JPH0739130Y2 - Vehicle lamp with an inner lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicular lamp having an inner lens, and more particularly to a vehicular lamp having an inner lens, which is improved so that the inner surface of the outer lens is not fogged. It is about.

[Conventional technology]

FIG. 3 is a horizontal sectional view showing a conventional example of this type of vehicle lamp.

A socket 2 is attached to the lamp housing 1, and a light source bulb 3 is assembled to the socket 2.

Hot melt grooves 1a, 1a ', 1b are provided around the front opening of the lamp housing 1.

On the outer peripheral portion of the outer lens 4, legs protruding rearward are provided.
4a is integrally molded. The leg 4a is inserted into the hot melt groove 1a and is bonded by the hot melt 6 which is a thermosoftening adhesive.

The inner lens 5 is arranged inside the outer lens 4, and its legs 5a are inserted into the hot melt groove 1b and bonded by the hot melt 6.

[Problems to be solved by the device]

There is a problem of lens fogging in all of the vehicular lamps, and the problem of lens fogging is serious in vehicular lamps equipped with an inner lens.

Fogging of the lens occurs when water vapor in the air becomes minute water droplets and adheres to the lens surface. Therefore, it can be prevented by sealing the vehicular lamp to completely block the invasion of water vapor, but as a practical matter, it is difficult to hermetically prevent the invasion of water vapor in the air.

The reason is that, if the lamp is turned on and the temperature is raised by the heat generated by the light source bulb even if it is completely sealed, the internal pressure rises due to thermal expansion and the weak spot is damaged.

Therefore, there is a breathing effect (thermal expansion and contraction) in the vehicle lighting.
As a result, water vapor invades, forming minute water droplets due to temperature changes and temperature gradients, which causes lens fogging.

Moisture in the lamp changes depending on the temperature gradient in the lamp, evaporates at high temperature and condenses at low temperature.

In the example of the vehicular lamp with an inner lens shown in FIG. 3,
The temperature of the outside of the inner lens 5 (between the outer lens 4) becomes lower than that of the inside of the inner lens 5, and the light source bulb 3
The shaded part away from is low in temperature and, for example, fogging is likely to occur in the vicinity of part C in the figure.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicular lamp with an inner lens that does not cause fogging in the shadow of the outer lens.

[Means for Solving the Problems]

The basic principle of the present invention created to achieve the above-mentioned object is outlined as follows.

That is, a vent is provided in the inner lens to allow the air to flow in the space defined by the inner lens. However, a louver type vent will be used so that this vent does not appear in the exterior.

As a concrete configuration based on the above-mentioned principle, a vehicular lamp including an inner lens according to the present invention has an outer lens attached to a front opening of a lamp housing and an inner lens arranged inside the outer lens. The vehicular lamp is characterized in that a louver-shaped vent hole is provided in a portion of the inner lens that does not receive direct light from the light source bulb.

[Action]

According to the above configuration, since the inner lens is provided with the ventilation hole, the air flow in the internal space defined by the inner lens is enabled and the lens fogging is prevented.

Since the vent hole is provided in a portion of the light source bulb that does not receive the direct light, it does not affect the optical characteristics of the lamp during lighting.

Furthermore, since the above-mentioned vent is configured in a louver shape,
It does not affect the appearance when it is not lit.

〔Example〕

FIG. 1 is a horizontal sectional view of a vehicular lamp including an inner lens according to an embodiment of the present invention.

In this embodiment, the present invention is applied to the conventional example (FIG. 3), and those having the same drawing reference numbers in FIG. 3 are the same or similar constituent members as in the conventional example. .

The inner lens 7 of this example is a louver-shaped vent hole 7a, 7b, 7c.
have.

The angle θ shown in the figure indicates the range in which the light flux emitted from the filament of the light source bulb 3 can enter the outer lens 4.

The vent holes 7a, 7b, 7c are provided outside the angle range θ, that is, in the shaded portions.

FIG. 2 (A) is a perspective view of the above-mentioned vent hole viewed in the direction of arrow II.
Shown in.

For convenience of reading, the inner lens 7 is provided with spots and the end face of the louver-shaped portion is hatched, as shown in FIG. 2 (B).

In FIGS. 2A and 2B, a part of the outer lens 4 is cut away, but the hatching on the inner lens 7 does not mean a cross section.

Since the vent holes 7a, 7b, 7c are provided outside the angle θ as shown in FIG. 1, they do not affect the optical characteristics of the lamp during lighting.

Further, since the louver-like configuration is adopted, there is no fear of affecting the appearance as seen from the direction of arrow D when the lamp is not lit.

[Effect of device]

As described above, when the present invention is applied to a vehicular lamp equipped with an inner lens, it is possible to prevent fogging of the lens without fear of affecting its optical characteristics or impairing its appearance.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view showing an embodiment of a vehicular lamp equipped with an inner lens according to the present invention. FIG. 2 (A) is a partially cutaway perspective view of the above embodiment as viewed in the direction of arrow II. FIG. 2 (B) is an explanatory diagram in which the inner lens of FIG. 2 (A) is provided with spots and the end surface of the louver portion is hatched. FIG. 3 is a horizontal sectional view showing a conventional example of a vehicular lamp equipped with an inner lens. 1 ... Lamp housing, 1a, 1a ', 1b ... Hot melt groove,
2 ... Socket, 3 ... Light source bulb, 4 ... Outer lens, 4a
... legs, 5 ... inner lens, 5a ... legs, 6 ... hot melt,
7 ... Inner lens, 7a, 7b, 7c ... Louver type vent.

Claims (1)

[Scope of utility model registration request] 1. A vehicular lamp in which an outer lens is mounted to cover a front opening of a lamp housing and an inner lens is arranged inside the outer lens, wherein direct light of a light source bulb is not received in the inner lens. It is characterized in that a louver-shaped vent is provided in a part,
A vehicle lamp equipped with an inner lens.