Vehicle lamp assembled with moisture-curing type adhesive

A vehicle lamp including a lens component made of a resin, an insertion portion disposed on the lens component, and a lamp body made of a resin and defining a groove for receiving the insertion portion, and the lens component is fixed to the lamp body by a moisture curing type adhesive injected into a gap in the groove. The gap has a constant thickness ranging from 0.1 mm to 1.0 mm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Japanese Patent Application No. 2014-135952, filed on Jul. 1, 2014, with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a vehicle lamp including a lens component attached to cover an opening of a lamp body.

BACKGROUND

In the related art, there is known a vehicle lamp that includes a light source within a lamp chamber defined by a lamp body having an opening and a lens component attached to cover the opening (see, e.g., Japanese Patent Laid-Open Publication No. 2010-267578). In the vehicle lamp, a hot melt seal material is introduced into a groove formed in the opening of the lamp body so that the lens component is fixed to the lamp body and the lamp chamber is sealed.

SUMMARY

The hot melt seal material is thermoplastic. Thus, the seal material may be fused, causing damage to the seal performance thereof when the temperature within the lamp chamber reaches a high temperature of 100° C. or more at the time of lighting. Therefore, attempts have recently been made to fix the lens component to the lamp body via a moisture curing type adhesive instead of the hot melt seal material. However, in the vehicle lamp as described above, there is room for improvement in productivity because a long time is required to cure the moisture curing type adhesive.

Accordingly, an object of the present disclosure is to provide a vehicle lamp in which the curing time of a moisture curing type adhesive is short.

A vehicle lamp according to the present disclosure is a vehicle lamp in which an insertion portion formed at a lens component made of a resin is inserted into a groove formed in a lamp body made of a resin and the lens component is fixed to the lamp body by a moisture curing type adhesive introduced into the groove. An inner surface of the groove in the cross section of the groove faces and is spaced apart from the insertion portion by a constant spacing in a range of 0.1 mm to 1.0 mm. The moisture curing type adhesive is introduced into the spacing.

With the vehicle lamp having the above-described configuration, since the spacing between the inner surface of the groove and the insertion portion is sufficiently narrow, the moisture curing type adhesive filled in the gap may be sufficiently cured by moisture contained in the resin of the lamp body or the lens component, which may result in reduced curing time. In a conventional structure, the curing by the moisture in the air absorbed from a surface exposed to the air was predominant. Thus, the curing time of the moisture curing type adhesive is reduced by adjusting the spacing between the inner surface of the groove and the insertion portion such that the curing by the moisture absorbed from the inner surface in contact with the resin becomes predominant.

In the vehicle lamp of the present disclosure, the inner surface of the groove may include a pair of side surfaces facing each other, and the insertion portion may include a leg portion extending in the depth direction of the groove and a protrusion protruding from the leg portion to one of the side surfaces of the groove. With the vehicle lamp having the above-described configuration, since the insertion portion may be placed in a stabilized posture in the groove by the leg portion and the protrusion, the positions of the lamp body and the lens component is hardly displaced during the curing of the moisture curing type adhesive.

In the vehicle lamp of the present disclosure, the protrusion may protrude along a bottom surface of the groove. With the vehicle lamp having the above-described configuration, the moisture curing type adhesive may be filled between the leg portion and one of the side surfaces and between the protrusion and the bottom surface such that the lamp body and the lens component may be bonded to each other on two intersecting surfaces. Thus, the lens component may be firmly fixed to the lamp body.

In the vehicle lamp of the present disclosure, the protrusion may be provided, at the tip end thereof, with an abutment portion extending along one of the side surface of the groove. With the vehicle lamp having the above-described configuration, the insertion portion may be placed in a stabilized posture in the groove by three portions including the leg portion, the protrusion, and the abutment portion. In addition, the lamp body and the lens component may be bonded to each other between the leg portion and the inner surface, between the protrusion and the inner surface, and between the abutment portion and the inner surface. Thus, high adhesion strength may be achieved.

In the vehicle lamp of the present disclosure, the protrusion may be a plate-shaped portion extending along a plane perpendicular to the depth direction of the groove. With the vehicle lamp having the above-described configuration, the protrusion may prevent the lens component from moving in relation to the lamp body in the in-plane direction perpendicular to the depth direction of the groove.

In the vehicle lamp of the present disclosure, the protrusion may be a plate-shaped portion extending along a plane perpendicular to the length direction of the groove. With the vehicle lamp having the above-described configuration, the protrusion may prevent the lens component from moving in relation to the lamp body in the in-plane direction perpendicular to the length direction of the groove.

