JP2013004423A - Vehicular lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lamp in which light distribution performance is improved while securing a high heat radiation performance and excellent workability at the time of assembly.SOLUTION: The vehicular lamp is provided with a lamp outer case 4 composed of a cover 3 and a lamp housing 2, a light-emitting module 9 which has a light-emitting element 14 arranged inside the lamp outer case and installed as a light source, and a circuit board 13 on which the light-emitting element is mounted, a support member 8 which is arranged inside the lamp outer case to support the light-emitting module and in which heat generated in the light-emitting module is conducted and which discharges the conducted heat, and a heat conductor 19 which is arranged between the circuit board and the support member in contact with the both and exists as a solid of sheet shape in the condition of a prescribed temperature or less and softens into gel form in the condition exceeding a prescribed temperature.

Description

  The present invention relates to a vehicular lamp. Specifically, a heat conductor whose state changes depending on the temperature is arranged between the circuit board of the light emitting module and the holding member that holds the light emitting module to improve workability and heat dissipation in the assembly operation of the light emitting module. It is related with the technical field to plan.

  Some vehicular lamps include a light emitting module in which a light emitting element, for example, a light emitting diode (LED) is mounted on a circuit board.

  In such a vehicular lamp, the light emitting module is held by a heat radiating holding member, and heat generated when the light emitting module is driven is released from the holding member so as to ensure a good operating state of the light emitting module. I have to. Therefore, the holding member functions as a heat sink that releases heat generated in the light emitting module.

  In the circuit board of the light emitting module, a connection terminal provided on a surface opposite to the surface on which the light emitting element is mounted is connected to a terminal electrode of the light emitting element through a through hole. A heat radiating sheet or heat radiating grease is disposed or applied between the circuit board and the holding member, and heat generated in the light emitting module is transmitted to the holding member via the heat radiating sheet or heat radiating grease (for example, Patent Document 1).

  In the vehicular lamp described in Patent Document 1, a flexible film-like heat dissipation sheet is disposed between a circuit board and a holding member.

JP 2010-267468 A

  However, since the heat dissipation sheet does not have fluidity like heat dissipation grease, the workability when assembling the circuit board to the holding member is high, but the contact thermal resistance between the circuit board and the holding member is large, and sufficient heat dissipation is achieved. There is a possibility that it cannot be secured. For example, since the heat dissipation sheet has a contact thermal resistance of about 1 to 3 ° C / W per square centimeter, the contact thermal resistance of about 2 to 6 ° C / W per square centimeter exists on both sides.

  On the other hand, since the heat dissipation grease is in the form of a fluid gel, the contact heat resistance between the circuit board and the holding member is small and it has good heat dissipation, but it is difficult to handle due to the fluidity, and when the circuit board is attached to the holding member There is a problem that workability is low.

  In addition, since the heat dissipation grease is in the form of a gel, the thickness is likely to be non-uniform, and if the non-uniformity of thickness occurs, the light emitting module is likely to be arranged in a tilted state with respect to the holding member, There is a possibility that the light distribution performance of the light emitting module is affected and a desired light distribution pattern cannot be formed.

  Accordingly, an object of the vehicular lamp of the present invention is to improve light distribution performance while ensuring high heat dissipation performance and good workability during assembly.

  In order to solve the above-described problem, a vehicular lamp includes a lamp outer casing configured by a cover and a lamp housing, a light emitting element disposed as a light source disposed inside the lamp outer casing, and the light emitting element. A light emitting module having a circuit board, a holding member that is disposed inside the lamp outer casing and holds the light emitting module, and heat that is generated in the light emitting module is conducted and released, and the circuit board. And a heat conductor that is disposed between and in contact with the holding member and is present as a sheet-like solid in a state below a predetermined temperature and softens in a gel state in a state exceeding the predetermined temperature. It is provided.

  Therefore, in the vehicular lamp, the state of the heat conductor arranged in contact with both between the circuit board and the holding member is changed depending on the temperature.

