JP4244015B2 - Projection type automotive headlamp - Google Patents

Description

  The present invention relates to a projection headlamp that projects and distributes light reflected from a substantially bowl-shaped reflector forward by a projection lens, and in particular, a projection type automobile that can switch light distribution by rotating a rotary shade. It relates to a headlamp.

  As a conventional technology of this type of headlamp, there are a substantially bowl-shaped reflector, a light source arranged at a first focus of the reflector, a projection lens arranged in front of the second focus of the reflector, and a first reflector of the reflector. A rotating shade for light distribution formation that is rotatably arranged in the vicinity of the two focal points and that is reflected by the reflector and blocks a part of the light directed to the projection lens; and a motor that generates a driving force for rotationally driving the rotating shade; It is equipped with a plurality of gears that transmit the driving force of the motor to the rotary shade, and the rotary shade is composed of a stepped cylindrical body and a horizontal support shaft formed at a position eccentric from the axis of the stepped cylindrical body. A clear cut line is formed by the outer shape of the attached cylindrical body (the shape of the side edge), and the rotary shade is rotated forward and backward by driving the motor, thereby clearing the clear cut line of the light distribution pattern. That the positions so as to adjust the vertical direction is proposed (see Patent Document 1).

  By the way, in a headlamp of an automobile or the like, the front range 2 is usually irradiated as shown in FIG. 15, but at this time, the irradiation range on the oncoming vehicle side is set so that the oncoming vehicle is not dazzled too much. The light from the light source is shielded by a shade (not shown) disposed in the lamp.

  However, if the road surface is illuminated with strong light from the headlamps when driving in rainy weather, the road surface reflection from the road surface portion 4 makes it difficult for the driver of the vehicle to check the situation of the road surface in front, Or give. Also, when traveling in the fog, if the fog is irradiated with the strong beam 6 of the headlamp, the road surface below the beam 6 will not be visible at all, so even the white line on the road (center line and lane mark on the shoulder) It may become impossible to confirm.

For this reason, conventionally, in the event of rain or fog, an auxiliary lamp such as a fog lamp is turned on instead of the headlamp, and the light is diffused widely over the front to mainly irradiate the road surface portions on both sides in front of the vehicle. It was necessary to make it easier to see the road surface portion in front and the road surface portions on both sides, particularly the white lines on the road, and to reduce glare to oncoming vehicles.
JP-A-6-139802 (2nd to 4th pages, FIGS. 1 to 5)

  However, if an auxiliary lamp or the like is provided as in the prior art described above, it becomes expensive.

  Therefore, the object of the present invention is to provide excellent visibility of the road surface portions on the front and both sides of the vehicle when traveling in rainy weather or fog without providing an auxiliary lamp, etc. When a predetermined light distribution corresponding to the rotation position is formed by the rotation shade, such as effective in reducing glare to the screen, the position is usually retreated above the light passage area above the rotation shade. To provide a projection type automotive headlamp capable of forming a desired light distribution in which only a light quantity at a predetermined position in an irradiation area in front of a vehicle is reduced by moving a certain second shade to a predetermined position in a light passage area. It is in.

In order to achieve the above object, in the projection type automotive headlamp of the invention according to claim 1,
A substantially saddle-shaped reflector; a light source disposed at a substantially first focal point of the reflector; a projection lens disposed in front of the second focal point of the reflector; and the projection in the vicinity of a substantially second focal point of the reflector. Extends in a direction substantially perpendicular to the optical axis of the lens and is rotatably arranged, and the side edge portion in the vicinity of the optical axis blocks a part of the light from the reflector side toward the projection lens, thereby providing a predetermined light distribution In a projection type automotive headlamp comprising a rotary shade for light distribution control configured to form a pattern, and a motor for rotating the rotary shade,
A cam connected coaxially to the rotary shade; and a second shade swinging in conjunction with the rotation of the rotary shade above the rotary shade;
The second shade moves up and down between a light passage area above the rotary shade and a retreat area above the light passage area, and functions as a light-shielding portion. A cam follower that is in sliding contact with the outer peripheral surface; and a frame-shaped swing arm that is formed in a U-shape that opens downward from the second shade body placement side to the cam placement side and supports the second shade body from above. Consists of.

(Operation) When the rotation shade for light distribution control is rotated to a predetermined rotation position by driving the motor, the distribution corresponding to the shape of the light shielding portion formed on the outer periphery in association with the rotation position of the rotation shade. A light pattern is formed. That is, on the outer periphery of the rotary shade, there are formed a plurality of light shielding portions that form a light distribution pattern corresponding to the driving situation such as a high beam, a lowby, and a rainy day running beam. By rotating the rotary shade, the driving situation Various light distribution patterns corresponding to can be formed. Further, the second shade swings in conjunction with the rotation of the rotary shade (cam) , and the second shade body moves between the light passage area and the retreat area according to the rotational position of the rotary shade. Therefore, the position of the second shade body can be controlled by the motor that drives the rotary shade. When the second shade main body at a predetermined position in the rotary shade above the light passage region is arranged form, only the light toward the predetermined part of the region of the irradiation light to the front of the vehicle blocked by the second shade Thus, the amount of irradiation light in a partial area in front of the vehicle is reduced. For this reason, a predetermined light distribution having a predetermined light distribution pattern corresponding to the shape of the light shielding portion of the rotary shade at a predetermined rotation position of the rotary shade and a reduced light intensity in a part of the vehicle front irradiation region is obtained. It is formed.

