JP4422740B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator used in an adaptive illumination system (AFS) that changes the headlight irradiation direction in accordance with the traveling state of a vehicle.

  Conventionally, as shown in FIG. 4, there is an AFS actuator 60 that drives a motor 64 in accordance with a turning angle of a vehicle handle (not shown) and rotates a lamp (not shown) left and right. It was. The actuator 60 includes an output shaft 61 that is connected to the lamp body and rotates the lamp body according to the rotation of the motor 64, a first gear 62 that is provided integrally with the output shaft 61, and a rotation shaft 64 a of the motor 64. A third gear 65 connected to transmit the rotation of the motor 64 and a second gear that meshes with the first gear 62 and the third gear 65 and transmits the rotation of the motor 64 transmitted from the third gear 65 to the first gear 62. A gear 63 and a non-contact Hall IC 66 and a magnet 67 that output a voltage value corresponding to the rotation angle of the output shaft 61 are provided. The magnet 67 is attached to the first gear 62, and the Hall IC 66 detects a change in the magnetic field according to the rotation of the first gear 62 and outputs a voltage value corresponding to the change, thereby rotating the first gear 62. The angle, that is, the rotation angle of the lamp is detected.

  In this actuator 60, an electronic control unit (hereinafter referred to as ECU) drives the motor 64 in accordance with the turning angle of the handle, and the motor 64 is connected via a transmission mechanism including first to third gears 62, 63, 65. The rotation is transmitted to the output shaft 61 to rotate the lamp body to the left and right. A voltage value corresponding to the rotation angle of the output shaft 61 output from the Hall IC 66 is input to the ECU, and the position (angle) of the lamp body is feedback-controlled.

There has also been proposed an actuator that detects a position (angle) of a lamp body by generating a pulse signal from a Hall element in accordance with a rotation angle of a rotor constituting a motor (see, for example, Patent Document 1). The actuator includes a first gear coupled to the motor, second and third gears that transmit the rotation of the motor, and a fourth gear that is coupled to the output shaft and transmits the rotation of the motor transmitted from the third gear to the output shaft. The rotation of the motor is decelerated by the first to fourth gears and transmitted to the output shaft, thereby rotating the lamp body to the left and right.
JP 2004-98851 A (paragraph [0014] -paragraph [0018] and FIGS. 4-5)

  In the former actuator 60 described above, since the rotation range of the first gear 62 is narrow and the change of the magnetic field is small, the rotation angle of the lamp cannot be accurately detected due to the influence of the electromagnetic field generated by the motor 64 or electrical noise. There was a fear. Furthermore, in this conventional example, the left and right lamps are provided with actuators 60, respectively, and if there are individual differences in the sensitivity of the Hall IC 66 and the magnetic flux density of the magnet 67, the voltage value from the Hall IC 66 varies with respect to the rotation angle. Therefore, in order to absorb this variation, it is necessary to initially set the voltage value output from the Hall IC 66 at a predetermined point in the rotation range for each actuator in the ECU. Therefore, it takes time to perform the initial setting.

  In the latter actuator, since the Hall element is provided in the vicinity of the motor, the actuator is easily affected by an electromagnetic field generated by the motor and electrical noise, and may malfunction. Since the individual gears are interposed, there is a possibility that the rotation angle of the lamp cannot be accurately detected due to the influence of backlash.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an inexpensive actuator with improved detection accuracy of the rotation angle of the headlight.

  According to the first aspect of the present invention, a motor, an output shaft connected to the headlight and rotating the headlight in accordance with forward / reverse rotation of the motor, a transmission mechanism for transmitting the rotation of the motor to the output shaft, and a rotation angle of the output shaft An angle sensor that generates an output signal having a magnitude corresponding to the first gear, and a transmission mechanism that engages with the first gear and a second gear that meshes with the first gear and transmits the rotation of the motor to the first gear. A reduction ratio between the first gear and the second gear so that the rotation range of the second gear is larger than the rotation range of the first gear, and an angle sensor is provided on the second gear. It is provided.

  The invention of claim 2 is characterized in that the reduction ratio is set so that the rotation range of the second gear is smaller than 360 °.

