JP2018006089A - Manufacturing method of outer lens for vehicular lamp, and vehicular lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an outer lens for a vehicular lamp having extremely high transmissivity and extremely inexpensive manufacturing cost.SOLUTION: An outer lens comprises: a planar design part as a light transmission path; an annular peripheral side part substantially vertically extending into a planar shape from a peripheral edge of the design part to a plate surface direction of the design part along the peripheral edge; an annular flange part extending into a planar shape from a peripheral edge part of the peripheral side part to the plate surface direction of the design part along the peripheral edge part; and an annular seal rib part extending into a planar shape from a peripheral end part of the flange part to a plate surface direction of the peripheral side part along the peripheral end part. Molding dies 30, 35 have a gate 41 connected to a seal rib part molding region 53 where the seal rib part is molded, and the gate 41 is disposed toward a direction vertical to a surface direction of the seal rib part molding region 53 on an extension line of a flange part molding region 52 where the flange part is molded. Acrylic resin is used as an injection molding material.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing an outer lens used for a vehicular lamp and a vehicular lamp.

  Conventionally, an outer lens that is located on the outermost side of a vehicular lamp and constitutes a transmitted light path of emitted light is generally formed of polycarbonate that has excellent impact resistance while ensuring transparency. However, polycarbonate is inferior in weather resistance and easily damaged, and in particular, it undergoes discoloration (yellowing change) upon receiving ultraviolet light from sunlight, thereby causing a decrease in transmittance and a change in the color tone of transmitted light.

In order to solve this problem, the outer lens base material is formed of polycarbonate having excellent properties such as impact resistance, heat resistance and transparency, and the outer surface (surface exposed to sunlight) of the base material is weather resistant. A layer of PMMA (polymethyl methacrylate: acrylic) with good properties such as impact resistance, water resistance and transparency is provided, and SiO with good properties such as scratch resistance and abrasion resistance is provided on the outer surface of the PMMA layer. There is one in which an outer lens having a three-layer structure is formed by providing _two layers (see Patent Document 1).

  Also, the lens (outer lens) body is made of hard acrylic that has higher transmittance than polycarbonate and has excellent heat resistance, and the lens body has a protective film made of soft acrylic that has excellent chemical cracking and impact resistance. Yes (see Patent Document 2).

JP 2009-26646 A JP-A-11-345503

  By the way, since all the outer lenses having the above-described configuration have a multilayer structure, the number of steps in the manufacturing process increases, which causes an increase in manufacturing cost.

  Moreover, the material cost of the material which forms each layer with a multilayer structure increases, and this also raises the manufacturing cost.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an outer lens for a vehicle lamp that has a very high transmittance and a very low manufacturing cost. Another object of the present invention is to provide a vehicular lamp using an outer lens for a vehicular lamp that has a very high transmittance and a very low manufacturing cost.

  In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is a method of manufacturing an outer lens disposed on the outermost side of a vehicular lamp, wherein the outer lens has a light transmission path. A plate-shaped design portion, an annular peripheral side portion extending in a plate shape substantially perpendicularly to the plate surface direction of the design portion along the peripheral edge from the peripheral edge of the design portion, and a peripheral end portion of the peripheral side portion An annular flange portion extending in a plate shape in the plate surface direction of the design portion along the peripheral end portion, and a plate in the plate surface direction of the peripheral side portion from the peripheral end portion of the flange portion along the peripheral end portion. And the molding die has a gate connected to a sealing rib part molding region of the cavity for molding the sealing rib part, and the gate forms a flange part molding region of the flange part. The side of the molding area of the seal rib part on the extension line Are arranged in a direction perpendicular to the injection molding material is one which is characterized by using an acrylic resin.

  The invention described in claim 2 of the present invention is characterized in that, in claim 1, the design portion is formed to a thickness of 3 mm or more.

According to a third aspect of the present invention, there is provided a light source disposed in a lamp chamber formed by a housing having an opening, an outer lens made of a transparent resin that covers the opening, and the housing and the outer lens. A vehicular lamp comprising a unit,
The outer lens extends in a plate shape substantially perpendicular to the plate surface direction of the design portion along the peripheral edge from the periphery of the design portion, and a design portion that is long in one direction located in front of the vehicle lamp in the irradiation direction. An annular circumferential side portion, an annular flange portion extending in a plate shape in the plate surface direction of the design portion along the circumferential end portion from the circumferential end portion of the circumferential side portion, and the circumferential end portion of the flange portion An annular seal rib portion extending in a plate shape in the plate surface direction of the peripheral side portion along the peripheral end portion,
The design portion, the peripheral side portion, the flange portion and the seal rib portion are made of the same material layer made of acrylic resin,
Of the annular flange portion, the gate mark remains on the outer periphery of the flange portion extending in the longitudinal direction of the design portion, and the gate mark does not remain in the design portion,
The design section has an average thickness of 3 mm or more, and the average thickness of the peripheral side section and the flange section is 70% or less of the average thickness of the design section and 1 mm or more. It is what.