  The vehicular lamp according to the present invention includes a lamp outer casing constituted by a cover and a lamp housing, a light emitting element disposed inside the lamp outer casing as a light source, and a circuit board on which the light emitting element is mounted. A module, a holding member disposed inside the lamp housing and holding the light emitting module, and heat generated in the light emitting module is conducted and released, and the heat is transmitted between the circuit board and the holding member. And a heat conductor that is disposed in contact with the two and is present as a sheet-like solid in a state below a predetermined temperature and softens in a gel state in a state exceeding the predetermined temperature. .

  Therefore, it is possible to improve the light distribution performance while ensuring high heat dissipation performance and good workability during assembly.

  In the invention described in claim 2, a flow preventing recess is formed around the heat conductor in the holding member.

  Therefore, adhesion of the heat conductor to each part that does not require contact with the heat conductor can be prevented by the flow preventing recess.

  In the invention described in claim 3, a plurality of positioning projections are provided at positions along the flow preventing recesses in the holding member, and the circuit board is disposed inside the plurality of positioning projections. The circuit board is inserted and positioned with respect to the holding member.

  Therefore, the circuit board can be easily and reliably positioned with respect to the holding member without causing an increase in manufacturing cost.

  In the invention described in claim 4, the protrusion for preventing flow is provided around the heat conductor in the holding member.

  Therefore, adhesion of the heat conductor to each part that does not require contact with the heat conductor can be prevented by the flow preventing protrusion.

  In the invention described in claim 5, a positioning protrusion is provided on the inner surface of the flow prevention protrusion, and the circuit board is inserted inside the flow prevention protrusion, and the outer peripheral surface of the circuit board. Is engaged with the positioning projection so that the circuit board is positioned with respect to the holding member.

  Accordingly, the protrusion for preventing flow can be used as a positioning portion for the holding member of the circuit board, and the positioning of the circuit board with respect to the holding member can be performed easily and reliably without increasing the manufacturing cost.

  The best mode for carrying out the vehicular lamp of the present invention will be described below with reference to the accompanying drawings.

  The vehicular lamp 1 is disposed at both left and right ends of the vehicle body. As the vehicular lamp, for example, a so-called daytime running lamp is used that irradiates the surrounding area with light in a time zone other than nighttime to alert the pedestrian or other vehicle driver to the presence of the vehicle. ing.

  However, the vehicular lamp 1 is not limited to a daytime running lamp. For example, various other vehicular lamps such as a headlamp, a cornering lamp, a rear lamp (rear combination lamp), a clearance lamp, a turn signal lamp, and a fog lamp. It can be widely applied to.

  As shown in FIG. 1, the vehicular lamp 1 includes a lamp housing 2 having a recess opened forward, and a cover 3 that closes the opening surface of the lamp housing 2. 4 is configured. The interior of the lamp outer casing 4 is formed as a lamp chamber 5.

  A lamp unit 6 is disposed in the lamp chamber 5. The lamp unit 6 includes a mounting member 7 and a plurality of light emitting modules 9, 9 attached to and held by the holding members 8, 8,. ..

  The mounting member 7 is formed of a plate-like resin material or metal material, and as shown in FIGS. 1 and 2, the first surface portions 7a, 7a,... And the second surface portions 7b, 7b,. .. are alternately formed in a staircase pattern. The attachment member 7 is attached to the lamp housing 2.

  The holding members 8, 8,... Are attached to the front surfaces of the second surface portions 7b, 7b,. The holding member 8 has a high heat dissipation property, for example, is formed in a predetermined shape with a plate-shaped metal material, and has a rectangular base surface portion 10 facing in the front-rear direction and side portions protruding forward from both side edges of the base surface portion 10. 11 and 11 and projecting surface portions 12 and 12 projecting from the front end portions of the side surface portions 11 and 11 in directions away from each other.

  The light emitting module 9 includes a circuit board 13, a light emitting element 14 mounted on the front surface of the circuit board 13, and a first reflector 15 and a second reflector 16 disposed on the opposite sides across the light emitting element 14. .

  A predetermined circuit pattern is formed on the circuit board 13, and connectors 13 a and 13 a connected to the circuit pattern are provided on the front surface of the circuit pattern 13. The circuit boards 13, 13,... Are connected to connection lines 17, 17,. One circuit board 13 is connected to a power circuit (not shown) provided outside the lamp housing 2 via a cable 18 connected to the connector 13a.

