Lamp body of a vehicle light fixture
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KOITO MFG CO LTD
- Filing Date
- 2022-08-03
- Publication Date
- 2026-05-22
AI Technical Summary
The challenge is to create a lamp body for vehicle lights that is both thin and has good moldability, as providing a gate at the center of a thin lamp body leads to welds and increased costs, while conventional solutions like vent pins are costly.
A lamp body design with a container-shaped structure featuring a seal groove around the front opening, a thinner main body, and a gate mark in the center of the seal groove, combined with a truss-like structure using beams for increased rigidity, ensuring even resin flow and preventing molding defects.
The design achieves a thinner lamp body with improved moldability and rigidity, reducing weight and maintaining structural integrity while minimizing molding defects and costs.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a lamp body for vehicle lamps, and more particularly to a lamp body in which a seal groove is provided at an opening, and the lamp body main body is configured to be thinner than the seal groove.
Background Art
[0002] Normally, in resin molding of a lamp body, a gate is provided at a position in the center of the back surface of the lamp body (for example, Patent Document 1). This is because the molten resin spreads evenly in the cavity of the mold, and defective molding such as sink marks can be suppressed.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in recent years, due to the requirement of weight reduction, the lamp body tends to be thinned. However, when a gate is provided at the center of the back surface of the thin lamp body, there is a problem that welds frequently occur at the end of the lamp body. On the other hand, if a vent pin is provided to deal with this, the cost will increase. Therefore, a lamp body having good moldability and being configured to be thin is desired.
[0005] The present case has been made in view of such problems, and an object thereof is to provide a lamp body having good moldability and being configured to be thin.
Means for Solving the Problems
[0006] To solve the aforementioned problem, a lamp body for a vehicle light fixture in one aspect of the present disclosure comprises a container-shaped lamp body body having a front opening and a seal groove provided around the front opening, wherein the lamp body body is thinner than the seal groove and has a gate mark approximately in the center of the seal groove, which is provided on one side of the lamp body body that constitutes the front opening.
[0007] In this embodiment, since a gate is provided in the lamp body mold at a position approximately in the center of the seal groove, the molten resin spreads through the cavity forming the seal groove as a sprue and fills evenly to the end, thereby suppressing the occurrence of molding defects such as gas burning caused by premature flow.
[0008] In one embodiment, the rear wall of the lamp body is connected via a ridge to at least one of the circumferential surfaces extending forward from the outer edge of the rear wall, and a plurality of beams with a substantially arc-shaped cross-section, which constitute a part of the rear wall, extend in a truss-like manner from the upper edge to the lower edge of the rear wall.
[0009] According to this embodiment, the truss structure provides high rigidity to the lamp body, and even if the lamp body is made thin, it retains sufficient rigidity. As a result, the lamp body can be made thinner, and the seal groove becomes relatively thicker.
[0010] In one embodiment, the gate mark is located approximately in the center of the seal groove, which is provided on the largest surface among the constituent surfaces of the lamp body. In this embodiment, the molten resin spreads evenly throughout the cavity of the lamp body mold, suppressing the occurrence of molding defects. [Effects of the Invention]
[0011] As is clear from the above explanation, a lamp body with good moldability and thin walls can be provided. [Brief explanation of the drawing]
[0012] [Figure 1] This is a front view showing a schematic configuration of a vehicle lighting device according to a preferred embodiment. [Figure 2] This is a front view of the lamp body. [Figure 3] This is a perspective view of the lamp body. [Figure 4] This is an end view of the lamp body. It follows each of the indicator lines (cut surfaces) shown in Figure 2. [Figure 5] This is an explanatory diagram illustrating a truss structure using beams. It corresponds to Figure 2. [Figure 6] This is an explanatory diagram of the lamp body shape. Figure 6(A) is a vertical end view of a conventional lamp body 102 for comparison. Figure 6(B) is a vertical end view of lamp body 2. [Figure 7] This is an end view along the FF line in Figure 2. It mainly shows the gate marks G. [Figure 8] This is the mold for the lamp body. It corresponds to Figure 7. [Modes for carrying out the invention]
[0013] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The embodiments are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. Furthermore, in the following descriptions of embodiments and modifications, the same components will be denoted by the same reference numerals, and redundant descriptions will be omitted as appropriate.