  According to a third aspect of the present invention, the angle sensor includes a rotary position sensor that changes a resistance value according to the rotation of the second gear and outputs a voltage value corresponding to the resistance value.

  According to the first aspect of the present invention, the speed reduction ratio is set so that the rotation range of the second gear is larger than the rotation range of the first gear, and the angle sensor is provided in the second gear, thereby providing the first gear. The rotation angle of the output shaft, that is, the rotation angle of the output shaft can be detected by magnifying it to a reduction ratio, so that the electrical change amount of the angle sensor with respect to the unit angle change of the output shaft can be expanded, and therefore the sensitivity of the angle sensor is improved. There is an effect that the rotation angle of the light can be accurately detected.

  According to the invention of claim 2, by setting the reduction gear ratio so that the rotation range of the second gear is smaller than 360 °, the rotation range of the angle sensor is set to 360 ° or less, that is, one rotation or less. Therefore, an inexpensive sensor can be used, and the arithmetic processing for converting the electrical change amount of the angle sensor into a rotation angle is simplified, so that the arithmetic circuit can be inexpensive, and thus an inexpensive actuator can be realized. There is an effect that can be done.

  According to the invention of claim 3, by using the rotary position sensor as the angle sensor, it is possible to change the resistance value according to the rotation of the second gear and output the voltage value according to the resistance value. There is an effect that the rotation angle can be detected with higher accuracy, and an inexpensive sensor can be obtained as compared with the first and second aspects, so that the manufacturing cost of the actuator can be further reduced. Further, since the resistance value is changed according to the rotation of the second gear and the voltage value corresponding to the resistance value is output, there is also an effect that the influence of the electromagnetic field generated by the motor and the electric noise can be reduced. .

  An embodiment of the present invention will be described with reference to FIGS. The actuator 3 according to the present invention constitutes the lamp system A as shown in FIG. 3 and is used in an adaptive illumination system (AFS) that changes the irradiation direction of the headlight 1 in accordance with, for example, the traveling state of the vehicle.

  As shown in FIG. 3, the lamp system A includes a headlight 1 that illuminates the front of the vehicle, a bracket 2 that rotatably supports the headlight 1, and an actuator 3 that is attached to the bracket 2 and rotates the headlight 1. And an electronic control unit (hereinafter referred to as ECU) 4 for controlling the actuator 3. The lamp system A is used as a set of two for one vehicle.

  The headlight 1 has a substantially cylindrical lamp body 5 which is open at both ends and has a light source (not shown) inside, and has a substantially circular shape at one end side of the lamp body 5 so as to close the opening. A lens 7 is attached. Further, a shaft portion 9 for supporting the bracket 2 is projected outward from the upper portion of the lamp body 5, and an output shaft 37 of an actuator 3 described later is provided at the lower portion of the lamp body 5. The fitting part 10 which fits is provided integrally.

  The bracket 2 has a horizontally long substantially rectangular plate-like main body 11, and an upper plate 13 and a lower plate 12 that extend toward the headlight 1 are integrally provided at both end edges along the width direction of the main body 11. ing. A bearing hole 16 for supporting the shaft portion 9 of the headlight 1 is provided on the distal end side (headlight 1 side) of the upper plate 13, and corresponds to the fitting portion 10 of the headlight 1 on the lower plate 12. The part is provided with an insertion hole 15 through which the fitting part 10 is inserted. In addition, a plurality of fixing portions 18 (three locations in the present embodiment) in which screw holes into which fixing screws 19 for fixing the actuator 3 are screwed are formed on the back surface side of the lower plate 12. When the headlight 1 is inserted into the bearing hole 16 of the bracket 2 and the fitting portion 10 is inserted into the insertion hole 15 in a state where the rear portion is inserted into the opening 11 a provided in the main body portion 11, When the fitting projection 37 a of the output shaft 37 of the actuator 3 is fitted to the fitting portion 10 so as to be pivotally supported by the bracket 2, the headlight 1 is rotated according to the rotation operation of the output shaft 37. .

