JPH0731447Y2 - Car headlamp - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a headlamp using a discharge bulb as a light source, and in particular, by moving a shade for forming a sub-beam, a discharge part, which is a light emitting source, is changed to a reflector. The present invention relates to an automobile headlamp capable of forming both a main beam and a sub beam by cutting off a part of light that is directed.

[Problems to be Solved by Prior Art and Invention]

As a conventional automobile headlamp, a bulb-type bulb is generally used. For example, an H ₄ bulb in which two filaments are arranged in parallel in the optical axis direction in a glass sphere, A main beam and a sub-beam are formed by switching the power supply to each filament.

However, since the filament, which is a light emitting source, and the filament supporting portion are heated to a high temperature, the filament may be broken due to long-term use, and there is a problem in durability. In addition, conventional bulbs use electric energy to heat a filament to emit light and utilize the light emitted by this filament. Most of the electric energy is radiated as heat energy, and only part of the heat energy is converted to light energy. Therefore, there is a problem that the energy efficiency is very poor and the power consumption is accordingly increased.

In view of the above-mentioned problems of the prior art, the discharge bulb of the type that emits light by the discharge between the electrodes has no problem of disconnection like the type that emits the filament described above, and the power consumption is higher than that of the filament type. In view of its small size and large light quantity, a discharge bulb has recently been attracting attention as a headlamp bulb. However, there is a problem in that two light emitting parts of the discharge bulb cannot be provided like the filament of the H ₄ type bulb, and one discharge bulb cannot form two different light distributions of the main beam and the sub beam.

Therefore, Japanese Patent Application No. 1-127877 has been proposed as a prior art for solving these problems. The headlamp in this prior art has a discharge bulb as a light source, a reflector having an effective reflection surface consisting of an upper region and a lower region with the position of the discharge bulb as a boundary, and moves forward and backward in the optical axis direction near the discharge part of the discharge bulb. With a structure including a possible shade member, the shade member is moved backward in the optical axis direction to block the light from the discharge part of the discharge bulb toward the lower region of the effective reflection surface to form a sub-beam, and conversely, the shade member. Is moved forward in the optical axis direction to form a main beam without blocking the light traveling from the discharge part of the discharge bulb to the effective reflection surface. That is, one discharge bulb enables two different light distributions of the main beam and the sub beam.

However, the effective reflection surface of the reflector is divided into the upper region and the lower region, and the means for controlling the light traveling from one discharge bulb to each region is too high in illuminance of the discharge bulb as compared with the conventional filament bulb. Therefore, new problems have been raised, such as the occurrence of a region where the illuminance is too high in the light distribution pattern of the main beam, and the shape of the shade member being complicated in order to obtain a light distribution pattern with an appropriate illuminance.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a vehicle headlamp using a discharge bulb as a light emitting source. Another object of the present invention is to provide an automobile headlamp that enables two light distributions of a sub beam and a light distribution pattern of appropriate illuminance without complicating the shape of the shade member.

[Means for Solving the Problems]

In order to achieve the above object, in the automobile headlamp according to claim (1), around a bulb insertion hole for illuminating a substantially upper half region of a light distribution pattern of a main beam, which is formed in a lamp body. A reflector having an effective reflection surface in the shape of a paraboloid, which has an inner region and an outer region around the inner region that illuminates a substantially lower half region of the light distribution pattern, and is inserted into the valve insertion hole. A discharge bulb that has a discharge part, which is a light emitting source, in the vicinity of a focal position of an effective reflection surface of the reflector; and a cylindrical shade member that surrounds the discharge bulb and is movable back and forth in the optical axis direction. When the shade member moves backward, the light traveling from the discharge part of the discharge bulb toward the inner area of the effective reflection surface is blocked by the shade member, and the sub-beam is reflected by the light reflected from the outer area. When the shade member moves forward, the light traveling from the discharge part of the discharge bulb to the effective reflection surface is not blocked by the shade member, and the main beam is formed by the reflected light in the inner region and the outer region. Configured to be.

Further, in the vehicle headlamp according to claim (2), in the claim (1), when the shade member moves forward, the discharge portion of the discharge bulb is moved to a peripheral portion of the effective reflection surface outer region. The main beam is dimmed by blocking the incoming light by the shade member.

[Action]

The discharge bulb is a structure that emits light by the discharge between the electrodes,
There is no risk of disconnection. Further, since the electrons are directly converted into light energy, the efficiency of energy conversion from electric energy to light energy is high, and therefore power consumption is low.

