Vehicle lamp

Abstract

The invention provides a vehicle lamp which can maintain the moisture absorption and desorption performance of a moisture absorption and desorption agent arranged on the inner side of a lamp body and can prolong the period until the moisture absorption performance of a drying agent is saturated. In a vehicle lamp (1), a lamp unit (5) for irradiating light forward is disposed on the inner side of a lamp body (4) comprising a housing (2) having an opening in the front and an outer lens (3) covering the opening of the housing (2), and a desiccant (D) and a moisture absorption / desorption agent (M) are disposed on the inner side of the lamp body (4).

Description

Technical Field

[0001] The invention relates to a vehicle lamp. Background Art

[0002] Conventionally, there is a vehicle lamp in which a lamp unit for irradiating light forward is arranged inside a lamp body composed of a housing having an opening at the front and an outer lens (cover lens) covering the opening of the housing.

[0003] Such a vehicle lamp has a structure in which components constituting a lamp unit, such as a light source lamp (light source), an inner lens (light guide), a reflector, and a projection, are arranged inside a lamp body and these components are mounted inside the lamp body.

[0004] However, in a vehicle lamp, the air in the lamp body expands / contracts due to temperature changes accompanying lighting / extinguishing of the lamp unit, and thus ventilation (intake / exhaust) is performed through a ventilation port (breathing hole) provided in the lamp body.

[0005] On the other hand, in a vehicle lamp, when the outside air temperature is lower than the temperature inside the lamp body, moisture (water) inside the lamp body may condense on the inner surface of the outer lens, causing fogging on the inner surface of the outer lens.

[0006] Furthermore, when condensation (fogging) occurs on the inner surface of the outer lens, not only the appearance is deteriorated, but also the transmittance of light emitted forward from the lamp unit is reduced, resulting in a reduction in lamp function (particularly, illumination).

[0007] Therefore, in order to solve such a problem, a desiccant (moisture absorber) is arranged inside the lamp body. On the other hand, the desiccant (moisture absorber) only absorbs moisture, so after its moisture absorption performance (absorption amount) is saturated, it is difficult to absorb moisture further. At this time, the desiccant (moisture absorber) needs to be replaced.

[0008] In this regard, the following scheme has been proposed: a humidity controlling sheet (humidity absorber / dehumidifier) ​​is arranged on the inner side of the lamp body, and when the humidity inside the lamp body is high, the humidity controlling sheet is used to quickly absorb (absorb) moisture (water). On the other hand, when the humidity inside the lamp body is low, the moisture (water) absorbed by the humidity controlling sheet is quickly released (released), thereby continuously (without replacement) using the humidity controlling sheet (humidity absorber / dehumidifier) ​​(for example, refer to the following patent document 1).

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Publication No. 2008-159310 Summary of the invention

[0012] Problems to be solved by the invention

[0013] However, the above-mentioned humidity-conditioning sheet (humidity absorber and dehumidifier) ​​has better moisture absorption responsiveness than a desiccant (humidity absorber), but has a lower moisture absorption rate (humidity absorption amount) than a desiccant (humidity absorber). When the moisture absorption amount is saturated, the above-mentioned problem caused by condensation will occur.

[0014] On the other hand, Patent Document 1 described above discloses that a desiccant (moisture absorbent) is mixed with a humidity-conditioning sheet (moisture absorbent / dehumidifier) ​​for use.

[0015] However, if a desiccant (moisture absorber) is mixed in a humidity conditioning sheet (moisture absorber / dehumidifier), the moisture (water) released (dehumidified) from the humidity conditioning sheet (moisture absorber / dehumidifier) ​​is absorbed by the desiccant (moisture absorber), and the period (lifespan) until the moisture absorption performance (absorption amount) of the desiccant (moisture absorber) reaches saturation may be shortened.

[0016] Furthermore, since the desiccant expands when absorbing moisture, when the desiccant and the desiccant are sealed in a single moisture-permeable bag for use, the surface area of ​​the desiccant in contact with air may be reduced, thereby hindering the desiccant's moisture absorption and desorption performance.