  The ECU 4 has a built-in microcomputer (not shown) for controlling the operation of the actuator 3 and an interface circuit (not shown) for inputting / outputting control signals to / from the actuator 3. It is connected to the actuator 3 through a connector that does not. The ECU 4 is electrically connected to a sensor (not shown) that generates an electrical signal corresponding to the turning angle of the handle, and the ECU 4 sets the target angle of the headlight 1 according to the electrical signal from the sensor. To do.

  As shown in FIG. 1, the actuator 3 includes a horizontally long box-shaped body 22 having an open top surface, a cover 21 attached to the body 22 so as to cover the opening of the body 22, and the headlight 1 attached to the body 22. And a motor 42 for generating a rotational force for rotation. Further, inside the body 22, an output shaft 37 that is connected to the headlight 1 and rotates the headlight 1, a first gear 38 that is formed integrally with the output shaft 37, and a small gear that meshes with the first gear 38. A second gear 39 integrally formed with a gear 49, a third gear 40 integrally formed with a small gear 41 that meshes with the second gear 39, and a third gear that is press-fitted and fixed to the rotating shaft 43 of the motor 42. A fourth gear 44 that meshes with 40, and a rotary position sensor (angle sensor) 32 that includes a semi-fixed resistor whose resistance value changes according to the rotation angle of the rotor 32b with the rotor 32b coupled to the second gear 39. Has been.

  The body 22 is made of, for example, synthetic resin, and plate-like mounting pieces 25 and 25 extending in the width direction of the body 22 are integrally provided on one end side in the longitudinal direction, and the body 22 is provided on the other end side in the longitudinal direction. A plate-like mounting piece 25 extending in the longitudinal direction is integrally provided. Insertion holes 25a through which the fixing screws 19 for attaching the actuator 3 to the bracket 2 are inserted, respectively, at the front end side of each attachment piece 25, and ribs upward at both ends along the longitudinal direction of the attachment piece 25 25b and 25b are projected. In addition, the side wall 22a of the body 22 is provided with a plurality of (four in this embodiment) engaging projections 26 having a triangular cross section that are inclined so that the amount of protrusion from the side wall 22a increases toward the lower side. A connecting portion 33 having a U-shaped cross section projects from a side wall 22 a on one end side in the width direction of 22. A plurality of (three in FIG. 1) connection pins 34 electrically connected to a rotary position sensor (hereinafter referred to as a sensor) 32 are arranged in the connection portion 33, and a cable from the ECU 4 is connected to the connection portion 33. By connecting the connector, the sensor 32 and the ECU 4 are electrically connected.

  Further, a shaft hole 27 for supporting the output shaft 37 is provided on one end side in the longitudinal direction of the bottom surface 22b of the body 22 and is press-fitted into the rotation shaft 43 of the motor 42 on the other end side in the longitudinal direction of the bottom surface 22b. An insertion hole 28 is provided through which the fixed fourth gear 44 is inserted. In addition, between the shaft hole 27 and the insertion hole 28 on the bottom surface 22 b of the body 22, a bearing hole 30 that supports the support shaft 36 that supports the third gear 40 and a support shaft 35 that supports the second gear 39. A bearing hole 51 (see FIG. 2B) is supported side by side along the longitudinal direction of the body 22. Furthermore, the body 22 is provided with fixing portions 29 and 29 having screw holes into which fixing screws 57 for fixing the motor 42 are screwed, at diagonal positions with the insertion hole 28 therebetween. The shaft hole 27, the insertion hole 28, the bearing hole 30, and the bearing hole 51 are provided so that their centers are arranged in a straight line in the longitudinal direction of the body 22.

  The cover 21 is made of the same synthetic resin as that of the body 22 and is formed in substantially the same shape as the body 22, and a portion corresponding to each mounting piece 25 of the body 22 has an extending direction of the corresponding mounting piece 25. Side-view substantially L-shaped attachment pieces 23 extending in the same direction are provided. Insertion holes 23 a communicating with the insertion holes 25 a of the attachment pieces 25 in the state where the cover 21 is attached to the body 22 are respectively penetrated at the distal ends of the attachment pieces 23. Further, in the cover 21, a portion corresponding to the engagement protrusion 26 provided on the side wall 22 a of the body 22 is projected toward the body 22 side and engaged with the engagement protrusion 26. The pieces 24 are integrally provided. Further, in the cover 21, portions corresponding to the shaft hole 27, the bearing hole 30, and the bearing hole 51 of the body 22 are provided with a bearing hole 54 that supports the shaft portion 53 on the back side of the rotating shaft 37 together with the shaft hole 27, a support shaft. A bearing hole 55 that pivotally supports 35 together with the bearing hole 51 and a bearing hole 56 that pivotally supports the support shaft 36 together with the bearing hole 30 are provided (see FIG. 2B). In addition, the width dimension of each attachment piece 23 is formed in the dimension substantially the same as the dimension between the ribs 25b and 25b provided in the both sides of the attachment piece 25, and each attachment piece 23 in the state which attached the cover 21 to the body 22. The position is regulated by both ribs 25b, 25b.

