JP2007227238A - Design method of die for molding reflector of vehicular lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent light reflected from a part with shrinkage generated therein from being emitted upward even when the shrinkage is generated on a reflecting surface in molding a reflector of a vehicular lamp. <P>SOLUTION: In this design method of a die for forming the reflector 2 for the vehicular lamp having the reflecting surface 2a on the front side and having a projection 2b1 on the back side, a part 2a1 within the reflecting surface 2a located on the side opposite to the projection 2b1 is corrected downward. Preferably, the part 2a1 within the reflecting surface 2a located on the side opposite to the projection 2b1 is corrected downward to satisfy a relationship of an expression: θ(°)=0.2×Da (mm)-0.5 by the diameter Da (mm) of the projection 2b1 and an angle θ(°) used for the downward correction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for designing a mold for molding a reflector for a vehicle lamp having a reflective surface on the front surface side and a protrusion on the back surface side, and in particular, sink marks are formed on the reflective surface during molding of the reflector for a vehicle lamp device. The present invention relates to a method for designing a reflector molding die for a vehicular lamp that can surely avoid the fact that reflected light from a portion where a sink mark has occurred is irradiated upward.

  2. Description of the Related Art Conventionally, a reflector for a vehicle lamp having a reflecting surface on the front surface side and a protrusion (rib) on the back surface side is known. An example of this type of vehicle lamp reflector is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-19018.

  In the reflector for a vehicular lamp described in Japanese Patent Laid-Open No. 2005-19018, the surface-side reflecting surface is divided into a plurality of reflecting surface elements. In detail, the protrusion (rib) is arrange | positioned in the part located in the other side of the boundary line of two adjacent reflective surface elements.

  Further, in Japanese Patent Application Laid-Open No. 2005-19018, even when sink marks occur in a portion of the reflecting surface located on the opposite side of the projection (rib) during molding of the reflector, the portion is adjacent. It is described that the mark of the sink mark is not noticeable because it is a boundary line between the two reflecting surface elements.

  By the way, in Japanese Patent Laid-Open No. 2005-19018, even when sink marks occur in a portion of the reflecting surface located on the opposite side of the projection (rib) during molding of the reflector, the portion is adjacent. Since it is the boundary line between the two reflecting surface elements, the reflected light from that part originally does not contribute to the formation of the light distribution pattern, so there is no possibility that the light distribution pattern is disturbed by the reflected light from that part. Are listed.

  However, in the reflector for a vehicular lamp described in Japanese Patent Application Laid-Open No. 2005-19018, a portion of the reflecting surface located on the opposite side of the protrusion (rib) is a boundary line between two adjacent reflecting surface elements. However, the emitted light from the light source is reflected by that portion. That is, the reflected light is irradiated from the portion of the reflecting surface located on the opposite side of the protrusion (rib).

  On the other hand, when sink marks occur on the reflecting surface, the irradiation position of reflected light from the portion where the sink marks are generated deviates from the irradiation position of reflected light that is designed to prevent sink marks.

  Therefore, in Japanese Patent Application Laid-Open No. 2005-19018, even when sink marks occur in a portion of the reflecting surface located on the opposite side of the projection (rib) during the molding of the reflector, the reflected light from that portion is reflected. Although it is stated that there is no possibility that the light distribution pattern will be disturbed by the light, the reflected light from the part where the sink mark is generated is actually irradiated upward from the reflected light designed not to generate the sink mark. There is enough fear.

  Furthermore, if the reflected light from the part where the sink mark is generated is irradiated upward from the reflected light designed not to generate the sink mark, the reflected light from the part where the sink mark has occurred is reflected on the passenger of the oncoming vehicle. There is a risk of dazzling glare light.

JP 2005-19018 A

  In view of the above problems, the present invention is such that even if sink marks are generated on the reflecting surface when forming a reflector for a vehicle lamp, the reflected light from the portion where the sink marks are generated is directed upward. It is an object of the present invention to provide a method for designing a reflector molding die for a vehicle lamp that can be reliably avoided.

  According to the first aspect of the present invention, in the mold design method for forming a reflector for a vehicle lamp having a reflective surface on the front surface side and a protrusion on the back surface side, There is provided a method for designing a reflector molding die for a vehicle lamp, wherein a portion located on the opposite side is corrected downward.

  According to the second aspect of the present invention, as the diameter of the protrusion is larger, the angle for correcting downward the portion of the reflecting surface located on the opposite side of the protrusion is increased. A method for designing a reflector molding die for a vehicle lamp is provided.

