Extension member

Abstract

To provide an extension member that suppresses the occurrence of breakage during injection molding.SOLUTION: An extension member having a plurality of openings of different sizes is made of PBT resin and has one or more pier sections provided to divide and form the plurality of openings, and the minimum cross-sectional area part of the pier section is configured to have a parting line scar formed on the side surface closer to the surface in the surface-backward direction. Since the two openings of different sizes are pulled in opposite directions to each other when the mold is opened, fracture is likely to occur at the point that is the minimum cross-sectional area part in a molded product. For this reason, for the molding mold of the minimum cross-sectional area part, the surface area of the core side molding surface is increased to make it stick to the core side mold, so that the minimum cross-sectional area part can resist the pulling force by the sticking force.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an extension member made of PBT resin. [Background technology]

[0002] In vehicle lamps, the extension members that conceal the internal structure are becoming more complex in shape due to design needs. For example, Patent Document 1 discloses a vehicle lamp equipped with multiple optical units, and such a combination lamp uses a large extension member with multiple openings through which the light emitted by each optical unit passes.

[0003] In recent years, the use of PBT (polybrylene terephthalate) resin, which has high heat resistance, excellent abrasion resistance, and is inexpensive, has been increasing for extension members. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2014-165130 Summary of the Invention [Problem to be solved by the invention]

[0005] However, PBT resin has a high vacuum adhesion and therefore tends to stick to the mold. An opening is formed in the extension member to allow the light emitted from the optical unit to pass through, but if there are multiple openings with different opening areas, when molding with PBT resin, the openings with larger opening areas tend to stick to the mold on the cavity side, and the openings with smaller opening areas tend to stick to the mold on the core side. This causes an imbalance in the stress applied to the molded product when the mold is opened, and the stress is concentrated at the smallest cross-sectional area points, such as the piers, in the small openings, causing breakage.

[0006] The present invention has been made in view of the above, and provides an extension member that is made of PBT resin and suppresses the occurrence of breakage during molding. [Means for solving the problem]

[0007] In order to achieve the above object, in one embodiment of the configuration of the present disclosure, an extension member is provided in a vehicle lamp having a plurality of optical units that emit light, and the extension member shields at least a portion of the optical units from the outside, the extension member being an injection molded product made of PBT resin, The extension member is configured to have one or more pier sections that divide the opening through which the light emitted from the optical unit passes into multiple sections with different opening areas, and the smallest cross-sectional area section of the pier section has a parting line mark formed on its side surface, in the front-to-back surface direction, closer to the front surface.

[0008] PBT resin has a high vacuum adhesion and is prone to sticking to the mold. In extension parts with two or more openings with different opening areas, the larger openings stick to the mold on the cavity side and the smaller openings stick to the mold on the core side, resulting in an unbalanced stress on the molded product when the mold is opened. The piers are formed thin to separate the openings, so when the mold is opened, the smallest cross-sectional area of ​​the pier is subjected to a large stress and breaks. In response to this, the mold boundary of the smallest cross-sectional area is moved closer to the core side, the core side molding surface is increased compared to the cavity side molding surface, and the pier is configured to come into contact with the core side more, so that the pier is firmly attached to the core side mold and breakage of the smallest cross-sectional area when the mold is opened is suppressed. The mold boundary remains on the molded product as a parting line mark.

[0009] In one embodiment, the cross-sectional area of ​​the smallest cross-sectional area is 0.2 cm 2 More than 0.4cm 2 Conventionally, the minimum cross-sectional area was set to 0.4 cm2 to prevent breakage. 2By configuring as described above, it is possible to make the minimum cross-sectional area smaller, which increases the degree of freedom in design and also makes it possible to reduce the weight.

[0010] In one embodiment, a pressing mark is formed on the back side of the pier portion including the minimum cross-sectional area portion. Since the core side molding surface is increased, the minimum cross-sectional area, which tends to stick to the core side mold, tends to remain in the core side mold during ejection. For this reason, a protrusion is provided on the core side mold of the minimum cross-sectional area to prevent breakage during the ejection process. The mark left by the protrusion remains as a pressing mark on the bottom surface of the minimum cross-sectional area of ​​the molded product.

