JPH0512884Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a projector type headlamp.

[Conventional technology]

Automobile headlights must have a light distribution pattern that brightly illuminates the area in front of the vehicle's own lane and does not dazzle oncoming vehicles.

As a headlamp having light distribution characteristics that meet the above requirements, a simple lens structure, and a small overall size, a projector-type automobile headlamp has been proposed. A technology relating to this projector-type headlamp is known, for example, from Japanese Patent Application Laid-Open No. 58-209801.

FIG. 6 shows the above-mentioned known projector type headlamp. The headlight of this known example is provided with a shell-type reflector, and the axial cross section of the inner reflective surface of this reflector each forms a part of an ellipse, and the eccentricity of the ellipse is perpendicular to the axial direction. In a vehicle headlamp increasing from the longitudinal section to the axially horizontal longitudinal section, the elliptical portion 10 of every axial section
The focal points 105 of 1,102 and the corresponding vertices 104 of the elliptical portions 101, 102 of all axial sections coincide.

110 is the outer focus of the ellipse 102, 110 is a light shielding plate-like dimmer, 112 is the outer focus of the ellipse 101,
113 is a lens.

FIG. 7 is a plan view schematically depicting an example of this type of projector type headlamp, FIG. 8 is a side view, and FIG. 9 is a front view.

1 is a concave mirror, and F is its focal point. The light source bulb 2 is provided so that the filament is located near the focal point F mentioned above.

A convex lens 3 is provided to share the optical axis Z with the concave mirror 1 described above.

I-j drawn in FIG. 4 indicate the meridional image plane of the convex lens 3, which emits light from the light source and passes through the concave mirror 1.
The light reflected by the lens enters this meridional image plane.

The above incident light is modulated by the convex lens 3 and projected forward (to the right in FIGS. 7 and 8).

If a screen is provided near the meridional image plane and the light distribution pattern is represented by an isoluminous curve, the 10th
It will look like the figure. H-H is a horizontal line on the screen, and V-V is also a vertical line.

As shown in FIGS. 7 to 9, a shade 4 having an edge along the meridional image plane is provided. Specifically, as shown in 4a in FIG. 9, a cut line 4a is formed so as to recede downward from the horizontal section ij of the meridional image plane. FIG. 10 shows how the light distribution pattern described above and the shade 4 overlap. As shown in Figure 10 of this book,
The upper half of the light beam passes through. Most of the lower half is blocked, but light is allowed to pass through the portion corresponding to the cut line 4a.

As the partially covered light beams as described above are focused on the meridional image planes ij and intersect with each other, the light beams projected in front of the headlight have a pattern that is an inversion of the one shown in Figure 10. form. FIG. 11 is an explanatory diagram showing the general shape of a light projection pattern using isoluminance curves on a screen provided in front of the headlight.

This conventional example is configured for left-hand traffic, and in the case of right-hand traffic, the left and right sides of FIGS. 9 to 11 are configured to be different.

[Problem that the invention attempts to solve]

As explained in FIGS. 10 and 11,
Cut line 4a' in the light distribution pattern of the projector type headlight is cut line 4 of shade 4.
a is projected. Therefore, in order to obtain an accurate light distribution pattern, the shade 4 must be placed in alignment with the meridional image plane of the convex lens 3.

When producing projector type headlights industrially,
At the design stage, the performance specifications of each component are set so that the above-mentioned light projection pattern has a desired shape. At the final stage of the production process, the position of the shade 4 is adjusted to make a final correction to the light projection pattern, and products that have passed inspection are shipped.

In order to perform the above adjustment, the shade 4 has a shape as shown in FIG. 12 and is attached as shown in FIG. 13.

In Fig. 12, 4b is a mounting leg, 4c
is a long hole for a mounting screw.

In FIG. 13, 5 is a lens barrel (frame) that supports the convex lens 3, and a boss 5a for attaching the shade.
It is equipped with

In FIG. 13, the lower surface of the boss 5a forms a plane parallel to the optical axis, and the shade leg 4b is attached by bringing the upper surface of the shade leg 4b into contact therewith.

The above-described attachment is performed by inserting the attachment screw 6 into the elongated hole 4c and screwing it into a screw hole (hidden in this figure) provided on the lower surface of the boss 5a.

Since the elongated hole 4c is made parallel to the optical axis, the shade 4 can be moved back and forth in the optical axis direction with the mounting screw 6 loosened to adjust its position.

