JP4708994B2 - Rotating drive - Google Patents

Description

  The present invention relates to a rotation drive device.

  Conventionally, in order to detect the rotational position of the output shaft, that is, the rotational angle of the output shaft, the rotation drive device is provided with a magnetic sensor as described in Patent Document 1, for example. More specifically, a cylindrical yoke is fixed to the inner peripheral surface of the sensor receiving recess formed at the lower end of the output shaft, and a pair of magnets are fixed to the inner peripheral surface of the yoke so as to be symmetrical to each other. Yes. The magnetic sensor is arranged at the center of the yoke and outputs a voltage signal corresponding to a change in the amount of magnetic flux of the magnet rotated by the rotation of the yoke together with the output shaft. That is, this magnetic sensor is a linear sensor. The rotational position of the output shaft is detected based on the voltage signal output from the magnetic sensor.

By the way, since the magnetic sensor is a linear type, it is desirable to secure a longer distance between the magnetic sensor and the magnet in order to detect the rotational position of the output shaft with high accuracy. For this reason, generally, a high-magnetic rare earth magnet is used as the magnet, and the yoke is provided to form a magnetic path of a pair of magnets arranged at a distance.
JP 2004-208418 A

  However, rare earth magnets are more expensive than magnets other than rare earth magnets (ferrite magnets, alnico magnets, etc.), and this has been a factor in increasing the manufacturing cost of the rotation drive device. For example, by using a highly sensitive magnetic sensor, it is possible to use a magnet other than the rare earth magnet instead of the rare earth magnet. However, if a highly sensitive sensor is used for the magnetic sensor, the magnetic sensor becomes expensive, and consequently it is difficult to reduce the manufacturing cost. In addition, when a highly sensitive magnetic sensor is used, there is a risk that the magnetic sensor may perform abnormal sensing due to a change in the rotational position of the output shaft caused by a slight dimensional error or the like of components constituting the rotation drive device.

  Further, if the pair of magnets are not arranged so as to be symmetric with respect to the magnetic sensor, the rotation angle of the output shaft is not correctly reflected in the voltage signal output from the magnetic sensor. Therefore, in order to correctly sense the rotational position of the output shaft, it is necessary to dispose a pair of magnets with high accuracy with respect to the yoke, which is also a factor in increasing the manufacturing cost of the rotation drive device. It was.

  The present invention has been made in view of such circumstances, and its object is to provide a rotational drive device that can reduce the manufacturing cost by constructing an inexpensive configuration for detecting the rotational position of the output shaft. Is to provide.

In order to solve the above-mentioned problem, the invention described in claim 1 is a motor having a rotating shaft, a driving gear attached to the rotating shaft, an intermediate gear for reducing the rotation of the driving gear, and the intermediate gear. An output gear having a gear portion that is rotated by rotation transmitted from the intermediate gear, an output shaft that rotates integrally with the gear portion, and a rotation portion of the gear portion that is provided at a stage subsequent to the output gear. A sensor gear that rotates at a higher speed than the sensor gear, a rotated position detector that rotates together with the sensor gear and detects the rotational position of the output shaft, and a rotational position of the rotated position detector a rotational position detecting unit which outputs a sensor signal is at the H level or the pulse signal potential level is switched to the L level, and detecting means for detecting a rotational position of the output shaft based on the pulse signal, the motor Outputs a command pulse signal for driving the motor to the motor, and a control means for counting the number of steps output by the command pulse signal, wherein, when the motor is forward, Within the switching range obtained by adding or subtracting the first error step number considering the error to the reference count value set in advance as the target count value when the potential level of the sensor signal switches, the sensor signal When the potential level is switched from one level to the other level, and within the same range as the switching range when the motor is reversed, the potential level of the sensor signal is changed from one level to the other. The absolute value of the difference from the count value when the level is switched to the second level is based on a second error step number that takes into account errors that occur during forward and reverse rotation of the motor. Compared with predetermined reference step difference Te, when the absolute value is larger than the reference step difference, the output shaft is the gist that determined not to be disposed in a normal position.

  According to this configuration, unlike the conventional magnetic sensor that linearly outputs a voltage signal according to the rotation position of the pair of magnets, the rotation position detection unit uses a pulse signal corresponding to the rotation position of the rotated position detection unit. Since a certain sensor signal is output, even if the rotation position detection unit and the rotation position detection unit are arranged at close positions, the detection accuracy of the rotation position of the output shaft is not adversely affected. Therefore, for example, when a magnet is used for the rotated position detection unit, a magnet other than the rare earth magnet can be used. In addition, since the rotational position detector outputs a pulse signal, for example, when a magnet is used for the rotated position detector, it is possible to use one magnet, and the voltage output from the magnetic sensor. Compared to the conventional configuration in which a pair of magnets are arranged symmetrically with high accuracy in order to correctly reflect the rotation angle of the output shaft in the signal, it is possible to reduce the labor required for assembling the magnets. Therefore, the cost required for arranging the pair of magnets with high accuracy can be reduced. For these reasons, the configuration for detecting the rotational position of the output shaft can be configured at low cost, and as a result, the manufacturing cost of the rotation drive device can be reduced.