  According to the present invention, the outer lens includes a plate-shaped design portion, an annular peripheral side portion extending in a plate shape substantially perpendicularly to the plate surface direction of the design portion along the periphery from the periphery of the design portion, and the peripheral side. An annular flange portion extending in a plate shape in the direction of the plate surface of the design portion along the peripheral end portion from the peripheral end portion of the portion, and a plate surface of the peripheral side portion along the peripheral end portion from the peripheral end portion of the flange portion It has a structure having an annular seal rib portion extending in a plate shape in the direction, and has a molding die having a gate connected to a cavity and a seal rib portion molding region for molding the seal rib portion, and the gate is a flange portion molding for molding the flange portion. It was set as the structure arrange | positioned on the extension line of an area | region toward the direction perpendicular | vertical to the surface direction of a seal rib part shaping | molding area | region, and acrylic resin was used for the injection molding material.

  As a result, the outer lens molded by injection molding has a mechanically strong skin layer formed on the surface at the time of injection molding. It can be used as an outer lens that is affected by the natural environment such as heat and heat, and that is subject to vibrations and intermittent impacts, and flying objects such as stones and sand that have come into contact with it.

  As a result, it is possible to provide an outer lens for a vehicle lamp and a vehicle lamp that have extremely high transmittance and are extremely inexpensive to manufacture.

It is a longitudinal cross-sectional view of the vehicle lamp using an outer lens. It is the perspective view which looked at the outer lens from the diagonally upper front. It is a front view of an outer lens. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is sectional drawing of an injection mold. It is a fragmentary sectional view of an injection mold. Similarly, it is a partial sectional view of an injection mold. It is sectional drawing of an injection molded product (outer lens). It is a table | surface of the test result of a spray test.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 10 (the same parts are denoted by the same reference numerals). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a longitudinal sectional view of a vehicular lamp using the outer lens of the present invention, FIG. 2 is a perspective view of the outer lens as seen obliquely from the front, FIG. 3 is a front view of the outer lens, and FIG. -A sectional view, FIG. 5 is a BB sectional view of FIG. In the present embodiment, a front fog lamp will be described as an example of a vehicle lamp.

  A vehicular lamp (hereinafter abbreviated as “lamp”) 1 includes a housing 2 having an opening and an outer lens 10 provided so as to cover the opening of the housing 2 to form a lamp chamber 3 formed of a closed space. A light source unit 6 having an optical system composed of a light source 4 and a projection lens 5 is accommodated in the chamber 3. The light source 4 is attached to a heat sink 7 in order to dissipate heat generated during lighting using a light emitting diode. The vehicular lamp 1 is installed at a position below a headlamp such as in a bumper on the front side of the vehicle (not shown).

  Then, the light emitted from the light source 4 is condensed by the projection lens 5 and emitted outside the lamp chamber 3 through the outer lens 10. That is, the outer lens 10 is positioned in front of the vehicle lamp in the irradiation direction.

  Next, the outer lens 10 will be described.

  The outer lens 10 has a horizontally long plate-shaped design portion 11 that is long in one direction, and an annular peripheral side portion that extends from the periphery of the design portion 11 in a plate shape substantially perpendicularly to the plate surface direction of the design portion 11 along the periphery. 12, an annular flange portion 13 extending in a plate shape from the peripheral end portion of the peripheral side portion 12 to the outside in the plate surface direction of the design portion 11 along the peripheral end portion, and the peripheral end portion of the flange portion 13 from the peripheral end portion An annular seal rib portion 14 extending in a plate shape in the plate surface direction of the peripheral side portion 12 is provided along the end portion.

  The outer lens 10 has an optical function of transmitting light emitted from the light source unit accommodated in the lamp chamber and emitting the light out of the lamp chamber. Therefore, in order to reduce the light transmission loss during transmission through the outer lens 10 as much as possible and increase the light utilization efficiency, it is required to have a high transmittance. In particular, a high transmittance is required for the design portion 11 serving as a light transmission path.