According to the invention described in claim 3, the diameter D (mm) of the protrusion and the angle θ (°) to be corrected downward are θ (°) = 0.2 × D (mm) −0.5.
3. The method for designing a reflector molding die for a vehicle lamp according to claim 2, wherein a portion of the reflecting surface located on the opposite side of the projection is corrected downward so as to satisfy the relationship. Is done.

  In the vehicle lamp fixture reflector molding die design method according to the first aspect, the portion of the reflecting surface located on the opposite side of the projection is corrected downward. Therefore, according to the method for designing a reflector molding die for a vehicle lamp according to claim 1, even if a sink occurs on the reflecting surface when the reflector of the vehicle lamp is molded, the portion where the sink occurs Therefore, it is possible to reliably avoid the reflected light from being irradiated upward.

  The larger the diameter of the protrusion, the greater the amount of deformation of the reflecting surface when sink marks occur. As a result, the reflected light irradiation position from the part where sink marks occur and the reflected light designed to prevent sink marks from occurring The deviation from the irradiation position increases.

  In view of this point, in the method for designing a reflector molding die for a vehicle lamp according to claim 2, the larger the diameter of the protrusion, the lower the portion of the reflecting surface that is located on the opposite side of the protrusion is corrected downward. The angle is increased. Therefore, according to the method for designing a reflector molding die for a vehicular lamp according to claim 2, even when the diameter of the protrusion is large and the amount of deformation of the reflecting surface due to the occurrence of the sink is large, sink marks are generated. It is possible to reliably avoid the reflected light from the generated portion being irradiated upward.

  By correcting the part of the reflective surface that is located on the opposite side of the protrusion downward, it is possible to prevent the reflected light from that part from being irradiated upward, but that part is corrected downward. If the angle is too large, the reflected light from that portion is irradiated below the lower edge of the light distribution pattern of the entire vehicle lamp, resulting in a dark light distribution pattern.

  Therefore, the present inventor avoids the reflected light from the part where the sink mark is generated being irradiated upward, and the reflected light from the part is lower than the lower edge of the light distribution pattern of the entire vehicle lamp. We have earnestly researched the correction angle that can avoid the irradiation of the lower side.

As a result of the research, the inventor found that the diameter D (mm) of the protrusion (specifically, the diameter D (mm) of the root portion of the protrusion) and the angle θ (°) to be corrected downward are θ (°). = 0.2 x D (mm)-0.5
(2.5 (mm) <D (mm) <15 (mm))
By correcting the portion of the reflecting surface located on the opposite side of the protrusion downward so that the reflected light from the portion where the sink mark has occurred is avoided from being irradiated upward. The present inventors have found that it is possible to avoid the reflected light from the portion being irradiated below the lower edge of the light distribution pattern of the entire vehicle lamp.

  That is, in the method for designing a reflector molding die for a vehicle lamp according to claim 3, the projection diameter D (mm) and the angle θ (°) to be corrected downward are in the above-described relationship. The portion of the reflecting surface located on the opposite side of the protrusion is corrected downward.

  Therefore, according to the method for designing a reflector molding die for a vehicle lamp according to claim 3, the reflected light from the portion where the sink mark is generated is prevented from being irradiated upward, and from that portion. It is possible to avoid that the reflected light is irradiated below the lower edge of the light distribution pattern of the entire vehicle lamp.

  Hereinafter, a first embodiment of a method of designing a reflector molding die for a vehicle lamp according to the present invention will be described. FIG. 1 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which the design method of the first embodiment is applied, and in which a reflector that does not cause sink marks is incorporated. FIG. 2 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which the design method of the first embodiment is applied, and in which a reflector having a sink mark is incorporated. FIG. 3 is a partial cross-sectional side view of a vehicular lamp that is a reflector that is molded without correction by the design method of the first embodiment and in which a reflector that does not cause sink marks is incorporated.

  1 to 3, 1 denotes a bulb, and 1 a denotes a light emitting portion of the bulb 1. Reference numeral 2 denotes a reflector for reflecting the light from the bulb 1 and irradiating it in front of the vehicle (left side in FIGS. 1 and 2). Reference numeral 2a denotes a reflecting surface formed on the surface side of the reflector 2 (left side in FIGS. 1 and 2).