[0014] (Vehicle lighting fixture 1) Figure 1 is a front view of a vehicle light fixture 1 according to a preferred embodiment of the present invention. The vehicle light fixture 1 is a headlight mounted on the left and right corners at the front of the vehicle.
[0015] As shown in FIG. 1, the vehicle lamp 1 includes a container-shaped lamp body 2 with an open front surface and a front cover 4 assembled to the front opening of the lamp body 2. The front cover 4 is made of a resin or glass having translucency, such as polycarbonate. When the front cover 4 is attached to the opening of the lamp body 2, a lamp chamber S is defined inside.
[0016] Inside the defined lamp chamber S, a high-beam lamp unit Hi and a low-beam lamp unit Lo are accommodated.
[0017] The high-beam lamp unit Hi and the low-beam lamp unit Lo are optical units configured to irradiate the emitted light from the light source forward of the vehicle to form high-beam light distribution / low-beam light distribution. Each lamp unit (Hi, Lo) uses a conventionally well-known configuration, such as a reflector type or a projector type lamp unit, and the type thereof is not limited.
[0018] (Lamp body 2) The shape of the lamp body 2 will be described in detail. FIG. 2 is a front view of the lamp body 2. FIG. 3 is a front perspective view of the lamp body 2.
[0019] The lamp body 2 is formed by injection molding using a hard synthetic resin material. The lamp body 2 mainly consists of a container-shaped lamp body main body 20 with an open front surface, a seal groove 3 provided around the front opening of the lamp body main body 20 to engage with the seal legs provided at the periphery of the front cover 4, and a vehicle body attachment portion 5 for attaching to the vehicle body.
[0020] The vehicle body attachment portion 5 is provided on the outer surface of the lamp body main body 20 at the boundary between the seal groove 3 and the lamp body main body 20. A part of the base end portion is connected to the seal groove 3, and it protrudes corresponding to the shape of the attachment portion on the vehicle body side. The vehicle body attachment portion 5 is provided at five locations in total, three locations upward and two locations leftward, on the outer surface of the lamp body main body 20.
[0021] The lamp body 2 has a rear wall 6, a top surface 7, a bottom surface 8, and left and right sides 9,9 as constituent surfaces. The rear wall 6 bulges outwards towards the rear and is connected to the adjacent top surface 7, bottom surface 8, and sides 9,9 via ridges. The top surface 7, bottom surface 8, and sides 9,9 are basically convex curved shapes that bulge gently outwards from the lamp body 2, and their edges curve gently, connecting them continuously without bends or steps. As a result, the lamp body 2 is formed as a rounded container shape overall. In this embodiment, the top surface 7 is formed extending from the opening of the lamp body 2 toward the rear, but the amount of extension is small, and it extends from the edge of the opening toward the lower rear, curving gently and connecting to the rear wall 6, thus being integrally formed with the rear wall 6. Thus, the constituent surfaces of the lamp body 2 are mainly composed of curved surfaces with a large radius of curvature rather than flat surfaces.
[0022] The seal grooves 3 are provided on the constituent surfaces of the lamp body 20, which constitute a part of the opening. A ceiling seal groove 31 is provided at the opening on the ceiling surface 7, a bottom seal groove 32 at the opening on the bottom surface 8, a left side seal groove 33 at the opening on the left side surface 9, and a right side seal groove 34 at the opening on the right side surface 9. The ceiling seal groove 31, bottom seal groove 32, left side seal groove 33, and right side seal groove 34 are provided continuously with adjacent seal grooves without any steps. Hereinafter, unless one of the ceiling seal groove 31, bottom seal groove 32, left side seal groove 33, or right side seal groove 34 is specifically designated, these will be collectively referred to as seal grooves 3.
[0023] The lamp body 2 has a first unit mounting hole 11 formed in the upper center of the rear wall 6 for mounting the low beam lamp unit Lo. Additionally, a second unit mounting hole 12 for mounting the high beam lamp unit Hi is formed in the upper left of the rear wall 6.