  Therefore, a drive current is supplied to the light-emitting elements 14, 14,... Mounted on the circuit boards 13, 13,... Via the cable 18 or the cable 18 and the connection line 17. Light is emitted from the light emitting elements 14, 14,.

  Is provided with a plurality of circuit boards 13, 13,... On which the light emitting elements 14, 14,... Are mounted, respectively, and the circuit boards 13, 13,. Although the example connected by 17, ... was shown, it is also possible to set it as the structure by which the light emitting elements 14, 14, ... are mounted in one flexible printed wiring board, for example.

  The circuit board 13 is disposed on the front surface of the base surface portion 10 of the holding member 8 via the heat conductor 19. The heat conductor 19 is a so-called phase change material that exists as a sheet-like solid in a state below a predetermined temperature and softens in a gel state when the temperature exceeds a predetermined temperature.

  The heat conductor 19 changes in a gel form at, for example, 50 ° C. to 60 ° C., and is, for example, about 0.3 ° C. to 0.7 ° C./W per square centimeter in the changed state in the gel form. It is a material with low contact thermal resistance.

  The heat conductor 19 is disposed between the circuit board 13 and the base surface part 10 with one surface being in contact with the rear surface of the circuit board 13 and the other surface being in contact with the front surface of the base surface part 10 in the holding member 8. Yes. The heat conductor 19 is disposed between the circuit board 13 and the base surface portion 10 when the vehicle lamp 1 is assembled at room temperature. At this time, the heat conductor 19 exists as a sheet-like solid.

  When the driving current is supplied to the light emitting module 9 in the lamp unit 6 and light is emitted from the light emitting elements 14, 14..., The emitted light is reflected by the first reflector 15 and the second reflector 16, respectively. Or reflected from either the first reflector 15 or the second reflector 16 and irradiated to the front or side through the cover 3.

  At this time, heat is generated in the light emitting module 9, the temperature of the light emitting module 9 rises, and heat generated in the light emitting module 9 is transmitted from the circuit board 13 to the holding member 8 through the heat transfer body 19 and released.

  As described above, when the temperature is increased by the heat generated in the light emitting module 9, the heat transfer body 19 is softened from the solid and changes into a gel. Accordingly, the thermal resistance of the heat transfer body 9 to the circuit board 13 and the base surface portion 10 of the holding member 8 is reduced, and the heat transfer efficiency from the circuit board 13 to the holding member 8 is increased.

  As described above, when light is emitted from the light emitting elements 14, 14,..., The heat transfer body 19 changes from a solid to a gel, and the thermal resistance of the heat transfer body 9 to the circuit board 13 and the base surface portion 10 is small. Thus, the heat transfer efficiency from the circuit board 13 to the holding member 8 is increased. Therefore, the amount of heat released from the heat holding member 8 generated in the light emitting module 9 is increased, the temperature rise of the light emitting module 9 is suppressed, and a good operating state of the light emitting module 9 is ensured.

  As described above, in the vehicular lamp 1, the circuit board 13 has the heat conductor 19 that exists as a sheet-like solid in a state below a predetermined temperature and softens in a gel state in a state in which the temperature exceeds a predetermined temperature. And the holding member 8 are in contact with both.

  Therefore, when the vehicle lamp 1 is assembled, the heat conductor 19 is disposed between the circuit board 13 and the holding member 8 in a solid state. Sex can be secured.

  Further, since the heat conductor 19 is a sheet-like solid when the circuit board 13 is attached to the holding member 8, the thickness of the heat conductor 19 is held constant, and the light emitting module 9 is inclined with respect to the holding member 8. The light-emitting module 9 is ensured to have a good light distribution performance and a desired light distribution pattern can be formed.

  In the state where the heat conductor 19 is softened in a gel state, the thickness of the heat conductor 19 may change. However, since the heat conductor 19 is uniformly softened according to the temperature, the thickness of the heat conductor 19 is changed. Inhomogeneity is unlikely to occur. Therefore, even when the heat conductor 19 is softened in a gel state, the light emitting module 9 is hardly inclined with respect to the holding member 8, and the light distribution performance of the light emitting module 9 is ensured and a desired light distribution pattern is obtained. It is formed.