In the vehicle lamp of the present disclosure, the insertion portion may include a leg portion extending in the depth direction of the groove, and the leg portion may be provided, above an opening of the groove, with a cover portion to cover at least a portion of the opening. With the vehicle lamp having the above-described configuration, the entry of impurities may be suppressed during the curing of the moisture curing type adhesive. In addition, the opening may be concealed.

According to the present disclosure, it is possible to provide a vehicle lamp in which the curing time of a moisture curing type adhesive is short.

DETAILED DESCRIPTION

Hereinafter, an exemplary embodiment of a vehicle lamp according to the present disclosure will be described by way of example with reference to the accompanying drawings.FIG. 1is a vertical sectional view illustrating a vehicle lamp10according to an exemplary embodiment of the present disclosure.

As illustrated inFIG. 1, the vehicle lamp10according to the present exemplary embodiment is, for example, a headlamp that is provided on a front portion of a vehicle to illuminate the front side of the vehicle. The vehicle headlamp10includes a lamp body11having an open front side and a lens component12attached to cover the opening of the lamp body11.

A hermetically sealed lamp chamber S is defined inside the vehicle lamp10as the lens component12is bonded to the lamp body11. A light source13and a reflector14are arranged within the lamp chamber S. The light source13is placed in the lamp chamber S and the reflector14is placed behind the light source13. The lamp body11and the lens component12are fixed to each other at the outer circumferential edges of respective openings thereof.

In addition, in the present exemplary embodiment, the term “forward” refers to a direction from the light source13to the lens component12in the vehicle lamp10(the leftward direction inFIG. 1), and the term “rearward” refers to a direction opposite to forward (the rightward direction inFIG. 1).

The lamp body11is integrally formed of, for example, a synthetic resin. For example, the synthetic resin may be polycarbonate resin (PC resin), polycarbonate ABS resin (PC-ABS resin), or acryl resin (PMMA). The lens component12is formed of, for example, a transparent or semitransparent synthetic resin. For example, the synthetic resin may be polycarbonate resin (PC resin), polycarbonate ABS resin (PC-ABS resin), or acryl resin (PMMA).

The lens component12is an outer cover that allows light to pass therethrough. In addition, a lens step may be provided on the surface of the lens component12covering the opening of the lamp body11so as to condense or diffuse light from the light source13.

The light source13is placed in the lamp chamber S defined by the lamp body11and the lens component12. The light source13is electrically connected to a socket21fixed to the lamp body11and emits light upon receiving power supplied from a power source (not illustrated) through the socket21.

The reflector14has a concave surface recessed in an approximately parabolic form toward the front side, and a through-hole22is formed in the center of the concave surface to enable passage of the light source13. The reflector14is placed behind the light source13in the lamp chamber S and reflects light from the light source13forward (toward the lens component12).

The lamp body11is formed with a groove31throughout the outer circumferential edge thereof. In addition, the lens component12includes a rearwardly protruding insertion portion41formed in the outer circumferential edge thereof. The insertion portion41is inserted into the groove31and fixed thereto by adhesive.

FIG. 2is a sectional perspective view illustrating a structure of a fixing position of the lamp body11and the lens component12in the vehicle lamp10according to the exemplary embodiment of the present disclosure.

As illustrated inFIG. 2, an opening35of a main body portion32of the lamp body11is provided with a laterally protruding bottom wall33and a side wall34upright from the front end of the bottom wall33. In addition, inFIG. 2, the inner circumferential side (toward the lamp chamber S) of the lamp body11is the left side and the outer circumferential side of the lamp body11is the right side.

The forwardly opened groove31is formed along the outer circumferential edge of the opening of the main body portion32. The groove31is constituted with a side surface32aof the main body portion32facing the outer circumference, an upper surface33aof the bottom wall33, and a side surface34aof the side wall34facing the inner circumference. The groove31includes the side surfaces32aand34awhich have the same shape and are arranged to face each other, and the side surfaces32aand34aare configured as surfaces having the same shape in the depth direction of the groove31. The pair of side surfaces32aand34aface and are spaced apart from each other by a constant spacing W in a range of 1 mm to 5 mm. In the following description, the side surfaces32aand34aand the upper surface33amay be collectively called an inner surface31aof the groove31.

The insertion portion41has a leg portion42extending in the depth direction of the groove31. A plate-shaped protrusion43is formed at the tip end of the leg portion42of the insertion portion41and extends along a plane perpendicular to the depth direction of the groove31. The protrusion43is integrally formed to protrude from the leg portion42toward the side surface34a. The protrusion43protrudes along the upper surface33a.

A laterally protruding cover portion44is formed on the leg portion42of the insertion portion41above the protrusion43. The cover portion44protrudes above the opening35of the groove31in a state where the insertion portion41is inserted in the groove31. The cover portion44covers at least a portion of the opening35of the groove31.

