JPH0648646Y2 - Lens for vehicle lighting - Google Patents

Description

[Detailed Description of the Invention] << Industrial Application Field >> The present invention relates to a lens for a vehicle lamp in which a concentric Fresnel prism is molded by a split mold.

<< Prior Art >> FIG. 5 shows an example of a vehicular lamp equipped with such a lens, and FIG. 6 is a sectional view taken along line AA of FIG.
FIG. 7 is a sectional view taken along line BB in FIG. 5, and FIG. 8 is C in FIG.
-C line sectional drawing, FIG. 9 is the DD sectional view taken on the line of FIG.

In these figures, one outer lens 1 on the front surface is colorless and transparent, and forms the front shape of a lamp with one side corresponding to the outside of the vehicle body wrapping around. A leg portion 2 is formed inward on the peripheral edge of the outer lens 1, and the leg portion 2 is inserted into a groove portion 4 formed in the front opening peripheral edge of the housing 3 and joined by a hot melt 5 which is a sealant. There is.
The housing 3 is divided into a turn signal lamp lamp chamber 6 and a tail stop lamp lamp chamber 7, and both lamp chambers are separated.
A groove-shaped light shielding portion 10 having a pair of light shielding walls 8 and 9 is provided at the boundary between the 6 and 7.
Are formed. Inside the outer lens 1, there is a lamp room 6
The orange transparent inner lens 11 and the red transparent inner lens 12 corresponding to the lamp chamber 7 and the adjacent leg portions 13 and 14 are ultrasonically bonded to each other, respectively, and their peripheral portions are It is sandwiched between the outer lens 1 and the housing 3. Further, an inner inner lens 15 is attached to the housing 3 inside the red inner lens 12. The orange inner lens 11 has a fisheye prism on the front surface and a Fresnel prism on the back surface, the red inner lens 11 has a fisheye prism on the back surface, and the colorless and transparent inner inner lens 15 has a Fresnel prism on the back surface. There is. Two lamp bulbs 16 and 17 are arranged in each lamp chamber 6 and 7. Reference numeral 18 indicates a rim.

<Problems to be solved by the invention> In the case of a lens provided with such a Fresnel prism, for example, the inner lens 11, if there is one optical axis of the Fresnel prism and it coincides with the center of the lens 11, a concentric circle Since the Fresnel prism is formed symmetrically with respect to the lens 11, it can be molded by one mold. However,
As shown in FIG. 3 and FIG. 4, two lamp bulbs 20 are arranged, Fresnel prisms 22 and 23 of the lens 21 are arranged in the lateral direction, and one end of them is combined to form
In the case of an asymmetrical type in which there is a total of two optical axes O for each lamp bulb 20 and the other end of the Fresnel prism 23 wraps around, a split mold is used for mold making. I have to do it. And conventionally, the mold is I, II, III
It was divided into two parts. If the mold is divided, the division lines a and b are formed at the position of the molded product corresponding to the mating surface, but the division line a is two separate Fresnel prisms 2
It is unavoidable that the dividing line a appears on the lens 21, which is a molded product, because the two and 23 discontinuous surfaces are joined together. On the other hand, it is desirable that the dividing line b does not appear in the molded product as much as possible because the continuous surfaces of one and the same Fresnel prism 23 are aligned with each other. Therefore, conventionally, the dividing line b is located as far away from the optical axis O or the lamp bulb 20 as possible so that the luminous flux does not reach sufficiently at the time of lighting so that the dividing line b is not noticeable even if it appears on the molded product. It was usual to set it to the department.

However, when the dividing line b is set in the peripheral portion of the lens in this way, the Fresnel prism 23 is divided obliquely, and it is necessary to machine the Fresnel prism 23 so that the dividing surfaces of the dies are aligned with each other. It is difficult to achieve, and since the amount of light flux is small in the peripheral area of the lens, even if there is a slight misalignment, it is more likely to be hidden. As a result, there is a problem that the dividing line b is inevitably visible on the molded product when the lamp is turned on.

Therefore, the object of the present invention is to make a lens for a vehicle lamp in which a concentric Fresnel prism is molded by a split mold, and a lens is devised so that the mold can be easily manufactured and the split line of the Fresnel prism does not appear on the lens as much as possible. To provide.