[0017] The present invention is proposed in view of the existing situation, and its purpose is to provide a vehicle lamp that can maintain the moisture absorption and desorption performance of the desiccant arranged on the inner side of the lamp body while preventing condensation on the inner surface of the outer lens, and can extend the period until the moisture absorption performance of the desiccant is saturated.

[0018] Means for solving problems

[0019] In order to achieve the above-mentioned object, the present invention provides the following means.

[0020] [1] A vehicle lamp, wherein a lamp unit for irradiating light forward is arranged inside a lamp body composed of an outer shell having an opening at the front and an outer lens covering the opening of the outer shell, wherein:

[0021] A desiccant and a moisture absorbing and releasing agent are respectively arranged inside the lamp body.

[0022] [2] The vehicle lamp according to [1] above, wherein the moisture absorption rate of the moisture absorbent is at least twice that of the desiccant.

[0023] [3] The vehicle lamp according to [1] above, wherein the weight of the desiccant is greater than the weight of the moisture absorbing and releasing agent.

[0024] [4] The vehicle lamp according to [1] above, wherein the moisture absorbing and releasing agent is arranged on a side closer to the outer lens than the desiccant.

[0025] Effects of the Invention

[0026] As described above, according to the present invention, a vehicle lamp is provided which can maintain the moisture absorption and desorption performance of the moisture absorption and desorption agent arranged inside the lamp body while preventing condensation on the inner surface of the outer lens and can extend the period until the moisture absorption performance of the desiccant is saturated. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view showing the structure of a vehicle lamp according to an embodiment of the present invention.

[0028] Figure 2 It is shown in Figure 1 The sectional view is a structure showing a change in the arrangement of the moisture absorbing and releasing agent in the vehicle lamp shown.

[0029] Figure 3 This is a graph showing the measurement results of the relative humidity in the lamp body when the boxes of Example 1 and Comparative Examples 1 and 3 were subjected to an accelerated test and a fogging test in the first example.

[0030] Figure 4 This is a graph showing the measurement results of the relative humidity in the lamp body when the use cycle test was performed on the boxes of Example 1 and Comparative Examples 1 and 3 in the second example.

[0031] Figure 5 This is a graph showing the measurement results of the relative humidity in the lamp body when the boxes of Example 1 and Comparative Example 1 were subjected to a durability cycle test in the third example.

[0032] Figure 6 This is a graph showing the measurement results of the relative humidity in the lamp body when the boxes of Comparative Examples 2 and 3 were subjected to a fogging test in the fourth embodiment.

[0033] Figure 7 This is a graph showing the results of measuring the moisture absorption rates of the desiccant and the moisture absorption and desorption agent in the fifth example.

[0034] Figure 8 This is a graph showing the measurement results of the relative humidity in the lamp body when the actual machine test was carried out on the boxes of Example 1 and Comparative Examples 1 and 3 in Example 6. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0036] In the drawings used in the following description, in order to make each component easier to see, the dimensional scales of the components may be different, and the dimensional ratios of the components are not necessarily the same as the actual ones.

[0037] As one embodiment of the present invention, for example Figure 1 The vehicle lamp 1 shown will be described.

[0038] It should be noted that Figure 1 It is a cross-sectional view showing the structure of the vehicle lamp 1 .

[0039] In addition, in the drawings shown below, an XYZ rectangular coordinate system is set, the X-axis direction is represented as the front-to-back direction (length direction) of the vehicle lamp 1, the Y-axis direction is represented as the left-right direction (width direction) of the vehicle lamp 1, and the Z-axis direction is represented as the up-down direction (height direction) of the vehicle lamp 1.

[0040] The vehicle lamp 1 of the present embodiment applies the present invention to, for example, vehicle headlamps mounted at both corners (the left front corner in the present embodiment) of the front end of a vehicle (not shown).

[0041] Specifically, if Figure 1 As shown, the vehicle lamp 1 has the following structure: a lamp unit 5 for irradiating light toward the front of the vehicle (+X axis direction) is arranged inside a lamp body 4 composed of a housing 2 with an opening at the front and a transparent outer lens (cover lens) 3 covering the opening of the housing 2.

