JPH051975A - Angle detection mechanism for headlamp irradiation angle adjustment device for automobile - Google Patents

Abstract

PURPOSE:To ensure higher accuracy in angle detection via the improvement of an angle detection mechanism for automating the optical axis adjustment of a headlamp, and improve reaction to a change in the specification of the head lamp. CONSTITUTION:There is provided a disc 12 (or cylinder not shown herein) to turn synchronously with the vertical motion of a headlamp 7. Conductive patterns 12a to 12d are formed on the surface of the rotary disc 12 (or peripheral surface of rotary cylinder), and an electrode 13 is provided in slidable contact therewith. In addition, output from a manual switch 10 and voltage from the disc 12 (or cylinder) are inputted to a window comparator 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle detecting device used in a drive mechanism for vertically adjusting the optical axis direction of a vehicle headlamp.

[0002]

2. Description of the Related Art In general, an automobile headlamp is installed on a vehicle body with its optical axis leveled. Therefore, the vehicle headlamp is provided with a manual adjustment mechanism (aiming mechanism) for vertically adjusting the optical axis direction, and the optical axis direction is properly adjusted in an automobile manufacturing factory or an automobile maintenance factory. . However, even if the optical axis direction is horizontal in the standard state, if the state of the load changes, the suspension spring bends and the vehicle body tilts, causing the adjustment state to go wrong. Therefore, in addition to the manual aiming mechanism, an electric remote control type optical axis adjusting mechanism (leveling mechanism) is provided in the vehicle headlamp. The optical axis adjusting device for a vehicle headlamp is provided with a manual (mostly lead screw type) aiming mechanism and an electric (remote control type) leveling mechanism for the reasons described above. Figure 5
[Fig. 3] is a two-view diagram for explaining the vertical adjustment of the optical axis.
FIG. 5A shows a front view, 1 is a lamp housing,
2 is a front lens. A reflector (not shown) is fixedly installed in the lamp housing 1, and an arrow Z indicates its optical axis. The lamp housing 1
The lamp housing is rotatably supported by two ball joints 3a and 3b at the upper and lower portions of the lamp. A bracket 4 is fixed below the lamp housing 1 and reciprocated in a direction perpendicular to the plane of the drawing by a driving means (not shown). This is shown in a side view as shown in FIG. 5 (B), and the bracket 4 is driven as indicated by an arcuate reciprocating arrow a-b. As a result, the lamp housing 1 is tilted between the posture shown by the solid line and the posture shown by the broken line in this figure (B), and the optical axis Z swings up and down. FIG. 6 is an explanatory view of a drive mechanism of a conventional example, and FIG. 6A is a drawing similar to FIG. 5, in which the drive mechanism is omitted. FIG. 6 (B) is a side view and 5 is a drive unit. (C) is a bottom view in which the drive unit 5 is shown. As shown in the above (B) diagram, the drive unit 5 has a male screw member 5a, and a receiving gear 5b having a female screw hole is screwed into the male screw member 5a. The receiving gear 5b is rotated by a motor provided in the case 5c via a reduction gear (both not shown). The male screw member 5a is provided with a mechanism (not shown) for locking the rotation around the axis, and is screw-fed in the front-rear direction (left-right direction in the drawing) with the rotation of the receiving gear 5b. It A nut member 6 is attached to the tip of the male screw member 5a. The aiming screw 7 attached to the bracket 4 is screwed onto the nut 6. As a result, the aiming screw 7 can be manually turned to rotate the nut member 6
(Relatively), the lamp housing 1 is rotated around the ball joints 3a and 3b. Further, when the receiving gear 5b is rotated by the motor (not shown) of the drive unit 5, the male screw member 5a is moved forward and backward (left and right in the figure), and the lamp housing 1 is moved to the ball joints 3a and 3b.
The optical axis Z is tilted up and down by being rotated around b.
In this conventional example, the aiming by the aiming screw and the leveling by the drive unit 5 are performed as described above. Leveling of the headlight by the drive unit (up and down tilt adjustment)
Is performed by a control method as shown in FIG. 7, for example. The headlamp 7 shown in FIG. 7 is tilted up and down by the forward and reverse rotations of the motor 8. This vertical tilt is caused by the motor 8
To the window comparator 1 via the relays 9a and 9b.
Done by 1. On the other hand, reference numeral 10 is a manual operation switch, and the connection to the voltage dividing terminals connected to the voltage dividing resistors R ₁ , R ₂ and R ₃ is switched by a rotary switch. The voltage dividing resistors R ₁ , R ₂ and R ₃ are connected in series, and the voltage Vz is applied via the fixed resistor R ₄ . The above voltage Vz is the input voltage Vc from the power supply.
Is obtained with a zener diode Zd to obtain a constant voltage. The above voltage Vz is grounded via the potentiometer 10. The potentiometer 10 rotates as the headlamp 7 tilts up and down, and a voltage Vp corresponding to the tilt angle is taken out. The combined voltage of the take-out voltage Vs that changes according to the switching operation of the switch 10 and the take-out voltage Vp that changes according to the tilt angle of the headlight 7 is input to the window comparator 11. If there is an imbalance between the two voltages Vs and Vp, the motor 8 is rotated in the normal direction or the reverse direction in the direction of eliminating the imbalance. Then, the motor 8 is stopped when both the voltages Vs and Vp are balanced. In this way, when the driver switches the switch 10, the headlight 7 is tilted at an angle according to the instruction. In this case, the switching positions 0 ', 1', and 3'of the switch 10 shown in FIG. 7 are, for example, 0'position when empty, 1'position when half-loaded, and when fully loaded. 2 '
The position is preliminarily set to the 3'position when the load is behind (the center of gravity of the load is tilted backward).