  Furthermore, since the contact thermal resistance of the heat conductor 19 is small, high heat dissipation during driving of the light emitting module 9 can be ensured, and a good operating state of the light emitting module 9 can be ensured.

  In this way, by using the heat conductor 19 as means for transferring heat from the circuit board 13 to the holding member 8 in the vehicle lamp 1, light distribution is ensured while ensuring high heat dissipation performance and good workability during assembly. The performance can be improved.

  Hereinafter, modified examples of the holding member and the light emitting module will be described (see FIGS. 3 to 6).

  Note that the holding member and the light emitting module according to the following modification are different from the above holding member 8 and the light emitting module 9 only in that a recess or a protrusion is formed. Only different parts compared to the light emitting module 9 will be described in detail, and the other parts will be denoted by the same reference numerals as those of the holding member 8 and similar parts in the light emitting module 9, and description thereof will be omitted.

  First, the holding member 8A and the light emitting module 9A according to the first modification will be described (see FIGS. 3 and 4).

  In the holding member 8A, flow preventing recesses 10a, 10a,... Opened forward are formed on the outer peripheral portions of the base surface portions 10A, 10A,. The flow preventing recess 10a is formed in a rectangular frame shape.

  The outer shape of the circuit board 13 of the light emitting module 9A is formed to be approximately the same size as the outer shape of the inner portion of the flow preventing recess 10a in the base surface portion 10A. Positioning projections 10b, 10b,... Are provided on the outer peripheral portion of the base surface portion 10A so as to protrude forward in a circumferential direction at positions along the flow preventing recess 10a.

  The circuit board 13 is inserted inside the positioning projections 10b, 10b,..., And the outer peripheral surface is engaged with the positioning projections 10b, 10b,. Therefore, the circuit board 13 is positioned with respect to the holding member 8A in a state where the outer peripheral edge is aligned with the inner peripheral edge of the flow preventing recess 10a.

  When the light emitting module 9A is driven, the heat conductor 19 softens in a gel shape due to the temperature rise, and the heat conductor 19 may protrude outside the circuit board 13. However, the protruding heat conductor 19 is in the flow preventing recess 10a. Fluidized. Therefore, adhesion of the heat conductor 19 to each part other than the base surface part 10A of the holding member 8A and each part other than the circuit board 13 of the light emitting module 9A can be prevented by the flow preventing recess 10a.

  Further, as described above, by providing the positioning projections 10b, 10b,... On the base surface portion 10A of the holding member 8A, the holding member 8A and the base surface portion 10A of the circuit board 13 do not cause an increase in manufacturing cost. Can be easily and reliably positioned.

  In particular, by providing the positioning protrusions 10b, 10b,... At a position along the flow preventing recess 10a, the circuit board 13 is accurately positioned with respect to the flow preventing recess 10a, and the heat conductor 19 is When protruding outside, the heat conductor 19 can surely flow into the flow preventing recess 10a.

  Furthermore, since the positioning of the circuit board 13 with respect to the holding member 8A can be reliably performed, it is possible to ensure a good light distribution performance of the light emitting module 9A without increasing the manufacturing cost.

  Next, the holding member 8B and the light emitting module 9B according to the second modification will be described (see FIGS. 5 and 6).

  The holding member 8B is provided with flow preventing protrusions 10c, 10c,... Protruding forward on the outer peripheries of the base surface portions 10B, 10B,. The flow preventing projection 10c is formed in a rectangular frame shape.

  Positioning projections 10d, 10d,... Projecting inward are provided on the inner peripheral surface of the flow prevention projection 10c so as to be spaced apart in the circumferential direction. The circuit board 13 is inserted inside the flow preventing projection 10c, and the outer peripheral surface is engaged with the positioning projections 10d, 10d,.