[0011] In one embodiment, the pressing marks on the minimum cross-sectional area portion are formed only in approximately half of the thickness direction of the pier portion. If a fillet is provided at the bottom corner of the minimum cross-sectional area portion, a very small protrusion corresponding to the fillet will be formed on the protruding member. To avoid this, the protruding member is configured so that only half of the minimum cross-sectional area is formed in the thickness direction. This prevents breakage during protrusion, and the molded product can be removed from the mold reliably. Effect of the Invention

[0012] As is clear from the above description, according to the present invention, it is possible to provide an extension member that is made of PBT resin and that is less susceptible to breakage during molding. [Brief description of the drawings]

[0013] [Figure 1] 1 is a front view showing a schematic structure of a vehicle lamp including an extension member according to an embodiment; [Diagram 2] 2(B) is a cross-sectional view taken along line II(B)-II(B) of FIG. 2(A) showing an extension member. [Diagram 3] 1A and 1B are perspective views of an extension member, in which (A) is a perspective view from the front side, and (B) is a perspective view from the back side. [Figure 4] FIG. [Diagram 5] This is a cross-sectional view of the mold for the pier section taken along line II(B)-II(B) in FIG. [Figure 6] 1A and 1B are schematic diagrams showing the arrangement of protruding members relative to the extension member, where (A) shows the arrangement of the protruding members of this embodiment, and (B) shows the arrangement of a conventional protruding member for comparison. [Figure 7] This is an example of a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all the features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0015] (Embodiment) 1 is a front view of a vehicle lamp 1 including an extension member 10 according to an embodiment. The vehicle lamp 1 is a right headlamp and is mounted on the front right side of a vehicle.

[0016] As shown in Fig. 1, a vehicle lamp 1 includes a lamp body 2 and a front cover 3. The lamp body 2 is formed in a box shape with an opening. The front cover 3 is made of a translucent resin, glass, or the like, and is attached to the opening of the lamp body 2 to form a lamp chamber. Three optical units LU1 to LU3 and an extension member 10 are arranged in the lamp chamber.

[0017] The optical units LU1 to LU3 are provided with light sources that are light-emitting elements, and emit light emitted from the light sources to the front of the vehicle. In this embodiment, the optical unit LU1 is a variable light distribution unit that forms a light distribution pattern adapted to the driving situation of the vehicle and the surrounding situation, and irradiates the light to the front of the vehicle. The optical units LU2 and LU3 are a turn signal lamp unit and a positioning lamp unit, respectively, and emit amber light and white light to the front of the vehicle. Hereinafter, except when a specific optical unit is specified, the three optical units LU1 to LU3 will be collectively referred to as the optical unit LU.

[0018] The optical unit LU uses a known configuration, such as a scanning mechanism device, a reflector type device, a projector type device, or the like, and the type is not limited. The configuration of the present disclosure is not limited to an extension member used in the headlamp of the above-mentioned combination lamp. It can be widely applied as an extension member that hides the internal configuration in various vehicle lamps in which a combination lamp using multiple optical units such as tail lamps, turn signal lamps, stop lamps, clearance lamps, daytime running lamps, cornering lamps, hazard lamps, positioning lamps, back lamps, and fog lamps is arranged.

[0019] (Extension parts) Figures 2 and 3 show the extension member 10, with Figure 2(A) being a front view, Figure 2(B) being a cross-sectional view taken along line II(B)-II(B) in Figure 2(A), Figure 3(A) being a front perspective view (oblique view from the front side), and Figure 3(B) being a rear perspective view (oblique view from the rear side). In Figures 2 and 3, the extension member 10 is colored in light ink to clearly show the opening.

[0020] The extension member 10 is positioned in front of the optical unit LU and covers the gap between the optical unit LU and the lamp body 2, as well as the gap between adjacent optical units LU, thereby preventing the internal structure of the optical unit LU from being seen from the outside. The extension member 10 is a thin-walled injection-molded product made of PBT (polybrylene terephthalate) resin.