<< Means for Solving the Problem >> A lens of a vehicular lamp according to the present invention comprises a pair of concentric Fresnel prisms arranged laterally with respect to each other, and both ends of both Fresnel prisms are aligned with each other. A lens of a vehicle lamp, which is molded by a split mold so that the other end of one of the Fresnel prisms has a wraparound part, and the split line of the split mold is a wraparound part with the fitting part of the both Fresnel prisms. The Fresnel prism having a section is set on the optical axis.

<Action> If the dividing line is set on the optical axis of the Fresnel prism,
The Fresnel prism will be divided at right angles to the tangent line of each concentric circle, which will facilitate the machining of the mold and allow each concentric circle of the Fresnel prism to be accurately continuous, and the division line will Since it is arranged in the most bright position, the division line is almost invisible due to the dazzling light.

<< Embodiment >> An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The lens 30 of the vehicular lamp is molded of transparent polycarbonate resin or polymethylmethacrylate resin, and has two concentric Fresnel prisms 31 and 32 on the back surface thereof. Each Fresnel prism 3
The mold for molding 1,32 is divided into a first mold I for making the Fresnel prism 31 and second and third molds II, III for making the Fresnel prism 32. . The mating surfaces of the first and second molds I and II are set substantially in the middle of the optical axes O of the Fresnel prisms 31 and 32, and the lens 30 has a division line a at the corresponding position. It is formed. The mating surfaces of the second and third molds II and III are set on the optical axis O of the Fresnel prism 32, and
A division line b is formed at 30 at the corresponding position.
Lamp bulbs 33 and 34 are arranged on the optical axes O of the Fresnel prisms 31 and 32, respectively.

Since the Fresnel prisms 31 and 32 collide with each other in the division line a and are apart from both optical axes O,
It appears as a clear line when the lamp is on. However, the other division line b is the optical axis O of the Fresnel prism 32.
It's located on the top, so it's hardly noticeable at all.

Thus, by setting the mating surfaces of the molds II and III on the optical axis O of the Fresnel prism 32, the Fresnel prism 32 is divided at right angles to the contact points of the respective concentric circles, and Since it is easy to machine and high dimensional accuracy can be obtained, it is possible to accurately connect each concentric circle. Therefore, in the lens 30 molded by these molds, the dividing line b is formed from the beginning. It's almost unnoticeable. Also, the division line b
Is arranged on the optical axis O of the Fresnel prism 32, which has the largest luminous flux, so that the division line b becomes almost invisible due to the dazzling of the light intensity. As described above, the conventional method of providing the dividing line b in the peripheral portion of the lens in order to make it inconspicuous is provided on the brightest optical axis of the lens by reversing the thought. Was resolved to.

<Effect of the device> As described above, the lens of the vehicle lighting device according to the present invention is
Since the dividing line of the Fresnel prism is set on the optical axis of the Fresnel prism, the die manufacturing becomes easy and the dividing line on the lens becomes almost inconspicuous when the lamp is turned on.

[Brief description of drawings]

FIG. 1 is a back view of a lens showing an embodiment of the present invention,
2 is a sectional view of the lens shown in FIG. 1, FIG. 3 is a rear view showing an example of a conventional lens, FIG. 4 is a sectional view of the lens shown in FIG. 3, and FIG. FIG. 6 is a front view showing an example of a vehicular lamp related to the present invention, and FIG.
A sectional view, FIG. 7 is a sectional view taken along line BB in FIG. 5, and FIG. 8 is
5 is a sectional view taken along line CC of FIG. 5, and FIG. 9 is a sectional view taken along line DD of FIG. 1 ... Outer lens, 3 ... Housing, 8,9 ... Shading wall, 10 ... Groove-shaped shading section, 11 ... Orange inner lens, 12 ...
… Red inner lens, 13,14 …… Lens junction leg, 15…
… Inner lens, 16,17 …… Lamp bulb, 18 ……
Rim, 20,33,34 …… Lamp bulb, 21,30 …… Lens, 2
2,23,31,32 …… Fresnel prism, O …… Optical axis, a, b…
… Dividing line, I, II, III …… Dividing mold.

Claims (1)

[Scope of utility model registration request] 1. A pair of concentric Fresnel prisms are arranged laterally to each other so that one ends of both Fresnel prisms are aligned with each other, and the other end of one of the Fresnel prisms has a wraparound portion. As described above, in the lens of the vehicle lamp molded by the split mold, the split line of the split mold is set on the optical axis of the Fresnel prism having the fitting part of the both Fresnel prisms and the wraparound part. A lens for a vehicular lamp.