  When the light emitting module 9B is driven, the heat conductor 19 softens in a gel shape due to the temperature rise, and the heat conductor 19 may protrude to the outside of the circuit board 13, but the protruding heat conductor 19 is a protrusion for preventing flow. The outward flow is prevented by 10c. Therefore, adhesion of the heat conductor 19 to each part other than the base surface part 10B of the holding member 8B and each part other than the circuit board 13 of the light emitting module 9B can be prevented by the flow preventing protrusion 10c.

  Further, as described above, by providing the positioning protrusions 10d, 10d,... On the flow preventing protrusion 10c of the holding member 8B, the flow preventing protrusion 10c is positioned with respect to the holding member 8B of the circuit board 13. As a result, the circuit board 13 can be easily and reliably positioned with respect to the holding member 8B without causing an increase in manufacturing cost.

  Furthermore, since the positioning of the circuit board 13 with respect to the holding member 8B can be reliably performed, it is possible to ensure good light distribution performance of the light emitting module 9B without increasing the manufacturing cost.

  In the second modification, an example is shown in which positioning protrusions 10d, 10d,... Are provided on the flow prevention protrusion 10c to position the circuit board 13 with respect to the holding member 8B. It is also possible to position the holding member 8B without providing the positioning projections 10d, 10d,.

  In this case, the outer shape of the circuit board 13 is formed to have the same size as the inner shape of the anti-flow protrusion 10c, and the circuit board 13 is fitted inside the anti-flow protrusion 10c. Positioning with respect to the holding member 8B can be performed.

  The shapes and structures of the respective parts shown in the above-described best mode are merely examples of implementations in carrying out the present invention, and the technical scope of the present invention is limitedly interpreted by these. It should not be done.

FIG. 2 to FIG. 6 show the best mode of the present invention, and this figure is a schematic sectional view of a vehicular lamp. It is a perspective view which isolate | separates and shows a light emitting module, a heat conductor, and a holding member in the state which abbreviate | omitted the reflector. FIG. 4 shows the holding member and the light emitting module according to the first modified example together with FIG. 4, and this figure is an enlarged exploded perspective view showing the reflector omitted. It is an expanded sectional view. FIG. 6 shows a holding member and a light emitting module according to a second modified example together with FIG. 6, and this figure is an enlarged exploded perspective view showing a state where the reflector is omitted. It is an expanded sectional view.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle lamp, 2 ... Lamp housing, 3 ... Cover, 4 ... Lamp outer casing, 8 ... Holding member, 9 ... Light emitting unit, 13 ... Circuit board, 14 ... Light emitting element, 19 ... Heat conductor, 8A ... Holding 9A ... Light emitting unit, 10a ... Flow prevention recess, 13 ... Circuit board, 10b ... Positioning projection, 8B ... Holding member, 9B ... Light emitting unit, 10c ... Flow prevention projection, 10d ... Positioning projection , 13 ... Circuit board

Claims (5)

A lamp outer casing constituted by a cover and a lamp housing;
A light emitting module having a light emitting element disposed inside the lamp outer casing and provided as a light source, and a circuit board on which the light emitting element is mounted;
A holding member that is disposed inside the lamp outer casing and holds the light emitting module, and heat generated in the light emitting module is conducted and the conducted heat is released;
Heat conduction that is disposed between the circuit board and the holding member while being in contact with each other and is present as a sheet-like solid in a state below a predetermined temperature and softens in a gel state in a state exceeding the predetermined temperature A vehicle lamp characterized by comprising a body. The vehicular lamp according to claim 1, wherein a recess for preventing flow is formed around the thermal conductor in the holding member. A plurality of positioning protrusions are provided at positions along the flow preventing recesses in the holding member,
The vehicular lamp according to claim 2, wherein the circuit board is inserted into the plurality of positioning protrusions so that the circuit board is positioned with respect to the holding member. The vehicular lamp according to claim 1, wherein a protrusion for preventing flow is provided around the heat conductor in the holding member. A positioning protrusion is provided on the inner surface of the flow preventing protrusion,
The circuit board is inserted inside the protrusion for preventing flow, the outer peripheral surface of the circuit board is engaged with the protrusion for positioning, and the circuit board is positioned with respect to the holding member. The vehicle lamp according to claim 4.

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