  1 to 3, reference numeral 2b1 denotes a valve on the back side (right side in FIGS. 1 and 2) of the reflector 2 in order to attach a component (not shown) for fixing the valve 1 to the reflector 2. The protrusion formed in the upper side (upper side of FIG. 1 and FIG. 2) from 1 is shown. 2b2 attaches a part (not shown) for fixing the valve 1 to the reflector 2 and is below the valve 1 on the back side (right side in FIGS. 1 and 2) of the reflector 2 (FIG. 1 and FIG. 2). The protrusion formed in the upper side of FIG. 2 is shown.

  Furthermore, in FIGS. 1-3, 2a1 has shown the part located in the other side of protrusion 2b1 among the reflective surfaces 2a. Reference numeral 2a2 denotes a portion of the reflecting surface 2a located on the opposite side of the protrusion 2b2. Reference numeral 3a denotes a screw inserted into the protrusion 2b1, and reference numeral 3b denotes a screw inserted into the protrusion 2b2. Reference numeral 4 denotes a hood for shielding a part of the light emitted from the bulb 1.

  In the first embodiment, the reflector 2 is formed by injection molding of a thermoplastic resin. Further, at the stage of designing the reflector molding die (not shown), the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a is corrected downward.

  Specifically, first, the reflector molding die is designed on the assumption that no sink marks occur in the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a when the reflector 2 is molded. Specifically, light L1 ′ (see FIG. 3) from the front end (left end in FIG. 3) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a. From the rear end (right end in FIG. 3) of the bulb 1 reflected by the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a. The mold is designed so that the light L2 ′ (see FIG. 3) is directed downward from the horizontal light L0.

  Next, even when sink marks occur in the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a when the reflector 2 is molded, the reflection is reflected by the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a. The light L3 (see FIG. 2) from the front end (left end in FIG. 2) of the light-emitting portion 1a of the bulb 1 that has been squeezed is lower than the horizontal light L0, and on the opposite side of the projection 2b1 in the reflective surface 2a. Of the reflecting surface 2a, the light L4 (see FIG. 2) from the rear end (right end in FIG. 2) of the bulb 1 reflected by the position 2a1 is directed downward from the horizontal light L0. The portion 2a1 located on the opposite side of the protrusion 2b1 is corrected downward.

  In other words, even when the sink 2 is formed when the reflector 2 is formed, even if the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a is deformed upward, the reflected light L3, L4 The portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a is corrected downward so that (see FIG. 2) is downward from the horizontal light L0.

  As a result, in the reflector 2 molded by the mold to which the design method of the first embodiment is applied, sink marks are generated in the portion 2a1 located on the opposite side of the projection 2b1 of the reflective surface 2a when the reflector 2 is molded. If not, the light L1 (see FIG. 1) from the front end (left end in FIG. 1) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a. ) Is lower than the horizontal light L0 (specifically, lower than the light L1 ′ (see FIG. 3)) and is reflected by the portion 2a1 of the reflecting surface 2a located on the opposite side of the projection 2b1. The light L2 (see FIG. 1) from the rear end (right end in FIG. 1) of one light emitting unit 1a is directed downward from the horizontal light L0 (specifically, from the light L2 ′ (see FIG. 3)).

  Further, in the reflector 2 molded by the mold to which the design method of the first embodiment is applied, sink marks are generated in the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a when the reflector 2 is molded. Even in this case, the light L3 (see FIG. 2) from the front end (the left end in FIG. 2) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a is horizontal. Light L4 from the rear end (right end in FIG. 2) of the bulb 1 reflected by the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a and facing downward from the light L0. 2) is lower than the horizontal light L0.

Specifically, in the first embodiment in which the basic thickness of the reflector 2 is set to 2.5 mm, the angle θ1 for correcting downward the portion 2a1 located on the opposite side of the projection 2b1 in the reflecting surface 2a. (°) is calculated based on the diameter Da of the protrusion 2b1 (specifically, the diameter Da of the root portion of the protrusion 2b1) and the following equation (1).
θ1 (°) = 0.2 × Da (mm) −0.5 (1)
(2.5 (mm) <Da (mm) <15 (mm))

  In the first embodiment, since the diameter Da of the protrusion 2b1 is set to, for example, 5 (mm), the portion 2a1 located on the opposite side of the protrusion 2b1 in the reflecting surface 2a based on the formula (1). Is corrected downward by 0.5 (°).

  In the first embodiment, the reflected light L1, L2, L3, L4 from the portion 2a1 is corrected from the horizontal light L0 by correcting the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2 downward. However, if the angle θ1 for correcting the portion 2a1 downward is too large, the reflected light L2 (see FIG. 1) from the portion 2a1 is reflected on the entire vehicle lamp. The light distribution pattern (not shown) is irradiated below the lower edge (lower side of FIG. 1), and as a result, a dark light distribution pattern may be formed.

