Illumination – Supported by vehicle structure – Housing
Reexamination Certificate
2002-04-03
2004-03-02
Cariaso, Alan (Department: 2875)
Illumination
Supported by vehicle structure
Housing
C362S345000, C362S519000
Reexamination Certificate
active
06698913
ABSTRACT:
BACKGROUNF OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle headlamp, and more particularly, to a structure of the portion of a vehicle headlamp where a light-source bulb is fixed to a reflector.
2. Prior Art
In a vehicle headlamp, a light-source bulb is generally fixed to a reflector by a bulb fixing member as shown in FIG.
7
.
In this vehicle headlamp, a light-source bulb
2
has a flange portion
2
d
formed on the peripheral surface of a bulb supporting portion
2
c
that supports a bulb body
2
b
. A reflector
4
has a bulb insertion hole
4
b
in the reflector body
4
A so that the bulb insertion hole
4
b
receives the bulb body
2
b
of the light-source bulb
2
. The reflector
4
has also an annular wall
4
B in the reflector body
4
A. The annular wall
4
B protrudes rearward from the periphery of the bulb insertion hole
4
b.
The bulb supporting portion
2
c
of the light-source bulb
2
is slid and fitted on the inner peripheral surface of the annular wall
4
B of the reflector
4
so that the flange portion
2
d
abuts on the rear end face of the annular wall
4
B. Then, a bulb fixing member
6
is fitted on the rear end of the annular wall
4
B so that the front and rear sides of the flange portion
2
d
of the bulb
2
are sandwiched and held between the annular wall
4
B and the bulb fixing member
6
. The light-source bulb
2
is thus fixed to the reflector
4
.
However, such a lamp fixture that has the bulb supporting portion
2
c
which is slid and fitted on the inner peripheral surface of the annular wall
4
B of the reflector
4
has problems. The bulb supporting portion
2
c
of the light-source bulb
2
completely closes the bulb insertion hole
4
b
of the reflector
4
. Therefore, the heat, which is radiated together with light from the filament
2
a
of the light-source bulb
2
when the light-source bulb
2
is turned-on, is confined inside the inner space of the reflector
4
.
This causes the temperature rise in the reflector
4
. When the reflector
4
is made of resins, a thermal deformation can easily occur in the reflector
4
.
Generally, a structure in which the bulb supporting portion
2
c
of the light-source bulb
2
is slid and fitted on the inner peripheral surface of the annular wall
4
B of the reflector
4
is often employed when the bulb supporting portion
2
c
of the light-source bulb
2
is molded with resins. In such a case, however, a thermal deformation can easily occur in the bulb supporting portion
2
c
or in the O-ring
8
mounted on the bulb supporting portion
2
c
for use in the sliding and fitting operation.
SUMMARY OF THE INVENTION
Accordingly, the present invention is to solve the above problems with the prior art lamp structure.
It is an object of the present invention to provide a vehicle headlamp capable of preventing a temperature rise in a reflector and thus reducing the thermal deformation of the reflector, etc.
The present invention accomplishes the above object by improving the structure of the annular wall of a reflector.
More specifically, the above object is accomplished by a unique structure of the present invention for a vehicle headlamp that includes:
a light-source bulb,
a reflector for reflecting light from the light-source bulb in a forward direction, and
a bulb fixing member for fixing the light-source bulb to the reflector; wherein
the light-source bulb is comprised of a bulb body, a bulb supporting portion for supporting the bulb body, and a flange portion formed on the peripheral surface of the bulb supporting portion,
the reflector includes a reflector body having a bulb insertion hole for inserting the bulb body therein and an annular wall protruding rearward from the periphery of the bulb insertion hole of the reflector body, and
the light-source bulb is fixed to the reflector by sliding and fitting the bulb supporting portion of the light-source bulb on an inner peripheral surface of the annular wall so that the flange portion abuts on the rear end of the annular wall, and then holding the front and rear sides of the flange portion by the annular wall and the bulb fixing member; and
in the present invention:
the annular wall is provided with at least one notch hole that extends through the annular wall, and such a notch hole is located at a position ahead of where the bulb supporting portion is fitted in the annular wall.
In this headlamp of the present invention, the “bulb fixing member” is not specifically limited in terms of the structure as long as the bulb fixing member serves to fix the light-source bulb to the reflector by holding, together with the annular wall, both front and rear sides of the flange portion of the light-source bulb.
Also, it should be noted that a part of the “bulb supporting portion” of the bulb that is slid and fitted on the inner peripheral surface of the annular wall of the reflector may be the outer peripheral surface of the bulb supporting portion itself. However, that part of the bulb supporting portion may be another member such as an O-ring mounted on the bulb supporting portion.
Furthermore, the “notch hole” is not specifically limited in terms of the structure including shape, size, position and number as long as it extends through the annular wall of the reflector and is formed at a position located ahead (or on the front side) of the position where the bulb supporting portion is fitted in the annular wall.
The present invention is for a vehicle headlamp of the type in which the light-source bulb is fixed to a reflector in such a manner that the bulb supporting portion of the light-source bulb is slid and fitted on the inner peripheral surface of the annular wall of the reflector, thus letting the flange portion abut on the rear end face of the annular wall; and then both front and rear sides of the flange portion are sandwiched by the end surface of the annular wall and the bulb fixing member. However, in this type of lamp fixtures, the bulb supporting portion of the light-source bulb completely closes the bulb insertion hole of the reflector. As a result, the heat radiated from the light-source bulb is confined within the inner space of the reflector.
In the vehicle headlamp of the present embodiment, however, at least one notch hole that extends through the annular wall is formed so as to be located ahead (or on the front side) of the position where the bulb supporting portion of the light-source bulb is fitted in the annular wall. Thus, the notch hole allows the inner space of the reflector to communicate with the outer space of the reflector, so that the heat in the inner space of the reflector is dissipated to the outside of the reflector through the notch hole.
Accordingly, in the headlamp of the present invention, the reflector is prevented from being heated to a high temperature. Even when the reflector is made of a resin material, it is less susceptible to a thermal deformation. Moreover, even when the bulb supporting portion of the light-source bulb is made of resins, the element such as the bulb supporting portion, the O-ring mounted thereto for the sliding and fitting operation are prevented from a thermal deformation.
In the above structure, one notch hole may be formed so as to positioned above the light-source bulb. This allows the heat generated in the inner space of the reflector to be more efficiently dissipated into the outer space through that notch hole.
In the above structure, screwing portions for screwing the bulb fixing member to the annular wall may be formed at a plurality of circumferential positions in the rear end face of the annular wall. When the reflector has such screwing portions, it is preferable that each of the notch holes be provided ahead of each screwing portion; and this structure provides several advantages as described below.
The screwing portions of the annular wall must be formed with a boss-like shape; and this requires the annular wall to have a large thickness. If such thick screwing portions of the annular wall are formed so as extend to the reflector body, then the
Cariaso Alan
Koda & Androlia
Koito Manufacturing Co. Ltd.
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