[0021] The extension member 10 is composed of a frame portion 11 that forms the peripheral wall, a first pier portion 20 that hangs from the inside of the frame portion 11 and extends horizontally, and a second pier portion 30 that hangs between the frame portion 11 and the first pier portion 20 and extends vertically.

[0022] The two piers 20, 30 spanning the frame 11 form openings OP1 to OP3 for passing the irradiated light from the optical unit LU at positions corresponding to the optical units LU1 to LU3, respectively.

[0023] First, the opening inside the frame 11 is largely divided in the vertical direction into two, an opening OP1 and openings OP2 and OP3, by the first pier 20 extending horizontally from the frame 11. The first pier 20 is provided upward from the center in the vertical direction, and the opening OP1 formed at the bottom is formed wider than the openings OP2 and OP3 formed at the top. The optical unit LU1 uses a large optical device as the device to irradiate high-intensity light at a wide angle to form a light distribution and ensure the driver's visibility in the dark, and the corresponding opening OP1 also has a very large opening area.

[0024] The second pier 30 spans the upper opening divided by the first pier 20, and is provided to the right of the center in the left-right direction. Therefore, the opening OP2 formed on the left is wider than the opening OP3 formed on the right. The second pier 30 further divides the opening on the inside of the frame 11 divided by the first pier 20.

[0025] With the above configuration, the opening areas of the openings OP1 to OP3 are all different, and the opening area of ​​the opening OP1 is larger than the combined opening area of ​​the openings OP2 and OP3.

[0026] As shown in Fig. 2(B), the cross-sectional shape of the first pier 20 and the frame 11 is an inverted U-shape. Therefore, as shown in Fig. 3(B), a peripheral wall 14 is formed extending vertically from the outer periphery of the opening OP1. In addition, a peripheral wall 15 extending vertically is formed on the outer periphery shared by the openings OP2 and OP3. The cross-sectional shape of the second pier 30 is an inverted J-shape, and the second pier 30 separating the relatively small opening OP2 and opening OP3 is formed shorter in the vertical direction than the first pier 20, has a narrower width, and is thin-walled, making it the smallest cross-sectional area portion smaller than any other portion of the extension member 10.

[0027] (Mold for bridge pier) Here, the second pier 30 and its molding method will be described. FIG. 4 is an enlarged perspective view of the second pier 30, and is a downward perspective view to show the features of the back side of the second pier 30. In FIG. 4, the dimensions of the depth of the pressing mark and the protruding length of the parting line mark do not reflect the actual dimensions, but show the configurations typically. FIG. 5 is a schematic diagram showing the schematic configuration of the pier mold 40 of the second pier 30, and is a cross-sectional view at a position corresponding to the line II(B)-II(B) in FIG. 2(A). The pier mold 40 constitutes a part of the mold for the extension member 10.

[0028] Before describing the features of the second pier portion 30, the molding die and molding method thereof shown in FIG. 5 will be described.

[0029] As shown in FIG. 5, the pier section mold 40 is composed of a cavity side mold 41 and a core side mold 42 having an ejection member 43.

[0030] The protruding member 43 is held in a hole 42b provided in the core side mold 42 so as to be slidable in the vertical direction. The protruding member 43 is provided so as to engage with only half of the bottom surface of the second pier portion 30 to be molded in the thickness direction.

[0031] A cavity side molding surface 41a and a core side molding surface 42a are formed on the opposing surfaces of the cavity side mold 41 and the core side mold 42 including the ejection member 43. When the cavity side mold 41 and the core side mold 42 are arranged facing each other and clamped, a molding space S1 corresponding to the shape of the second pier portion 30 is defined therein by the two molding surfaces 41a and 42a.

