GB2355065A

GB2355065A - Vehicle headlamp leveling apparatus

Info

Publication number: GB2355065A
Application number: GB0023470A
Authority: GB
Inventors: Hirohisa Deguchi; Nobumi Yokoyama
Original assignee: Koito Manufacturing Co Ltd
Current assignee: Koito Manufacturing Co Ltd
Priority date: 1999-09-30
Filing date: 2000-09-25
Publication date: 2001-04-11
Anticipated expiration: 2020-09-25
Also published as: GB2355065B; DE10046301C5; JP3928687B2; DE10046301C2; JP2001097107A; GB0023470D0; DE10046301A1

Abstract

A vehicle headlamp leveling apparatus comprising a casing body (2,3,4), a motor (26) and a threaded worm wheel (10) supported on the casing body in such a manner as to be rotatable but not able to move axially and adapted to be rotated by the motor. A shaft (17) is supported in such a manner as not to be rotatable but to be movable axially and an adjusting screw (21) is supported on the shaft. An engaging support portion (11b) is provided on the worm wheel which engages with a rib (9) provided on the casing body to thereby support the worm wheel in such a manner as to allow rotation but not axial movement relative to the casing body.

Description

2355065 VEHICLE HEADLAMP LEVELING APPARATUS The present invention relates

to a novel vehicle headlamp leveling apparatus and more particularly to a technology for improving the ease of assembling such apparatus.

It is known to provide a vehicle headlamp leveling apparatus comprising an adjusting screw connected to a tilting member for changing the irradiation angle of irradiated light as said tilting member is tilted, a threaded shaft holding said adjusting screw and adapted not to rotate but to move axially, and a worm wheel supported on a casing body in such a manner as to rotate but not to move axially.

In the vehicle headlamp leveling apparatus as described above, when the worm wheel is caused to rotate by a remote controlled motor, the shaft thread fitted to the worm wheel is then fed in an axial direction, and the tilting member is tilted via the adjusting screw supported on the shaft, whereby the irradiated angle of irradiated light is changed.

In a conventional vehicle headlamp leveling apparatus, the casing body is divided into front and rear halves, and the worm wheel is supported in such a manner as to rotate but not to move axially in a state in which the worm wheel is held between the front and rear casing bodies.

Due to this construction, the mounted condition of the worm wheel is unstable until the front and rear casing bodies are connected to each other, this causing a problem that assembly of the worm wheel is difficult.

To cope with this existing problem, an object of the invention is to go at least some way towards overcoming the above disadvantage by improving the ease of assembly of the worm wheel by stabilizing its position even before the casing body is completely assembled.

Accordingly, a vehicle headlamp levelling apparatus according to the invention consists in:

2 a casing body, a motor, a worm wheel supported on said casing body in such a manner as to be rotatable but not movable axially and adapted to be rotated by said motor, and a shaft which is engaged with said worm wheel in such a manner as to be non-rotatable but movable axially, wherein an engaging portion is provided on said worm wheel and engaged with an engaging support portion integrally provided on said casing body so that said worm wheel is rotatable but is not movable axially.

Thus, with the vehicle headlamp leveling apparatus according to the invention, the worm wheel can easily be mounted and there is no risk of the position of the worm wheel threatening to become unstable during assembly.

Further, the degree of freedom at which the components are disposed within the casing body can be increased, thereby making it possible to make the entire apparatus thinner.

Still further, the interior of the casing can be made smaller, whereby the overall thickness of the casing can be reduced further such that the wheel portion may be moved closer to the support portion (the wall of the casing body), so that rotation of the wheel can also be stabilised. Particular embodiments of the invention will now be described with reference to the accompanying drawings; in which:30 Fig. 1 is a longitudinal sectional view showing one embodiment of a vehicle headlamp leveling apparatus according to the invention; Fig. 2 is a front view of the vehicle headlamp leveling apparatus of Fig. 1; 35 Fig. 3 is a rear view of the vehicle headlamp leveling apparatus of Fig. 1; 3 Fig. 4 is a rear view of the front of the vehicle headlamp leveling apparatus of Fig. 1 casing with the rear casing removed; Fig. 5 is a sectional view taken along the line V-V of Fig. 1; Fig. 6 is a sectional view taken along the line VI-VI of Fig. 5; Fig 7 is an enlarged sectional view taken along the line VII-VII of Fig. 4; Fig. 8 is an enlarged sectional view taken along the line VIII-VIII of Fig. 1; and Fig. 9 is a longitudinal sectional view showing a modified example of the vehicle headlamp leveling apparatus of Fig. 1.