The groove31is filled with a moisture curing type adhesive51. The insertion portion41is inserted into the groove31filled with the moisture curing type adhesive51and adhesively fixed to the groove31by the moisture curing type adhesive51. The moisture curing type adhesive51is an adhesive that is cured via reaction with a small amount of surrounding moisture and may acquire higher adhesion strength as an application thickness thereof decreases. When the groove31of the lamp body11and the insertion portion41of the lens component12are fixed to each other via the moisture curing type adhesive51, sealing efficiency between the outside and the inside of the lamp chamber S is acquired.

In this way, at a fixing position of the lamp body11and the lens component12which are fixed to each other via the moisture curing type adhesive51, when viewed in the cross section of the groove31(the cross section illustrated inFIG. 2), at least a portion of the inner surface31aof the groove31faces and is spaced apart from the insertion portion41by a constant spacing t in a range of 0.1 mm to 1.0 mm in which the moisture curing type adhesive51is filled. In the present exemplary embodiment, a gap t between the side surface32aof the main body portion32and the leg portion42of the insertion portion41has a constant spacing in a range of 0.1 mm to 1.0 mm along the outer circumferential edge of the opening of the lamp body11. The moisture curing type adhesive51is filled in the gap.

In the related art, the groove31was formed with the relatively large opening35because a hot melt seal material that has widely been used at the fixing position of the lamp body11and the lens component12has relatively high viscosity. As such, the seal material has been efficiently injected into the groove31through an application nozzle (not illustrated).

Here, a reference example of a fixing structure of the lamp body11and the lens component112will be described.FIG. 3is a sectional perspective view illustrating a structure of a fixing position of the lamp body11and a lens component112in the vehicle lamp10according to the reference example.

As illustrated inFIG. 3, in the reference example, a structure of a conventional vehicle lamp is directly employed and, instead of the hot melt based seal material, the moisture curing type adhesive51is introduced to the gap.

Even in the reference example, the pair of side surfaces32aand34aconstituting a portion of the inner surface31aof the groove31face and are spaced apart from each other by a constant spacing W in a range of 1 mm to 5 mm. Meanwhile, in the reference example, no protrusion143is formed at a leg portion142of an insertion portion141of the lens component112and the leg portion142of the insertion portion141inserted in the groove31is located at the center of the width direction of the groove31. In addition, the moisture curing type adhesive51is filled in a gap between the inner surface31aof the groove31and the periphery of the leg portion142. In this reference example, a gap t1between the side surface32aand the leg portion142and a gap between the side surface34aand the leg portion142is in a range of 2 mm to 3 mm.

Like the reference example, when the structure of the conventional vehicle lamp is directly employed and, instead of the hot melt seal material, the moisture curing type adhesive51is introduced to the gap, the long time is required until the moisture curing type adhesive51is cured. This is because, although the moisture curing type adhesive51filled in the gap is designed to be cured by absorbing moisture of air from a surface exposed to the air, moisture has difficulty in reaching the moisture curing type adhesive51deeply located in the groove31distant from the surface, thus causing a long time to be taken for curing.

Accordingly, the inventors have completed the present disclosure based on the fact that the moisture curing type adhesive51is cured by the moisture contained in the resin of the lamp body11as well.

With the vehicle lamp10according to the present disclosure, a spacing between the inner surface31aof the groove31and the insertion portion41is sufficiently narrow. Thus, the moisture curing type adhesive51filled in the gap may be sufficiently cured by moisture contained in a resin of the lamp body11or the lens component12, which may reduce the curing time. In the conventional structure, curing by moisture in the air absorbed from a surface exposed to the air was predominant. Thus, the curing time of the moisture curing type adhesive51is reduced by adjusting the spacing t between the inner surface31aof the groove31and the insertion portion41such that curing by the moisture absorbed from the inner surface in contact with the resin becomes predominant.

Since the gap between the inner surface31aof the groove31and the insertion portion41is originally narrow, the moisture curing type adhesive51has a small volume, a short curing time, and high adhesion strength. Further, the manufacturing costs may be reduced.

The insertion portion41has the leg portion42extending in the depth direction of the groove31and the protrusion43protruding toward the side surface34aof the groove31from the leg portion42. Thus, the insertion portion41may be placed in a stabilized posture in the groove31by the leg portion42and the protrusion43. Therefore, the positions of the lamp body11and the lens component12are hardly displaced during the curing of the moisture curing type adhesive51.

The protrusion43protrudes along the upper surface33aof the bottom wall33in the groove31. As such, since the moisture curing type adhesive51may be filled between the leg portion42and the side surface32aand between the protrusion43and the upper surface33aso as to bond the lamp body11and the lens component12to each other at two intersecting surfaces, the lens component12may be firmly fixed to the lamp body11.

