JP2008226767A - Reflector and vehicular lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector capable of solving the problems of deterioration in light distribution performance due to the undercoating of a BMC reflector and weight and the problems of deformation in a light distribution pattern due to shortage in torsional stiffness in a PEI reflector and a cost increase due to large material costs. <P>SOLUTION: In a reflector member, when a range possibly becoming not less than 180°C is set to be a heat-resistant range S and a range less possibly becoming not less than 180°C is set to be a non-heat-resistant range B, a PEI material (unfilled polyetherimide) or a PPS resin (polyphenylenesulfide) is used for at least a partial range in the heat-resistant range S, and a PC resin (polycarbonate) is used for the non-heat-resistant range B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reflector and a vehicular lamp used for an automotive headlamp.

  FIG. 1 is a diagram showing a configuration example of an automotive headlamp. In the example of FIG. 1, an automotive headlamp includes a bulb (halogen type or HID discharge lamp type) 101, a reflector 102 that functions as a reflecting mirror that reflects part of light emitted from the bulb 101, and an extension 103. And an outer lens 104. Here, in the example of FIG. 1, the reflector 102 is configured as a parabolic surface type whose reflecting mirror surface is a parabolic surface.

  By the way, conventionally, a BMC material (bulk molding compound) which is a thermosetting resin is generally used as a member for a reflector used for an automotive headlamp as described above, for example, as disclosed in Patent Document 1. It has been. A BMC material (bulk molding compound) has advantages of high heat resistance (200 ° C.), excellent mechanical strength (rigidity) and dimensional stability, and a low material unit price.

  However, on the other hand, the reflector using the BMC material has a heavy weight, and there is a problem in reducing the weight of the vehicle headlamp. Further, since an undercoat is required on the reflecting mirror surface (that is, the BMC material contains GF (glass fiber) and a filler (calcium carbonate, etc.), the surface roughness is large, and a predetermined metal (for example, In order to obtain a reflective mirror surface by evaporating Al), an organic solvent paint base treatment process (hereinafter referred to as undercoat) is required) There is also a problem that improvement cannot be achieved.

  In addition, even with the light distribution performance as a reflector, the film thickness of the stepped portion is likely to be uneven due to the paint viscosity due to the undercoat, and it is difficult to achieve the performance according to the light distribution design aimed at (Fig. 2 ( a), see (b)). 2A is a diagram showing the light distribution performance when the undercoat coating is not applied (a diagram showing a case where the light distribution performance is good), and FIG. 2B is a diagram when the undercoat coating is applied. It is a figure which shows a light distribution characteristic (figure which shows the case where a light distribution characteristic is bad). That is, the BMC material has a problem that the light distribution performance is deteriorated by applying an undercoat coating to a reflecting mirror surface on which a predetermined metal (for example, Al) is deposited as shown in FIG.

On the other hand, in recent years, it has been proposed to use a PEI material (unfilled polyetherimide), which is a thermoplastic resin, as a member for a reflector. Since PEI material (unfilled polyetherimide) has high heat resistance (180 ° C.) and the surface roughness of the resin itself is small, a predetermined metal (for example, Al) is placed on the PEI material (unfilled polyetherimide). It is possible to obtain a reflecting mirror surface by direct vapor deposition (hereinafter referred to as direct vapor deposition), and it has the advantage that the specific gravity is as light as 1.27 and the material can be recycled because it is a thermoplastic resin. Since mechanical strength (rigidity) is weak, twisting as a reflector housing is likely to occur due to insufficient torsional rigidity (light distribution pattern deformation due to twisting is likely to occur), and the material unit price is expensive compared to BMC material, There is a problem that even if direct vapor deposition is possible, it is not cheap.
JP 2004-228025 A

  The present invention relates to the above-mentioned problems in the reflector of BMC material and the reflector of PEI material (that is, the problem of the light distribution performance deterioration and weight due to the undercoat of the BMC reflector, the deformation of the light distribution pattern due to the insufficient torsional rigidity of the PEI reflector) An object of the present invention is to provide a reflector and a vehicular lamp that can solve the problem of cost increase due to high material costs.

  In order to achieve the above object, the invention according to claim 1 is a reflector member in which a temperature range that is likely to be 180 ° C. or higher is defined as a heat resistant range, and a temperature range that is less likely to be 180 ° C. or higher. Is a non-heat-resistant range, PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) is used in at least a part of the heat-resistant range, and PC resin (polyphenylene sulfide) is used in the non-heat-resistant range. Polycarbonate) is used.

  The invention according to claim 2 is the reflector according to claim 1, characterized in that the non-heat-resistant range has a basic thickness of 2.8 mm or more.

  According to a third aspect of the present invention, in the reflector according to the first or second aspect, a predetermined metal film is directly formed in the heat-resistant range and the non-heat-resistant range without being undercoated. A reflecting mirror surface is formed.