However, as shown in FIG.
Since the structure is such that the leg portion 4b is fixedly attached, the support is unstable, which is disadvantageous in terms of vibration resistance.

Furthermore, as shown in FIG. 13, it is necessary to provide a large boss 5a on the frame 5, which increases the weight of the headlight and increases the cost.

This idea was created in view of the above circumstances.
To provide a lightweight, low-cost projector type headlamp that does not require providing a large boss on a frame and can stably fix a shade with a single mounting screw.

[Means to solve the problem]

In order to achieve the above object, the projector type headlight of the present invention has a shoe at the bottom of the shade, and sliding pieces on the left and right sides of the shade.
Further, a frame including a cylindrical portion for supporting a convex lens is constructed, and a guide groove is provided to fit into the shoe and a guide groove to fit into the slide piece.

[Effect]

According to the above configuration, the shade is supported by the shade below and the left and right slide pieces, so it is stable and has good vibration resistance.

Furthermore, since there is no need to provide a large boss on the frame, it can be constructed lightweight.

〔Example〕

FIG. 2 is a partially cutaway side view of an embodiment of the projector type headlamp according to the present invention.

7 is a frame, and 4 is for attaching it to the concave mirror 1.
It has a book leg 7c and a cylindrical portion 7a for supporting the convex lens 3.

FIG. 3 is a sectional view of the frame 7, and FIG. 4 is a view thereof in the direction of arrows.

A guide groove 7b is provided in the lower part of the cylindrical portion 7a in the optical axis direction (left-right direction in FIG. 3, perpendicular to the paper surface in FIG. 4).

Furthermore, guide grooves 7d and 7d' in the optical axis direction are provided on the left and right sides of the cylindrical portion 7a.

FIG. 5 shows a shade 8 used by being attached to the frame 7 mentioned above.

This shade 8 has a cylindrical shape as a whole, but the corners are rounded to form arcuate parts 8f and 8f' so that the shade 8 can fit into the cylindrical part 7a. A shoe 8b is formed in a bent shape. A long hole 8c is provided in the shoe 8b.

Slide pieces 8d and 8d' are provided at both the left and right ends of this shade. 8e is a cut line.

As shown in FIG.
Then, the slide pieces 8d' are respectively fitted into the guide grooves 7d'. Although hidden in FIG. 1, the slide piece 8d is fitted into the guide groove 7d.

Then, the mounting screw 6 is inserted into the elongated hole 8c, and screwed into the female threaded hole 7e provided at the bottom of the guide groove 7b and tightened.

When the above-mentioned mounting screw 6 is loosened, the shade 8 can be slid in the optical axis direction, and when the mounting screw 6 is tightened, it is fixed.

In the fixed state, the shade 8 is supported at three places: the shade 8b and the slide pieces 8d and 8d', so its position and posture are stable and it has excellent vibration resistance.

[Effect of idea]

As explained above, the projector type headlight of the present invention is lightweight and inexpensive because there is no need to provide a large boss on the frame, and the shade is located in three places: the shoe below and the slide pieces on the left and right. Because it is supported, it is stable and has excellent vibration resistance.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Fig. 1 is an exploded perspective view, Fig. 2 is an assembled view with a part cut away, Fig. 3 is a sectional view of the frame, Fig. 4 is a view in the direction of the arrow in Fig. 3, and Fig. 5 is a shaded view. FIG. FIGS. 6 to 11 are explanatory diagrams of a known projector type headlamp. Figures 12 and 13
The figure is an explanatory diagram of problems in a conventional projector type headlamp. 7... Frame, 7a... Cylindrical portion, 7b... Guide groove, 7c... Leg, 7d, 7d'... Guide groove, 8...
...shade, 8b...shew, 8c...long hole, 8
d, 8d'...Slide piece.

Claims (1)

[Scope of utility model registration request] A projector in which a light source bulb is installed near the focal point of a reflecting mirror, the light emitted from the light source bulb is reflected by the reflecting mirror and focused near a shade having a cut line, and the reflected light is projected forward by a convex lens. type headlight, the frame includes a cylindrical part that supports the convex lens, a guide groove in the optical axis direction provided at the bottom of the cylindrical part, and inner surfaces on the left and right sides of the cylindrical part. A guide groove in the optical axis direction provided respectively, a shoe provided at the bottom of the shade and slidably fitted into a guide groove at the bottom of the cylindrical part, and a cylindrical guide groove provided on the left and right sides of the shade, respectively. A projector-type headlamp characterized by comprising slide pieces that slidably fit into guide grooves on the left and right sides of the part.