[0024] In addition, the lamp body 2 has mounting holes 41 for a first aiming member, 42 for a second aiming member, and 43 for a third aiming member formed around the mounting hole 11 for the first unit. Aiming members (not shown) are mounted in each of the aiming member mounting holes 41, 42, and 43.
[0025] The first aiming member mounting hole 41 is located between the first unit mounting hole 11 and the second unit mounting hole 12 in the left-right direction, and is provided on the lower edge of the rear wall 6 in the up-down direction. The second aiming member mounting hole 42 is provided in a position that is approximately symmetrical to the first aiming member mounting hole 41 with respect to the first unit mounting hole 11. For this reason, the second aiming member mounting hole 42 is provided on the lower edge of the rear wall 6, offset to the right from the left side where the first aiming member mounting hole 41 is located, by a distance approximately equal to the distance from the first unit mounting hole 11 to the first aiming member mounting hole 41. The third aiming member mounting hole 43 is formed above the second aiming member mounting hole 42 at the upper end of the rear wall 6.
[0026] Furthermore, the lamp body 2 has a breathing hole 50 formed in the rightmost region of the rear wall 6, to the right of the mounting hole 43 for the third aiming member. This breathing hole 50 allows for the expansion and contraction of air inside the lamp chamber S due to heat generated by the lighting of the Hi and Lo light sources of the lamp unit and changes in temperature, while also allowing moisture inside the lamp chamber S to escape to the outside, preventing moisture from accumulating inside the lamp chamber S. This prevents fogging inside the lamp chamber S caused by moisture inside the lamp chamber S adhering to the front cover 4 from the inside of the lamp chamber S.
[0027] (Back wall and beam) The rear wall 6 has a first beam 61, a second beam 62, a third beam 63, a fourth beam 64, and a fifth beam 65 that extend from the upper end to the lower end of the rear wall 6, forming a part of the rear wall 6. Here, the part of the rear wall 6 other than the components of beams 61-65 is referred to as the rear wall body 69.
[0028] The first beam 61 extends straight upward from the first aiming member mounting hole 41 provided at the lower end of the rear wall 6 to the upper end of the rear wall 6, when viewed from the front.
[0029] The second beam 62 extends from the lower first aiming member mounting hole 41 and the upper second unit mounting hole 12 as its endpoints, connecting the two. For this reason, the second beam 62 is formed with a tilt to the right when viewed from the front.
[0030] The third beam 63 extends from the lower second aiming member mounting hole 42 and the upper first unit mounting hole 11 as its endpoints, connecting the two. Therefore, when viewed from the front, the third beam 63 is formed to be tilted to the left, in the opposite direction to the second beam 62.
[0031] The fourth beam 64 extends from the lower second aiming member mounting hole 42 and the upper third aiming member mounting hole 43 as its endpoints, connecting the two. Therefore, when viewed from the front, the fourth beam 64 is formed almost vertically.
[0032] The fifth beam 65 extends from the lower second aiming member mounting hole 42 and the upper breathing hole 50, connecting the two. Therefore, when viewed from the front, the fifth beam is formed with a tilt to the right.
[0033] Figure 4 is an end view along the cutting line shown in Figure 2. Figure 4(A) is an end view along line AA in Figure 2, mainly showing the cross-sectional shape of the first beam 61. Figure 4(B) is an end view along line BB in Figure 2, mainly showing the cross-sectional shape of the second beam 62. Figure 4(C) is an end view along line CC in Figure 2, mainly showing the cross-sectional shape of the third beam 63. Figure 4(D) is an end view along line DD in Figure 2, mainly showing the cross-sectional shape of the fourth beam 64. Figure 4(E) is an end view along line EE in Figure 2, mainly showing the cross-sectional shape of the fifth beam 65.
[0034] As shown in Figures 5(A) to 5(E), each beam 61 to 65 has a cross-sectional shape perpendicular to its extension direction, and although their radii of curvature, width, and projection differ, they are all configured to be approximately arc-shaped. Beams 61, 62, 63, and 65 are formed so that the projection direction of their curved surfaces is towards the lamp room S (forward). Beam 64 is formed so that its curved surface and projection direction are towards the outside of the lamp room S (rear direction).