For example, when a light distribution switching operation for irradiating a rainy beam is performed, the rotary shade rotates to a predetermined position, and a light shielding portion corresponding to the rotational position (light shielding formed in a shape corresponding to rainy weather). Part) will form a clear cut line in rainy weather. In this case, the cam (wet cam) is linked to the light distribution switching operation when irradiating the beam for rainy weather, and the short diameter side is in contact with the cam follower and linked to the light distribution switching operation when irradiating other beams. Then, the long diameter side comes into contact with the cam follower. The swing arm swings up and down integrally with the cam follower, and when the cam follower comes into contact with the short diameter side of the wet cam, the second shade body wet shade is moved to the light passage area above the rotary shade. When the cam follower comes into contact with the long diameter side of the wet cam, the wet shade is raised to the retreat area above the light passage area. The second shade body (wet shade main body) part of the light towards the projection lens by when (light for illuminating a portion of the road surface of the vehicle front) is shielded, some areas of the road surface of the vehicle front The amount of light applied to the vehicle is reduced, and the visibility is not lowered due to wet road surface reflection during rainy weather, and glare is not generated on the oncoming vehicle. In addition, when traveling in fog, the amount of light applied to a part of the road surface in front of the vehicle is reduced, and the strong irradiation light from the headlamps is scattered by the fog in front of the vehicle and shines white as in the past. There is no problem that the road surface is completely invisible.

Swing arm formed in a U-shape opening downward positioned rotation shade upward, when swinging, or, in the case where the second shade body becomes disposed form in the light passage region also, it does not block light towards the projection lens through the light passage region of the rotary shade upwardly. In particular, if the width of the oscillating arm with respect to the front surface of the second shade body supporting portion is formed small, light contributing to the light distribution formation can be prevented from being blocked as much as possible.

Oite the invention according to claim 2, Te projection vehicle headlight smell of claim 1, prior Symbol second shade body, the swinging arm and the cam follower so as to constitute an integral molding of the sheet metal did.

(Operation) By pressing the sheet metal, a molded body in which the second shade, the swing arm main body and the cam follower are integrated can be easily formed.

Oite the invention according to claim 3, the projection type headlamp for motor vehicles according to claim 1 or 2, and a pre hear beam so that a metal.

  (Operation) The lamp chamber becomes hot and the heat may be transmitted to the motor through the rotary shade, but the cam functions as a heat sink and suppresses the heat of the rotary shade from being transmitted to the motor. Accordingly, the temperature rise of the motor is suppressed.

As is clear from the above description, according to the projection type automotive headlamp of the invention of claim 1, the predetermined light distribution pattern corresponding to the shape of the light shielding portion of the rotary shade is obtained at the predetermined rotational position of the rotary shade. And a predetermined light distribution in which the amount of irradiation light in a part of the vehicle front irradiation region is reduced. For example, the front and both sides of the road surface in the case of rain or fog, even if only a headlamp is provided without a supplementary lamp or the like by the rotary shade and the second shade formed with a light-shielding part for running on rainy weather. The glare to the oncoming vehicle can be reduced while making the part visible. At this time, since the light passing through the light passage area above the rotary shade is not shielded by the swing arm, a predetermined light distribution as designed can be formed.

Further, between the rotary shade above the light passage area and the light passing areas above the save area region illumination light amount change of the second shade body headlamps move to Rukoto up and down, the road illumination pattern Therefore, the driver hardly perceives the uncomfortable feeling of light distribution.

  In addition, since the positions of the rotary shade and the second shade can be controlled by a single drive source, the apparatus structure is simplified accordingly.

According to the invention of claim 2, on production of the second shade it is easy, the swing mechanism of the second shade also becomes concise.

According to the third aspect of the present invention , the function of the cam as the heat sink suppresses the temperature rise of the motor, and ensures the long-term use of the light distribution control switching mechanism with the rotation of the rotary shade.

  Next, embodiments of the present invention will be described based on examples. 1 to 5 show a projection type automotive headlamp according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of an optical projection unit which is a main part of the projection type automotive headlamp. FIG. FIG. 3 is a side view of the same light projection unit, FIG. 4 is a plan view of the same light projection unit partially shown in cross section, and FIG. It is the rear view which removed the reflector from the light projection unit and was seen from back.