[0032] A boundary 44 between the cavity-side mold 41 and the core-side mold 42 is configured to be flush with the surface of the second pier 30 to be molded. For this reason, the cavity-side molding surface 41a is substantially flat and configured to mold only the surface 31 of the second pier 30. On the other hand, the core-side molding surface 42a forms the parts of the second pier 30 other than the surface 31, and is therefore formed by being dug down from the surface of the core-side mold 42 by the height of the second pier 30.

[0033] As described above, by configuring the pier mold 40 so that the boundary 44 between the cavity-side mold 41 and the core-side mold 42 is flush with the surface 31 of the second pier 30, the area of ​​the core-side molding surface 42a is made much larger than the area of ​​the cavity-side molding surface 41a. Therefore, the molded product molded with the pier mold 40 adheres closely to the core-side mold 42.

[0034] (Action and effect) Among the openings OP1 to OP3 provided in the extension member 10, the opening OP1 has a larger opening area than the openings OP2 and OP3. The opening OP3 has a smaller opening area than the opening OP2. In addition, the PBT resin constituting the extension member 10 is generally widely used in injection molding because it has high heat resistance, excellent abrasion resistance, and is inexpensive, and has a higher degree of vacuum adhesion than, for example, polypropylene resin, polyester resin, etc.

[0035] Conventionally, in injection molded products made of polyester resin, the parting line (boundary) is located at the bottom of the molded product. The front side of the molded product is formed by the cavity side mold, and the back side is formed by the core side mold having an ejecting member. If there is an opening, the peripheral wall surface of the opening is formed by the molding surface on the cavity side. When molding with PBT resin using a mold configured so that the parting line is the bottom part, the opening of the molded product adheres closely to the cavity side mold having the molding surface because the vacuum adhesion of PBT resin is high. When a molded product has multiple openings with different opening areas, the opening with a large opening area has a large surface area in contact with the cavity side mold, so it is likely to stick to the cavity side mold. However, since the opening with a small opening area has a relatively small surface area in contact with the cavity side mold, it is likely to remain on the core side mold when the mold is opened, and the balance of stress applied to the molded product when the mold is opened is poor. For this reason, when the mold is opened, stress is concentrated at the minimum cross-sectional area of ​​the molded product, and the molded product easily breaks at the minimum cross-sectional area.

[0036] In the extension member 10 of this embodiment, the opening area of ​​the opening OP1 is large, and the inner surface (opening side) of the peripheral wall 14 is in close contact with the cavity side mold. The opening areas of the openings OP2 and OP3 are small in comparison, so that although the inner side of the peripheral wall 15 is in close contact with the cavity side mold, the area in contact with the cavity side mold is smaller than that of the peripheral wall 14. 15 tends to remain in the core side mold. During the mold opening process for the extension member 10, the frame portion 11, which has the largest volume and surface area, tends to remain in the core side mold, so the entire portion remains in the core side mold. However, when the peripheral wall 14 is pulled by the cavity side mold, the periphery of the openings OP2, OP3 is also pulled by the cavity side mold, and the second pier portion 30, which has the smallest cross-sectional area, is subjected to the greatest stress.

[0037] In this embodiment, the pier mold 40 is configured so that the boundary portion 44 is flush with the surface 31 of the molded product, so that the core-side molding surface 42a is much larger than the cavity-side molding surface 41a. Since the area in contact with the core-side mold 42 is large, the second pier 30 adheres firmly to the core-side mold 42. This adhesion force can counter the pulling force applied to the second pier 30, which is the smallest cross-sectional area, toward the cavity-side mold when the mold is opened, and the molded product including the second pier 30 remains in the core-side mold. This suppresses the occurrence of breakage at the smallest cross-sectional area when the mold is opened for molded products with different openings. As with the pier mold 40, the effect of suppressing breakage occurring in the molded product is achieved by simply increasing the core-side molding surface only to the smallest cross-sectional area where the most stress is applied.