[0042] The lamp unit 5 includes, for example, a light source 6 that emits white light (hereinafter referred to as light) and a reflector 7 that reflects the light emitted from the light source 6 , and is configured to irradiate the light reflected by the reflector 7 toward the front of the vehicle.

[0043] In addition, an extension portion 8 covering the periphery of the front side of the reflector 7 (lamp unit 5) is arranged inside the lamp body 4. Furthermore, a bracket (not shown) for mounting the above components inside the lamp body 4 is arranged inside the lamp body 4. It should be noted that the shape of the lamp body 4 can be appropriately changed in accordance with the design of the vehicle lamp 1.

[0044] The lamp unit 5 is not necessarily limited to a structure that irradiates the light reflected by the reflector 7 toward the front of the vehicle, and may be a structure that irradiates the light emitted from the light source 6 toward the front of the vehicle using a light guide (not shown) such as an inner lens.

[0045] As for the light source 6, for example, a halogen lamp, HID lamp or other light source lamp can be used. In addition to the above light source lamps, light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) can also be used. Furthermore, the number of light emitting elements is not limited to one, and can also be two or more.

[0046] However, in the vehicle lamp 1 of the present embodiment, the air in the lamp body 4 expands / contracts due to the temperature change associated with the lighting / extinguishing of the lamp unit 5, so ventilation (intake / exhaust) is performed through the ventilation port (breathing hole) 9 provided on the back side of the housing 2 (lamp body 4).

[0047] On the other hand, in the vehicle lamp 1 , when the outside air temperature is lower than the temperature inside the lamp body 4 , moisture (water) inside the lamp body 4 may condense on the inner surface of the outer lens 3 , causing fogging on the inner surface of the outer lens 3 .

[0048] In order to prevent condensation (fogging) from occurring on the inner surface of the outer lens 3 , the vehicle lamp 1 of the present embodiment has a structure in which a desiccant D and a moisture absorption / release agent M are disposed inside the lamp body 4 .

[0049] In this embodiment, a desiccant D is arranged on the inner surface of the housing 2 located on the back side of the reflector 7 and below the light source 6 , and a moisture absorbing and releasing agent M is arranged on the inner surface of the housing 2 above the light source 6 .

[0050] When the desiccant D and the desiccant M are arranged on the inner surface of the housing 2 , it is preferable to arrange the desiccant M having excellent moisture absorption responsiveness (moisture absorption speed) on the side closer to the ventilation port 9 than the desiccant D.

[0051] Thus, the desiccant M can be used to efficiently absorb (absorb) the moisture (water) contained in the air inhaled from the ventilation port (breathing hole) 9, and on the other hand, the moisture (water) absorbed (absorbed) by the desiccant M can be efficiently released (dehumidified) into the air discharged from the ventilation port (breathing hole) 9.

[0052] The desiccant D may be any desiccant known in the art as long as it absorbs (absorbs moisture) in the lamp body 4. For example, magnesium chloride is used as the desiccant D in the present embodiment.

[0053] The desiccant M may be any desiccant known in the art as long as it absorbs (absorbs moisture) or releases (releases moisture) in the lamp body 4. For example, a desiccant polymer is used as the desiccant M in this embodiment.

[0054] The desiccant M has a better responsiveness (moisture absorption speed) in moisture absorption than the desiccant D, so when the humidity in the lamp body 4 is high, the moisture (water) is quickly absorbed (absorbed) by the desiccant M. On the other hand, when the humidity in the lamp body 4 is low, the moisture (water) absorbed (absorbed) by the desiccant M is quickly released (released). In addition, the desiccant M can also cope with a sudden increase in humidity in the lamp body 4.

[0055] In contrast, the desiccant D has a higher moisture absorption rate (absorption amount) than the desiccant M. Therefore, when the humidity in the lamp body 4 is high and the moisture absorption amount of the desiccant M is saturated, the desiccant D absorbs (absorbs) moisture (water).

[0056] Thus, in the vehicle lamp 1 of the present embodiment, it is possible to prevent condensation (fogging) from occurring on the inner surface of the outer lens 3 .