  At the same time, since the outer lens 10 is directly exposed to the outside environment when the lamp is mounted on the vehicle, the outer lens 10 is affected by natural environments such as ultraviolet rays and heat of sunlight. There is a concern that it will be damaged by impacts of flying objects such as stones and sand that flew along with the impact.

  Therefore, the outer lens 10 is also required to have mechanically excellent characteristics such as impact resistance, scratch resistance, and wear resistance.

  In the present invention, the outer lens 10 is optically and mechanically superior by considering the transmittance with respect to the outer lens 10 and improving various mechanical characteristics.

  Specifically, an outer lens that is mechanically superior to an outer lens made of a conventional acrylic resin can be realized by injection molding using an acrylic resin having a higher transmittance than that of a polycarbonate resin as a molding material.

  Next, an outer lens molding method will be described. FIG. 6 is a view showing a clamping state of a molding die for injection molding the outer lens.

  In the mold, a fixed mold 30 and a movable mold 35 are arranged to face each other with a parting surface 40 interposed therebetween. The cavity formed by the fixed mold 30 and the movable mold 35 includes a region (design portion molding region) 50 for molding a design portion of a molded product (outer lens), and a region for molding a peripheral side portion (circumferential side portion molding). An area) 51, an area for forming a flange portion (flange portion forming area) 52, and an area for forming a seal rib portion (sealing rib portion forming area) 53.

  The gate 41 extends in a direction perpendicular to the surface direction of the seal rib portion molding region 53 on the extension line of the flange portion molding region 52 of the seal rib portion molding region 53. The gate 41 is located in the seal rib portion molding region 53 corresponding to the center position in the longitudinal direction of the horizontally long design portion forming region 50. The injection position from the gate 41 in the outer lens 10 is located at the center in the left-right direction in FIG. 3 and above the design portion. No gate is provided in the design portion molding region 50. Accordingly, in the outer lens 10, a gate mark (not shown) remains outside the flange portion 13.

  The gate 41 is connected to a concave nozzle touch portion (molten resin injection port) 44 through a runner 42 and a sprue 43. In the nozzle touch portion 44, the tip of the nozzle 46 of the cylinder 45 of the molding machine abuts at the time of injection molding, and molten resin supplied from the molding machine is injected into the molds 30 and 35 through the nozzle 46.

  At the time of injection molding, acrylic resin (Telpet Asahi Kasei Co., Ltd.) was used as a molding material, and it was put into the cylinder 45 after preliminary drying for 2 to 6 hours. The set temperature of the molten acrylic resin in the cylinder was set to a temperature near the upper limit of the recommended molding conditions. By increasing the temperature of the molten resin, particularly the nozzle side temperature (a temperature near the upper limit of the recommended molding conditions), the fluidity was increased and the resin filling time in the cavity was shortened. In addition, if the temperature exceeds the temperature of the recommended molding conditions, there is a high possibility that the material is denatured and burned, which is not preferable.

  Therefore, the molten resin injected from the nozzle 45 of the molding machine and injected into the sprue 43 of the fixed mold 30 is sent to the gate 41 through the sprue 43 and the runner 42.

  As shown in FIG. 7, the molten resin 47 sent to the gate 41 is injected at a predetermined flow rate from the gate 41 to the seal rib portion molding region 53 of the cavity connected to the gate 41. At this time, since the nozzle side temperature is increased (temperature near the upper limit of the recommended molding conditions) to improve fluidity, the resin injected into the cavity via the gate 41 also lowers the nozzle side temperature (recommended molding). Compared with the case where the temperature is near the lower limit of the condition, the flow velocity is faster.

  The molten resin 47 injected from the gate 41 into the seal rib part molding region 53 at a predetermined flow rate directly hits the surface 51a on the movable mold 35 side that forms the peripheral side part molding region 51 located in the front, and then As shown in FIG. 8, the flow is adjusted while spreading in the longitudinal direction in the circumferential side portion molding region 51 to the design portion molding region 50, and the flow in the design portion molding region 50 is made uniform in the longitudinal direction. Then, it sequentially flows through the peripheral side portion forming region 51 and the flange portion forming region 52 to reach the seal rib portion forming region 53. Thereby, the molten resin 47 is filled in the entire cavity.