  In these drawings, a lamp body 10 of a projection type automobile headlamp is formed in a container shape, and a front lens 12 is assembled to a front opening of the lamp body 10 to define a lamp chamber S. (See FIG. 2). In the lamp chamber S, the light projection unit can adjust the tilt of the irradiation axis (the optical axis of the light projection unit 14) L of the headlamp by the aiming mechanism and can swivel the same optical axis L in the left-right direction by the swivel mechanism. 14 is housed.

  That is, the light projection unit 14 is provided with a pair of upper and lower support shafts 22a and 22b coaxially, and an upper surface of the unit frame 100 (see FIG. 5) having a substantially rectangular frame shape in front view with an opening (opening 101) at the center. The support shafts 22a and 22b are supported on the wall 100a and the lower wall 100b, and the light projection unit 14 is configured to be swingable in the left-right direction around the swivel axis L22 (see FIGS. 1 and 5) with respect to the unit frame 100. Further, the lower support shaft 22 b is configured by an output shaft of the swivel actuator 40 fixed to the lower surface wall 100 b of the unit frame 100. The support shaft 22b, which is an output shaft capable of rotating in the forward and reverse directions of the swivel actuator 40, is fixedly integrated with the light projection unit 14 (the lens holder 30 thereof), and the drive of the swivel actuator 40 (the rotation of the support shaft 22b) ) Causes the light projection unit 14 to swing (swivel) in the left-right direction. For example, the swivel actuator 40 is driven in conjunction with the steering of the steering wheel, the light projection unit 14 is swiveled in the steering direction of the steering wheel and in proportion to the steering amount, and the front of the steering direction of the vehicle is illuminated brightly.

  On the other hand, the aiming mechanism interposed between the lamp body 10 and the unit frame 100 is not illustrated and described, but is provided at a position orthogonal to the front view with respect to the left and right aiming screws, the upper and lower aiming screws, and the two aiming screws. It is mainly composed of a tilting fulcrum such as a ball joint. Then, in FIG. 5 showing a rear view when the reflector 26 is detached from the light projection unit 14 integrated with the unit frame 100 and viewed from the rear, the upper left corner portion of the unit frame 100 is screwed into the upper and lower aiming screws. A rectangular hole 102a which is long at the top and bottom when the nut member is inserted, and a rectangular hole 102b which is long at the left and right when the nut member is screwed into the left and right aiming screws are provided at the lower right corner portion of the unit frame 100. A circular hole 102c for inserting a tilting fulcrum component member such as a ball joint is formed in the lower left corner portion of 100. In this embodiment, the light projection unit 14 is supported by the aiming mechanism. However, when the light projection unit 14 is supported by the auto leveling mechanism instead of the aiming mechanism, the leveling fixed to the lamp body 10 is performed. A slider (not shown) capable of moving back and forth of an actuator (not shown) extends forward, and a nut member that supports the tip of the slider is inserted into the hole 102a. .

  When the upper and lower aiming screws and the left and right aiming screws are rotated, the unit frame 100 and the light projection unit 14 are tilted integrally. Tilt adjustment (aiming) of the optical axis L in the vertical and horizontal directions can be performed. Reference numeral 18 denotes an extension reflector that surrounds the light projection unit 14 and is disposed so as not to interfere with the unit frame 100 (light projection unit 14) that can be tilted and swiveled.

  The light projection unit 14 includes an aluminum die-cast reflector 26 having an approximately ellipsoidal shape in front view and a front face side where the discharge bulb 24 is inserted, and a projection lens 28 disposed in front of the reflector 26. An annular mounting bracket for holding the projection lens 28 with a structure in which an aluminum die-cast lens holder 30 formed in a cylindrical shape and whose axial rear end is screwed to the front side of the reflector 26 is integrated. 32 is fixed to the lens holder 30 by screws.

  An ellipsoidal reflecting surface 26a subjected to aluminum vapor deposition is formed inside the reflector 26. The ellipsoidal reflecting surface 26a has a first focal point F1 and a second focal point F2, and the discharge valve 24 is located at the first focal point F1. The discharge center is located. Further, near the second focus F2 and at the focal position of the projection lens 28, a metal (for example, aluminum) for forming a clear cut line by blocking a part of the light reflected by the reflector 26 and traveling toward the projection lens 28. A rotating shade 34 is provided. Light emitted from the bulb 24 reflected by the reflector 26 is collected on the rotary shade 34, and the collected light is guided to the front of the rotary shade 34. The projection lens 28 converts the light into substantially parallel light in front of the headlamp. Projected light distribution.

  The rotary shade 34 includes a rotary shaft 36 arranged in a direction orthogonal to the irradiation axis L of the headlamp (the optical axis of the projection lens 28) L, and a plurality of rotary shades 34 arranged at predetermined intervals in the circumferential direction of the rotary shaft 36. The light shielding plate 38 (38a, 38b, 38c, 38d, 38e, 38f) is provided. Details of the shape of the light shielding plates 38a to 38f will be described in detail later. When the stepping motor 58 is driven, the rotary shade 34 (rotary shaft 36) rotates in the forward and reverse directions, and each light shielding plate 38 is created each time the light shielding plate 38 is positioned at the irradiation axis (optical axis) L. A clear cut line corresponding to the light distribution pattern is formed.