  According to the same configuration, the number is within the switching range, and the count value when the motor is normally rotated and the potential level of the sensor signal is switched from one level to the other level is the same range as the switching range. By comparing the absolute value of the difference with the count value when the motor signal is reversed and the potential level of the sensor signal switches from the other level to one level, the output shaft is It is determined whether or not it is arranged at a normal position. If there is no error between the count value when the potential level of the sensor signal switches when the motor is rotated forward and the count value when the sensor signal potential level switches when the motor is rotated reverse, The value should also be the reference count value. Even when there is an error, the count value when the potential level of the sensor signal switches when the motor is rotated forward and the count value when the potential level of the sensor signal switches when the motor is reversed The value should be a number within the same switching range. When the motor is rotated forward and backward, for example, an assembly variation error caused by assembling various components having dimensional errors to form a rotation drive device can be ignored. As described above, when the motor is rotated forward and backward, there is an error that can be ignored or canceled by performing forward and reverse rotation. For this reason, within the same switching range, the count value when the potential level of the sensor signal is switched when the motor is rotated forward and the count value when the potential level of the sensor signal is switched when the motor is reversed. When comparing the values, it is not necessary to take into account errors that can be ignored or canceled out in order to reverse the motor forward and backward. Therefore, the absolute value of the count value when the potential level of the sensor signal is switched when the motor is rotated forward and the count value when the potential level of the sensor signal is switched when the motor is reversed is calculated. When the determination is made by comparing the absolute value with the reference step difference set based on the error that occurs only when the motor is rotated in the forward and reverse directions, the error to be considered is reduced. A failure can be detected.

According to a second aspect of the present invention, there is provided a motor having a rotation shaft, a drive gear attached to the rotation shaft, an intermediate gear for reducing the rotation of the drive gear, and the intermediate gear meshing with the intermediate gear. An output gear having a gear portion that is rotated by the transmitted rotation, an output shaft that rotates integrally with the gear portion, and a rear stage than the output gear, and is rotated at a speed higher than the rotation of the gear portion. A sensor gear that rotates with the sensor gear, a rotated position detector provided to detect the rotational position of the output shaft, and a potential at an H level or an L level according to the rotational position of the rotated position detector. a rotational position detecting unit which outputs a sensor signal which is a pulse signal whose level is switched, and detection means for detecting a rotational position of the output shaft based on the pulse signal, a command for driving the motor And outputs a pulse signal to said motor, and a control means for counting the number of steps output by the command pulse signal, the control means, the count value when the potential level of the sensor signal switches is the In the case where the number is not within the switching range obtained by adding or subtracting the first error step number considering the error to the reference count value set in advance as the target count value when the potential level of the sensor signal is switched. The output shaft is determined to be normal when it is determined that the output shaft is not disposed at a normal position, and when the potential level of the sensor signal is switched, the switching of the potential level does not correspond to the rotation direction of the motor. The gist is that it is determined that it is not placed at a proper position .
According to this configuration, unlike the conventional magnetic sensor that linearly outputs a voltage signal according to the rotation position of the pair of magnets, the rotation position detection unit uses a pulse signal corresponding to the rotation position of the rotated position detection unit. Since a certain sensor signal is output, even if the rotation position detection unit and the rotation position detection unit are arranged at close positions, the detection accuracy of the rotation position of the output shaft is not adversely affected. Therefore, for example, when a magnet is used for the rotated position detection unit, a magnet other than the rare earth magnet can be used. In addition, since the rotational position detector outputs a pulse signal, for example, when a magnet is used for the rotated position detector, it is possible to use one magnet, and the voltage output from the magnetic sensor. Compared to the conventional configuration in which a pair of magnets are arranged symmetrically with high accuracy in order to correctly reflect the rotation angle of the output shaft in the signal, it is possible to reduce the labor required for assembling the magnets. Therefore, the cost required for arranging the pair of magnets with high accuracy can be reduced. For these reasons, the configuration for detecting the rotational position of the output shaft can be configured at low cost, and as a result, the manufacturing cost of the rotation drive device can be reduced.

  According to this configuration, if the output shaft rotates normally, the count value when the potential level of the sensor signal is switched is a number within the switching range, so the potential level of the sensor signal is switched. It is possible to determine whether or not the output shaft is disposed at a normal position only by determining whether or not the count value at the time is a number within the switching range. If one count value is obtained when the potential level of the sensor signal is switched, the determination can be performed. For example, the determination is performed using two count values when the potential level of the sensor signal is switched. Compared to the case, it is difficult to limit the determination time, and the control by the control means is simplified.