  At this time, in a process in which the molten resin 47 flows in the cavity, a layer having a lower temperature than the molten resin 47 and in contact with the cavity forming surface is instantaneously solidified to form a so-called skin layer 48. The skin layer 48 forms a mechanically strong layer having a high resin density by making the inner core layer 49 amorphous.

  As a result, the molded product (outer lens 10) taken out from the molds 30 and 35 has a mechanically strong skin layer 48 with an appropriate thickness on the entire surface as shown in FIG.

  As described above, by increasing the temperature of the molten resin and increasing the temperature difference from the molding die, it is possible to increase the time until the core layer is solidified to ensure the thickness of the skin layer and to arrange the gate. By setting the position to an appropriate position of the cavity, a solid skin layer in which the molten resin flowing in the design portion molding region 50 is arranged to flow uniformly and the uniformity of amorphization is enhanced. An outer lens having the above is realized.

  When the vehicular lamp 1 is a front fog lamp, it is fixed to the front of the vehicle. When the front fog lamp is viewed from the front of the vehicle, the light emitted from the light source unit 6 is emitted toward the front of the vehicle through the design portion of the outer lens 10 which is the front. At this time, the outer lens 10 is formed by integral molding of the cavity design part molding region 50, the peripheral side part molding region 51, the flange part molding region 52, and the seal rib part molding region 53 made of the same acrylic resin. The manufacturing cost can be reduced as compared with the case where different materials or the same kind of isomers are stacked. Therefore, a vehicular lamp that can achieve bright illumination in which attenuation of light emitted through the design portion is suppressed is realized.

  Next, the thickness of the outer lens 10, that is, the distance between the molds of the cavity will be described.

  The thickness of the design portion 11 of the outer lens 10 (distance between the molds of the design portion molding region 50 of the cavity) is set to 3.0 mm or more. Conventional outer lenses for polycarbonate headlamps or front fog lamps generally have a thickness of about 2.0 mm (about 1.8 mm to 2.2 mm). By forming the design part thick, even if flying objects such as stones and sand that fly when the vehicle travels collide and get damaged, the design part will crack and increase the damage. Can be prevented. At the same time, the weld problem described later can be reduced. In particular, not only the average thickness of the entire design portion 11 is set to 3.0 mm or more, but the thickness of the thinnest portion in the design portion 11 is 3.0 mm or more, that is, both the average thickness and the minimum thickness are 3 By setting the thickness to 0.0 mm or more, the mechanical strength can be further improved.

  The peripheral side portion 12 of the outer lens 10 (distance between molds in the peripheral side portion molding region 51 of the cavity), the flange portion 13 (flange portion molding region 52), and the seal rib portion 14 (seal rib portion molding region 53) are thick. Is made thinner than 3.0 mm. Specifically, the thickness of the peripheral side part 12 and the flange part 13 is 2.0 mm. The thickness of the seal rib portion 14 is reduced to 2.0 mm on the flange portion 13 side and 1.9 mm on the front end side so as to gradually become thinner.

  The gate 41 is located outside the flange portion forming region 52 as shown in FIGS. As described above, the molten resin 47 is injected from the gate 41 into the cavity. The molten resin 47 injected from the gate 41 into the seal rib part molding region 53 at a predetermined flow rate directly hits the surface 51a on the movable mold 35 side that forms the peripheral side part molding region 51 located in the front, and then As shown in FIG. 8, the inside of the peripheral side portion forming region 51 and the design portion forming region 50 are directed. At this time, since the distance between the molds of the peripheral side molding region 51 and the flange portion molding region 52 is formed thinner than the distance between the molds of the design portion molding region 50, the peripheral side molding formed thinly. The molten resin 47 filled in the design part molding region 50 formed thicker than the region 51 and the flange part molding region 52 proceeds faster. Specifically, the distance between the molds in the peripheral side molding region 51 and the flange portion molding region 52 is 2.0 mm, and the distance between the molds in the design portion molding region 50 is 3.5 mm.