  Specifically, as shown in FIGS. 3 to 5, disks 42 and 44 for supporting the light shielding plates 38 a to 38 f are fixed to both ends of the rotating shaft 36. Outside the disks 42 and 44, a metal bearing bracket 50 extending across the lens holder 30 is rotatably supported via bearings 46 and 48. The bearing bracket 50 is screwed to the lens holder 30, and the bearings 46 and 48 are inserted together with the rotary shaft 36 into a through hole (not shown) formed in the bearing bracket 50. A wet cam 52, which is a metal eccentric cam, is attached to one end of the rotating shaft 36 in the axial direction (left side in FIGS. 4 and 5). A driving force is provided between the wet cam 52 and the bearing 48. A transmission mechanism 56 is disposed.

  The driving force transmission mechanism 56 is interposed between the stepping motor 58 and the rotary shade 34. As shown in FIG. 4, the stepping motor 58 is a region on the side of the reflector 26, that is, near the curved portion of the reflector 26. Is located in the area. The stepping motor 58 is configured as a drive source that generates a driving force for rotationally driving the rotary shade 34, and its output shaft 60 is arranged in a direction orthogonal to the rotary shaft 36 of the rotary shade 34. When the driving force of the stepping motor 58 is transmitted to the rotary shaft 36 via the driving force transmission mechanism 56, the driving force transmission mechanism 56 is configured using a plurality of gear trains.

  That is, the driving force transmission mechanism 56 is attached to the rotation shaft 36 of the rotary shade 34 and is formed with a helical gear (first helical gear) 62 formed of brass and a helical gear (helical gear) 62. A synthetic resin helical gear (second helical gear) 64 meshed with the helical gear 62 below, a brass connecting shaft 66 connected to the helical gear (helical gear) 64, and an axis of the connecting shaft 66 A brass spur gear 68 connected to the end of the direction and a brass spur gear 70 meshing with the spur gear 68 and mounted on the output shaft 60 of the stepping motor 58 are provided. A metal disk 72 (see FIGS. 3 and 4) is fixed in the middle of the connecting shaft 66, and a metal stopper pin 74 projects from the outer periphery of the disk 72. The helical gear 64 is configured using a resin (for example, PEEK resin or nylon resin) in consideration of heat resistance as an intermediate gear. The flat gear 70 that is a driving gear transmits the driving force of the stepping motor 58 to the flat gear 68 that is the driven gear, and the driving force transmitted to the flat gear 68 is transmitted to the helical gear 64 via the connecting shaft 66. The driving force transmitted to the helical gear 64 is transmitted to the rotary shade 34 (rotary shaft 36) via the helical gear 62. In this case, the direction of the driving force is converted by 90 degrees by the helical gear 62 and the helical gear 64. That is, the pair of helical gears 62 and 64 constitutes an orthogonal conversion gear.

  Further, the stepping motor 58 is fixed to a motor bracket 76 fixed to the lens holder 30, and a connecting shaft 66 that connects the flat gear 68 and the helical gear 64 is a bearing 78, 80 that is inserted into the motor bracket 76. (Refer to FIG. 3). As shown in FIGS. 3, 4, and 6 (c), the motor bracket 76 is formed with stopper portions 77 (77 a, 77 b) that protrude on the rotation path of the stopper pin 74 and latch the stopper pin 74. When the rotary shade 34 (connection shaft 66) rotates in the forward direction, the stopper pin 74 comes into contact with one side surface 77b of the stopper portion 77, as shown in FIGS. 6C and 7B. Further, when the rotation shade 34 (connection shaft 66) rotates in the reverse direction, the rotation shade 34 (connection shaft 66) is prevented from further rotation, and FIG. 6 (c) and FIG. 7 (a). As shown in FIG. 4, the stopper pin 74 comes into contact with the other side surface 77a of the stopper portion 77, so that the rotation shade 34 (connection shaft 66) is prevented from further rotation. That is, the rotary shade 34 (connection shaft 66) can be rotated within a range of 0 to 315 degrees, for example, but further rotation is caused by the contact between the stopper pin 74 and the stopper portion 77 (77a, 77b). It is blocked by contact. Thereby, initial setting (initialization) for correcting a positional shift in the drive control of the stepping motor 58 can be performed. 1 and 4 is a position detector (potentiometer) for detecting the rotation angle of the stepping motor 58.