[0003]

In the prior art described above, a. The potentiometer performs the action of converting the vertical tilt angle of the headlight 7 into a voltage signal (Vp). However, the potentiometer has poor temperature characteristics, and the output voltage signal becomes unstable due to voltage fluctuations. Since it is difficult to detect the angular position of, the high-precision vertical tilt angle adjustment (leveling) could not be performed. b. The potentiometer 10 performs the operation of converting the vertical tilt angle of the headlight 7 into a voltage signal (Vp), and the operation command signal voltage (Vs) is changed to the manual changeover switch 10.
It is performed by a fixed resistor R ₁ to R ₃ and. For this reason,
There is a single angle adjustment pattern. For this reason, in the case of multi-model production of automobiles, in order to perform leveling suitable for each model, it is necessary to design and manufacture a dedicated electrical component for each model. As a result, the cost reduction effect of mass production cannot be obtained, and the man-hours required for production and assembly are increased. Not only that, the stock number of spare parts increases, and the stock quantity increases, which is uneconomical. The present invention has been made in view of the above circumstances, and an object thereof is to provide an angle detection mechanism for leveling, which is capable of highly accurate leveling, and which can be adapted to each vehicle type by simple parts replacement. To do.

[0004]

As a structure for achieving the above object, a first invention of a detection mechanism according to the present invention is an angle detection in which a partial pressure extraction voltage changes according to a vertical tilting angle of a headlight. A mechanism, which is used in combination with a switch means having a plurality of partial pressure extraction terminals, and which has an extraction voltage of the angle detection mechanism,
In an angle detection mechanism for inputting a combined voltage with a voltage taken out from the switch means to a window comparator to positively or reversely rotate the leveling electric motor of the headlight through the relay means, in accordance with the vertical tilt of the headlight. A rotating disk made of an electrically insulating material is formed, and two large and small circles and a plurality of radial straight lines passing through the center of rotation are assumed on the disk.
The conductive pattern along the arc of the great circle in the part sandwiched by two adjacent straight lines and the conductive pattern along the arc of the small circle in the part sandwiched by two adjacent straight lines are alternately arranged. In addition, each of the connection points of a large number of fixed resistors connected in series and each of the conductive patterns, and arranged in the linear direction, a conductive pattern along a great circle arc And a contact electrode facing the conductive pattern along the small circular arc is provided, and when the headlamp tilts and the disc rotates, the contact electrode always moves along the small circular arc. Conducting contact with at least one of the conductive pattern and the conductive pattern along the large arc, and when the contact electrode and any of the radial straight lines face each other, the conductive pattern along the small arc and along the large arc Both with a conductive pattern Characterized in that the contact, a structure in which conductive. A second aspect of the present invention is an angle detection mechanism in which the divided voltage extraction voltage changes according to the vertical tilting angle of the headlight, and is used in combination with switch means having a plurality of divided voltage extraction terminals. In the angle detection mechanism for inputting the combined voltage of the output voltage of the headlamp and the output voltage from the switch means to the window comparator, and rotating the leveling motor of the headlamp forward and backward through the relay means, A cylinder made of an electrically insulating material that rotates with tilting up and down is formed, and two circles in the circumferential direction and a plurality of straight lines parallel to the axis of the cylinder are assumed to be adjacent to each other on the cylinder surface. A conductive pattern along one arc of a portion sandwiched between two straight lines and a conductive pattern along the other arc of a portion sandwiched between two adjacent straight lines are alternately arranged and connected in series. Connection of multiple fixed resistors connected to Respectively of a point,
Interconnecting each of the conductive patterns, and
Contact electrodes, which are arranged in the straight line direction and are opposed to the conductive pattern along one circular arc and the conductive pattern along the other circular arc, are provided, and the headlight tilts to rotate the cylinder. When moving, the contact electrode is always in contact with at least one of the conductive pattern along one arc and the conductive pattern along the other arc, and,
When the contact electrode and one of the straight lines face each other, the contact electrode is in contact with and conductive to both the conductive pattern along one circular arc and the conductive pattern along the other circular arc.