[0035] Each beam, from 61 to 65, is smoothly connected to the back wall body 69 via its ridge, regardless of its protruding direction. The corresponding cross-sectional shape of the ramp body 2 is continuously constructed without any bends, while maintaining a constant thickness.
[0036] For example, the longitudinal cross-sectional shape of the back wall 6 including the second beam 62 will be explained in detail in Figure 4(B). As shown in Figure 4(B), a ceiling seal groove 31 is provided at the upper edge of the opening of the lamp body 2 (see also Figure 2), and the back wall body 69, which is integrated with the ceiling surface 7, extends downward from here toward the back, and at the boundary with the second beam 62, it curves forward and smoothly connects with the second beam 62. The second beam 62 extends downward, curves forward, and then curves backward again, forming a roughly arc shape that bulges forward. At its lower edge, the second beam 62 curves forward and downward and smoothly connects again with the back wall body 69. The back wall body 69 extends forward and downward, curves inward toward the inside of the lamp room S, and connects to the edge of the bottom surface 8 which is curved with the same curvature. The bottom surface 8 continues to extend forward and connects to the bottom seal groove 32 provided at the lower edge of the opening of the lamp body 2. In this way, the ceiling surface 7 and the rear wall body 69, the rear wall body 69 and the second beam 62, and the rear wall body 69 and the bottom surface 8 are smoothly connected by curving with the same curvature at their respective connection points, without forming any bends or steps.
[0037] As shown in Figures 5(A),(C),(D), and(E), the first beam 61, the third beam 63, the fourth beam 64 (with the convex direction of the beam portion in the opposite direction), and the fifth beam 65 are also connected to the back wall body 69 via their edges in the same manner. In this way, each beam 61 to 65 extends from the upper end to the lower end of the back wall 6, maintaining a roughly arc-shaped cross-section in the direction of extension, and is connected to the back wall body 69 continuously and smoothly at the ends, without forming steps or corners between adjacent surfaces.
[0038] The cross-sectional shape of the lamp body 2, as described above, is composed of a series of complex, wavy curves. Furthermore, the back wall 6, ceiling surface 7, bottom surface 8, and side surfaces 9,9 are similarly connected via ridges, and at the boundary, they curve with the same curvature, creating a smooth and continuous connection. The back wall 6, ceiling surface 7, bottom surface 8, and side surfaces 9,9 themselves are generally curved surfaces with a large radius of curvature, gently bulging outwards, and adjacent curved surfaces are smoothly continuous. As a result, the lamp body 2 itself is mainly composed of curved surfaces, reducing the formation of corners and maintaining a generally constant thickness.
[0039] As described above, the rear wall 6 and lamp body 2 are constructed with higher rigidity than conventional lamp bodies, allowing them to be made thinner. This will be explained using Figures 5 and 6. Figure 5 is a front view of the lamp body 2, with beams 61-65 of the lamp body 2 shown in light gray.
[0040] As shown in Figure 5, each beam 61-65 extends from the upper end to the lower end of the back wall 6, and other beams extend diagonally from the end of one beam, forming a truss structure based on triangles. As a result, the ramp body 2, including the back wall 6, is a structure that is resistant to deformation under load. Furthermore, since the beams 61-65 themselves have a curved surface with a roughly arc-shaped cross-section that distributes stress, they have a highly rigid structure that is more resistant to deformation. This improves the rigidity of the ramp body 2, and the increased rigidity allows for thinner walls.
[0041] The shape of the lamp body 2 will be explained in comparison with the conventional configuration. Figure 6(A) is a vertical cross-sectional view showing a schematic diagram of the conventional lamp body 102 for comparison. Figure 6(B) is a vertical cross-sectional view of the lamp body 2.
[0042] As shown in Figure 6(A), a conventional lamp body 102 has a generally planar back wall 106, a top surface 107, and a bottom surface 108. The top surface 107 and bottom surface 108, which are horizontal planes, are connected to the upper and lower ends of the vertically positioned back wall 106. As a result, a 90-degree corner is formed at the connection point. Corners formed by the collision of two planes are prone to stress concentration. To suppress deformation due to stress concentration and ensure rigidity, ribs 110 are provided at the corner.