  The motor 42 uses, for example, a stepping motor that rotates in accordance with the pulse power output from the ECU 4, and has a substantially disc-shaped main body 42a. Is protruding. In addition, insertion holes 45 through which the fixing screws 57 are inserted diagonally with the rotation shaft 43 in between are provided on the outer edge of the main body portion 42a, and the fixing screws 57 are inserted into these insertion holes 45, respectively. The motor 42 is attached to the body 22 by being screwed into the fixing portion 29 of the body 22.

  The output shaft 37 is formed in a substantially cylindrical shape made of synthetic resin, and a fitting projection 37a that is formed in a substantially triangular cross section and fits with the fitting portion 10 of the headlight 1 is integrally provided on the distal end side. 37, a shaft portion 53 that is pivotally supported by the bearing hole 54 of the cover 21 protrudes from a portion opposite to the fitting protrusion 37a. In addition, a first gear 38 having a plurality of projecting teeth 38 a formed on the circumferential surface is integrally provided at a portion of the output shaft 37 on the motor 42 side. In the present embodiment, the rotation range of the first gear 38 is set to 20 ° (10 ° counterclockwise and 10 ° clockwise from the state of FIG. 2A).

  The second gear 39 is made of synthetic resin and has a substantially disc-shaped main body 39a. The main gear 39a is integrally formed with the main gear 39a so that the center of the small gear 49 coincides with the main body 39a. The small gear 49 is provided with protruding teeth 49a meshing with the protruding teeth 38a of the first gear 38 over the entire circumference. Further, a shaft portion 52 is integrally provided at a portion of the small gear 49 opposite to the main body portion 39a so that the center thereof coincides with the main body portion 39a and the small gear 49. Are integrally provided with a plurality of teeth 39b along the circumferential direction. Further, a pair of stoppers 58 project from the surface of the main body 39a on the cover 21 side along the circumferential direction, and the stoppers 58 are attached to contact portions (not shown) provided on the inner surface of the cover 21. By making contact, the clockwise rotation and the counterclockwise rotation of the second gear 39 are restricted. In the present embodiment, the reduction ratio of the first gear 38 to the second gear 39 is set to 1/45, and therefore the second gear 39 has a rotation range of 90 ° (see FIG. 2A). 45 degrees counterclockwise and 45 degrees clockwise). Further, the shaft portion 52 is provided with a D-cut portion (not shown), and the rotor 32b rotates in accordance with the rotation of the shaft portion 52 by making contact with a D-cut surface 32c of the rotor 32b described later.

  The third gear 40 is made of synthetic resin and has a substantially disc-shaped main body portion 40a. The main gear portion 40a is integrally formed on the surface on the cover 21 side so that the small gear 41 coincides with the main body portion 40a. The small gear 41 is provided with protruding teeth 41a that mesh with the protruding teeth 39b of the second gear 39 over the entire circumference. In addition, projecting teeth 40b are integrally provided on the outer edge of the main body 40a over the entire circumference.

  The fourth gear 44 is made of a synthetic resin, and is press-fitted and fixed to the rotating shaft 43 of the motor 42. A protruding tooth 44a that meshes with the protruding tooth 40b of the third gear 40 is formed over the entire circumference. Here, the first gear 38, the second gear 39, the third gear 40, and the fourth gear 44 constitute a transmission mechanism.