[0005]

According to the above construction, the motor is stopped when the contact electrode straddles the two conductive patterns and contacts and becomes conductive. The motor stops in this way when the contact electrode faces any one of a plurality of straight lines,
It is possible to stop at a fixed position with high accuracy regardless of the temperature characteristics and voltage fluctuations of the resistor. Further, by exchanging the disc or the cylinder without changing the switch means or the resistors, it is possible to cope with each vehicle type. The above-mentioned disc means a member that is mechanically equivalent to a disc, and even if a polygonal plate is used, it is within the technical scope of the present invention.

[0006]

1 shows an embodiment of an angle detecting mechanism according to the present invention. This example is an improvement made by applying the present invention to the conventional example (FIG. 7). The difference from the conventional example (FIG. 7) is that instead of the potentiometer 10, series resistors Rv _{1 to} Rv ₆ for voltage division, the rotary plate 12 having a conductive pattern, and the conductive pattern are contacted. That is, the contact electrode 13 that conducts electricity is provided. The rotating plate 1
FIG. 2 shows an explanatory diagram of the vicinity of 2. Six radial straight line passing through the center of the rotating plate (i.e. radius) r _1, 2 pieces of concentric large arc Sl and small circular arc Ss with assuming r ₂ ~r ₆
Assume A circular arc-shaped conductive pattern 12a having a width is formed along a portion where the large arc Sl is sandwiched between the _two radii r ₁ and r ₂ . Along a portion of the small arc Ss is sandwiched two radius r _2, r _3, constitutes a circular arc-shaped conductive pattern 12b having the width. A large arc Sl has two radii r ₃ ,
An arc-shaped conductive pattern 12c having a width is formed along the portion sandwiched by r ₄ . Along a portion sandwiched radius r _4, r ₅ of small circular arc Ss is two, constitutes an arc-shaped conductive pattern 12d having the width. A circular arc-shaped conductive pattern 12e having a width is formed along a portion where the large arc Sl is sandwiched between two radii r ₅ , r ₆ . Rotating plate 1 above
2 is reciprocally rotated in conjunction with vertical tilting of the headlight 7 (see FIG. 1). Six fixed resistors Rv ₁ and Rv _{2 to} Rv ₆ are connected in series and a voltage Vz is applied. Fixed resistance Rv ₁
And the connection point between the same Rv ₂ and the conductive pattern 12a. The connection point between the fixed resistors Rv ₂ and Rv ₃ is connected to the conductive pattern 12b. Fixed resistance Rv ₃
And a connection point between the same Rv ₄ and the conductive pattern 12c. The connection point between the fixed resistors Rv ₄ and Rv ₅ is connected to the conductive pattern 12d. Fixed resistance Rv ₅
And a connection point of Rv ₆ and the conductive pattern 12e. Then, the contact electrode 13 is disposed across the large arc Sl and the small arc Ss. This contact electrode 13
Are conductive patterns 12b, 1 arranged on the small arc Ss.
The inner contact 13s corresponding to 2d and the outer contact 13l corresponding to the conductive patterns 12a, 12c, 12e arranged on the large arc Sl are arranged in the radial direction, and the inner and outer contacts 13s, 13l are mutually arranged. It is a connected structure. Now, when the rotary plate 12 rotates as shown by the arrow c with the tilting of the headlight, the contact electrode 1
The relative position of 3 with respect to the rotary plate 12 moves as indicated by an arc arrow d to come into contact with the conductive pattern 12a, and then sequentially comes into contact with the conductive patterns 12b to 12c. When facing the radius r ₂ on the way, the conductive pattern 12a
And the conductive pattern 12b are connected, and the fixed resistor Rv ₂ is short-circuited. When facing the radius r ₃ on the way, the conductive pattern 12b and the conductive pattern 12c are connected and the fixed resistor Rv ₃ is short-circuited. When facing the radius r ₄ on the way, the conductive pattern 12c and the conductive pattern 12d are connected and the fixed resistor Rv ₄ is short-circuited. When facing the radius r ₅ on the way, the conductive pattern 12d and the conductive pattern 12e are connected and the fixed resistor Rv ₅ is short-circuited. In this way, the contact electrode 13 has radii r ₂ , r ₃ , r