According to a third aspect of the present invention, there is provided a motor having a rotation shaft, a drive gear attached to the rotation shaft, an intermediate gear for reducing the rotation of the drive gear, and the intermediate gear meshing with the intermediate gear. An output gear having a gear portion that is rotated by the transmitted rotation, an output shaft that rotates integrally with the gear portion, and a rear stage than the output gear, and is rotated at a speed higher than the rotation of the gear portion. A sensor gear that rotates with the sensor gear, a rotated position detector provided to detect the rotational position of the output shaft, and a potential at an H level or an L level according to the rotational position of the rotated position detector. a rotational position detecting unit which outputs a sensor signal which is a pulse signal whose level is switched, and detection means for detecting a rotational position of the output shaft based on the pulse signal, a command for driving the motor A case that outputs a pulse signal to the motor and counts the number of steps of the output command pulse signal, and houses a plurality of the gears, the rotated position detector, and the rotated position detector After outputting the command pulse signal to rotate the output shaft to the abutting position at which the abutting part formed on any one of the plurality of gears contacts the abutted part provided in The command pulse signal is output by a preset number of initial position steps, and the output shaft is rotated by the number of initial position steps in a positive direction in which the abutting portion is separated from the abutted portion. Control means for performing initialization for arranging the output shaft at an initial position, and when the control means performs the initialization, the potential level of the sensor signal is applied to the abutting portion. But Recognizing that it is equal to the potential level of the sensor signal output from the rotational position detector when contacting, the first potential level of the sensor signal when the output shaft is rotated in the forward direction from the abutting position. having a number of steps by adding the number of the adder of error steps with the number of error steps caused by rebound that occurs when parts butting the first of the object abutting part against the reference count value is a count value of the target strikes when the switches After the first command pulse signal is output to the motor and the abutting portion rotates the output shaft in a direction opposite to the forward direction approaching the abutted portion, the first command pulse is output. A second command pulse signal having a number of steps smaller than the number of steps of the signal and larger than the first reference count value is output to the motor to output the output shaft Is rotated in the positive direction, and the output shaft based on the first command pulse signal is recognized when the potential level of the sensor signal is switched when the output shaft rotates in the positive direction based on the second command pulse signal. The gist is to determine that the abutting part is in contact with the abutted part when rotating in the reverse direction.
According to this configuration, unlike the conventional magnetic sensor that linearly outputs a voltage signal according to the rotation position of the pair of magnets, the rotation position detection unit uses a pulse signal corresponding to the rotation position of the rotated position detection unit. Since a certain sensor signal is output, even if the rotation position detection unit and the rotation position detection unit are arranged at close positions, the detection accuracy of the rotation position of the output shaft is not adversely affected. Therefore, for example, when a magnet is used for the rotated position detection unit, a magnet other than the rare earth magnet can be used. In addition, since the rotational position detector outputs a pulse signal, for example, when a magnet is used for the rotated position detector, it is possible to use one magnet, and the voltage output from the magnetic sensor. Compared to the conventional configuration in which a pair of magnets are arranged symmetrically with high accuracy in order to correctly reflect the rotation angle of the output shaft in the signal, it is possible to reduce the labor required for assembling the magnets. Therefore, the cost required for arranging the pair of magnets with high accuracy can be reduced. For these reasons, the configuration for detecting the rotational position of the output shaft can be configured at low cost, and as a result, the manufacturing cost of the rotation drive device can be reduced.

  According to the same configuration, when the control unit recognizes that the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detection unit when the butted portion comes into contact with the butted portion, The first command pulse signal is output, and then the second command pulse signal is output. When the potential level of the sensor signal output from the rotational position detection unit is equal to the potential level of the sensor signal when the abutting part comes into contact with the abutted part, the maximum is added to the first reference count value If the motor is rotated by the number of steps including the number of side error steps and the output shaft is rotated in the reverse direction, the abutting portion may come into contact with the abutted portion. When the abutting part is actually in contact with the abutted part, the motor is rotated by the number of steps smaller than the number of steps of the first command signal and larger than the first reference count value. When the output shaft is rotated in the positive direction, the potential level of the sensor signal is switched. Therefore, when the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detection unit when the abutting portion comes into contact with the abutted portion, the control means performs the first command pulse. After outputting the signal, by outputting the second command pulse signal and recognizing the change of the potential level of the sensor signal, it is possible to bring the abutting part into contact with the abutting part, It can be determined whether or not the abutting portion is in contact with the abutting portion. As a result, the potential level of the sensor signal when the abutting part comes into contact with the abutted part by actually arranging the abutting part at a position close to the abutted part. Is equal to the time required for initialization of the output shaft, rather than inputting a command pulse signal having a number of steps sufficient to rotate the entire rotation range of the output shaft in order to rotate the output shaft to the butting position. Can be shortened.