  According to a fourth aspect of the present invention, there is provided a vehicular lamp including a bulb and a reflector that functions as a reflecting mirror that reflects a part of light emitted from the bulb. The reflector as described in any one of 3 is used, It is characterized by the above-mentioned.

According to the first to fourth aspects of the invention, the light distribution performance deteriorates due to the undercoat of the BMC reflector and the weight is heavy, the light distribution pattern is deformed due to the insufficient torsional rigidity of the PEI reflector, and the cost is increased due to the high cost of the material. The problem can be solved. That is, all the problems in the reflectors of the BMC material and the reflectors of the PEI material can be solved, and other necessary elements can be at the same level as the reflectors of the BMC material and the reflector of the PEI material. More specifically, the conventional reflector member uses the same material in all parts, but in the present invention, the required heat resistance range (at least a part of the heat resistance range) is limited to PEI resin / PPS resin. However, by constructing the non-heat-resistant range that does not require heat resistance with an inexpensive PC resin, the necessary heat resistance can be ensured and the weight can be reduced, and the problem of cost increase can be solved. In the non-heat-resistant range, a predetermined metal film is directly formed and a reflecting mirror surface is formed without applying an undercoat (that is, specifically, by direct vapor deposition), thereby reducing the light distribution performance. In addition, the non-heat-resistant range can also solve the lack of torsional rigidity when the basic thickness is 2.8 mm or more (that is, due to the appropriate thickness of the PC resin).

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  The inventor of the present application examined the temperature distribution of the reflector when the bulb 101 of the vehicular lamp as shown in FIG. 1 was turned on (temperature distribution from the front of the reflector). FIG. 3 shows the temperature distribution of the reflector when the bulb 101 is turned on (temperature distribution from the front of the reflector). FIG. 3 shows that when the bulb 101 is turned on, the reflector member has a range in which the temperature may be 180 ° C. or higher and a range in which the temperature is less likely to be 180 ° C. or higher.

  Therefore, in the present invention, when the range in which the temperature is likely to be 180 ° C. or higher among the reflector members is defined as the heat resistant range, and the range in which the temperature is unlikely to be 180 ° C. or greater is defined as the non-heat resistant range, PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) is used for at least a part of the range, and PC resin (polycarbonate) is used for the non-heat-resistant range. .

  FIG. 4 is a schematic view when the reflector member is viewed from the front. When the width and height of the reflector member are W and H, respectively, and the valve center (optical axis) is A, the heat resistance range is the valve center ( The optical axis is a range S starting from A and including all of the width W in a height upward direction from A. Further, in this heat-resistant range S, the range S ′ where the temperature is likely to be 180 ° C. or more is set as the minimum range of the heat-resistant range, and this is defined as the width left and right direction (W / 4) × height upward direction from the A origin. (H / 2) The above range.

  Further, in FIG. 4, a range B including the entire width W in a direction lower than A from the valve center (optical axis) A is defined as a non-heat-resistant range serving as a base portion.

  Here, an inexpensive PC resin (polycarbonate: specific gravity 1.20) is used in the non-heat-resistant range B serving as the base portion. In addition, PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) can be used for the entire heat resistant range S including the minimum heat resistant range S ′. PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) is used only for the minimum range S ′ (specifically, for example, the range S ′ where the temperature is likely to be 180 ° C. or higher). You can also In addition, when using PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) only in the minimum heat range S ′ of the heat resistance range S, heat resistance excluding the minimum heat range S ′ For example, an inexpensive PC resin can be used for the portion of the range S. At this time, the PEI material (unfilled polyetherimide) or the PPS resin is added to the entire heat resistant range S including the minimum heat resistant range S ′. Cost can be reduced compared with the case of using (polyphenylene sulfide).

  Further, the basic thickness of the portion of the heat resistant range S including the minimum range S ′ is 2.0 to 2.5 mm.

On the other hand, the portion of the non-heat resistant range B (PC resin portion) has a basic thickness of 2.8 mm or more in order to prevent light distribution pattern deformation (torsional rigidity). In other words, for the lack of torsional rigidity, which is a problem with conventional PEI reflectors, the PC resin used in the non-heat-resistant range B, which is the base, is not highly rigid. Need to hold. In this case, the basic thickness of the PC resin can be set using “flexural modulus JISK7203”, which is a mechanical property value of the resin, as the torsional rigidity index. 5 and 6 are diagrams for explaining a method of setting the basic thickness of the PC resin using “bending elastic modulus JISK7203”. In FIG. 5, L, b, and h are the length, width, and thickness of the test piece (beam), respectively, and F is the load (N). As shown in FIG. 5, when the deflection (mm) of the test piece (beam) when a load F (N) is applied is Y, the flexural modulus E _b (MPa) is
E _b = (L ³ / (4b · h ³ )) · (F / Y)
Therefore, the deflection Y (mm) is expressed by the following equation (Equation 1).