  The sensor 32 has a rectangular plate-like main body portion 32a, and a rotor 32b having a D-cut surface 32c is provided at a substantially central position of the main body portion 32a so as to be rotatable with respect to the main body portion 32a. The sensor 32 is mounted on a rectangular plate-shaped substrate 31 and is electrically connected to the connection pins 34 via the substrate 31. The sensor 32 changes its resistance value according to the rotation angle of the rotor 32b, and outputs a voltage value (for example, a voltage value of DC1V to 4V) corresponding to this resistance value. In the present embodiment, the rotation range of the rotor 32b is 360 °, that is, one rotation or less.

  Here, the assembly of the actuator 3 will be described. First, the motor 42 is attached to the body 22 by bringing the motor 42 into contact with the body 22 from the back side of the body 22 and screwing the fixing screw 57 into the fixing portion 29 of the body 22 through the insertion hole 45. In this state, the fourth gear 44 is disposed inside the body 22 through the insertion hole 28 of the body 22. Next, the substrate 31 on which the sensor 32 is mounted is attached to the bottom surface 22 b of the body 22 using the fixing screw 50. In this state, the substrate 31 is arranged so that the center of the rotor 32 b of the sensor 32 coincides with the center of the bearing hole 51. Further, the support shaft 35 is press-fitted and fixed to the bearing hole 51 through the center hole of the rotor 32 b, and the support shaft 36 is press-fitted and fixed to the bearing hole 30. Next, the output shaft 37 is housed in the body 22 with the fitting protrusion 37 a exposed to the back side of the body 22 through the shaft hole 27, and the support shaft 36 is inserted into the center hole of the third gear 40. The third gear 40 is accommodated in the body 22. Thereafter, the support shaft 35 is inserted into the center hole of the second gear 39, the D cut portion at the tip of the shaft portion 52 is brought into contact with the D cut surface 32c of the rotor 32b, and the projecting teeth 38a and the third gear 38 of the first gear 38 are engaged. The second gear 39 is housed in the body 22 in a state of being engaged with the protruding teeth 41 a of the gear 40. Finally, when the engagement protrusions 24 are respectively engaged with the corresponding engagement protrusions 26 and the cover 21 is attached to the body 22, the actuator 3 is assembled.

  Note that a positioning hole 46 for inserting a positioning pin (not shown) is provided on the bottom surface 22b of the body 22 so that the first and second gears 38 and 39 can be inserted into the body 22 when the first and second gears 38 and 39 are accommodated in the body 22. The initial positions of the first gear 38 and the second gear 39, that is, the zero point adjustment of the sensor 32 can be adjusted by inserting the positioning pins inserted into the positioning holes 46 through the insertion holes 47 and 48 provided in the first and second gears 38 and 39. Made. After the cover 21 is attached to the body 22, the positioning pin is extracted from the insertion hole 59 provided in the cover 21.

  Next, the operation of the actuator 3 will be described. First, an electrical signal is input to the ECU 4 from a sensor (not shown) according to the turning angle of the handle, and the ECU 4 sets a target angle of the headlight 1 according to the electrical signal. At the same time, an electrical signal corresponding to the current rotation angle of the output shaft 37 (the rotation angle of the headlight 1) is input from the sensor 32 to the ECU 4 via the connector. In the ECU 4, an angle to be actually rotated is set from the set target angle and the current rotation angle of the output shaft 37, and pulse power corresponding to the rotation angle is supplied to the motor 42. The motor 42 rotates according to the supplied pulse power, and the rotational force of the motor 42 is transmitted in the order of the fourth gear 44, the third gear 40, the second gear 39, and the first gear 38, and the output shaft 37 rotates. . Then, the headlight 1 connected to the output shaft 37 rotates, and the light irradiation direction follows the turning angle of the handle. In addition, after the headlight 1 is rotated, an electric signal corresponding to the current rotation angle of the output shaft 37 is input from the sensor 32 to the ECU 4, and if it does not coincide with the set target angle, pulse power is supplied to the motor 42. The supplied angle correction is performed.

  In this embodiment, since the reduction ratio of the first gear 38 to the second gear 39 is set to 1/45, the rotational force of the motor 42 transmitted to the second gear 39 is 1/4. .5 and is transmitted to the first gear 38. Therefore, when the second gear 39 rotates 45 °, the first gear 38 rotates 10 °.