When facing either ₄ or r ₅ , the motor 8 is stopped and the headlamp 7 is stopped at a predetermined tilt angle as described below. Since the headlight stops at the mechanically set contact position, the tilt angle can be controlled with high accuracy without being affected by a change in resistance value due to temperature or a change in power supply voltage. In FIG. 1, the power supply voltage of the vehicle-mounted battery is applied to the input Vc. The above power supply voltage is fixed resistor Rr
, The comparators A and B, one ends of the exciting coils of the relays A ′ and B ′, and the NC pin of the relay. The illustrated diode D ₁ and capacitors C ₁ and C ₂ are for reverse connection prevention, surge absorption, and voltage fluctuation absorption, respectively. The fixed resistor Rr is for limiting the current flowing through the Zener diode Zd, and the Zener voltage Vz is kept substantially constant by this Zener diode. The stable voltage Vz is applied to the switch 1 via the fixed resistor Rt.
Fixed resistors Rv _{1 to} R for dividing voltage
It is grounded via v ₆ . Fixed resistors Ra, Rb, R
c is set so that Ra = Rc and Rb << Ra, Rc. As a result, the voltage Vz
Is divided into voltages Va and Vb. And Ra = R
From the condition of c, Va≈Vb. The reason why Va = Vb is not set is to ensure the switching operation of the comparator and prevent chattering. The voltage V
a is connected to the inverting input of comparator A, and voltage Vb is connected to the non-inverting input of comparator B. The non-inverting input of the comparator A and the inverting input of the comparator B are connected and extend to the sensor side (the rotating plate 12 side in this example). This connection method is called a window comparator and is a well-known technique widely used for detecting whether or not it is within a certain voltage range. In the figure, voltage V
If k is an intermediate value between Va and Vb, the outputs O ₁ , O ₂
Is the LO level, and when Vc>Va> Vb, the output O ₁
LO level output O ₂ becomes HI level, and Vc> Vb
When> Va, the output O ₁ becomes HI level output and O ₂ becomes LO level. There is a circuit from the point Vz to the switch 10 via the fixed resistance Rt, and a circuit to be grounded via the fixed resistances Rt and Ru. Rt <R ₁ + R ₂ + R ₃ and
And _{Ru >> R 1 + R 2 +} R 3. When the switching position of the switch 10 is set to O ', the conduction state shown in FIG. 3 (A) is established and Vs becomes 0. When the switching position of the switch 10 is set to 1 ', Ru >> R ₁ is obtained, and therefore approximately FIG.
The conduction state shown in (B) is reached, and the value of Vs becomes Vs ₁ . When the switching position of the switch 10 is set to 2 ', FIG.
As in (C), when the switching position is set to 3 ', it becomes as shown in FIG. 3 (D). Therefore, Vs ₀ = 0 (unit is Volt) Vs ₁ = Vz × R ₁ / (Rt + R ₁ ) Vs ₂ = Vz × (R ₁ + R ₂ ) / (Rt + R ₁ + R ₂ ) Vs ₃ = Vz × (R ₁ + R) ₂ + R ₃ ) / (Rt + R ₁ + R ₂ + R ₃ ). When the contact electrode 13 is in contact with the vicinity of the middle of the conductive pattern 12a except both ends thereof, the conductive pattern 12
The conductive pattern 12 does not come into contact with conductive patterns other than a
The divided voltage Vs ₁ is applied via a. Contact electrode 13
However, when the conductive pattern 12b is in the vicinity of the middle of the conductive pattern 12b except for both ends, it does not contact the conductive patterns other than the conductive pattern 12b, and the divided voltage V is generated via the conductive pattern 12b.
Given s ₂ . The contact electrode 13 has the conduction pattern 12