[0057] In the vehicle lamp 1 of the present embodiment, the desiccant D and the desiccant M are disposed inside the lamp body 4 , respectively, so that moisture (water) released (dehumidified) from the desiccant M is less likely to be absorbed by the desiccant D.

[0058] Thus, in the vehicle lamp 1 of the present embodiment, it is possible to extend the period (lifespan) until the moisture absorption performance (moisture absorption amount) of the desiccant D is saturated.

[0059] Furthermore, in the vehicle lamp 1 of the present embodiment, even after the moisture absorption performance (moisture absorption amount) of the desiccant D is saturated, the moisture absorption performance of the moisture absorption / release agent M is maintained, and the moisture (water) in the lamp body 4 can be absorbed (absorbed) by the moisture absorption / release agent M.

[0060] In the present embodiment, the moisture absorption rate of the desiccant M is preferably at least twice as high as that of the desiccant D. Thus, the desiccant M can preferentially absorb (absorb) moisture (water) in the lamp body 4 rather than the desiccant D.

[0061] The weight of the desiccant D is preferably greater than that of the desiccant M. Specifically, the weight of the desiccant D is preferably greater than that of the desiccant M, more preferably at least twice as large. Thus, the hygroscopic performance (absorption amount) of the desiccant D can be sufficiently ensured.

[0062] Furthermore, in order to prevent condensation (fogging) from occurring on the inner surface of the outer lens 3 , it is preferable to arrange a moisture absorbing and releasing agent M having excellent moisture absorption responsiveness (moisture absorption speed) on the side closer to the outer lens 3 than the desiccant D.

[0063] In this case, for example, Figure 2 The configuration of the moisture absorbing and releasing agent M is shown. It should be noted that, Figure 2 It is a cross-sectional view showing a structure in which the arrangement of the moisture absorbing and releasing agent M is changed in the vehicle lamp 1 .

[0064] Specifically, in this Figure 2 In the vehicle lamp 1 shown, a desiccant M is disposed on the inner lower surface of the outer lens 3 located on the front side of the extension portion 8. Thus, the desiccant M can efficiently absorb moisture (water) near the inner surface of the outer lens 3.

[0065] It should be noted that the arrangement of the desiccant D and the desiccant M is not necessarily limited to the above arrangement, and the desiccant D and the desiccant M can be arranged at the best positions respectively in accordance with the shape of the lamp body 4, the position of the ventilation port 9, etc. In addition, the desiccant D and the desiccant M can also be arranged at multiple positions for optimization.

[0066] When the moisture absorption performance (absorption amount) of the desiccant D is saturated, it can be replaced with a new desiccant D. In this case, the desiccant D is preferably arranged at an easily replaceable position in the lamp body 4 (for example, the inner surface of the back side of the housing 2).

[0067] As described above, in the vehicle lamp 1 of the present embodiment, while preventing condensation (fogging) from forming on the inner surface of the outer lens 3, the moisture absorption and desorption performance of the moisture absorber and desorber M arranged on the inner side of the lamp body 4 can be maintained, and the period (lifespan) until the moisture absorption performance (moisture absorption amount) of the desiccant D is saturated can be extended.

[0068] It should be noted that in the vehicle lamp 1 of the present embodiment, when the moisture (water) absorbed (absorbed) by the desiccant M is released (dehumidified), although the humidity inside the lamp body 4 becomes relatively high, since the inside of the lamp body 4 is in a low humidity state, there is almost no effect on the degree of condensation (fogging) on ​​the inner surface of the outer lens 3.

[0069] It should be noted that the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

[0070] For example, in the above-mentioned embodiment, the case where the present invention is applied to a vehicle headlamp (headlight) is illustrated, but the vehicle lamp to which the present invention is applied is not limited to the above-mentioned front vehicle lamp, and for example, the present invention can also be applied to rear vehicle lamps such as rear combination lamps.

[0071] Example

[0072] The effects of the present invention will be further clarified by way of the following examples. It should be noted that the present invention is not limited to the following examples, and can be implemented by appropriately changing the scope of the present invention.