  Specifically, in the first embodiment, the reflected light L3 (see FIG. 2) from the portion 2a1 where the sink mark is generated is prevented from being irradiated upward from the horizontal light L0, while the portion 2a1 So that the reflected light L2 (see FIG. 1) is irradiated below the lower edge (lower side of FIG. 1) of the light distribution pattern of the entire vehicle lamp (1). ) Is set.

  Therefore, according to the design method of the reflector molding die for the vehicular lamp of the first embodiment, when sink marks occur in the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a, While reliably avoiding the reflected light L3 (see FIG. 2) from the portion 2a1 being irradiated upward from the horizontal light L0, the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a. Even when sink marks do not occur, the reflected light L2 (see FIG. 1) from the portion 2a1 is applied to the lower side (lower side in FIG. 1) of the lower edge of the light distribution pattern of the entire vehicle lamp. Can be avoided.

  In the first embodiment, as described above, since the diameter Da of the protrusion 2b1 is set to 5 (mm), for example, on the reflection surface 2a, the opposite side of the protrusion 2b1 based on the formula (1). Although the portion 2a1 positioned at 2 is corrected downward by 0.5 (°), in the second embodiment, instead, the diameter Da of the protrusion 2b1 (specifically, the diameter Da of the root portion of the protrusion 2b1) For example, it is set to 7.5 (mm), and the portion 2a1 located on the opposite side of the projection 2b1 of the reflecting surface 2a is corrected downward by 1 (°) based on the formula (1).

  Alternatively, in the third embodiment, instead, the diameter Da of the protrusion 2b1 (specifically, the diameter Da of the root portion of the protrusion 2b1) is set to, for example, 10 (mm), and based on the expression (1), Of the reflecting surface 2a, a portion 2a1 located on the opposite side of the protrusion 2b1 is corrected downward by 1.5 (°).

  That is, in the method for designing a reflector molding die for a vehicle lamp according to the first to third embodiments, the larger the diameter of the protrusion 2b1, the more the portion 2a1 located on the opposite side of the protrusion 2b1 of the reflecting surface 2a. The angle θ1 to be corrected downward is increased. Therefore, according to the method for designing a reflector molding die for a vehicle lamp according to the first to third embodiments, the projection 2b1 has a large diameter, and the deformation amount of the reflecting surface 2a due to the occurrence of sink marks is large. However, it is possible to reliably avoid the reflected light L3 (see FIG. 2) from the portion 2a1 where the sink mark is generated being irradiated upward from the horizontal light L0.

  Hereinafter, a fourth embodiment of the method for designing a reflector molding die for a vehicle lamp according to the present invention will be described. FIG. 4 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which the design method of the fourth embodiment is applied, and in which a reflector that does not cause sink marks is incorporated. FIG. 5 is a partial cross-sectional side view of a vehicular lamp that is a reflector formed by a mold to which the design method of the fourth embodiment is applied, and in which a reflector having a sink mark is incorporated. FIG. 6 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded without correction by the design method of the fourth embodiment, and in which a reflector that does not cause sink marks is incorporated.

  The reflector 2 molded by the mold to which the design method of the fourth embodiment is applied is substantially the same as the reflector 2 molded by the mold to which the design method of the first embodiment is applied, except as described below. It is constituted similarly.

  In the reflector 2 formed by a mold to which the design method of the first embodiment is applied, a hood 4 is provided as shown in FIGS. 1 and 2, but the design method of the fourth embodiment is the same. In the reflector 2 molded by the applied mold, the hood 4 is not provided as shown in FIGS. 4 and 5. Therefore, a part of the light radiated from the bulb 1 is reflected by the portion 2a2 located on the opposite side of the projection 2b2 in the reflecting surface 2a, and irradiated to the front of the vehicle (left side in FIGS. 4 and 5). The

  In the fourth embodiment, similarly to the first embodiment, the reflector 2 is formed by injection molding of a thermoplastic resin. Furthermore, in the fourth embodiment, at the stage of designing a reflector molding die (not shown), the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a is corrected downward.