The vehicle headlamp leveling apparatus 1 has a casing body 2, and required components are accommodated or supported in the casing body 2.

The casing body 2 is divided into two halves; a f ront casing 3 and a rear casing 4.

The front casing 3 has a substantially rectangular plate-like frontal portion 3a and a low peripheral wall portion protruding rearward from the peripheral edge portion of the frontal portion 3a, and a substantially cylindrical protruding portion 5 is formed thereon in such a manner as to protrude forward from a position longitudinally deviating to one end of the front casing 3.

An inner cylindrical portion G is formed inside the cylindrical protruding portion 5 slightly spaced away therefrom, and a front end of the inner cylindrical portion 6 terminates slightly more rearward than a front end of the cylindrical protruding portion 5. Ribs 7, extending as far as the front end of the cylindrical protruding portion 5 are formed at equal intervals in a circumferential direction between the inner cylindrical portion 6 and the cylindrical protruding portion 5 whereby the inner cylindrical portion 6 and the cylindrical protruding portion 5 are connected to each other. Additionally, an 4 annular body 8 having a smaller diameter than that of the inner cylindrical portion 6 is formed so as to link the ribs 7, at leading ends thereof. An engagement rib 9 protruding inwardly is f ormed at the leading end portion of the inner cylindrical portion 6.

A worm wheel 10 comprises a wheel portion 12 integrally formed at a rear end of a barrel-like body 11, and a threaded groove 11a is formed in an internal surface of the barrel-like body 11, and additionally an annularly extending engagement groove 11b is formed in an external surface of the cylindrical body at the leading end thereof. Then, the barrel-like body 11 of the worm wheel 10 is inserted into the inner cylindrical portion 6 of the front casing 3 from the rear, and the engagement groove 11b formed in the external surface of the barrel-like body 11 at the leading end thereof is brought into slidable engagement with the engagement rib of the inner cylindrical portion 6, whereby the worm wheel 10 is supported on the front casing 3 in such a manner as to rotate but not to move longitudinally (or axially).

A printed-circuit board 13 (Fig. 4) is disposed inside the front casing 3, and a variable sliding resistance 14 is attached to the printed-circuit board 13. Additionally, three terminal pieces 15, are provided so as to protrude rearward. The slide resistance 14 is provided at a position close to the wheel portion 12 of the worm wheel 10, and a slider is positioned so as to move longitudinally. Furthermore, a connecting protrusion 14a of the slider is formed in such a manner as to protrude toward where the worm wheel 10 is located.

A guide portion 16 is integrally formed on the front casing 3 in such a manner as to protrude rearward at an opposite position to the position where the slide resistance 14 is disposed relative to the worm wheel 10.

The guide portion 16 is bifurcated except for a proximal portion thereof so as to form a guide slit 16a opening toward a rear end thereof.

A shaft 17 is formed into a longitudinally long cylindrical shape, and a guide arm 18 is provided at a rear end portion thereof so as to protrude sideways, and a connecting arm 19 is provided at the rear end portion so as to protrude sideways from an opposite side to the portion where the guide arm 18 is provided to protrude. Two holding pieces 19a, are provided so as to protrude in parallel rearward from a leading end portion of the connecting arm, and deflectable holding arms 19b, are provided on confronting surfaces of leading end portions of the holding pieces 19a, so as to protrude therefrom.

An elongation of threads 20 is formed in an external surface of the shaft 17 over substantially a latter half portion thereof.

An adjusting screw 21 is held on the shaft 17. The adjusting screw 21 has a substantially oval cross-section at a rear end portion 21a thereof, and the remaining portion of the latter half portion 21b constitutes a portion to be held, while a former half portion 21c thereof constitutes a threaded shaft portion. Then, the portion 21b to be held is inserted through the shaft 17 for rotatable support.

As described above, the elongation of threads 20 of the shaft 17 rotatably holding the adjusting screw 21 is thread fitted in the thread groove 11a of the worm wheel 10 and held therein. When this happens, the guide arm 18 of the shaft 17 slidably engages in the guide groove 16a of the guide portion 16 of the front casing 3, whereby the shaft 17 is allowed to move longitudinally but is not allowed to rotate. Additionally, the connecting protrusion 14a of the slider of the slider resistance 14 is held between the two holding pieces 19a, of the connecting arm 19 of the shaft 17, and the dislocation of the connecting protrusion 14a from between the two holding pieces 19a, is prevented with the holding arms 19b.