[0073] (First embodiment)

[0074] In the first embodiment, there are prepared a box of embodiment 1 in which a desiccant and a desiccant are respectively arranged in a box simulating a lamp body, a box of comparison example 1 in which only a desiccant is arranged in a box simulating a lamp body, and a box of comparison example 3 in which neither a desiccant nor a desiccant is arranged in a box simulating a lamp body.

[0075] Then, the boxes of Example 1 and Comparative Examples 1 and 3 were subjected to an acceleration test simulating an environment before vehicle delivery.

[0076] Before delivery, the vehicle is stored for a long time with the engine stopped during transportation or at a sales store. In this case, the absorption (hygroscopicity) of moisture (water) in the box progresses. On the other hand, after delivery, the heat discharged from the engine, etc. heats the box while the vehicle is running, so the moisture (water) in the box begins to be released (dehumidified). Therefore, the vehicle lamp before delivery is in an environment where the absorption (hygroscopicity) of moisture (water) in the box progresses.

[0077] 30 g of magnesium chloride was used as the desiccant. The moisture absorption rate of the desiccant was 0.6% / day, and the moisture absorption rate at this time was 50% or more. On the other hand, 15 g of a hygroscopic polymer was used as the desiccant. The moisture absorption rate of the desiccant was 8% / day, and the moisture absorption rate at this time was 25% or more.

[0078] In the accelerated test, the boxes of Example 1 and Comparative Examples 1 and 3 were placed in an atmosphere of 40°C and 90% humidity for a period of more than 100 hours. The results of the measurement of the relative humidity (%) in the box during this period are shown in FIG. Figure 3 in the curve graph.

[0079] It should be noted that in an environment with a temperature of 40°C and a humidity of 90%, the moisture absorption rate of the desiccant after 100 hours was 2% / day, and the moisture absorption rate of the desiccant after 24 hours was 35%.

[0080] The results, such as Figure 3 As shown in the graph of , it was confirmed that the boxes of Comparative Example 1 and Example 1 had lower relative humidity than the box of Comparative Example 3. In addition, in the case of the box of Example 1, although the relative humidity from the start of the accelerated test was higher than that of the box of Comparative Example 1, it showed the same relative humidity as that of the box of Comparative Example 1 over time.

[0081] Next, after the accelerated test, the boxes of Example 1 and Comparative Examples 1 and 3 were subjected to a fogging test in which the temperature and humidity in the box were increased and then the surface of the box was cooled to forcibly generate condensation (fogging) on ​​the inner surface of the box.

[0082] The results, such as Figure 3 As shown in the graph of , in the case of the box of Comparative Example 3, the relative humidity is higher than that of the boxes of Comparative Example 1 and Example 1, and condensation (fogging) occurs on the inner surface of the box.

[0083] From the test results, it was confirmed that the desiccant disposed in the lamp body is effective in preventing condensation (fogging) from occurring on the inner surface of the lamp body.

[0084] On the other hand, in the fogging test, it was confirmed that the box of Example 1 had a lower relative humidity than the box of Comparative Example 1 with respect to the rapid humidity rise in the box.

[0085] Therefore, according to the test results, the box of Example 1 can suppress the humidity inside the box to a lower level than the boxes of Comparative Examples 1 and 3 in the acceleration test simulating the environment before vehicle delivery and the fogging test forcibly generating condensation (fogging) on ​​the inner surface of the box.

[0086] (Second embodiment)

[0087] In the second example, boxes of Example 1 and Comparative Examples 1 and 3 were prepared.

[0088] Then, the boxes of Example 1 and Comparative Examples 1 and 3 were subjected to a usage cycle test in which a high humidity (moisture absorption) state and a high temperature (moisture release) state simulating the usage environment of a vehicle were alternately repeated.

[0089] In the use cycle test, the boxes of Example 1 and Comparative Examples 1 and 3 were placed for 500 hours in an environment atmosphere that alternately repeated a high humidity (moisture absorption) state and a high temperature (moisture release) state. The results of the measurement of the relative humidity (%) in the box during this period are shown in Figure 4 Graph of the curve.

[0090] The results, such as Figure 4 As shown in the graph of , it was confirmed that the box of Example 1 had a lower relative humidity than the boxes of Comparative Examples 1 and 3.