[0043] In contrast, as shown in Figure 6(B), in the lamp body 2, the back wall 6, the top surface 7, and the bottom surface 8 are connected to each other via ridges. Thus, the lamp body 2 is mainly composed of curved surfaces, and adjacent surfaces are connected by curving with the same curvature at their boundaries. The constituent surfaces are smoothly continuous, and no bends are formed at the connection points, and no corners are formed due to stress concentration. By suppressing the formation of corners where stress concentrates, stress is distributed, resulting in a highly rigid structure that is resistant to deformation. In this embodiment, all constituent surfaces are connected by ridges, but it is sufficient that at least the back wall 6 is connected to one of the surfaces of the top surface 7, bottom surface 8, or sides 9,9 via ridges.
[0044] Similarly, beams 61-65 are connected to the back wall body 69 via ridges, and the connection is smoothly continuous. As a result, the cross-sectional shape of the back wall 6 is configured as a wave shape without bends, which suppresses stress concentration at the corners and improves rigidity. In this case, as long as it is not a plane, the direction in which each beam 61-65 curves relative to the extension direction (the protruding direction of the approximately arc-shaped cross-section) can be either forward or backward (towards the back).
[0045] In lamp body 2, beams are provided on the rear wall, but beams may also be provided on the ceiling, bottom, and sides. Furthermore, the extension direction and shape of each beam are merely examples, and other types of truss shapes may be used as long as a truss structure based on triangles is formed.
[0046] In the lamp body 2, the ends of each beam 61-65 are provided with mounting holes 11 for the first unit and mounting holes 41, 42, and 43 for the aiming member, which are located in the back wall 6. This is because, due to the nature of mounting other components, the mounting holes are thicker and more rigid than other parts of the back wall 6. By utilizing these structurally necessary components in parts of the beams, especially at important beam joints, the rigidity of the back wall 6 and, consequently, the lamp body 2 is improved. Furthermore, the breathing holes 50 are surrounded by a waterproof wall, making them highly rigid areas, similar to the mounting holes.
[0047] As described above, the lamp body 2 has high rigidity, allowing it to be made thinner than conventional models. However, the sealing groove 3 at the opening is constructed with the same plate thickness as the conventional product, without being made thinner than the conventional product, due to the nature of the front cover 4 being attached to it.
[0048] In other words, in the lamp body 2, only the lamp body main body 20 is made thin, while the seal groove 3 is not made thin, and the seal groove 3 is made thicker than the lamp body main body 20.
[0049] Therefore, a portion of the seal groove 3 also constitutes part of the truss structure. By using at least a portion of the seal groove 3 to form a truss structure together with beams 61-65, the rigidity of the ramp body 2 is improved.
[0050] (Resin molding of lamp body 2) The injection molding process and the gate position of the mold for the lamp body 2, which is configured as described above, will now be explained.
[0051] The white arrows in Figures 2 and 3 indicate gate marks G. Figure 7 is a cross-sectional view along the FF line in Figure 2, primarily showing gate marks G. Figure 8 shows the mold 80 for forming the lamp body 2. Figure 8 corresponds to Figure 7.
[0052] As described above, the seal grooves 3 are provided on the structural surfaces that constitute part of the openings of the lamp body 2, more specifically the lamp body main body 20. The ceiling seal groove 31 is provided at the opening of the ceiling surface 7, the bottom seal groove 32 is provided at the opening of the bottom surface 8, the left side seal groove 33 is provided at the opening of the left side surface 9, and the right side seal groove 34 is provided at the opening of the right side surface 9.
[0053] In this embodiment, a gate mark G is formed approximately in the center of the bottom seal groove 32, which is provided on the bottom surface 8, among the seal grooves 3 that are provided around the opening of the lamp body 20. In this embodiment, the lamp body 2 has no gate marks other than this gate mark G, and the gate mark G is the only gate mark on the lamp body 2.