  Specifically, first, the reflector molding die is designed on the assumption that no sink marks occur in the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a when the reflector 2 is molded. Specifically, light L5 ′ (see FIG. 6) from the front end (left end in FIG. 6) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a2 located on the opposite side of the projection 2b2 in the reflecting surface 2a. From the rear end (right end in FIG. 6) of the bulb 1 reflected by the portion 2a2 of the reflecting surface 2a that is located on the opposite side of the projection 2b2. The mold is designed so that the light L6 ′ (see FIG. 6) of the light is directed downward from the horizontal light L0 ′.

  Next, when sink marks occur in a portion 2a2 located on the opposite side of the projection 2b2 in the reflecting surface 2a when the reflector 2 is molded, the reflection is reflected by the portion 2a2 located on the opposite side of the projection 2b2 in the reflecting surface 2a. The light L7 (see FIG. 5) from the front end (left end in FIG. 5) of the light-emitting portion 1a of the bulb 1 that has been squeezed is lower than the horizontal light L0 ′, and the reflective surface 2a is opposite to the projection 2b2. The reflecting surface 2a is such that the light L8 (see FIG. 5) from the rear end (right end in FIG. 5) of the bulb 1 reflected by the portion 2a2 located at the lower side is lower than the horizontal light L0 ′. Of these, the portion 2a2 located on the opposite side of the protrusion 2b2 is corrected downward.

  In other words, the reflected light L7, L8 is generated even when the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a is deformed upward as sink marks are generated when the reflector 2 is formed. The portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a is corrected downward so that (see FIG. 5) is downward from the horizontal light L0 ′.

  As a result, in the reflector 2 molded by the mold to which the design method of the fourth embodiment is applied, sink marks are generated in the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a when the reflector 2 is molded. If not, the light L5 from the front end (left end in FIG. 4) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a (see FIG. 4). ) Is lower than the horizontal light L0 ′ (specifically, lower than the light L5 ′ (see FIG. 6)), and is reflected by the portion 2a2 located on the opposite side of the protrusion 2b2 of the reflective surface 2a. The light L6 (see FIG. 4) from the rear end (right end in FIG. 4) of the light-emitting portion 1a of the bulb 1 is lower than the horizontal light L0 ′ (more specifically than the light L6 ′ (see FIG. 6)). Become.

  Furthermore, in the reflector 2 molded by the mold to which the design method of the fourth embodiment is applied, sink marks are generated in the portion 2a2 located on the opposite side of the projection 2b2 of the reflective surface 2a when the reflector 2 is molded. Even in this case, the light L7 (see FIG. 5) from the front end (left end in FIG. 5) of the light emitting portion 1a of the bulb 1 reflected by the portion 2a2 located on the opposite side of the projection 2b2 in the reflecting surface 2a is horizontal. Light L8 (from the rear end (right end in FIG. 5) of the light emitting portion 1a of the bulb 1 reflected downward by the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a. 5) is lower than the horizontal light L0 ′.

Specifically, in the fourth embodiment in which the basic thickness of the reflector 2 is set to 2.5 mm, the angle θ2 for correcting downward the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a. (°) is calculated based on the diameter Db of the protrusion 2b2 (specifically, the diameter Db of the root portion of the protrusion 2b2) and the following equation (2).
θ2 (°) = 0.2 × Db (mm) −0.5 (2)
(2.5 (mm) <Db (mm) <15 (mm))

  In the fourth embodiment, since the diameter Db of the protrusion 2b2 is set to, for example, 5 (mm), the portion 2a2 located on the opposite side of the protrusion 2b2 in the reflective surface 2a based on the formula (2). Is corrected downward by 0.5 (°).

  In the fourth embodiment, the reflected light L5, L6, L7, L8 from the portion 2a2 is corrected to the horizontal light L0 ′ by correcting downward the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2. However, if the angle θ2 for correcting the portion 2a2 downward is too large, the reflected light L5 (see FIG. 4) from the portion 2a2 is emitted from the vehicle lamp. It is considered that there is a possibility that the light is irradiated on the lower side (lower side in FIG. 4) of the lower edge of the entire light distribution pattern (not shown), resulting in a dark light distribution pattern.

  Specifically, in the fourth embodiment, the reflected light L8 (see FIG. 5) from the portion 2a2 where the sink mark is generated is prevented from being irradiated upward from the horizontal light L0 ′, while the portion 2a2 is avoided. So that the reflected light L5 (see FIG. 4) from the lower side of the light distribution pattern of the entire vehicular lamp is not irradiated on the lower side (the lower side of FIG. 4). 2) is set.