[0091] Therefore, from the test results, it can be seen that the box of Example 1 can suppress the humidity inside the box to a lower level than the boxes of Comparative Examples 1 and 3 in the use cycle test simulating the use environment of a vehicle.

[0092] (Third embodiment)

[0093] In the third example, the boxes of Example 1 and Comparative Example 1 were prepared.

[0094] Then, the boxes of Example 1 and Comparative Example 1 were subjected to the following durability cycle test: a high humidity (moisture absorption) state and a high temperature (moisture release) state simulating a saturated state (end of life) of the moisture absorption performance (absorption amount) of the desiccant were repeated alternately.

[0095] Regarding the test conditions, in order to reproduce the saturated state of the moisture absorption performance (absorption amount) of the desiccant, a desiccant with a moisture absorption rate of 1.2% / day after 720 hours in an environment atmosphere of 40°C and 90% humidity was used. Other than this, the test conditions were the same as those of the second embodiment.

[0096] In the durability cycle test, the boxes of Example 1 and Comparative Example 1 were placed for 500 hours in an environment atmosphere that alternately repeated a high humidity (moisture absorption) state and a high temperature (moisture release) state. The results of the measurement of the relative humidity (%) in the box during this period are shown in Figure 5 Graph of the curve.

[0097] The results, such as Figure 5 As shown in the graph of , it was confirmed that the box of Example 1 had a lower relative humidity than the box of Comparative Example 1.

[0098] Therefore, according to the test results, the box of Example 1 can suppress the humidity inside the box to a lower level than the box of Comparative Example 1 in the endurance cycle test simulating the saturated state (end of life) of the moisture absorption performance (absorption amount) of the desiccant.

[0099] (Fourth embodiment)

[0100] In the fourth embodiment, boxes of Comparative Examples 2 and 3 were prepared in which only the moisture absorbent and dehumidifier was arranged in a box simulating a lamp body.

[0101] Then, the boxes of Comparative Examples 2 and 3 were subjected to humidity control for more than 24 hours in an environment of 23° C. and 55% humidity in order to reproduce the state of saturated moisture absorption performance (absorption amount) of the desiccant.

[0102] Then, after raising the temperature and humidity in the box, the surface of the box was cooled, thereby implementing a fogging test in which condensation (fogging) was forcibly generated on the inner surface of the box. In addition, the measurement results of the relative humidity (%) in the box during this period are shown in Figure 6 Graph of the curve.

[0103] It should be noted that the test conditions used were the same as those of the first embodiment except that a moisture absorbent and desorbent having a moisture absorption rate of 30% after 24 hours in an environment of 40°C and 90% humidity was used.

[0104] The results, such as Figure 6 As shown in the graph of , it was confirmed that the box of Comparative Example 2 had a lower relative humidity than the box of Comparative Example 3 during the fogging test.

[0105] Therefore, it is understood from the test results that even after the moisture absorption performance (absorption amount) of the desiccant is saturated, the fogging prevention effect of the outer lens can be obtained by the moisture absorption of the moisture absorption and release agent.

[0106] (Fifth embodiment)

[0107] In the fifth embodiment, boxes of Comparative Examples 1 and 2 were prepared.

[0108] Then, the boxes of these comparative examples 1 and 2 were subjected to a test for measuring the moisture absorption rate. Figure 7 Graph of the curve.

[0109] The results, such as Figure 7 As shown in the curve graph, the following results are shown: the box of Comparative Example 2 has a higher moisture absorption rate than the box of Comparative Example 1 from the start of the test, but after the moisture absorption amount of the desiccant is saturated, the moisture absorption rate of the box of Comparative Example 1 becomes higher than that of the box of Comparative Example 2 as time goes by.

[0110] Therefore, from the test results, it is understood that the desiccant has a higher responsiveness to moisture absorption (moisture absorption rate) than the desiccant, but the desiccant has a higher moisture absorption rate (moisture absorption amount) than the desiccant.

[0111] It should be noted that, if the desiccant is used alone to obtain the same hygroscopic performance (absorption amount) as the desiccant, the desiccant needs to be about 4 times heavier than the desiccant. In this case, it is difficult to configure the required weight of desiccant in the lamp, and the cost also increases.