  The distance between the molds of the peripheral side molding region 51 and the flange portion molding region 52 is set to be between 50% and 70% based on the distance between the molds of the design portion molding region 50. The distance between the molds of the peripheral side molding region 51 and the flange portion molding region 52 is made thicker than 1.0 mm. If it is thinner than 1.0 mm, the strength of the entire outer lens, which is a molded product, decreases. If it is smaller than 50%, the difference in relative thickness between the peripheral side portion 12 and the flange portion 13 with respect to the design portion 11 becomes too large, and the impact on the peripheral side portion 12 and the flange portion 13 is concentrated, and the flange portion is broken. It becomes easy. If it exceeds 70%, the molten resin 47 injected into the peripheral side molding region 51 and the flange portion molding region 52 before the design portion molding region 50 will wrap around. Therefore, a weld is likely to occur in the design portion 11, which is not preferable. If it is between 50% and 70%, the molten resin 47 injected from the outside of the flange part molding region 52 through the gate 41 wraps around the entire circumference of the peripheral side molding region 51 and the flange part molding region 52. First, the entire design portion molding region 50 is filled. That is, injection into the entire design portion molding region 50 having a low flow resistance proceeds before filling, and filling of the entire circumference of the peripheral side molding region 51 and the flange portion molding region 52 is performed in the design portion molding region. After 50 injections. Accordingly, the weld is less likely to occur in the design portion molding region 50 even though it may occur in the peripheral side molding region 51 and the flange portion molding region 52.

  Further, the distance between the molds of the peripheral side molding region 51 and the flange portion molding region 52 is more preferably between 61% and 67% based on the distance between the molds of the design part molding region 50, and the design. The minimum distance of the part forming region 50 is set to 3.0 mm to 4.0 mm. If the thickness of the design portion 11 of the outer lens which is a molded product is thicker than 4.0 mm, the weight becomes undesirably high. When the thickness is less than 3.0 mm, the resistance to scratches is inferior, and at the same time, the thicknesses of the peripheral side portion 12 and the flange portion 13 are also relatively thin, and the overall strength is reduced.

  Moreover, in the design part 11, the skin layer 48 of an acrylic resin is uniformly formed in the surface by finishing before filling to the perimeter of the peripheral side part shaping | molding area | region 51 and the flange part shaping | molding area | region 52. Can do. In other words, since the molten resin 47 is injected so that the weld does not occur in the design portion 11, the skin layer formed in the design portion 11 is the peripheral side molding region 51 or the flange portion molding region in which the weld is formed. 52, and the design portion 11 is thicker than the skin layer. Therefore, the mechanical characteristics can be improved.

  Next, for the test piece of the outer lens manufactured by the above method, in order to confirm the resistance against mechanical deterioration, a spray test using a spray gun is performed to determine the change rate of transmission and the change rate of diffusion after the test. Since it investigated, it demonstrates below.

  The test equipment spray gun was 1.3 mm in diameter, working pressure 6.0 bar and equipped with a nozzle with a liquid flow rate of 0.24 per minute. Under this operating condition, the fan-shaped pattern formed on the surface that is subject to deterioration at a distance of 380 mm ± from the nozzle is 170 mm in diameter.

As the composition of the test mixture, silica sand having a Mohs hardness of 7, a particle size of 0 to 0.2 mm, a normal distribution, and an angular coefficient of 1.8 to 2 was used. In the case of a mixture of 25 g of silica sand per liter of water, it was sprayed with water whose hardness did not exceed 205 g / mm ³ .

  In the test, one or more sprays of silica sand produced as described above are applied to the outer surface of the test piece. Spraying is performed at a substantially right angle to the test target surface of the test piece.

  Check for degradation by placing one or more glass samples as a reference near the test sample under test. The mixture is sprayed until the variation in diffusion on the glass sample, measured by the method described below, is Δd = (T5−T4) /T2≦0.0250±0.0025.

The measurement method of the glass sample is to limit the beam of the semi-diffused β / 2 = 17.4 × 10 ⁻⁴ rd collimator K with a diaphragm _DT having a 6 mm aperture, and place a sample stage against it.
The diaphragm _DT and the light receiver R are connected by a convergent achromatic lens L ₂ corrected for spherical aberration. The diameter of the lens L ₂ is a degree not narrowed by the diaphragm the light diffused by the glass sample into a cone of semi-vertical angle β / 2 = 14 °.
placing the annular diaphragm _{D D} with an angle of a / 2 = 1 ° and _a max / 2 = 12 ° to the lens _{L 2} Zoase plane.
In order to eliminate the light directly reaching from the light source, an opaque central portion of the diaphragm is required. It is assumed that the central portion of the diaphragm can be moved from the light beam and returned to its original position.
The distance L _{2 DT} and the focal length F ₂ ¹ of the lens L ₂ are selected so that the image of _DT completely covers the light receiver R.
If the initial incident flux is 1000 units, the absolute accuracy of each reading shall be greater than 1 unit.
The following values shall be measured.