When it is in contact with the vicinity of the middle except for both ends of c, it does not contact the conductive patterns other than the conductive pattern 12c, and the divided voltage Vs ₃ is applied through the conductive pattern 12c. When the contact electrode 13 is in contact with the middle of the conductive pattern 12d except for both ends thereof, it does not contact with the conductive patterns other than the conductive pattern 12d, and the divided voltage Vs ₄ is applied via the conductive pattern 12d. When the contact electrode 13 is in contact with the middle of the conductive pattern 12e except for both ends thereof, it does not contact with the conductive patterns other than the conductive pattern 12e, and the divided voltage Vs ₅ is applied through the conductive pattern 12e. When the contact electrode 13 is located at a position directly facing the radius r ₂ and contacts the conductive patterns 12a and 12b, the fixed resistor Rv ₂ is short-circuited and the contact electrode 13
Is given a composite potential V ₁ . In FIG. 2, this is r ₂
It was displayed as (V ₁ ). When the contact electrode 13 is located at a position directly facing the radius r ₃ and contacts the conductive patterns 12b and 12c, the fixed resistor Rv ₃ is short-circuited, and the contact electrode 13 gives a composite potential V ₂ . To be In FIG.
This was designated as r ₃ (V ₂ ). The contact electrode 13 has a radius r ₄
And the same as the conduction pattern 12c.
The fixed resistor Rv ₄ is short-circuited when it contacts with d, and the contact electrode 13 is given a composite potential V ₃ . Figure 2
This was designated as r ₄ (V ₃ ). Contact electrode 13
Becomes a position directly facing the radius r ₅ and the conduction pattern 12
When a contact is made across d and 12e, the fixed resistance Rv
₅ is short-circuited and the contact electrode 13 is given a composite potential V ₄ . In FIG. 2, this was designated as r ₅ (V ₄ ). At this time, the relationship between the above respective potentials is Vs ₁ > V ₁ > Vs ₂ > V ₂ > Vs ₃ > V ₃ > Vs ₄ > V ₄ > Vs ₅ . This provides an effect similar to that of a normal variable resistor. In FIG. 1, almost all the current passing through the contact electrode 13 passes through the fixed resistors Rq and Rp and flows from the point F to the switch 10 side. The reason is that the input impedance of the comparator is very large and the fixed resistance Ru is
This is because the resistance value of is also large. Next, the operation will be described. It is now assumed that the switch 10 is in the switching position 0 '.
Since Vs is 0 (volt), the potential at point F is also 0. At this time, a potential of Ve = V ₁ × Rp / (Rp + Rq) is generated at the point E, and if this Ve is set so that Va>Ve> Vb, the comparator outputs O ₁ and O ₂ are both The relay is not activated due to HI, and the motor 8 is stopped. At this time (when the switch 10 is at position 0 '), if the contact electrode 13 is in contact and conducted at a position other than r ₂ (V ₁ ) shown in FIG. 2, the motor 8 is rotated and the headlamp 7 and the rotating plate are rotated. The motor 8 stops when 12 rotates and the contact electrode 13 reaches the r ₂ (V ₁ ) position. However, in order to perform the above-mentioned operation, the rotation direction of the motor 8 must be set so that the contact electrode approaches the radius r ₂ . Next, the contact electrode 13 when it is in the r ₃ (V ₂₎ position, the case where switch 10 is operated to switch position 1 '. At this time, the potential of Vs is Vs = Vz
× R ₁ / (Rt + R ₁ ), and this potential Vs is equal to the potential at the point F, so the potential Ve at the point E is Ve = (V ₂ −V ₁ ) Rp / (Rq + Rp). Since Ve so that this time Va>Ve> Vb is are set, the comparator output O _1, O ₂ both HI next motor 8 is stopped. Now, considering the case where the contact electrode 13 is at the r ₂ (V ₁ ) position and the switch changeover position is 1 ′, the potential Ve ′ at the point E.
Is Ve ′ = (V ₁ −Vs) Rp / (Rq + Rp) = {(V ₁ −Vz) × R ₁ / (Rt + R ₁ )} × Rp / (Rq + Rp), which is the difference from the original stop potential Ve. This potential at point E is about (V ₁ −Vz) Rp / (Rq + Rp) rather than Va.
Then, the comparator A becomes LO, the relay A ′ moves to the normally open side, and the motor 8 is energized and rotated. As the motor 8 rotates, the headlamp tilts up and down, and the rotary plate 12 rotates in the direction of arrow c (FIG. 2). In the above, the contact electrode 13 is at the r ₂ (V ₁ ) position and the switch 1