[0112] (Sixth embodiment)

[0113] In the sixth example, boxes of Example 1, Comparative Example 1, and Comparative Example 3 were prepared.

[0114] Then, a real machine test was carried out in which the boxes of Example 1 and Comparative Examples 1 and 3 were mounted on a vehicle. The relative humidity (%) in the box during this period was measured and the results are shown in FIG. Figure 8 Graph of the curve.

[0115] The results, such as Figure 8 As shown in the graph of , it was confirmed that the box of Example 1 had a lower relative humidity than the boxes of Comparative Examples 1 and 3.

[0116] Therefore, it can be seen from the test results that the tank of Example 1 suppressed the humidity inside the tank to a lower level than the tanks of Comparative Examples 1 and 3 in the actual machine test mounted on the vehicle.

[0117] It should be noted that if Figure 8 As shown in the graph of , the box of Example 1 has a higher relative humidity than the box of Comparative Example 1. This is considered to be the effect of moisture release from the desiccant, but it was confirmed that the relative humidity in the box was low and was not at a level that would cause condensation (fogging) on ​​the inner surface of the box.

[0118] In this embodiment, in addition to the desiccants and dehumidification agents exemplified in the above-mentioned first to fifth embodiments, for example, the desiccants and dehumidification agents exemplified below can be appropriately used.

[0119] A desiccant with a moisture absorption rate of 0.6% / day or more after 720 hours in an environment with a temperature of 40°C and a humidity of 90%.

[0120] In an environment with a temperature of 40°C and a humidity of 90%, the moisture absorption rate is 0.6% / day. The moisture absorption rate of the desiccant at this time is 80% or more.

[0121] A desiccant with a moisture absorption rate of 1.8% / day or more after 100 hours in an environment with a temperature of 40°C and a humidity of 90%.

[0122] A desiccant having a moisture absorption rate of 25% or more after humidity control for 24 hours or more in an environment with a temperature of 23°C and a humidity of 55%, and then in an environment with a temperature of 40°C and a humidity of 90% for 24 hours.

[0123] A desiccant that has a moisture release rate of 15% or less in an atmosphere of 10°C and 50% humidity after humidity control for more than 24 hours in an atmosphere of 23°C and 55% humidity.

[0124] The desiccant has a moisture absorption rate of 0.6 to 6% / day after 720 hours in an environment with a temperature of 40°C and a humidity of 90%.

[0125] In an environment with a temperature of 40°C and a humidity of 90%, the moisture absorption rate is 0.6% / day, and the moisture absorption rate of the desiccant is 50-300%.

[0126] ·Desiccant with a moisture absorption rate of 1.8 to 30% / day after 100 hours in an environment with a temperature of 40°C and a humidity of 90%.

[0127] A desiccant with a moisture absorption rate of 1% / day or more after 100 hours in an environment with a temperature of 40°C and a humidity of 90%.

[0128] In an environment with a temperature of 40°C and a humidity of 90%, the moisture absorption rate is 1% / day. The moisture absorption rate of the desiccant at this time is 40% or more. BRIEF DESCRIPTION OF THE DRAWINGS

[0130] 1 ... vehicle lamp 2 ... housing 3 ... outer lens 4 ... lamp body 5 ... lamp unit 6 ... light source 7 ... reflector 8 ... extension 9 ... ventilation port D ... desiccant M ... moisture absorption and release agent

Claims

1. A vehicle lamp, wherein a lamp unit for irradiating light forward is arranged inside a lamp body composed of an outer shell with an opening at the front and an outer lens covering the opening of the outer shell, wherein: A desiccant and a moisture absorbing and releasing agent are respectively arranged inside the lamp body.

2. The vehicle lamp according to claim 1, characterized in that: The moisture absorption rate of the desiccant is more than 2 times greater than that of the desiccant.

3. The vehicle lamp according to claim 1, characterized in that: The weight of the desiccant is greater than the weight of the moisture absorbing and desorbing agent.

4. The vehicle lamp according to claim 1, characterized in that: The moisture absorbing and releasing agent is arranged on a side closer to the outer lens than the desiccant.

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