According to a fourth aspect of the present invention, there is provided a motor having a rotation shaft, a drive gear attached to the rotation shaft, an intermediate gear for reducing the rotation of the drive gear, and the intermediate gear meshing with the intermediate gear. An output gear having a gear portion that is rotated by the transmitted rotation, an output shaft that rotates integrally with the gear portion, and a rear stage than the output gear, and is rotated at a speed higher than the rotation of the gear portion. A sensor gear that rotates with the sensor gear, a rotated position detector provided to detect the rotational position of the output shaft, and a potential at an H level or an L level according to the rotational position of the rotated position detector. Rotation position detection unit that outputs a sensor signal that is a pulse signal whose level is switched, detection means that detects the rotation position of the output shaft based on the pulse signal, and a command for driving the motor A case that outputs a pulse signal to the motor and counts the number of steps of the output command pulse signal, and houses a plurality of the gears, the rotated position detector, and the rotated position detector After outputting the command pulse signal to rotate the output shaft to the abutting position at which the abutting part formed on any one of the plurality of gears contacts the abutted part provided in The command pulse signal is output by a preset number of initial position steps, and the output shaft is rotated by the number of initial position steps in a positive direction in which the abutting portion is separated from the abutted portion. Control means for performing initialization for arranging the output shaft at an initial position, and when the control means performs the initialization, the potential level of the sensor signal is applied to the abutting portion. But Recognizing that it is equal to the potential level of the sensor signal output from the rotational position detector when contacting, the first potential level of the sensor signal when the output shaft is rotated in the forward direction from the abutting position. The first command pulse signal having the number of steps obtained by adding the number of error steps on the addition side to the first reference count value, which is the target count value when the is switched, is output to the motor, and the abutting portion is subjected to the collision After the output shaft is rotated in the opposite direction opposite to the forward direction approaching the contact portion, the number of steps smaller than the number of steps of the first command pulse signal and larger than the first reference count value A second command pulse signal having a number is output to the motor to rotate the output shaft in the positive direction, and the center of the output shaft is rotated in the positive direction based on the second command pulse signal. When recognizing that the potential level of the sensor signal has been switched, it is determined that the abutting portion is in contact with the abutted portion during the reverse rotation of the output shaft based on the first command pulse signal, and The control means outputs the first command pulse signal to the motor to rotate the output shaft in the reverse direction, and then outputs the second command pulse signal to the motor to forward the output shaft in the forward direction. If it is not recognized that the potential level of the sensor signal has been switched even when the output shaft is rotated, the abutting portion is moved to the abutting portion when the output shaft rotates in the reverse direction based on the first command pulse signal. A third command pulse signal having a number of steps sufficient to rotate the output shaft over the entire rotation range of the output shaft, and output the third command pulse signal to the motor and rotate the output shaft in the reverse direction. It has as its gist.
According to this configuration, unlike the conventional magnetic sensor that linearly outputs a voltage signal according to the rotation position of the pair of magnets, the rotation position detection unit uses a pulse signal corresponding to the rotation position of the rotated position detection unit. Since a certain sensor signal is output, even if the rotation position detection unit and the rotation position detection unit are arranged at close positions, the detection accuracy of the rotation position of the output shaft is not adversely affected. Therefore, for example, when a magnet is used for the rotated position detection unit, a magnet other than the rare earth magnet can be used. In addition, since the rotational position detector outputs a pulse signal, for example, when a magnet is used for the rotated position detector, it is possible to use one magnet, and the voltage output from the magnetic sensor. Compared to the conventional configuration in which a pair of magnets are arranged symmetrically with high accuracy in order to correctly reflect the rotation angle of the output shaft in the signal, it is possible to reduce the labor required for assembling the magnets. Therefore, the cost required for arranging the pair of magnets with high accuracy can be reduced. For these reasons, the configuration for detecting the rotational position of the output shaft can be configured at low cost, and as a result, the manufacturing cost of the rotation drive device can be reduced.
In addition, when the control means recognizes that the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detection unit when the butted portion comes into contact with the butted portion, the first command A pulse signal is output, and then a second command pulse signal is output. When the potential level of the sensor signal output from the rotational position detection unit is equal to the potential level of the sensor signal when the abutting part comes into contact with the abutted part, the maximum is added to the first reference count value If the motor is rotated by the number of steps including the number of side error steps and the output shaft is rotated in the reverse direction, the abutting portion may come into contact with the abutted portion. When the abutting part is actually in contact with the abutted part, the motor is rotated by the number of steps smaller than the number of steps of the first command signal and larger than the first reference count value. When the output shaft is rotated in the positive direction, the potential level of the sensor signal is switched. Therefore, when the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detection unit when the abutting portion comes into contact with the abutted portion, the control means performs the first command pulse. After outputting the signal, by outputting the second command pulse signal and recognizing the change of the potential level of the sensor signal, it is possible to bring the abutting part into contact with the abutting part, It can be determined whether or not the abutting portion is in contact with the abutting portion. As a result, the potential level of the sensor signal when the abutting part comes into contact with the abutted part by actually arranging the abutting part at a position close to the abutted part. Is equal to the time required for initialization of the output shaft, rather than inputting a command pulse signal having a number of steps sufficient to rotate the entire rotation range of the output shaft in order to rotate the output shaft to the butting position. Can be shortened.

  According to this configuration, after the control means recognizes that the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detector when the abutting portion comes into contact with the abutted portion. Even if the first command pulse signal and the second command pulse signal are output, if it is not determined that the abutting portion is in contact with the abutted portion, the third command pulse signal is output to output the third command pulse signal. Regardless of the position of the shaft, the abutting portion can be brought into contact with the abutted portion.