  Therefore, according to the method for designing a reflector molding die for a vehicle lamp according to the fourth embodiment, when sink marks occur in the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a, The portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a while reliably avoiding the reflected light L8 (see FIG. 5) from the portion 2a2 being irradiated upward from the horizontal light L0 ′. Even if there is no sink mark, the reflected light L5 (see FIG. 4) from the portion 2a2 is irradiated to the lower side (lower side in FIG. 4) of the lower edge of the light distribution pattern of the entire vehicle lamp. Can be avoided.

  In the fourth embodiment, as described above, the diameter Db of the protrusion 2b2 is set to, for example, 5 (mm). Therefore, on the reflection surface 2a, the opposite side of the protrusion 2b2 based on the expression (2). Although the portion 2a2 located at the position 2 is corrected downward by 0.5 (°), in the fifth embodiment, instead, the diameter Db of the protrusion 2b2 (specifically, the diameter Db of the root portion of the protrusion 2b2) For example, it is set to 7.5 (mm), and the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a is corrected downward by 1 (°) based on the equation (2).

  Alternatively, in the sixth embodiment, instead, the diameter Db of the protrusion 2b2 (specifically, the diameter Db of the root portion of the protrusion 2b2) is set to, for example, 10 (mm), and based on Expression (2), Of the reflecting surface 2a, a portion 2a2 located on the opposite side of the protrusion 2b2 is corrected downward by 1.5 (°).

  That is, in the method for designing a reflector molding die for a vehicle lamp according to the fourth to sixth embodiments, the larger the diameter of the projection 2b2, the more the portion 2a2 located on the opposite side of the projection 2b2 of the reflecting surface 2a. The angle θ2 to be corrected downward is increased. Therefore, according to the method for designing a reflector molding die for a vehicle lamp according to the fourth to sixth embodiments, the diameter of the protrusion 2b2 is large and the amount of deformation of the reflecting surface 2a due to the occurrence of sink marks is large. However, it is possible to reliably avoid the reflected light L8 (see FIG. 5) from the portion 2a2 where the sink mark is generated being irradiated upward from the horizontal light L0.

  In the first to sixth embodiments, portions 2a1 and 2a2 located on the opposite side of the protrusions 2b1 and 2b2 for attaching a component (not shown) for fixing the bulb 1 to the reflector 2 in the reflecting surface 2a. However, in the seventh embodiment, instead, it is also possible to correct a portion of the reflective surface 2a located on the opposite side of any other protrusion (not shown).

  In the first to sixth embodiments, the basic thickness of the reflector 2 is set to 2.5 mm. However, in the eighth embodiment, the basic thickness of the reflector 2 is set to an arbitrary thickness other than 2.5 mm. Can be set to a value.

1 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which a design method according to a first embodiment is applied and in which a sink does not occur. It is the reflector formed by the metal mold | die to which the design method of 1st Embodiment was applied, Comprising: It is a partial cross section side view of the vehicle lamp with which the reflector which the sinking generate | occur | produced was integrated. It is a partial section side view of a vehicular lamp which is a reflector formed without correction by the design method of a 1st embodiment, and the reflector which did not generate sink marks was built. FIG. 9 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which a design method according to a fourth embodiment is applied and in which a sink does not occur. FIG. 10 is a partial cross-sectional side view of a vehicular lamp that is a reflector molded with a mold to which a design method according to a fourth embodiment is applied, and in which a reflector having a sink mark is incorporated. FIG. 9 is a partial cross-sectional side view of a vehicular lamp that incorporates a reflector that is molded without correction by the design method of the fourth embodiment and that does not cause sink marks.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bulb 1a Light emission part 2 Reflector 2a Reflecting surface 2a1, 2a2 Part 2b1, 2b2 Protrusion 3a, 3b Screw 4 Hood

Claims (3)

  In a mold design method for forming a reflector for a vehicle lamp having a reflective surface on the front surface side and a protrusion on the back surface side, a portion of the reflective surface located on the opposite side of the protrusion is corrected downward. A method for designing a reflector molding die for a vehicle lamp.   2. The reflector molding die for a vehicle lamp according to claim 1, wherein as the diameter of the protrusion is larger, an angle for correcting downward the portion of the reflecting surface located on the opposite side of the protrusion is increased. Design method. The diameter D (mm) of the protrusion and the angle θ (°) to be corrected downward are θ (°) = 0.2 × D (mm) −0.5
3. The method for designing a reflector molding die for a vehicle lamp according to claim 2, wherein a portion of the reflecting surface located on the opposite side of the projection is corrected downward.

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