module having a light-emitting element is provided on one end side of the socket; A heat transfer unit provided between the socket and the light-emitting module; It is equipped with, A vehicle lighting device in which, when viewed from a direction along the central axis of the vehicle lighting device, the contour of the heat transfer portion includes an outwardly projecting arc, and the portion of the heat transfer portion including the arc is located outside the light-emitting module.

2. The vehicle lighting device according to claim 1, wherein the contour of the heat transfer section includes the arc, a pair of straight lines whose one end is connected to each of the endpoints of the arc, and a straight line connecting the ends of the pair of straight lines on the side opposite to the arc.

3. The vehicle lighting device according to claim 1, wherein the contour of the heat transfer section includes the arc and a chord connecting the two endpoints of the arc.

4. The vehicle lighting device according to claim 1, wherein the contour of the heat transfer section includes a shape in which a part of a circle is cut out.

5. The vehicle lighting device according to claim 1 or 2, wherein the heat transfer section further comprises at least one fin extending inside the socket.

6. The vehicle lighting device according to claim 1 or 2, wherein a step is provided outside the area of ​​the heat transfer section in which the light-emitting module is provided.

7. A vehicle lighting device according to any one of claims 1 to 4; A housing on which the aforementioned vehicle lighting device is attached; A vehicle lighting fixture equipped with the following features.

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