[0054] The formation of the gate marks G will be explained starting with the molding method of the lamp body 2. As shown in Figure 8, the mold 80 for molding the lamp body 2 has a fixed mold 83 and a movable mold 84, and is configured to form a cavity C corresponding to the shape of the lamp body 2 between the fixed mold 83 and the movable mold 84. The cavity C mainly consists of a first cavity C1 corresponding to the shape of the lamp body main body 20 and a second cavity C2 corresponding to the shape of the seal groove 3. In the second cavity C2, the distance between the cavity forming surface of the fixed mold 83 and the cavity forming surface of the movable mold 84 is relatively far, and the space is relatively wide. However, in the first cavity C1, the distance between the cavity forming surface of the fixed mold 83 and the cavity forming surface of the movable mold 84 is closer than that of the second cavity, and the space is narrower.
[0055] The mold 80 is provided with a single gate 85 located approximately in the center of the bottom seal groove 32. Molten resin, heated to its melting temperature, is injected through the gate 85 into the cavity C, filling the cavity C. The resin then cools and solidifies, and is removed from the mold 80, thereby forming the lamp body 2.
[0056] In conventional molds for forming lamp bodies, a direct gate is provided at the center of the back of the lamp body. Since the gate is generally located in the center of the cavity space, when molten resin is poured into the cavity from the gate, it spreads radially and reaches the edges of the cavity. In conventional lamp bodies, both the lamp body itself and the seal groove are made of roughly the same thickness, and the molten resin spreads fairly evenly within the cavity, including the seal groove.
[0057] In contrast, as shown in Figure 7, unlike conventional lamp bodies where the thickness of the lamp body body and the seal groove are equal, the lamp body body 20 has a thickness T2 that is thinner than the thickness T1 of the seal groove 3. The lamp body body 20 has high rigidity due to its truss structure, and even though it is thinner than conventional lamp bodies, it can maintain the same level of rigidity as conventional lamp bodies, so it is made thinner for weight reduction. In contrast, the seal groove 3 engages with the front cover 4 of another component, so it is not made thinner and retains its conventional thickness. For this reason, the lamp body body 20 is relatively thinner than the seal groove 3.
[0058] In a lamp body 2 where the lamp body body 20 is thinner than the seal groove 3, if a direct gate is provided in the mold for molding the lamp body 2 at a position corresponding to the center of the back of the lamp body body 20, a problem arises in which molding defects occur frequently. This is because, since the seal groove 3 is thicker than the lamp body body 20, the second cavity C2 is wide and thick, which unintentionally acts as a sprue, causing premature flow, and as a result, gas burning (weld line) occurs at the end. In addition, because the lamp body body 20 is thin, if a direct gate is provided in the first cavity C1, the molten resin does not spread evenly in the narrow space, and molding defects are likely to occur at the gate position. This phenomenon is not limited to lamp body 2, but occurs when molding lamp bodies in which a seal groove thicker than the plate thickness of the lamp body body is provided around the opening. If a gas vent insert is provided to suppress the occurrence of molding defects, the mold cost will increase.
[0059] Therefore, in this embodiment, the problem of molding defects is avoided by providing a gate 85 in the mold 80 for molding the lamp body 2 at a position approximately in the center of the bottom seal groove 32, which is one side constituting the seal groove 3. That is, if a gate is provided in the first cavity C1, the second cavity C2 will become an unintended sprue. Conversely, a gate 85 is provided in the second cavity C2 to make the second cavity C2 function as a sprue and prevent premature molding. The trace of the gate 85 remains as a gate mark G on the molded lamp body 2. The above molding method suppresses molding defects and improves the moldability of the lamp body 2.
[0060] When molten resin is poured into cavity C from gate 85 of mold 80, the molten resin flows through the wide and easily passable second cavity C2 as a sprue, flows from the second cavity C2 into the first cavity C1, and fills cavity C. Because the molten resin fills cavity C from the outer periphery inward, gas burning at the end is less likely to occur. In addition, only one gate, gate 85, is provided to control the flow of the molten resin and avoid molding defects caused by unintended leakage. Since the second cavity C2 is relatively wide, molding defects are less likely to occur at the gate location.
[0061] As described above, the seal groove 3 consists of a top seal groove 31, a bottom seal groove 32, a left side seal groove 33, and a right side seal groove 34. The gate 85 of the mold 80 is not limited to a position corresponding to the approximate center of the bottom seal groove 32, but may be provided at a position corresponding to the approximate center of any of the seal grooves.