  On the other hand, a wet shade body 82 having a rectangular shape in front view is disposed above the rotary shade 34 so as to be movable up and down. The wet shade body 82 is swingable around a fulcrum of a pin 88 provided at a side position of the lens holder 30 and has a U-shape in a front view arranged so as to cross the notch 30 a on the side of the lens holder 30. The swing arm 84 is integrally formed on the tip side. The wet shade main body 82 descends (hangs down) to a region near the irradiation axis (optical axis) L in the region above the rotary shade 34 only when forming a light distribution pattern during rainy weather as a shade for rainy weather travel. In other cases, it moves away from the rotary shade 34 and moves toward the lens holder 30 so as not to affect the light distribution pattern.

  Further, the base end side of the swing arm 84 is connected to a belt-shaped curved cam follower 86 formed of a leaf spring. Specifically, the wet shade main body 82 and the swing arm 84 that constitute the wet shade 81, and the cam follower 86 are formed of a plate spring-like sheet metal integrated molded body. The distal end side of the cam follower 86 is pressed against the outer peripheral surface of the wet cam 52, and the proximal end side is fixed to the motor bracket 76 via a pin 88.

  That is, a coil spring 90 is mounted between the base end portion of the cam follower 86 and the motor bracket 76, one end side 90 a of the coil spring 90 is locked to the motor bracket 76, and the other end side 90 b is the upper surface of the cam follower 86. The spring force (elastic force) of the coil spring 90 acts in the direction in which the cam follower 86 presses the outer peripheral surface of the wet cam 52.

  The wet cam 52 rotates in the forward / reverse direction together with the rotary shade (rotary shaft 36), and while the cam follower 86 is in contact with the outer peripheral surface of the long diameter side of the wet cam 52, as shown by phantom lines in FIG. When the wet shade main body 82 is disposed at a position away from the rotary shade 34 (a position far away from the rotary shade 34), while the cam follower 86 contacts the outer peripheral surface of the wet cam 52 on the short diameter side, As indicated by the solid line 3, the wet shade body 82 hangs down in the vertical direction and is disposed in the vicinity of the upper portion of the rotary shade 34, and at the same time, the light shielding plate 38 d comes to be in the vicinity of the irradiation axis (optical axis) L. Yes.

  That is, the wet shade main body 82 is integrated with a cam follower 86 that follows the outer peripheral surface of the wet cam 52 via the swing arm 84, and the wet cam 52 is used for light distribution switching operation for irradiating a rainy weather beam. In conjunction with the rotation of the rotation shade 34 based on the rotation, the short diameter side comes into contact with the cam follower 86, and in association with the rotation of the rotation shade 34 based on the light distribution switching operation for irradiating the other beams, the long diameter side is the cam follower. 86 abuts on the surface. The swing arm 84 extends to the upper part of the rotary shade 34 with the connection point with the cam follower 86 as a fulcrum to support the wet shade main body 82, and the cam follower 86 abuts on the short diameter side of the wet cam 52. The wet shade main body 82 is suspended to the light passage region, and when the cam follower 86 contacts the long diameter side of the wet cam 52, the wet shade main body 82 is raised to the retreat region. For this reason, the wet cam 52 rotates in conjunction with the rotation of the rotary shade 34 as the stepping motor 58 is driven, and the wet shade main body 82 emits light according to the rotational position of the rotary shade 34 (wet cam 52). Since it moves between the passing area and the retreat area, the position of the wet shade main body 82 can also be controlled by the stepping motor 58 for rotating the rotary shade 34.

  Further, the swing arm 84 is formed so as to straddle the light passage area above the rotary shade 34. When the swing arm 84 swings, the wet shade main body 82 is disposed in the light passage area. Even in this case, the swing arm 84 is held so as to straddle the light passage region, and does not block the light traveling toward the projection lens 28 through the light passage region above the rotary shade 34.

  Further, a portion 84a that vertically supports the wet shade main body 82 from above at the tip of the swing arm 84 is bent so as to be orthogonal to the horizontal region 84b of the swing arm 84, and the plate width direction is the optical axis L direction. It matches. For this reason, only the area corresponding to the plate thickness of the distal end portion 84a of the swing arm 84 blocks light in the light passage region, but the light blocking amount is negligible in forming light distribution.

  Further, as shown in FIG. 6, the light shielding plates 38 a to 38 f of the rotary shade 34 arranged radially with respect to the rotation shaft 36 are counterclockwise in the circumferential direction with reference to the position where the light shielding plate 38 a is arranged. The light shielding plate 38b is disposed at 90 °, the light shielding plate 38c at 135 °, the light shielding plate 38d at 180 °, the light shielding plate 38e at 225 °, and the light shielding plate 38f at 315 °. This is because when the rotary shade 34 is rotated 180 degrees in the forward direction from the initial position shown in FIG. 7A, the light shielding plate 38d is closest to the optical axis L as shown in FIG. 6B. The cam follower 86 is in contact with the outer peripheral surface on the short diameter side of the wet cam 52, and the wet shade main body 82 is suspended vertically and disposed near the upper portion of the rotary shade 34.