Calculate the thickness setting value to make the deflection amount (= light distribution pattern deformation) when the same torsional load is applied with the same reflector shape with the reflector (Ref) recommended rigid resin and PC resin based on the equation (1). . That is, as shown in FIG. 6, the bending elastic modulus of the Ref recommended rigid resin is 6000 (MPa), and the basic thickness of the Ref recommended rigid resin is 2.0 mm, while the bending elastic modulus of the PC resin is 2200 ( MPa), and when the basic wall thickness is x, from Equation 1, 1 / ((2.0) ³ × 6000) = 1 / (x ³ × 2200) holds, and from this, x is about 2. It is calculated as 8. Thus, the portion of the non-heat-resistant range B (PC resin portion) preferably has a basic thickness of 2.8 mm or more in order to prevent light distribution pattern deformation (torsional rigidity).

  The reflector of the present invention as described above, that is, a PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) used in at least a part of the heat-resistant range S, and used in a non-heat-resistant range. Both PC resin (polycarbonate) can be formed by two-color molding or insert molding.

  In this case, since the two-color molded or insert molded PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) and PC resin (polycarbonate) are both low in surface roughness, for example, Al Direct vapor deposition is possible. That is, in both the heat-resistant range S (including S ′) and the non-heat-resistant range B, a predetermined metal film is directly formed without forming an undercoat and a reflecting mirror surface is formed. As described above, in the present invention, an aluminum vapor deposition film, for example, as a predetermined metal film (specifically as a reflecting mirror film) can be directly applied to the resin surface by sputtering vacuum vapor deposition or the like. In this case, deterioration of light distribution performance (increased glare) due to uneven film thickness at the stepped portion, which has been a problem with undercoat coating in conventional BMC reflectors, is eliminated, and stable light distribution performance is supplied. Can do.

  As described above, in the present invention, in the reflector member, the range in which the temperature is likely to be 180 ° C. or higher is defined as the heat resistant range S, and the range in which the temperature is unlikely to be 180 ° C. or higher is defined as the non-heat resistant range B. In this case, PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) is used in at least a part of the heat resistant range S, and PC resin (polycarbonate) is used in the non-heat resistant range B. Because it is used, it can solve the problem of light distribution performance deterioration and weight due to the undercoat of the BMC reflector (that is, the light distribution characteristics are improved and the weight can be reduced compared to the conventional BMC reflector). Moreover, it can be made cheaper than the PEI reflector (cost can be reduced).

  Furthermore, in the non-heat-resistant range B, since the basic thickness is 2.8 mm or more, the lack of torsional rigidity, which has been a problem with conventional PEI reflectors, can be solved.

FIG. 7 is a diagram showing a configuration example of a vehicular lamp using the reflector of the present invention. In FIG. 7, the same parts as those in FIG. In the example of FIG. 7, the vehicular lamp is configured as an automotive headlamp, and includes a bulb (halogen type or HID discharge lamp type) 101 and a reflecting mirror that reflects a portion of the light emitted from the bulb 101. A reflector 52 that functions as an extension, an extension 103, and an outer lens 104. Here, in the example of FIG. 7, the reflector 52 is configured as a parabolic type whose reflecting mirror surface is a parabolic surface, and the reflector of the present invention described above is used as the reflector 52. Yes.

It is a figure which shows the structural example of the headlamp for motor vehicles. It is a figure for demonstrating the light distribution performance of a reflector. It is a figure which shows the temperature distribution (temperature distribution from the reflector front view) of a reflector when a bulb is lighted. It is a schematic diagram when the reflector member is viewed from the front. The basic wall thickness of the PC resin can be set. 5 and 6 are diagrams for explaining a method of setting the basic thickness of the PC resin using “bending elastic modulus JISK7203”. The basic wall thickness of the PC resin can be set. 5 and 6 are diagrams for explaining a method of setting the basic thickness of the PC resin using “bending elastic modulus JISK7203”. It is a figure which shows the structural example of the vehicle lamp using the reflector of this invention.

Explanation of symbols

S Heat-resistant range S 'Minimum range of heat-resistant range B Non-heat-resistant range 52 Reflector

Claims (4)

Among the reflector members, when a range where the temperature is likely to be 180 ° C. or higher is defined as a heat resistant range and a range where the temperature is unlikely to be 180 ° C. or higher is defined as a non-heat resistant range, at least a part of the heat resistant range The reflector is characterized in that PEI material (unfilled polyetherimide) or PPS resin (polyphenylene sulfide) is used in the range, and PC resin (polycarbonate) is used in the non-heat resistant range. 2. The reflector according to claim 1, wherein the non-heat-resistant range has a basic thickness of 2.8 mm or more. 3. The reflector according to claim 1, wherein a predetermined metal film is directly formed in the heat-resistant range and the non-heat-resistant range without being undercoated, and a reflecting mirror surface is formed. And a reflector. The reflector according to any one of claims 1 to 3, wherein the reflector includes a bulb and a reflector that functions as a reflecting mirror that reflects a part of light emitted from the bulb. A vehicular lamp characterized in that is used.

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