[0038] (Arrangement of protruding parts) After the mold is opened, in the ejection process, the molded product attached to the core side mold is ejected upward by the ejection member 43 and removed. Here, the arrangement of the ejection members of the entire extension member 10 will be described with reference to FIG. 6. FIG. 6 shows a schematic arrangement of the ejection members relative to the rear view (rear view) of the extension member. FIG. 6(A) shows the arrangement of the ejection members relative to the extension member 10 in this embodiment, and FIG. 6(B) shows the arrangement of the conventional ejection members. The extension member 110 in FIG. 6(B), shown for comparison, has the same shape as the extension member 10 and has a pier portion 130. In order to clearly show each opening, the extension members 10 and 110 are colored with light ink, and the ejection members P and 43 are hatched.

[0039] As shown in Figure 6(A), in this embodiment, the extension member 10 is provided with four protruding members P on each of the four sides, three protruding members P in the opening OP1, and a protruding member 43 hanging from the second pier portion 30.

[0040] In contrast, in the conventional embodiment, as shown in Fig. 6(B), the arrangement of the ejection members P is the same, but the ejection member 43 is not provided. This is because in the conventional embodiment, even if an ejection member is not provided in an opening with a small opening area, the molded product is released from the core side mold by being ejected by another ejection member.

[0041] However, as mentioned above, PBT resin tends to stick to the mold. The pier 130 in FIG. 6(B) is the smallest cross-sectional area, so stress tends to concentrate on it during ejection. For this reason, it may break when it tries to remain in the core-side mold during the ejection process. Furthermore, in this embodiment, in order to prevent the molded product from breaking during the mold opening process, the pier mold 40 for the second pier 30 is configured so that the boundary portion 44 is flush with the surface 31 of the molded product. For this reason, the second pier 30 adheres firmly to the core-side mold 42 in the small opening portion.

[0042] For this reason, as shown in Figures 5 and 6(A), by providing a protruding member 43, the second pier portion 30, which has the smallest cross-sectional area and is prone to stress concentration, is reliably pushed out, thereby enabling the extension member 10 to be removed.

[0043] (Second pier) The second pier 30 formed by the pier mold 40 having the above-mentioned configuration will now be described in detail with reference to FIG.

[0044] As shown in Fig. 4, parting line marks 34 are formed along the longitudinal direction at the corners of the surface 31 of the second pier. The parting line marks 34 are formed as burrs at the boundary 44 between the cavity side mold 41 and the core side mold 42 that mold the second pier 30, protruding laterally. The parting line marks are formed in a line shape during injection molding, and when the protruding portion is polished in a post-process, they remain on the pier as polishing marks. Such parting line marks are also included in the scope of the present invention.

[0045] Moreover, a pressing mark 35 is formed on a part of the bottom surface of the second pier 30. The pressing mark 35 is formed as a small rectangular depression on the bottom surface of one leg of the second pier 30, approximately at the center in the longitudinal direction, and only on approximately the outer half in the thickness direction.

[0046] The impression is left in a portion where an ejection member provided on the mold pushes up the molded product that sticks to the mold during ejection in order to remove the molded product from the mold during injection molding. In this embodiment, the impression is formed on the molded product by an ejection member 43 provided on the pier mold 40 ejecting the molded product remaining in the core side mold 42. Since the impression is formed by protruding a hook into the molded product by at least a part of the protruding surface, not only the shape of the protruding surface such as a circle or a rectangle remains as it is as the impression, but also in some cases only a part of the protruding surface such as a semicircle remains, and such impression is also included in the scope of the present invention.

[0047] The protruding member 43 is arranged so that it only engages half of the bottom surface of the second pier portion 30 in the thickness direction to be molded. To prevent non-rounded corners from injuring the hands, the corners of the molded product, including the bottom corners, are provided with a fillet with an extremely small radius of curvature (not shown in this embodiment). When the protruding member is configured to match the bottom surface of the molded product, it is necessary to form a very small protrusion to form this small fillet. In order to avoid the formation of a very small protrusion, it is configured so that it only engages half of the thickness direction in this way. It is not limited to this, but it is also possible to provide a nest and configure the protruding member so that it engages entirely in the thickness direction.