  In this case, the light shielding plate 38a corresponds to the high beam Hi-L in the left light distribution, the light shielding plate 38b corresponds to the low beam Lo-L in the left light distribution, and the light shielding plate 38c is the high speed beam MW in the left light distribution. The light shielding plate 38d corresponds to the rain beam (wet beam) Wet-L in the left light distribution, the light shielding plate 38e corresponds to the low beam Lo-R in the right light distribution, and the light shielding plate 38f This corresponds to the high beam Hi-R in the right light distribution, and when the driver performs a light distribution switching operation for irradiating one of the beams, the rotary shade 34 is rotated according to the operation. It has become.

  That is, the stepping motor 58 is connected to a control circuit (not shown) via a lead wire (not shown), and the control circuit has a light distribution switching operation switch (not shown) for operation by the driver. ) Is input. Then, by the driver's light distribution switching operation, for example, as shown in FIG. 7A, from the initial position where the left light distribution high beam Hi-L is formed, the low beam Lo-L and the high speed beam MW When a beam to be irradiated is selected in the order of -L, the rain beam (wet beam) Wet-L, the right light distribution low beam Lo-R, and the high beam Hi-R, the control circuit applies to the stepping motor 58. Thus, pulse signals corresponding to the operation positions of the operation switches are sequentially output. Thereby, the stepping motor 58 is rotated in the forward direction, and the light shielding plates 38a to 38f are sequentially moved to positions near the irradiation axis (optical axis) L in the process in which the stepping motor 58 is rotated in the forward direction. It has become.

  Specifically, when an operation for sequentially rotating the rotary shade 34 in the forward direction from the position where the left light distribution high beam Hi-L shown in FIG. 7A is formed, the left light distribution is performed. When the low beam Lo-L is selected, the light shielding plate 38b is positioned in the vicinity of the optical axis L. Next, when the left light distribution high-speed beam MW-L is selected, the light shielding plate 38c is aligned with the optical axis. Next, when the rain light beam (wet beam) Wet-L for left light distribution is selected, the light shielding plate 38d is in the vicinity of the optical axis L. Further, when the right light distribution low beam Lo-R is selected, the light shielding plate 38e is positioned in the vicinity of the optical axis L. Thereafter, when the right light distribution high beam Hi-R is further selected, the light shielding plate 38e is selected. 38f is a position near the optical axis L.

  In this case, the wet shade main body 82 is movable between a light passing area that is reflected by the reflector 26 and is directed to the projection lens 28 in an area above the rotary shade 34 and a retreat area that is out of the light passing area. When the light distribution switching operation for irradiating the rainy weather beam is performed, the light is suspended from the retreat area to the light passage area in conjunction with the rotation of the rotary shade 34 and reflected by the reflector 26. Of the light traveling toward the projection lens 28, light for irradiating a part of the road surface in front of the vehicle is blocked. For this reason, even if it is only a headlamp, the road surface part of the front and both sides can be seen well at the time of rain and fog, and the glare to an oncoming vehicle can be reduced.

  On the other hand, an operation for sequentially rotating the rotary shade 34 in the reverse direction from the formation position of the high beam Hi-R for right light distribution shown in FIG. 7B is executed, and the low beam Lo-R for right light distribution is executed. , Rain light beam (wet beam) Wet-L for left light distribution, high-speed beam MW-L for left light distribution, low beam Lo-L for left light distribution, and high beam Hi-L for left light distribution When a beam to be irradiated is selected, a pulse signal corresponding to the operation position of the operation switch is sequentially output from the control circuit to the stepping motor 58. Thus, in the process in which the stepping motor 58 rotates in the reverse direction and the stepping motor 58 rotates in the reverse direction, the light shielding plates are arranged in the order of the light shielding plates 38f, 38e, 38d, 38c, 38b, and 38a. It moves to a position near the optical axis (L).

  Also in this case, the wet shade main body 82 hangs down from the retreat area to the light passage area in conjunction with the rotation of the rotary shade 34 during the light distribution switching operation for irradiating the rain beam, and is reflected by the reflector 26. Since the light for irradiating a part of the road surface in front of the vehicle is blocked out of the light directed toward the projection lens 28, the road surface portions on the front and both sides are not covered with a headlamp alone when it is raining or foggy. You can see better and reduce glare to oncoming vehicles.

  Next, the shape of the light shielding plate 38 of the rotary shade 34 when the projection lens 28 side is viewed from the reflector 26 is shown in FIGS. (a) shows the shape of the light-shielding plate 38b for forming the low beam Lo-L in the left light distribution. (b) shows the shape of the light shielding plate 38c for forming the high-speed beam MW-L in the left light distribution. (C) shows the positional relationship between the shape of the light shielding plate 38d for forming the wet weather beam Wet-L and the wet shade main body 82 in the left light distribution. (d) shows the shape of the light shielding plate 38e for forming the low beam Lo-R in the right light distribution. (e) shows the shape of the light shielding plates 38a and 38f for forming the high beams Hi-L and Hi-R in the left light distribution and the right light distribution.