[0062] Here, since the vehicle light fixture 1 has a rectangular parallelepiped shape that is long in the left-right direction, it is preferable to provide the gate 85 at a position corresponding to the ceiling seal groove 31 or the bottom seal groove 32 on the long side, as this provides a good balance in the length of the flow path.
[0063] The lamp body 20 consists of a rear wall 6, a top surface 7, a bottom surface 8, and left and right sides 9,9. Of the surfaces where the seal groove 3 is provided, the top surface 7 has the smallest area, while the bottom surface 8 has the largest area. In the mold 80, a gate 85 is provided at a position approximately corresponding to the center of the bottom seal groove 32, which is located on the bottom surface 8, the largest surface area. In the cavity C of the mold 80, the cavity that forms the bottom surface 8 has the largest volume among the cavities that make up each of the constituent surfaces. Therefore, when the gate 85 is provided at a position corresponding to the bottom seal groove 32, the molten resin that flows into cavity C fills the cavity that forms the bottom surface 8, then flows through the second cavity C2, and sequentially fills the cavities that form the left and right sides 9,9 and the top surface 7. The molten resin spreads evenly throughout cavity C, making it less likely for defects to occur at the ends. Thus, in the mold for forming the lamp body 2, it is preferable that the gate be provided approximately in the center of the seal groove, which is located on the largest surface among the constituent surfaces of the lamp body 20.
[0064] Furthermore, as shown in Figure 7, the seal groove 3 is composed of an inner circumferential wall 3a, an outer circumferential wall 3c, and a side wall 3b connecting the inner circumferential wall 3a and the outer circumferential wall 3c. A protruding base portion 3d is further provided on the outer circumferential wall 3c approximately in the center of the bottom seal groove 32, and the gate mark G is formed on the outer circumferential surface of the base portion 3d. In injection molded products, the base portion 3d may be cut off, and such traces are also included in the gate mark G.
[0065] In the mold 80, a gate may be provided at a position corresponding to the front surface of the base portion 3d (see gate mark G' in Figure 7). In this case, the flow direction of the molten resin injected from the gate is in the front-to-back direction, which coincides with the extension direction of the cavity forming the bottom surface 8. Therefore, the fluidity of the molten resin in the cavity C is good, which is preferable.
[0066] Alternatively, the base portion 3d may be omitted, and the gate 85 may be provided at a position corresponding to the outer perimeter wall 3c. Since the gate mark G remains in an inconspicuous location, such as the bottom surface of the lamp body 2, it does not affect the design of the vehicle lighting fixture 1.
[0067] Although preferred embodiments of the present invention have been described above, these embodiments are merely examples of the present invention, and it is possible to combine them based on the knowledge of those skilled in the art, and such combinations are also included within the scope of the present invention. [Explanation of symbols]
[0068] 1: Vehicle lighting fixtures 2: Lamp body 3: Seal groove 4: Front cover 6: Back wall 7: Ceiling surface 8: Bottom 9: Side view 11-12: Holes for unit mounting 20: Lamp body 32: Bottom sealing groove 41-43: Holes for mounting aiming components 61~65: Beam S:Lamp room G: Gate mark
Claims
1. A container-shaped lamp body with a front opening, A sealing groove is provided around the front opening, Equipped with, The rear wall of the lamp body has a beam with a substantially arc-shaped cross-section that forms part of the rear wall, The lamp body is constructed to be thinner than the seal groove, The seal groove, provided on one side of the front opening of the lamp body, has a gate mark approximately in the center of the extension direction of that side. A lamp body for a vehicle light fixture characterized by the following features.
2. The rear wall of the lamp body is connected via a ridge to at least one of the circumferential surfaces extending forward from the outer edge of the rear wall, and a plurality of beams with a substantially arc-shaped cross-section, which constitute a part of the rear wall, extend in a truss-like manner from the upper edge to the lower edge of the rear wall. A lamp body for a vehicle lighting device as described in feature 1.
3. The gate mark is located approximately in the center of the seal groove, which is provided on the largest surface of the lamp body that constitutes a part of the front opening. A lamp body for a vehicle light fixture according to claim 1 or 2.