0 is operated to the switching position 1 ', the potential at the point E becomes higher than Va, and the rotating plate 12
Turns in the direction of arrow c and stops when the contact electrode 13 reaches the r ₃ (V ₂ ) position. Similarly, when the contact electrode 13 is operated to the switching position 1'when the contact electrode 13 is at the position r ₄ (V ₃ ) for example, the electric potential at the point E becomes lower than Va, contrary to the above, and the rotary plate 12 becomes opposite arrow c. And stops when the contact electrode 13 reaches the r ₃ (V ₂ ) position. Although the above is an example of a typical case, in short, the contact electrode 13 is r ₂
When the switch 10 is operated to the switching position 1'when it is in a position other than (V ₁ ), the contact electrode 13 moves to r
_The motor 8 rotates in the direction approaching the ₂ (V ₁ ) position, and when the contact electrode 13 reaches the r ₂ (V ₁ ) position, the motor 8 stops and the tilting of the headlight stops. The contact electrode 13 is r
When the switch 10 is operated to the switching position 1'when the switch 10 is in a position other than ₃ (V ₂ ), the contact electrode 13 is moved to r
_The motor 8 rotates in a direction approaching the ₃ (V ₂ ) position, and when the contact electrode 13 reaches the r ₃ (V ₂ ) position, the motor 8 stops and the tilting of the headlight stops. The contact electrode 13 is r
₄ When the switch 10 is operated to switch position 1 'when (V ₃₎ is in a position other than, the contact electrode 13 is r
_The motor 8 rotates in a direction approaching the ₄ (V ₃ ) position, and when the contact electrode 13 reaches the r ₄ (V ₃ ) position, the motor 8 stops and the tilting of the headlight stops. The contact electrode 13 is r
When the switch 10 is operated to the switching position 1'when the switch 10 is in a position other than ₅ (V ₄ ), the contact electrode 13 is moved to r
_The motor 8 rotates in a direction approaching the ₅ (V ₄ ) position, and when the contact electrode 13 reaches the r ₅ (V ₄ ) position, the motor 8 stops and the tilting of the headlight stops. As is apparent from the above-described operation, the stop operation of the motor 8 (the tilting stop of the headlight) in the present embodiment is performed by the contact electrode 13 accompanying the rotation of the rotary plate 12.
Since it is controlled by the relative movement of the conductive patterns 12a to 12e, it can be performed with high accuracy without being affected by the resistance value change due to the temperature change and the fluctuation of the power supply voltage. Moreover, if a rotating plate having a conductive pattern suitable for each vehicle type is prepared in advance, it is possible to deal with each vehicle type only by exchanging the rotating plate without exchanging electric parts. In addition to cost reduction, it is easy to manage production processes and spare parts. Figure 4
3 is a schematic view of an embodiment different from the above, and corresponds to FIG. 2 of the above embodiment. In this embodiment, instead of the rotary plate 12 in the above-described embodiment, a column 21 made of an electrically insulating material is configured to rotate in association with the vertical tilt of the headlight 7 (FIG. 1). 21a is the cylindrical surface. The developed figure of the cylindrical surface 21a is shown as 21b. This example (FIG. 4)
The rotary plate 12 shown in FIG. 2 of the above-mentioned embodiment is replaced with a cylinder 21, and the operating principle is the same. Column 2
Six straight lines r ₁ ′, r ₂ ′, r ₃ ′, which are parallel to the central axis of 1,
r ₄ ′, r ₅ ′ and r ₆ ′ respectively correspond to the _six radii r _{1 to} r 6 in FIG. 2 of the above embodiment. The strip-shaped arc-shaped conductive patterns 12a 'to 12e' along the outer circumference of the cylinder 21 correspond to the arc-shaped conductive patterns 12a to 12e in FIG. In addition, the same reference numerals as those in FIG. 2 denote the same or similar constituent parts as those in the above-described embodiment. According to this example (FIG. 4), the same operation and effect as those in the above-described embodiment can be obtained.