According to a fifth aspect of the present invention, in the rotation drive device according to the third or fourth aspect , the control means reverses the output shaft so that the abutting portion is brought into contact with the abutted portion. When rotating in the direction, the potential level of the sensor signal is equal to the potential level of the sensor signal output from the rotational position detector when the abutting portion is in contact with the abutted portion. Compared with the case where the potential level of the sensor signal is different from the potential level of the sensor signal output from the rotational position detection unit when the butted portion is in contact with the butted portion. The gist is to reduce the pulse rate of the pulse signal.

  According to this configuration, the control means determines whether the command pulse signal is in accordance with whether or not the potential level of the sensor signal is equal to the potential level of the sensor signal when the abutting portion is in contact with the abutted portion. The pulse rate is different. When the output shaft is rotated in the reverse direction to bring the abutting part into contact with the abutted part, the potential level of the sensor signal is the sensor signal when the abutting part is in contact with the abutted part. If it is equal to the potential level, there is a possibility that the abutting part comes into contact with the abutted part. Therefore, in this case, by reducing the pulse rate as compared with the case where the potential level of the sensor signal is different from the potential level of the sensor signal when the abutting portion is in contact with the abutted portion, When the rotation speed of the gear and the output shaft is reduced and the abutting portion comes into contact with the abutted portion, the abutting portion is suppressed from bouncing against the abutted portion. As a result, the amount by which the output shaft is pushed back in the positive direction due to the bounce can be reduced, and the number of error steps due to the bounce can be reduced. On the other hand, when the potential level of the sensor signal is different from the potential level of the sensor signal when the abutting portion is in contact with the abutted portion, there is no possibility that the abutting portion abuts on the abutted portion. Therefore, in this case, the pulse rate is increased and each gear and the gear level are compared with the case where the potential level of the sensor signal is equal to the potential level of the sensor signal where the abutting portion is in contact with the abutted portion. By increasing the rotation speed of the output shaft, the time required for initialization can be further shortened.

According to a sixth aspect of the present invention, in the rotation drive device according to any one of the third to fifth aspects, the control means is configured such that the count value is the collision object immediately before the initialization. The command pulse is used to rotate the motor so that the count is the same as the count value when the output shaft is rotated in the positive direction by the initial position step number from the state where the abutting portion is in contact with the abutting portion. A signal is output, and the initial position step number is set in a positive direction until the potential level of the sensor signal first switches from a state in which the abutting portion is in contact with the abutted portion. When the first initial position step number is smaller than the number of steps necessary for rotation, when the initialization is performed, the first command pulse signal is output to the motor to output the output shaft. Rotated in reverse direction In the case where the initial position step number is a second initial position step number larger than the first initial position step number, the abutting part is placed on the abutted part when performing the initialization. The command pulse signal is output to the motor to rotate the output shaft in the reverse direction until the position where the potential level of the sensor signal is switched first when the output shaft is rotated in the forward direction from the contact state After recognizing that the potential level of the sensor signal output from the rotational position detector is equal to the potential level of the sensor signal when the abutting portion is in contact with the abutted portion. The gist is to output one command pulse signal to the motor and rotate the output shaft in the reverse direction.

  According to the same configuration, the control unit rotates the output shaft in the positive direction by the initial position step number from the state where the abutting portion is in contact with the abutted portion immediately before the initialization. A command pulse signal is output to rotate the motor so as to be the same as the count value at the time. Therefore, when the initialization is performed, the abutting part is brought into contact with the abutted part when the initial position step number is the first initial position step number and when the initial position step number is the second initial position step number. The minimum number of steps required to make it different. Further, for example, when the rotation drive device is used to rotate the vehicle lamp of the vehicle headlamp device, and the position where the vehicle lamp faces the front of the vehicle is the initial position of the output shaft. Since the output shaft is often placed at the initial position even before the initialization, in most cases, if the output shaft is rotated in the opposite direction by the number of initial position steps, The abutting part can be brought into contact with the part. Therefore, the command to be input to bring the abutting part into contact with the abutted part depending on whether the initial position step number is the first initial position step number or the second initial position step number. By varying the number of steps of the pulse signal, the time required for initialization can be further shortened when the initial position step number is the first initial position step number.

Invention according to claim 7, in rotation drive device according to any one of claims 1 to 6, wherein the control means, by a predetermined time measuring the potential level of the sensor signal, the The gist is that the potential level of the sensor signal is recognized, and the predetermined time is shorter than the cycle of the pulse rate of the command pulse signal.

  According to this configuration, since the time for measuring the potential level of the sensor signal so that the control means recognizes the potential level of the sensor signal is shorter than the cycle of the pulse rate of the command pulse signal, the rotational position detection unit The time from when the sensor signal is output until the control means recognizes the potential level of the sensor signal can be suppressed within the time of one step of the command pulse signal.

According to an eighth aspect of the present invention, in the rotation driving device according to the seventh aspect , the predetermined time is a time close to the period of the pulse rate so as to prevent hunting in recognition of the potential level of the sensor signal. Its gist is that it is set.