  The test results are shown in the table of FIG.

  About three test pieces, the test piece is formed by using the acrylic resin described in the embodiment to increase the temperature of the molten resin, particularly the nozzle side temperature (temperature near the upper limit of the recommended molding conditions). And the surface is not coated. The rate of change in transmission Δt = (T2−T3) / T2 after the test before the test is 0.030 (3%), 0.027 (2.7%), and 0.028 (2.8%), respectively. Met. As a result, for example, when the acrylic transmittance is 93% and the polycarbonate transmittance is 86%, the transmittance of the acrylic after the spray test is higher than that of the polycarbonate.

  That is, since the outer lens molded by injection molding has a mechanically strong skin layer formed on the surface at the time of injection molding, it can maintain transmittance far exceeding that of polycarbonate even in a spray test. For this reason, the surface has been affected by the natural environment such as ultraviolet rays and heat of sunlight, and has been subjected to vibration and intermittent impacts without being subjected to a strengthening treatment such as a hard coat on the surface as in the past. It can also be used as an outer lens for vehicles where objects such as stone and sand collide.

  As a result, an outer lens for a vehicular lamp is realized that has a very high transmittance and a very low manufacturing cost.

  In the above-described embodiment, the outer lens of the front fog lamp has been described as an example. However, the present invention is not limited to this. It can also be applied to the outer lens of a vehicle headlamp.

DESCRIPTION OF SYMBOLS 1 ... Vehicle lamp 2 ... Housing 3 ... Light chamber 4 ... Light source 5 ... Projection lens 6 ... Light source unit 7 ... Heat sink 10 ... Outer lens 11 ... Design part 12 ... Peripheral side part 13 ... Flange part 14 ... Seal rib part 30 ... Fixed Mold 35 ... Movable mold 40 ... Parting surface 41 ... Gate 42 ... Runner 43 ... Sprue 44 ... Nozzle touch part 45 ... Cylinder 46 ... Nozzle 47 ... Molten resin 48 ... Skin layer 49 ... Core layer 50 ... Design part molding region 51 ... Peripheral side portion forming region 52 ... Flange portion forming region 53 ... Seal rib portion forming region

Claims (3)

A method of manufacturing an outer lens disposed on the outermost side of a vehicular lamp,
The outer lens includes a plate-shaped design portion serving as a light transmission path, and an annular peripheral side portion extending in a plate shape from the periphery of the design portion along the periphery to the plate surface direction of the design portion. An annular flange portion extending in a plate shape from the peripheral end portion of the peripheral side portion along the peripheral end portion in the plate surface direction of the design portion, and from the peripheral end portion of the flange portion along the peripheral end portion An annular seal rib portion extending in a plate shape in the plate surface direction of the peripheral side portion;
The molding die has a gate connected to a seal rib portion molding region for molding the seal rib portion of the cavity, and the gate is a surface of the seal rib portion molding region on an extension line of the flange portion molding region for molding the flange portion. Arranged in a direction perpendicular to the direction,
A method for manufacturing an outer lens for a vehicle lamp, wherein an acrylic resin is used as the injection molding material.   The method for manufacturing an outer lens for a vehicle lamp according to claim 1, wherein the design portion is formed to a thickness of 3 mm or more. A vehicle lamp comprising a housing having an opening, an outer lens made of a transparent resin covering the opening, and a light source unit arranged in a lamp chamber formed by the housing and the outer lens,
The outer lens extends in a plate shape substantially perpendicular to the plate surface direction of the design portion along the peripheral edge from the periphery of the design portion, and a design portion that is long in one direction located in front of the vehicle lamp in the irradiation direction. An annular circumferential side portion, an annular flange portion extending in a plate shape in the plate surface direction of the design portion along the circumferential end portion from the circumferential end portion of the circumferential side portion, and the circumferential end portion of the flange portion An annular seal rib portion extending in a plate shape in the plate surface direction of the peripheral side portion along the peripheral end portion,
The design portion, the peripheral side portion, the flange portion and the seal rib portion are made of the same material layer made of acrylic resin,
Of the annular flange portion, the gate mark remains on the outer periphery of the flange portion extending in the longitudinal direction of the design portion, and the gate mark does not remain in the design portion,
The design section has an average thickness of 3 mm or more, and the average thickness of the peripheral side section and the flange section is 70% or less of the average thickness of the design section and 1 mm or more. Vehicle lamp.