When the tubular shade member is moved backward, the shade member is positioned between the discharge part and the reflector inner area of the effective reflection surface, and the shade member blocks the light traveling from the discharge part of the discharge bulb to the inner area of the effective reflection surface. The light remaining without being reflected is reflected by the outer area of the effective reflection surface to form a sub-beam.
On the other hand, when the shade member is moved forward, the shade member is not located between the discharge part and the effective reflection surface, the shade member does not block the light traveling from the discharge part of the discharge bulb to the effective reflection surface, and effectively reflects this light. The inner and outer regions of the surface are reflected and form the main beam.

In claim (2), when the shade member is moved forward,
The rear end of the shade member blocks light traveling from the discharge part of the discharge bulb to the peripheral edge of the outer area of the effective reflection surface, and the light distribution equivalent to the reflected light (interrupted light) at the peripheral edge of the outer area is reduced. Form the main beam.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

1, 2, and 3 show a vehicle headlamp according to an embodiment of the present invention, and FIG. 1 is a perspective view of the headlamp with a lens removed. Further, FIG. 2 shows a sub-beam forming state of the same lamp, and FIG. 3 shows a main beam forming state thereof.
[FIG. 3] is a front view of a reflector for explaining a light reflection state on an effective reflection surface.

In these drawings, reference numeral 10 is a container-shaped lamp body that opens forward, and reference numeral 11 is a lens provided on the front surface of the lamp body 10. The lamp body 10 is fixed to a vehicle body (not shown), and an aluminum vapor-deposited reflector 12 is integrally formed on the inner peripheral surface thereof. A bulb insertion hole 14 is formed in the rear top portion of the lamp body 10, and a discharge bulb 20 that emits light due to discharge between the electrodes is inserted therein. Reference numeral 21 is a discharge part of the discharge bulb 20.
The emitted light of 21 is reflected by the effective reflection surface area 15 of the reflector 12 having a parabolic shape, becomes substantially parallel light and enters the lens 11, and a diffusion step (not shown) formed on the back surface of the lens 11. Diffused light distribution in a predetermined direction by
A headlamp beam is formed. Note that reference numeral 1 is an irradiation axis (optical axis) of the headlamp.

The effective reflection surface area 15 includes boundaries L ₁ and L ₂ that extend in an arc shape around the valve insertion hole 14 and a boundary L that extends horizontally from the valve insertion hole 14.
₃ , the outer area upper side 1 by the boundary L ₄ extending diagonally downward
5A, the lower side 15D, and the inner area upper side 15C, the lower side 15B are divided into four areas. 2 (a) and 3 (a), the reflector 12 is provided near the bulb discharge part 21.
Points A, B, C, and D arranged in order from a position near to indicate the focal positions of the reflector outer region upper side 15A, the inner region lower side 15B, the inner region upper side 15C, and the outer region lower side 15D, respectively.
Therefore, the outer region upper side 15A is recessed from the inner region upper side 15C with the boundary L ₁ as a boundary, and is recessed from the outer region lower side 15D with the boundaries L ₃ and L ₄ as a boundary. Also, the inner area lower side 1
5B is recessed with the boundary L ₂ as a boundary with respect to the outer region lower side 15D,
The inner region upper side 15C is recessed with the boundaries L ₃ and L ₄ as boundaries. Then, the outer region 15A, 15D irradiates the lower half of the horizontal axis of the screen arranged at the lamp front predetermined position,
The inner regions 15B and 15C are set to irradiate approximately the upper half of the horizontal axis, and the sub-beam (beam for passing) is radiated in approximately the lower half, and the main beam (running is radiated by combining the approximately lower half and the approximately upper half). Beam) is formed.

Reference numeral 30 is a thin cylindrical shade member, and reference numerals 30a, 30b
Shows the front end and the rear end of the shade member 30. A leg portion 31 is fixed to a lower portion of the shade member 30, a long hole 13 extending in the front-rear direction is formed on the lower surface of the lamp body 10, and the leg portion 31 extends through the long hole 13 to the outside of the lamp body 10. It is supported by a moving unit (not shown) fixed to the vehicle body or the lamp body 10. Inside the moving unit, a moving mechanism using a solenoid valve or a motor electrically controlled by a switch (not shown) as a driving means is provided, and the leg 31 can be moved back and forth in the optical axis 1 direction. That is, the shade member 30 integrated with the leg portion 31 moves back and forth in the direction of the optical axis l, and the front position (the shade member rear end portion 30b covers the front portion of the discharge bulb 20) shown in FIG. 3 (a). Position) and a rear position (shade member front end portion 30a) shown in FIG. 2 (b).
Can cover the rear part of the discharge bulb 20).