  Next, the irradiation light distribution patterns on the screen corresponding to the shade shapes shown in FIGS. 8A to 8E are shown in FIGS. 9A to 9E, and the irradiation light distribution patterns on the road surface are illustrated. 10 (a) to (e). 9 (a) and 10 (d), the light distribution patterns are the same except that the left light distribution and the right light distribution are different. 9 (b) and 10 (c), the light distribution pattern by the light shielding plate is the same. However, in FIG. 9 (c), since there is the wet shade main body 82, another region is located in the region near the front of the vehicle. A darker area A is formed, and it is possible to prevent the beam from being reflected on a wet road surface and causing glare to the oncoming vehicle. 9 and 10, (e) shows the same pattern in which the left light distribution and the right light distribution are distributed as a high beam over a wide range from the front side of the vehicle to a distant place.

  As described above, according to the present embodiment, when a light distribution switching operation for irradiating a rainy weather beam is performed, a clear cut line in rainy weather is formed by the light shielding plate 38d accompanying the rotation of the rotary shade 34. In addition, in conjunction with the rotation of the rotary shade 34, the wet shade main body 82 hangs down from the retreat area to the light passage area, and is reflected by the reflector 26 and is partially reflected in front of the vehicle. Since the light for irradiating the road surface is blocked, it is possible to see the road surface parts on the front and both sides well in rainy weather or fog, even if it is only a headlamp without providing auxiliary lamps, etc. Glare to oncoming vehicles can be reduced.

  Further, according to the present embodiment, the wet cam 52 rotates in conjunction with the rotation of the rotary shade 34 accompanying the driving of the stepping motor 58, and according to the rotational position of the rotary shade 34 (wet cam 52). Since the wet shade main body 82 moves between the light passing area and the retreat area, the position of the wet shade main body 82 can also be controlled by the stepping motor 58 for rotating the rotating shade 34 (wet cam 52).

  Furthermore, according to the present embodiment, since the metal wet cam 52 is fixed to the rotating shaft 36 of the rotary shade 34, the heat of the rotary shade 34 can be obtained by using the wet cam 52 as a heat sink (heat radiating plate). Transmission to the stepping motor 58 can be suppressed.

  11 to 14 show a projection type automobile headlamp according to a second embodiment of the present invention. FIG. 11 is an exploded perspective view of a light projection unit which is a main part of the headlamp. FIG. 13 is a side view of the projection unit, FIG. 13 is a plan view of the same light projection unit partially shown in cross section, and FIG. 14 is a rear view of the same light projection unit integrated with the unit frame as seen from the rear side. .

  The light projection unit 14 in the first embodiment described above is configured such that the driving force of the motor 58 is transmitted to the rotary shade 34 via the driving force transmission mechanism 56 configured by an orthogonal conversion gear. In the light projection unit 14A of the second embodiment, the output shaft 60 of the stepping motor 58 and the rotary shade 34 (rotary shaft 36) are connected in series. That is, a wet cam 52 that is an eccentric cam, an Oldham coupling 56, and a stepping motor 58 are connected in series to one end side in the axial direction of the rotary shade 34 (rotating shaft 36), and the wet cam 52 is connected to the bearing 48. Adjacent to the rotary shaft 36 is screwed coaxially. An Oldham coupling 56A, which is a driving force transmission mechanism, is screwed to the axial end of the rotating shaft 36 adjacent to the wet cam 52. The stepping motor 58 is configured as a drive source that generates a driving force for rotationally driving the rotary shade 34 by a predetermined angle in response to a pulse signal generated in accordance with the light distribution switching operation. Further, since the Oldham coupling 56A is interposed between the output shaft 60 of the stepping motor 58 and the rotation shaft 36 of the rotary shade 34, it is possible to prevent an axial shift between the output shaft 60 and the rotation shaft 36.

  Further, a disk 72 having a stopper pin 74 projectingly formed is fixed to the outer periphery of the Oldham coupling 56, and the stopper pin 74 is hooked on a stopper portion 77 provided on the motor bracket 76, thereby rotating the rotary shade 34. A range is specified.

  Other configurations are the same as those of the first embodiment described above, and the same reference numerals are given to omit redundant description.

  In the second embodiment, the rotary shade 34 is connected in series to the motor 58 via an Oldham coupling 56A, which is a driving force transmission mechanism, and a driving force transmission mechanism (having a large number of gears) between the rotary shade 34 and the motor 58 (see FIG. Compared to the first embodiment with the orthogonal transformation gear mechanism) 56 interposed therebetween, the number of parts is small, the configuration is simple, and the manufacturing cost is low. Further, since the number of parts constituting the driving force transmission mechanism is small, the loss of power transmitted by the driving force transmission mechanism is small, the driving force transmission efficiency is excellent, and a small capacity motor is used as the driving source of the rotary shade 34. Therefore, the cost can be reduced accordingly.

