JPH11185503A - Resin reflection mirror and head lamp provided with the resin reflection mirror - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent effect in an improvement of performance of a head lamp by obtaining a required rigidity with a minimum necessary weight increase, generating no deformation on a resin reflection mirror during aiming and constantly obtaining a luminous intensity distribution characteristic of a normally correct form. SOLUTION: This resin reflection mirror 1 comprises reinforcement ribs 3c at least two of which are formed vertically on a rear surface while at least two of which are formed latterally thereon so as to be a lattice shape, wherein a ratio of a rib thickness D of the rib 3C to a fundamental wall thickness (t) of the resin reflection mirror 1 is in a range of 0.5<=(D/t)<=2.5, and a cross sectional area (S) of the rib 3C is in a range of 3<=S<=50 (mm<2> ). With such a constitution, the mirror 1 can obtain a required rigidity with a minimum necessary weight increase, improve the performance and minimize a cost increase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a headlamp for use in automobiles and two-wheeled motor vehicles. More specifically, the present invention relates to a headlamp, in which a reflecting mirror which is a part of a member constituting the headlamp is formed of resin. The present invention relates to a configuration in which the reflecting mirror also has an aiming mechanism for adjusting the irradiation direction of the headlamp.

[0002]

2. Description of the Related Art In automotive parts, weight reduction and cost reduction have always been pursued. The headlamp 90 is no exception, as shown in FIG. 4 due to the improvement of the heat resistance of the resin member or, for example, the improvement of the heat resistance by the additive.
, A lens 92 through which light rays, that is, heat rays are transmitted,
The reflection mirror 93 which is closest to the bulb 94, which is a heat source, is also being made of resin, and is being reduced in weight and cost.

In order to further reduce the weight and cost, an attempt has been made to combine an aiming mechanism 93a for adjusting the irradiation direction with the resin-made reflecting mirror 93 with the headlamp 90 mounted on an automobile. However, since the reflecting mirror 93 made of resin is less rigid than a reflecting mirror made of, for example, an iron material, the aiming mechanism 9 is used.
When the user operates 3a, the reflecting mirror 93 is deformed and the shape of the light distribution characteristic is changed, thereby causing a problem that a predetermined standard cannot be satisfied.

[0004]

As means for solving the above-mentioned problems, means for increasing the basic thickness t of the reflecting mirror 93 has been used in order to improve the rigidity of the reflecting mirror 93. In this case, When the basic thickness t of the reflecting mirror 93 is increased as shown by a two-dot chain line in the figure so that the required rigidity is sufficiently obtained, for example, if the basic thickness t is increased by 50%, the weight of the reflecting mirror 93 is increased. Also increase by 50%.

[0005] Therefore, the cost increases as the amount of material used increases, and the advantage of weight reduction with respect to the reflector made of iron material is lost, and the purpose of cost reduction is lost due to the increase in cost due to the increase in material used. This causes problems. In addition, when the weight of the reflector 93 is extremely increased, another problem such as insufficient strength of the support of the reflector 93 and reinforcement is required, and solving these points is a problem. Had become.

[0006]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, there is provided a resin reflector having an aiming mechanism. For the basic thickness t of the reflector,
There are at least two reinforcing ribs in the longitudinal direction that are in the range of 0.5 ≦ (D / t) ≦ 2.5 and whose rib cross-sectional area S is in the range of 3 ≦ S ≦ 50 (mm ² ). An object of the present invention is to solve the problem by providing a resin reflecting mirror characterized in that at least two grids are provided on the back surface in the direction.

[0007]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 and FIG.
1 shows a resin reflecting mirror according to the present invention, FIG. 1 shows a state seen from the back side, and FIG. 2 shows a state where the head lamp 10 is assembled. This resin reflecting mirror 1 is formed of a resin member, and is provided with an aiming mechanism 2 having a boss shape or the like on the back side, as in the conventional example.

Here, in the present invention, even when the aiming mechanism 2 is provided, the rigidity can be improved without changing the basic thickness t (typically t = 2 mm) of the resin reflecting mirror 1. In order to maintain the weight and cost advantages of the resin reflecting mirror 1 as a specific means, a reinforcing rib 3C in the form of a lattice is provided on the back surface of the resin reflecting mirror 1 as specific means. .

FIG. 3 is a graph summarizing the results of trial manufacture and examination by the inventor for realizing the present invention. In FIG. 5 shows the relationship between the thickness D of the reinforcing ribs 3V and the improvement in rigidity when three reinforcing ribs 3V (not shown) are provided in the vertical direction when the reinforcing ribs 3V are attached to the vertical direction.

A curve indicated by reference numeral HL in FIG. 3 shows a similar relationship when three reinforcing ribs 3H (not shown) are provided in the lateral direction with respect to the resin reflecting mirror 1. The curve indicated by the reference numeral CL in FIG. 3 shows a similar relationship when the resin reflecting mirror 1 is provided with reinforcing ribs 3C each having two lattices in the vertical and horizontal directions. At this time, the reinforcing ribs 3V, 3H, and 3C have the same width W. FIG. 3 shows respective curves VL, HL,
In order to facilitate comparison of CL, the rigidity when the thickness of the reinforcing rib 3C is 5 mm is shown as 100%.

Here, the relationship between the thickness D of the reinforcing ribs (3V, 3H, 3C) and the rate of improvement in rigidity is roughly calculated from the curves VL, HL, and CL. 2 (%) × D, 2.0 (%) × D in the reinforcing rib 3H, and 3.0 (%) × D in the reinforcing rib 3C.
2 (%) × D, that is, it was confirmed that the effect of improving rigidity was most excellent when the reinforcing ribs 3C were in the form of a lattice.