Two rearward protruding bearing portions 22, are provided on the front casing 3 at a position close to where 6 the worm wheel 10 is disposed so as to be spaced away from each other. U-shaped receiving recessed portions 22a are formed in these bearing portions 22 in respective confronting faces thereof in such a manner as to open rearwardly.

A worm member 23 has a worm wheel portion 23a at one end portion thereof and the remaining portion thereof constitutes a worm near portion 23b, shaft portions 23c being provided so as to protrude from ends thereof. The worm member is supported in the receiving recessed portions 22a of the bearing portions 22 at the shaft portions 23c thereof, respectively, whereby the worm member is rotatably supported on the front casing 3 and the worm gear portion 23b mesh engages with the wheel portion 12 of wheel 10.

Two motor supporting portions 24, 25 are provided on the front casing 3 in such a manner as to protrude therefrom. A first of the motor supporting portions 24 is provided at a position close to one of the bearing portions 22, and has two supporting arms 24a, extending in parallel.

The other motor supporting portion 25 is formed at a position spaced away from the first motor supporting portion 24 and has a substantially U-shaped receiving portion 25a which opens at a rear end thereof.

A motor 26 has protrusions 26a at respective end portions thereof, a first protrusion 26a is supported by the supporting arms 24a of the f irst motor supporting portion 24 in such a manner that the f irst protrusion 26a is held between the supporting arms 24a. The other protrusion 26b is supported by the receiving portion 25a of the other motor supporting portion 25, whereby the motor 26 is supported on the front casing 3.

A worm gear 27 is fixed to a motor shaft 26c of the motor 26, and when the motor 26 is attached to the front casing 3 as described above, the worm gear 27 mesh engages with the worm wheel portion 23a of the worm member 23.

The rear casing 4 has a shape which covers the rear of the front casing 3, and a plurality of engagement pieces 7 28, are provided so as to protrude forward from an external portion at a front end thereof and engagement holes 28a are formed in the engagement pieces 28.

A plurality of engagement projections 29 are provided S on an external 25 surface of the peripheral wall portion 3b of the front casing 3 in such a manner as to project therefrom. When a rear end of the peripheral wall portion 3b of the f ront casing 3 is brought into abutment with the front end of the rear casing 4, the engagement projections 29 of the front casing 3 are brought into engagement with the engagement holes 28a of the rear casing 4, whereby the front casing 3 and the rear casing 4 are connected to each other.

A barrel portion 30 is formed on the rear casing 4 at a position corresponding to the cylindrical protruding portion 5 formed on the front casing 3.

An adjusting gear body 31 comprises a barrel-like portion 32 and a crank gear portion 33 integrally provided on a rear end portion of the barrel-like portion 32. The barrel-like portion 32 is rotatably supported by the barrel portion 30 and the crank gear portion 33 is positioned outside the rear casing 4. A connecting hole 32a is formed in the barrel-like portion 32 which opens at a front end thereof, the connecting hole 32a being formed substantially into an oval in section.

When the front casing 3 on which the worm wheel 10 is supported and the rear 15 casing 4 on which the adjusting gear body 31 is supported are connected to each other as described above, a rear end portion 21a of the adjusting screw 21 is inserted into the connecting hole 32a of the adjusting gear body 31. The adjusting screw 21 is not allowed to rotate but is allowed to move axially relative to the adjusting gear body 31.

Additionally, a recessed portion 34 opening rearward is formed in the rear casing 4 and passage holes 35 are formed in a bottom portion of the recessed portion 34.

Then, when the front casing 3 and the rear casing 4 are 8 connected together as described above, the terminal pieces 15 provided on the printed-circuit board 13 supported on the front casing 3 so as to protrude therefrom pass through the passage holes to thereby be located inside the recessed 5 portion 34 where a connector portion 36 is formed.

The leveling apparatus 1 described heretofore is, for instance, fixed at a housing of an automotive vehicle headlamp, and the threaded shaft portion 21c of the adjusting screw 21 is thread fitted in a nut body supported at a tilting end of a reflector (a tilting member) supported tiltably on the housing.