  According to this configuration, hunting can be prevented in recognition of the potential level of the sensor signal in the control means, and the accuracy of various determinations made by the control means can be increased. The “proximity time” is a time during which hunting can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the drive device for rotation which can reduce manufacturing cost can be provided by comprising cheaply the structure for detecting the rotation position of an output shaft.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, a pair of vehicle headlamp devices 2 are provided at the front end of the vehicle 1 in the traveling direction. As shown in FIG. 2, in a housing 3 of each vehicle headlamp device 2, a rotation drive device 4 and a vehicle lamp 5 rotated in the left-right direction of the vehicle 1 by the rotation drive device 4. And is housed. These vehicle headlamp devices 2 are controlled by an AFS-ECU (Adaptive Front Lighting System-Electronic Control Unit) 6.

  As shown in FIG. 3, the rotation drive device 4 includes a case 13 including a lower case 11 and an upper case 12 whose opening is closed by the lower case 11. The lower case 11 has a substantially rectangular plate shape. The upper case 12 is integrally formed with a substantially rectangular ceiling 12a and a side wall 12b extending downward in FIG. 3 so as to be perpendicular to the ceiling 12a from the peripheral edge of the ceiling 12a. A plurality of gear receiving recesses 14 are formed in the ceiling portion 12a.

  A stepping motor 21 (hereinafter referred to as a motor 21) is fixed to the outer surface 12c of the ceiling portion 12a. An annular stator 23 is fixed to an inner peripheral surface of a bottomed cylindrical housing case 22 constituting the motor 21, and a rotor 24 is rotatably supported inside the stator 23. . The rotor 24 has a rotary shaft 27 rotatably supported by a bearing 25 fixed to the center of the bottom of the housing case 22 and a bearing 26 fixed to the ceiling portion 12a of the upper case 12. A cylindrical magnet 29 is fixed via a cylindrical support portion 28. The lower end of the rotary shaft 27 is inserted into the case 13 through an insertion hole 12d formed in the ceiling portion 12a.

  As shown in FIG. 4, the case 13 is transmitted from the drive gear 40 fixed to the lower end of the rotary shaft 27 so as to be integrally rotatable, the reduction gear group 50 for reducing the rotation of the drive gear 40, and the reduction gear group 50. An output gear 60 that is rotated by a rotational force, a sensor gear 70 that detects the rotational position of the output gear 60, and a driver circuit 80 that controls driving of the motor 21 are housed.

As shown in FIG. 3, the reduction gear group 50 includes three intermediate gears, that is, first to third intermediate gears 51 to 53.
The substantially disc-shaped first intermediate gear 51 protrudes from the first lower bearing 11 f protruding from the inner surface 11 a of the lower case 11 and the inner surface 12 e of the ceiling portion 12 a of the upper case 12. The first upper shaft 12f is rotatably supported by a first support shaft 54 that is rotatably supported, and meshes with the drive gear 40. The outer diameter of the first intermediate gear 51 is formed larger than the outer diameter of the drive gear 40.

  The second intermediate gear 52 meshes with the first intermediate gear 51 and is formed integrally with the large-diameter gear portion 52a having a larger diameter than the first intermediate gear 51 and the upper surface of the large-diameter gear portion 52a in FIG. The small-diameter gear portion 52b is smaller in diameter than the large-diameter gear portion 52a. The second intermediate gear 52 includes a second lower bearing 11g that protrudes from the inner surface 11a of the lower case 11 and a second upper bearing 14g that protrudes from the inner surface 14b of the ceiling portion 14a of the gear receiving recess 14. The second support shaft 55 is rotatably supported by the second support shaft 55 so as to be integrally rotatable.

  The third intermediate gear 53 meshes with the small diameter gear portion 52b of the second intermediate gear 52, and has a large diameter gear portion 53a having a larger diameter than the small diameter gear portion 52b, and a lower surface of the large diameter gear portion 53a in FIG. The small-diameter gear portion 53b is formed integrally and has a smaller diameter than the large-diameter gear portion 53a. The third intermediate gear 53 includes a third lower bearing 11h projecting from the inner side surface 11a of the lower case 11 and a third upper bearing 14h projecting from the inner side surface 14b of the ceiling portion 14a of the gear receiving recess 14. Are fixed to a third support shaft 56 that is rotatably supported.

  As shown in FIG. 5, the large-diameter gear portion 53 a is formed with an annular annular recess 53 c that opens to the ceiling portion 14 a side of the gear housing recess 14. A projecting portion 57 is formed on the bottom surface of the annular recess 53c so that the shape of the large-diameter gear portion 53a viewed from the axial direction is substantially a fan shape.

  Further, on the inner side surface of the ceiling portion 14a of the gear receiving recess 14 for storing the large-diameter gear portion 53a, the shape viewed from the thickness direction of the ceiling portion 14a is substantially at a position facing the annular recess 53c in the axial direction. A fan-shaped butted portion 58 is provided so as to protrude. The abutted portion 58 is inserted into the annular recess 53c in a state where the third intermediate gear 53 is assembled in the case 13, and the tip surface of the abutted portion 58 and the bottom surface of the annular recess 53c. A slight gap is formed between the two.