[0048] Conventionally, to prevent breakage during molding, the minimum cross-sectional area was 0.4 cm 2 It has been considered necessary to have at least this much. Extension members have become more complex, and design and weight-saving needs have led to a demand for a smaller minimum cross-sectional area. With the above-mentioned configuration, the occurrence of breakage at the minimum cross-sectional area of ​​the molded product during injection molding is suppressed, so the minimum cross-sectional area can be made smaller than before. Specifically, the cross-sectional area of ​​the second pier portion 30, which is the minimum cross-sectional area of ​​the extension member 10, is:0.2 cm 2 End 0.4 cm 2 The configuration of the present disclosure allows for greater freedom in designing the extension member.

[0049] The cross-sectional shape of the smallest cross-sectional area is 0.2 cm 2 More than 0.4cm 2 If it is less than Inverted U or J shape The shape may be either of the above.

[0050] (Modification) Fig. 7 shows modified examples, and Fig. 7(A) shows the second pier 30' as a modified example. Fig. 7(B) shows a pier mold 40', which is a mold for forming the second pier 30'. Components having the same configuration as the above embodiment are given the same reference numerals and the description will be omitted. Note that the protruding member 43 is omitted.

[0051] As shown in FIG. 7(B), a parting line mark 34 is formed on a side surface 36 of the pier portion 30', slightly closer to the front surface 31 than to the center in the up-down direction (front-rear direction).

[0052] As shown in Fig. 7(B), the pier mold 40' is configured so that the boundary 44 is not flush with the surface of the second pier 30' but is located approximately in the center of the side surface 36. Since PBT resin is relatively soft, the mold is not provided with a draft angle to make it easier to remove the molded product.

[0053] In the above embodiment, the pier mold 40 is configured so that the boundary 44 is flush with the surface 31 of the second pier 30, but at least the effect of suppressing breakage during molding can be obtained by simply moving the boundary, which is conventionally configured to be flush with the bottom surface of the molded product, toward the surface side. By increasing the area of ​​the core side mold molding surface and decreasing the area of ​​the cavity side molding surface, the force of adhesion to the core side mold can be increased, and the resistance can be increased. As shown in Figure 7 (B), it is preferable to configure the mold so that the boundary 44 is formed slightly closer to the surface than the center in the surface-rear surface direction of the molded product, as this will increase the suppression of breakage.

[0054] The above describes preferred embodiments of the present invention. However, the above embodiments are merely examples of the present invention, and these can be combined based on the knowledge of those skilled in the art, and such forms are also included in the scope of the present invention. [Explanation of symbols]

[0055] 1: Vehicle lighting fixtures 10: Extension member 20: First pier 30: Second pier 31 :Surface 34: Parting line marks 35: Press mark LU: Optical unit OP1~OP3: Opening

Claims

1. An extension member is provided in a vehicle lamp having a plurality of optical units that emit light, the extension member is disposed in front of the optical units, has a plurality of openings formed therein for passing light emitted from the plurality of optical units, and covers gaps between the optical units to conceal an internal structure of the optical units from being seen from the outside, It is an injection molded product made of PBT resin. A frame-shaped frame portion with a large opening on the inside, At least one pier portion that is attached to the inside of the frame portion and is formed thinner than the frame portion, A plurality of openings having different opening areas are formed inside the frame by the pier portion, the frame portion has a parting line mark formed on a bottom surface portion, which is a back surface that is a non-design portion of the injection molded product, in a front-back direction; At least one of the piers has a parting line formed near the surface, which is a design portion of the injection molded product, in the front-back direction; The cross-sectional shape of the pier having the parting line mark formed near the surface is an inverted U-shape or an inverted J-shape. An extension member characterized by:

2. At least one of the piers has a cross-sectional area of ​​0.2 cm ２ 0.4cm or more ２ is less than 2. The extension member according to claim 1 .

3. At least one of the piers has a pressing mark formed on the back side thereof.

2. The extension member according to claim 1 .

4. The pressure mark of at least one of the piers is formed only in half of the thickness direction of the pier.

4. The extension member according to claim 3.

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