  In the above-described embodiment, as shown in FIG. 8E, the light shielding plates 38a and 38f corresponding to the high beams Hi-L and Hi-R have a height that slightly protrudes from the rotating shaft 36. Therefore, the high beams Hi-L and Hi-R in the left light distribution and the right light distribution are formed at the upper end of the light distribution pattern (front illumination area) as shown in the phantom lines in FIGS. 9 (e) and 10 (e). The front end side is cut in a horizontal shape, but by setting the height of the light shielding plates 38a, 38f to 0, for example, the distribution of the high beams Hi-L, Hi-R in the left light distribution and the right light distribution. 9 (e) and 10 (e), the light can be configured in an elliptical shape including a virtual line.

  Further, the rotary shade 34 in the above-described embodiment has a structure in which the light shielding plates 38a to 38f are arranged in the circumferential direction of the rotary shaft 36. However, the present invention is not limited to such a structure. As described in Japanese Patent Laid-Open No. 6-139802 described above, a plurality of light distribution patterns can be formed by rotating a stepped cylindrical body around a horizontal support shaft formed at a position deviated from its axis. In such a configuration, the reflector 26 extends in the direction perpendicular to the optical axis L of the reflector 26 in the vicinity of the second focal point of the reflector 26 and is rotatably arranged. The side edge in the vicinity of the optical axis L is on the reflector 26 side. Any rotation shade for light distribution control configured to form a predetermined light distribution pattern by blocking part of the light traveling from the light toward the projection lens 28 may be used.

It is a disassembled perspective view of the light projection unit which is the principal part of the projection type vehicle headlamp which is one Example of this invention. It is a longitudinal cross-sectional view in the optical axis position of the headlamp. It is a side view of the same light projection unit. It is a top view of the same light projection unit which shows a part in section. It is the rear view which removed the reflector from the same light projection unit integrated with the unit frame, and was seen from back. (a) is a figure for demonstrating the change of the height of the wet cam linked with rotation of a rotation shade, (b) is for demonstrating the relationship between a wet cam, a cam follower, and a rotation shade (its light-shielding plate). (C) It is a figure which shows the stopper pin and stopper part which regulate the rotation range of a rotation shade. It is a figure for demonstrating the relationship between the rotation direction of a rotation shade, and a beam. It is a figure for demonstrating the shape of the light-shielding plate corresponding to a light distribution pattern. It is a figure for demonstrating the irradiation light distribution pattern to a screen. It is a figure for demonstrating the irradiation light distribution pattern to a road surface. It is a disassembled perspective view of the light projection unit which is the principal part of the projection type vehicle headlamp which is the 2nd Example of this invention. It is a side view of the same light projection unit. It is a top view of the same light projection unit which shows a part in section. It is the rear view which removed the reflector from the same light projection unit integrated with the unit frame, and was seen from back. It is a figure for demonstrating the road surface irradiation state of the conventional headlamp.

Explanation of symbols

10 Lamp body 12 Front lens 14, 14A Light projection unit L Head lamp irradiation axis (light projection unit optical axis)
L22 Swivel shaft 24 Discharge bulb 26 Reflector 26a Elliptic reflecting surface 28 Projection lens 30 Lens holder 34 Rotating shade 36 Rotating shaft 38a to 38f Light shielding plate 52 serving as a light shielding portion for forming a light distribution pattern 52 Wet cam 56 serving as an eccentric cam 56, 56A Driving force transmission mechanism 58 Stepping motor 81 Wet shade that is the second shade 82 Wet shade body that is the second shade body 84 Swing arm 86 Cam follower 100 Unit frame

Claims (3)

A substantially saddle-shaped reflector; a light source disposed at a substantially first focal point of the reflector; a projection lens disposed in front of the second focal point of the reflector; and the projection in the vicinity of a substantially second focal point of the reflector. Extends in a direction substantially perpendicular to the optical axis of the lens and is rotatably arranged, and the side edge portion in the vicinity of the optical axis blocks a part of the light from the reflector side toward the projection lens, thereby providing a predetermined light distribution In a projection type automotive headlamp comprising a rotating shade for light distribution control configured to form a pattern, and a motor for rotating the rotating shade,
A cam connected coaxially to the rotary shade; and a second shade swinging in conjunction with the rotation of the rotary shade above the rotary shade;
The second shade moves up and down between a light passage area above the rotary shade and a retreat area above the light passage area, and functions as a light-shielding portion. A cam follower that is in sliding contact with the outer peripheral surface; and a frame-shaped swing arm that is formed in a U-shape that opens downward from the second shade body placement side to the cam placement side and supports the second shade body from above. projection vehicle headlight, characterized in that it is composed of. 2. The projection type automotive headlamp according to claim 1, wherein the second shade body, the swing arm, and the cam follower are formed of a sheet metal integrally formed body. 3. The projection type automobile headlamp according to claim 1, wherein the cam is made of metal.

Images