Since the protrusion43is a plate-shaped portion extending along a plane perpendicular to the depth direction of the groove31, the protrusion43may prevent the lens component12from moving in relation to the lamp body11in the in-plane direction perpendicular to the depth direction of the groove31.

The cover portion44is installed to the leg portion42above the opening35of the groove31to cover a portion of the opening35. Thus, entry of impurities may be suppressed during the curing of the moisture curing type adhesive51. In addition, the opening35may be concealed.

The inner surface of the groove31includes one pair of side surfaces32aand34awhich face and are spaced apart from each other by a constant spacing W in a range of 1 mm to 5 mm. Thus, the moisture curing type adhesive51may be easily introduced into the groove31. In addition, the lamp body11, which is used in a vehicle lamp using the existing hot melt seal material, may be used.

Next, modifications of the present disclosure will be described,

FIG. 4is a sectional perspective view illustrating a structure of a fixing position of the lamp body11and a lens component212according to Modification 1.

As illustrated inFIG. 4, at a fixing position of the lamp body11and the lens component212which are fixed to each other via the moisture curing type adhesive51, when viewed in the cross section of the groove31(the cross section illustrated inFIG. 4), at least a portion of the inner surface31aof the groove31faces and is spaced apart from an insertion portion241by a constant spacing t in a range of 0.1 mm to 1.0 mm in which the moisture curing type adhesive51is filled. In the present modification, a gap between the side surface32aof the main body portion32and a leg portion242of the insertion portion241has a constant spacing t in a range of 0.1 mm to 1.0 mm along the outer circumferential edge of the opening of the lamp body11. The moisture curing type adhesive51is interposed in the gap. In addition, the inner surface of the groove31has the pair of side surfaces32aand34awhich face and are spaced apart from each other by a constant spacing W in a range of 1 mm to 5 mm.

As illustrated inFIG. 4, in Modification 1, an abutment portion245is provided at the tip end of a protrusion243formed at the insertion portion241. The abutment portion245extends from the tip end of the protrusion243toward the opening35of the groove31along the side surface34a. In addition, a laterally curved locking portion246is formed at the end of the abutment portion245.

In Modification 1, when the insertion portion241provided with the abutment portion245is inserted into the groove31, the insertion portion241may be placed in a stabilized posture in the groove31by three portions including the leg portion242, the protrusion243and the abutment portion245. In addition, the lamp body11and the lens component212may be bonded to each other between the leg portion242and the inner surface31a, between the protrusion243and the inner surface31a, and between the abutment portion245and the inner surface31a, thereby achieving high adhesion strength.

In addition, when the locking portion246at the end of the abutment portion245comes into contact with the end surface of the side wall34, the insertion portion241may be more surely placed in a stabilized posture in the groove31, and positioning of the insertion portion241in the insertion direction with respect to the groove31may be performed.

FIG. 5is a sectional perspective view illustrating a structure of a fixing position of the lamp body11and a lens component312according to Modification 2.

As illustrated inFIG. 5, at a fixing position of the lamp body11and the lens component312which are fixed to each other via the moisture curing type adhesive51, when viewed in the cross section of the groove31(the cross section illustrated inFIG. 5), at least a portion of the inner surface31aof the groove31faces and is spaced apart from an insertion portion341by a constant spacing t in a range of 0.1 mm to 1.0 mm in which the moisture curing type adhesive51is filled. In the present modification, a gap between the side surface32aof the main body portion32and a leg portion342of the insertion portion341has a constant spacing t in a range of 0.1 mm to 1.0 mm along the outer circumferential edge of the opening of the lamp body11. The moisture curing type adhesive51is interposed in the gap. In addition, the inner surface of the groove31has one pair of side surfaces32aand34awhich face and are spaced apart from each other by a constant spacing W in a range of 1 mm to 5 mm.

As illustrated inFIG. 5, in Modification 2, the leg portion342is formed with a protrusion347. The protrusion347is configured as a plate-shaped portion extending along a plane perpendicular to the length direction of the groove31. In addition, in Modification 2, the leg portion342is formed with a slope342anear the opening35of the groove31. The slope342ais inclined toward the bottom of the groove31, i.e. toward the inner circumference of the lamp body11. In Modification 2, a cover portion344formed on the leg portion342comes into contact with the end of the side wall34and the opening35of the groove31is blocked by the cover portion344.

In Modification 2, since the protrusion347extends along the plane perpendicular to the length direction of the groove31, the protrusion347may prevent the lens component312from moving in relation to the lamp body11in the in-plane direction perpendicular to the length direction of the groove31.

The present disclosure may be applied to any lamp tool, for example, a tail lamp or a fog lamp, without being limited to the headlamp so long as it is a vehicle lamp including a lamp body and a lens component.