  As shown in FIG. 3, the output gear 60 extends in the radial direction from a substantially cylindrical output shaft 61 extending in the vertical direction in FIG. 3 and a position displaced downward from the axial center of the output shaft 61. The provided fan-shaped gear part 62 is integrally formed. As shown in FIG. 4, the gear portion 62 is formed by integrally forming an output gear portion 62 a and a transmission gear portion 62 b that are both fan-shaped and arranged in the circumferential direction. The output gear portion 62 a meshes with the small diameter gear portion 53 b of the third intermediate gear 53. As shown in FIG. 6, the transmission gear portion 62b is formed to have a smaller axial thickness than the output gear portion 62a, and the output gear portion 62a and the transmission gear portion 62b include the output gear portion 62a. One end surface (the end surface on the upper case 12 side) in the axial direction and one end surface (the end surface on the upper case 12 side) in the axial direction of the transmission gear portion 62b are integrally formed so as to be disposed in the same plane. . Accordingly, a step 62c is formed on the lower case 11 side (lower side in FIG. 6) of the gear portion 62 by the output gear portion 62a and the transmission gear portion 62b.

  As shown in FIG. 3, a support recess 61 a is formed at the lower end of the output shaft 61. The output gear 60 is pivotally supported by the shaft support portion 11k by inserting the shaft support portion 11k protruding from the inner surface 11a of the lower case 11 into the support recess 61a. On the other hand, the upper end of the output shaft 61 protrudes outside the case 13 from a through hole 14 k formed in the ceiling portion 14 a of the gear housing recess 14. And the said vehicle lamp 5 is fixed to the upper end of the output shaft 61 protruded outside the case 13 so that integral rotation is possible (refer FIG. 2).

  An annular spring accommodating recess 61b is formed around the supporting recess 61a, and a torsion coil spring 63 is accommodated in the spring accommodating recess 61b. As shown in FIG. 4, one end of the torsion coil spring 63 is locked to a spring locking portion 12k formed at a position near the output gear 60 on the side wall 12b, and the other end is a spring accommodating recess. It is latched by a spring latching groove 61c extending in the axial direction from the opening of 61b toward the bottom of the spring accommodating recess 61b. The torsion coil spring 63 applies a biasing force in one circumferential direction to the output gear 60, and the backlash of the output gear 60 provided between the drive gear 40, the reduction gear group 50 and the output gear 60 is Prevents rattling.

  The sensor gear 70 is disposed at a position subsequent to the output gear 60. As shown in FIG. 6, the sensor gear 70 has a substantially cylindrical support shaft 71 extending in the same direction as the axial direction of the output shaft 61, and the upper case 12 side (upper side in the drawing) from the axial direction of the support shaft 71. The sensor gear portion 72 is integrally formed at the displaced position, and the disk-shaped magnet fixing portion 73 is formed integrally with the support shaft 71 on the lower case 11 side (lower side in the figure) of the sensor gear portion 72. ing. The sensor gear 70 is pivotally supported by a sensor gear shaft support portion (not shown) formed on the inner side surface 11 a of the lower case 11.

  The sensor gear part 72 is formed in a substantially disk shape having a radius smaller than the radius of the transmission gear part 62 b, and accelerates the rotation of the transmission gear part 62 b that is rotated with the rotation of the output shaft 61. Incidentally, the gear ratio between the transmission gear portion 62b and the sensor gear portion 72 is “transmission gear portion: sensor gear portion = R1: R2 (where R1 <R2)”. The magnet fixing portion 73 is formed to have an outer diameter larger than that of the sensor gear portion 72. As shown in FIG. 4, the magnet fixing portion 73 is formed with an annular spring accommodating recess 73 a having an opening on the end surface in the axial direction on the side opposite to the sensor gear portion 72, and the spring accommodating recess. A torsion coil spring 74 is accommodated in 73a. One end of the torsion coil spring 74 is locked to a spring locking groove 73b formed in the inner peripheral surface of the spring accommodating recess 73a so as to extend in the axial direction, and the other end is a ceiling portion of the upper case 12. In 12a, it is latched by the spring latching | locking part 12m which protruded in the vicinity of the sensor gear 70. FIG. The torsion coil spring 74 applies a biasing force in one circumferential direction to the sensor gear 70 to prevent the sensor gear 70 from rattling due to backlash provided between the transmission gear portion 62b and the sensor gear 70. Yes.

  A sensor magnet 75 having an annular shape and an inner diameter equal to the outer diameter of the magnet fixing portion 73 is fixed to the outer peripheral surface of the magnet fixing portion 73 so as to be integrally rotatable. As shown in FIG. 6, the sensor magnet 75 is formed such that its axial thickness is equal to the axial thickness of the magnet fixing portion 73, and four north and south poles are alternately arranged in the circumferential direction. Is magnetized.