Then, for instance, the leading end of a phillips-head screwdriver is brought into mesh engagement with the crank gear portion 33 of the adjusting gear body 31, and the phillips-head screwdriver is rotationally operated, the adjusting gear body 31 is rotated, whereby the adjusting screw 21 is in turn rotated. When the adjusting screw 23. is rotated, since the threaded shaft portion 21c thereof is screwed in or screwed back relative to the nut body of the tilting member, the portion where the nut body is supported moves longitudinally, whereby the tilting member is tilted and the irradiation angle of the automotive vehicle headlamp is altered.

In addition, when the irradiation angle is remote controlled, the motor 26 is driven. When the motor 26 is driven, the worm wheel 10 is rotated via the worm gear 27 fixed to the motor shaft 26c, the worm wheel portion 23a of the worm member 23 and the worm gear portion 23b of the same worm member 23. The rotation of the worm wheel 10 feeds the shaft 17 forward or backward as it is in mesh engagement with the thread groove 11a of the worm wheel 10 at the elongation of threads 20 thereof, as a result of which, the adjusting screw 21 supported on the shaft 17 is moved forward and/or backward. This moves the portion of the shaft portion 21c where the nut body of the tilting member is fitted back and forth, whereby the tilting member is tilted to alter the irradiation angle of the automotive 9 vehicle headlamp. Additionally, since the back and forth movement of the shaft 17 changes the resistance value of the slide resistance 14, the position of the adjusting screw 21 or the irradiation angle is detected by reading such a change in resistance value.

In the aforesaid automotive vehicle headlamp leveling apparatus, since the worm wheel 10 is supported on the f ront casing 3 in such a manner as to rotate but not to move longitudinally by allowing the engagement groove lib thereof to engage with the engagement rib 9 f ormed on the inner cylindrical portion 6 of the f ront casing 8, the attachment of the worm wheel 10 to the casing body 2 is made simple. The position of the worm wheel 10 during assembly is therefore stabilized, whereby the assembling is property of the worm wheel 10 can be improved.

Fig. 9 shows a modified example of a vehicle headlamp leveling apparatus 1A which, according to this modified example is different from the aforesaid vehicle headlamp leveling apparatus 1 in that the example 1A has no adjusting screw.

Namely, a shaft 37 thread fitted in a worm wheel 10 is different from the shaft 17 of the vehicle headlamp leveling apparatus 1 in that the former has a spherical portion 38 at a leading end thereof and that the former has no hole through which the adjusting screw is passed, but the shaft 37 is similar to the shaft 17 with respect to the remaining features, and therefore, the illustration and description of the similar portions will be omitted.

The spherical portion 38 provided at the leading end of the shaft 37 is connected to a sphere receiving member provided on a reflector (a tilting member) in a spherical joint f ashion.

Then, when the irradiation angle is remote controlled, a motor 26 is driven. When the motor 26 is driven, the worm wheel 10 is rotated via a worm gear 27 fixed to a motor shaft 26c, a worm wheel portion 23a of a worm portion 23 and a worm gear portion 23b of the same worm portion 23.

The rotation of the worm wheel 10 feeds the shaft 37 back and forth which is in mesh engagement with a thread groove at an elongation of threads. As a result, a tilting end portion of a tilting member moves back and forth which supports the sphere receiving member connected to the spherical portion 38 of the shaft 37 in the spherical joint fashion. The tilting member is thereby tilted, and the irradiation angle of the automotive vehicle headlamp leveling apparatus is altered. Additionally, since the back and forth movement of the shaft 37 changes the resistance value of a slide resistance 14, the position of the shaft 37 or the irradiation angle is detected by reading such a change in resistance value.

11

Claims

1 A vehicle headlamp leveling apparatus comprising:

acasing body, a motor, a worm wheel supported on said casing body in such a manner as to be rotatable but not movable axially and adapted to be rotated by said motor, and a shaft which is engaged with said worm wheel in such a manner as to be non-rotatable but movable axially, wherein an engaging portion is provided on said worm wheel and engaged with an engaging support portion integrally is provided on said casing body so that said worm wheel is rotatable but is unable to move axially.

2. A vehicle headlamp leveling apparatus according to claim 1, wherein a cylindrical portion protrudes outwardly from the casing body, and the engaging support portion of the casing body is formed on said cylindrical portion.

3. A vehicle headlamp leveling apparatus according to claim 1 or claim 2, wherein a wheel portion, which transmits rotation of the motor to a distal end portion of the worm wheel, is provided close to an internal surface of the casing body.

4. A vehicle leveling apparatus substantially as herein described with reference to and as illustrated by the accompanying drawings.