  In the actuator 3, the rotor 32 b of the sensor 32 is rotated integrally with the second gear 39, whereby the rotation angle of the first gear 38, that is, the rotation angle of the output shaft 37 is reduced by a reduction ratio (4.5 in this embodiment). Magnified). Therefore, for example, when the angle error in the second gear 39 is ± 0.5 °, the angle error in the first gear 38 is ± 0.11 °. The rotation angle of the shaft 37 can be detected with high accuracy. Further, the rotation range of the second gear 39 (set to 90 ° in the present embodiment) is smaller than 360 ° and larger than the rotation range of the first gear 38 (set to 20 ° in the present embodiment). By setting the reduction ratio, the rotation range of the sensor 32 can be 360 ° or less, that is, one rotation or less, so an inexpensive sensor can be used, and the rotation range of the sensor 32 is one rotation or less. Since the calculation process for converting the electrical change amount of the sensor 32 into the rotation angle is simplified, the calculation circuit to be used can be inexpensive, and the inexpensive actuator 3 can be realized.

  Further, since a rotary position sensor whose resistance value changes according to the rotation angle is used as the sensor 32 and a voltage value corresponding to the resistance value is output as a signal, the influence of the electromagnetic field generated by the motor 42 and electrical noises is output. Can be reduced. Further, by providing the sensor 32 in the second gear 39, the number of gears interposed between the sensor 32 and the output shaft 37 is smaller than in the case where the sensor 32 is provided in the gear after the third gear 40. The influence of backlash between gears can be reduced, and the rotation angle of the output shaft 37 can be detected with high accuracy.

  In the present embodiment, the reduction ratio of the first gear 38 to the second gear 39 is set to 1 / 4.5, and the rotation range of the first gear 38 is set to 20 °. The reduction ratio and the rotation range of the first gear 38 are not limited to the present embodiment, and may be set as appropriate according to the usage mode. In the second gear 39, the case where the clockwise rotation angle and the counterclockwise rotation angle are the same angle (that is, the left and right rotation angles are symmetrical) has been described as an example. However, the rotation angle is limited to the present embodiment. Instead, the positional relationship between the contact portion of the cover 21 and the stopper 58 of the second gear 39 may be changed so that the counterclockwise rotation angle and the clockwise rotation angle are asymmetric.

  Further, in the present embodiment, the case where the sensor 32 has a detection angle range of 360 ° or less, that is, one rotation or less has been described as an example. However, the sensor to be used is not limited to the present embodiment. The angle range may be 360 ° or more, that is, one rotation or more. Further, the sensor is not limited to the rotary position sensor, and any sensor that can detect the angle may be used.

  In the present embodiment, the case where four gears are used has been described as an example. However, at least two gears are sufficient, and there may be three or five or more gears.

It is a disassembled perspective view which shows the actuator of this embodiment. The same as above, (a) is a front view with the cover removed, and (b) is a sectional view. It is a disassembled perspective view of the lamp system using the same. The actuator of a prior art example is shown, (a) is the front view which removed the cover, (b) is sectional drawing.

Explanation of symbols

1 Headlight 3 Actuator 32 Rotary position sensor (Angle sensor)
37 Output shaft 38 First gear 39 Second gear 42 Motor

Claims (3)

  A motor, an output shaft that is connected to the headlight and rotates the headlight according to the forward / reverse rotation of the motor, a transmission mechanism that transmits the rotation of the motor to the output shaft, and an output that corresponds to the rotation angle of the output shaft An angle sensor that generates a signal, and the transmission mechanism includes at least a first gear provided on the output shaft, and a second gear that meshes with the first gear and transmits the rotation of the motor to the first gear. The reduction ratio of the first gear and the second gear is set so that the rotation range of the second gear is larger than the rotation range of the first gear, and an angle sensor is provided in the second gear. Actuator.   The actuator according to claim 1, wherein the reduction ratio is set so that a rotation range of the second gear is smaller than 360 °.   The angle sensor comprises a rotary position sensor that changes a resistance value according to the rotation of the second gear and outputs a voltage value corresponding to the resistance value. The actuator according to item 1.

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