Then, as shown in FIG. 2 (a), the shade member
When 30 is positioned rearward, the shade member front end portion 30a comes to a position where it covers the rear portion of the discharge bulb 20, and the light traveling from the bulb discharge portion 21 toward the effective reflection surface inside regions 15B, 15C is blocked. Therefore, the light emitted from the bulb discharge part 21 is reflected only in the effective reflection surface outer regions 15A and 15D to form the sub-beam s. FIG. 2 (b) shows the function of the effective reflection surface of the reflector in the state shown in FIG. 2 (a). The cross hatched portion is a portion where light does not reach, the one diagonal portion is a portion where light reaches, The white parts indicate the parts where light can reach.

Further, as shown in FIG. 3 (a), the shade member 30
Is positioned forward, the shade member rear end portion 30b is located at a position covering the front end portion of the discharge bulb 20, and only the light traveling from the bulb discharge portion 21 to the peripheral portions (reference numeral 15a) of the effective reflection surface outer regions 15A and 15D. Blocked. Therefore, the light emission of the bulb discharge part 21 is effective reflection surface inside area 15B, 15C and outside area 15A, 15D.
The main beam m is formed by being reflected by the portion except the peripheral portion 15a. That is, by reducing the light distribution equivalent to the reflected light at the peripheral edge portion 15a, the main beam has a light distribution pattern with an appropriate illuminance that is not too high. FIG. 3 (b) shows the function of the effective reflecting surface of the reflector in the state shown in FIG. 3 (a). The cross hatched portion is a portion where light does not reach, the one diagonal portion is a portion where light reaches, The white parts indicate the parts where light can reach.

The area of the shade member 30 and the leg portion 31 viewed from the direction of the optical axis l is made as small as possible so as not to block the effective reflected light from the reflector 12 that contributes to the light distribution.

[Effect of device]

As is clear from the above description, according to the vehicle headlamp according to the present invention, since the discharge bulb used as the light source has no risk of disconnection, a vehicle headlamp which does not require bulb replacement for a long period of time can be obtained. . Moreover, since the discharge bulb has a high conversion efficiency from electric energy to light energy, it consumes less power.

By moving the shade member back and forth in the optical axis direction and changing its position, it is possible to obtain light distribution for both the sub-beam and the main beam. Light is realized.

When the main beam is formed, the shade member blocks the light traveling from the discharge part of the discharge bulb to the peripheral part of the outer area of the effective reflection surface, so that the light distribution equivalent to the reflected light at the peripheral part can be reduced. Is the proper illuminance.

Moreover, since the shade member is not a complicated shape but a simple tubular shape, the molding process is easy.

[Brief description of drawings]

1 is a perspective view of a headlamp according to an embodiment of the present invention with a lens removed, FIG. 2 (a) is a horizontal sectional view showing a sub beam forming state of the headlamp, and FIG. 2 (b). Is a front view of the reflector for explaining the reflection of light on the effective reflection surface, FIG. 3 (a) is a horizontal sectional view showing the main beam forming state of the same headlamp, and FIG. 3 (b) is an effective reflection surface. FIG. 3 is a front view of a reflector for explaining the reflection state of the light of FIG. 10 …… Lamp body, 12 …… Reflector, 15 …… Reflector effective reflection surface, 15A …… Effective reflection surface outer area upper side, 15B …… Effective reflection surface inner area lower side, 15C …… Effective reflection surface inner area upper side , 15D ...... 15a on the lower side of the area outside the effective reflection surface
...... Effective reflection surface outer peripheral area, 20 ...... Discharge bulb, 21
...... Discharge part which is a light source, 30 …… Shade member, s ……
Sub beam, m ... Main beam, l ... Headlamp irradiation axis (optical axis).

Claims (2)

[Scope of utility model registration request] 1. An inner region around a bulb insertion hole, which is formed in a lamp body and illuminates a substantially upper half region of a main beam light distribution pattern, and a substantially lower half region of the same light distribution pattern. A reflector having a parabolic effective reflection surface consisting of the outer area around the inner area, and a discharge part, which is inserted into the bulb insertion hole and is a light emitting source, near the focal position of the effective reflection surface of the reflector. A headlamp for an automobile, comprising: a discharge bulb, and a tubular shade member that surrounds the discharge bulb and is movable back and forth in the optical axis direction, wherein when the shade member moves backward, Light traveling from the discharge part of the discharge bulb toward the inner area of the effective reflection surface is blocked by the shade member, and a sub-beam is formed by the reflected light of the outer area, and when the shade member moves forward. The discharge light toward the effective reflecting surface from the discharge portion of the valve is not blocked by the shade member, vehicle headlight, characterized in that the main beam is formed by the reflected light of the inner and outer regions. 2. When the shade member moves forward, the light traveling from the discharge portion of the discharge bulb toward the peripheral portion of the outer region of the effective reflection surface is blocked by the shade member, and the main beam is dimmed. The automobile headlamp according to claim 1, wherein the headlamp is an automobile headlamp.