When examining another factor, the rate of increase in weight, the reinforcing rib 3V has a weight increase rate of 0.6% per 1 mm of the thickness D.
The weight increase rate of H for the same thickness D is 1.5%,
The weight increase rate for the same thickness D of the reinforcing rib 3C is 1.4.
%.

Comparing the above results, the reinforcing rib 3C has the same thickness D as the reinforcing rib 3V and has a rigidity of about 2.7 times (3.2 / 1.2 ≒ 2.7). On the contrary, in order to obtain the same rigidity with the reinforcing ribs 3V as with the reinforcing ribs 3C, the thickness D must be about 2.7 times. And the weight increase rate per 1 mm of the reinforcing rib 3V is 0.6%.
Therefore, when the thickness D is 2.7 times, the weight increase rate is about 1.6%, which is heavier than the reinforcing rib 3C having the same rigidity.

Similarly, in order to obtain the same rigidity in the reinforcing rib 3H as in the reinforcing rib 3C, the thickness D must be about 1.6 times, and the weight increase rate at this time is about 2.4%. And the reinforcing ribs 3C having the same rigidity as the reinforcing ribs 3V. Therefore, based on the above results, the present invention has decided to employ the reinforcing ribs 3C in a lattice shape.

In the course of the same experiment and examination, a number of this type of resin reflecting mirror 1 were examined.
It has been found that the improvement in rigidity is good in the range of approximately 5 to 20%. From this, the thickness D of the reinforcing rib 3C is 0.5 ≦ (D / t) ≦ 2.5, that is, When the basic thickness t of the resin reflecting mirror 1 is 2 mm, the reinforcing rib 3C
If the thickness D is set in the range of 1 to 5 mm, practically sufficient rigidity can be obtained.

At this time, not only the thickness D but also the width W contributes to the improvement of the rigidity of the reinforcing ribs 3C. In some cases, there is a case where there is not much difference in terms of weight from the case where the rigidity is improved by increasing the basic thickness t. Therefore, in the present invention, the setting of the thickness D of the reinforcing ribs 3C is prioritized, and the width W of the reinforcing ribs 3C is effective for improving the rigidity and does not increase the weight. 3 ≦ S ≦ 50 (mm ² ). The cross-sectional area S at this time is calculated by (rib thickness D × rib width W).

Referring again to FIG. 2, what is shown in FIG. 2 is a headlamp 10 employing the above-described resin reflecting mirror 1 as described above.
By reinforcing with the reinforcing ribs 3C in the form of a lattice, an increase in weight for improving rigidity is minimal. Therefore, the problem of deformation of the resin reflecting mirror 1 at the time of aiming is solved by the reinforcement, and it is possible to realize the headlamp 10 which can always obtain light distribution characteristics of an accurate shape, and the headlamp 10 due to an increase in the number of materials used. Cost can be minimized.

The fact that the weight increase of the resin reflecting mirror 1 can be suppressed means that the load on a member such as the housing 4 which holds the resin reflecting mirror 1 withstands vibration and impact during running of the automobile. With the configuration of the present invention, the necessity of reinforcing these members such as the housing 4 can be eliminated. In the figure, reference numeral 5 denotes a lens, and reference numeral 6 denotes a light bulb.

[0019]

As described above, according to the present invention, in the resin reflecting mirror, the rib thickness D is 0.5 ≦ (D / t) ≦ 2.5 with respect to the basic thickness t of the resin reflecting mirror. And at least two reinforcing ribs having a rib cross-sectional area S in a range of 3 ≦ S ≦ 50 (mm ² ) are provided on the back surface in a lattice shape of at least two in the vertical direction and at least two in the horizontal direction. By adopting a resin reflecting mirror characterized by the fact that rigidity required as a minimum weight increase is obtained,
As a thing that does not cause deformation at the time of aiming in the resin reflecting mirror, as a thing that always obtains the light distribution characteristics of an accurate shape,
It has an excellent effect on improving the performance of headlights.

Further, since the above-mentioned increase in weight is minimized, the increase in the amount of resin material required when forming the resin reflecting mirror is also minimized, and a desired effect can be obtained. This has the effect of minimizing the cost. Furthermore, the member for supporting the resin reflecting mirror, such as the housing, does not need to be reinforced, and the effect of reducing the degree of cost increase can be achieved more reliably.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a resin reflecting mirror according to the present invention.

FIG. 2 is a graph showing the effect of reinforcing rigidity according to the present invention in comparison with other reinforcing methods.

FIG. 3 is a cross-sectional view showing a headlamp provided with the resin reflecting mirror according to the present invention.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Resin reflector 2 ... Aiming mechanism 3C ... Reinforcing rib 4 ... Housing 5 ... Lens 6 ... Light bulb 10 ... Headlamp D ... Reinforcement rib thickness W ... Reinforcement rib width S ... … Cross-sectional area of reinforcing rib

Claims (2)

[Claims] 1. A resin reflecting mirror having an aiming mechanism, wherein a rib thickness D of the resin reflecting mirror is 0.5 ≦ (D / t) ≦ 2 with respect to a basic thickness t of the resin reflecting mirror. 5 and the rib cross-sectional area S is 3 ≦ S ≦ 50 (mm
² ) the reinforcing ribs in the range of
A resin reflector, wherein at least two grids are provided on the back side in a lateral direction. 2. A headlamp comprising the resin reflecting mirror according to claim 1.