[0007]

As described above, when the present invention is applied, highly accurate leveling is possible, and it is effective for cost reduction, and moreover, it can be adapted to each vehicle type by simple parts replacement.

[Brief description of drawings]

FIG. 1 is a wiring diagram of one embodiment of the present invention.

FIG. 2 is a schematic diagram of a rotating plate in the above embodiment.

FIG. 3 is an operation explanatory view of the above embodiment.

FIG. 4 is a schematic view of a cylinder in an embodiment different from the above.

FIG. 5 is an explanatory diagram of optical axis adjustment.

FIG. 6 is a three-sided view showing an external appearance of a mechanical portion of a conventional headlight drive mechanism.

FIG. 7 is a wiring diagram of the above conventional example.

[Explanation of symbols]

7 ... Headlight, 8 ... Motor, 9a, 9b ... Relay, 10 ...
Potentiometer, 11 ... Wind comparator, 12
... Rotating plate, 12a to 12e ... Conductive pattern, 13 ... Contact electrode, 21 ... Cylinder, 21a ... Cylindrical surface, 21b ... Development surface.

Claims (2)

[Claims] 1. An angle detection mechanism in which a partial pressure extraction voltage changes according to a vertical tilting angle of a headlight, which is used together with a switch means having a plurality of partial pressure extraction terminals, and which is an extraction voltage of the angle detection mechanism. In the angle detection mechanism for inputting the combined voltage of the output voltage from the switch means and the window comparator to the window comparator, the angle detecting mechanism for reversing the leveling motor of the headlamp forward and backward, the vertical tilting of the headlamp is performed. A disk made of an electrically insulating material that rotates together is formed, and two large and small circles and a plurality of radial straight lines passing through the center of rotation are assumed on the disk, and two adjacent straight lines are assumed. The conductive pattern along the arc of the great circle in the part sandwiched by and the conductive pattern along the arc of the small circle in the part sandwiched by two adjacent straight lines are alternately arranged and connected in series. The number of fixed resistor connection points The conductive patterns are connected to each other and are arranged in the straight line direction so as to face the conductive pattern along the great circular arc and the conductive pattern along the small circular arc. When a contact electrode is provided and the headlamp tilts to rotate the disk, the contact electrode is always at least one of a conductive pattern along a small arc and a conductive pattern along a large arc. One of the structures is in contact with one side, and when the contact electrode and any of the radial straight lines face each other, both the conductive pattern along the small circular arc and the conductive pattern along the large circular arc are in contact and conductive. An angle detection mechanism for an automobile headlamp irradiation angle adjusting device, which is characterized in that: 2. An angle detection mechanism in which a partial pressure extraction voltage changes according to a vertical tilting angle of a headlight, which is used together with a switch means having a plurality of partial pressure extraction terminals, and which is an extraction voltage of the angle detection mechanism. In the angle detection mechanism for inputting the combined voltage of the output voltage from the switch means and the window comparator to the window comparator, the angle detecting mechanism for reversing the leveling motor of the headlamp forward and backward, the vertical tilting of the headlamp is performed. A cylinder made of an electrically insulating material that rotates with it is formed, and two circles in the circumferential direction and a plurality of straight lines parallel to the axis of the cylinder are assumed on the cylinder surface, and two adjacent circles are assumed. A conductive pattern along one arc of a portion sandwiched between straight lines, and a conductive pattern along the other arc of a portion sandwiched between two adjacent straight lines,
Alternating with each other, connecting each of the connection points of a large number of fixed resistors connected in series, and each of the conductive patterns, and arranged in the linear direction, in one arc A contact electrode facing the conductive pattern along the other and the conductive pattern along the other arc is provided, and when the headlamp tilts and the cylinder rotates, the contact electrode is always on one side. Conducting contact with at least one of the conductive pattern along the arc and the conductive pattern along the other arc, and when the contact electrode and any of the straight lines face each other, a conductive pattern along the one arc An angle detection mechanism for an automobile headlamp irradiation angle adjustment device, which has a structure of being in contact with and conducting with both of a conductive pattern along the other arc.