  As shown in FIG. 4, a substantially L-shaped circuit board 81 is disposed in the case 13 at a position that does not overlap the drive gear 40 and the reduction gear group 50 in the axial direction. A plurality of circuit elements 82 constituting the driver circuit 80 are arranged on the circuit board 81. The driver circuit 80 is electrically connected to the AFS-ECU 6 and outputs a command pulse signal for driving the motor 21 to the motor 21. The driver circuit 80 counts the number of steps of the command pulse signal. Specifically, the driver circuit 80 sets the count value when the abutting portion 57 contacts the abutted portion 58 when the vehicular lamp 5 is rotated toward the inside of the vehicle 1 to zero. When the driver circuit 80 outputs a command pulse signal to rotate the vehicle lamp 5 toward the outside of the vehicle 1, the driver circuit 80 adds the count value of the step number (pulse number) to When outputting a command pulse signal to rotate the vehicle 1 toward the inside, the count value of the number of steps is subtracted.

  A Hall IC 83 is disposed on the circuit board 81 at a position facing the sensor magnet 75 in the axial direction. The Hall IC 83 is electrically connected to the driver circuit 80, and outputs a sensor signal corresponding to the magnetic flux of the sensor magnet 75 that is changed by rotating together with the sensor gear 70 to the driver circuit 80. This sensor signal is set to the H level or the L level (H level> L level) according to the magnetic flux of the sensor magnet 75 changed by rotating together with the sensor gear 70, that is, according to the rotational position of the sensor magnet 75. This is a pulse signal for switching the potential level.

  Here, the sensor signal will be described. In the description of the sensor signal, when the vehicular lamp 5 is rotated most toward the inside of the vehicle 1, the circumferential direction of the abutted portion 58 formed in the ceiling portion 14 a of the gear accommodating recess 14 is increased. The position where the abutting portion 57 formed on the third intermediate gear abuts on one end surface is defined as the abutting position of the output shaft 61.

  When the output shaft 61 is rotated from the state where the output shaft 61 is in the abutting position so that the vehicle lamp 5 faces the outside of the vehicle 1, the abutting against the other end surface in the circumferential direction of the abutted portion 58. Until the part 57 comes into contact, the Hall IC 83 outputs a sensor signal as shown in FIG. In other words, the gears 40, 51 to 53, 60, 70 are configured such that the sensor signal as shown in FIG. 7 is output from the Hall IC 83 when the sensor gear 70 rotates as the output shaft 61 rotates. It is assembled. That is, the gears 40, 51 to 53, 60, and 70 are assembled so that the sensor signal output from the Hall IC 83 is at the H level when the output shaft 61 is in the abutting position. Further, when the output shaft 61 is rotated so that each of the gears 40, 51 to 53, 60, 70 rotates from the abutting position so that the vehicle lamp 5 faces the outside of the vehicle, the count value of the number of steps of the command pulse signal is The sensor signal is assembled so as to switch from the H level to the L level when it becomes “K1” (the reference count value and the first reference count value).

  Since the sensor magnet 75 has eight magnetic poles, when the output shaft 61 rotates, the sensor signal changes from H level to L level or from L level to H level whenever the sensor gear 70 rotates 45 °. Switch to level. Further, the rotation drive device 4 is configured such that when the command pulse signal is input to the motor 21 by one step, the output shaft 61 rotates by θ1. Therefore, the step number “N1” input to rotate the sensor gear 70 by 45 ° is “N1 = (45 ° / (R2 / R1)) / θ1” (N1 is a positive integer, and the calculation result is an integer. If not, the value after the decimal point is raised to N1). Therefore, the potential level of the sensor signal is switched every time the command pulse signal is input to the motor 21 by “N1” step. Therefore, when the output shaft 61 is rotated so that the vehicle lamp 5 faces the outside of the vehicle 1 from the abutting position, when the count value of the command pulse signal is “K1”, “K2 (K2 = When “K1 + N1)”, “K3 (K3 = K2 + N1)”, and “K4 (K3 + N1)”, the potential level is switched. When the output shaft 61 is rotated from the abutting position toward the outside of the vehicle 1, the sensor signal is switched from the H level to the L level when the count value is “K1”, and from the L level when the count value is “K2”. The level is switched to the H level. When the level is “K3”, the level is switched from the H level to the L level. When the level is “K4”, the level is switched from the L level to the H level. Each of the gears 40, 51 to 53, 60, 70 has the abutting portion 57 on the other end surface in the circumferential direction of the abutting portion 58 when the count value of the number of steps of the command pulse signal is “Ks”. It is comprised so that it may contact | abut (however, Ks is a positive integer, K1> K2> K3> Ks> K4). For this reason, in the present embodiment, there are two ranges in which the sensor signal is at the L level within the entire rotation range of the output shaft 61.

  The rotation drive device 4 configured as described above rotates the vehicle lamp 5 in the left-right direction in conjunction with the rotation of the steering wheel (not shown) of the vehicle 1. In addition, the turning drive device 4 is arranged in the same direction as the rotation direction of the steering wheel and the swinging type in which the left and right vehicle lamps 5 are rotated in both the left and right directions in conjunction with the rotation of the steering wheel. Only the vehicle lamp 5 is driven in any one of the swing-type manners that are rotated in conjunction with the rotation of the steering wheel. Specifically, in the case of the double swing type, when the steering wheel is rotated clockwise from a state where the rotation angle of the steering wheel is 0 °, both the left and right vehicle lamps 5 are rotated to the right side. When the steering wheel is rotated counterclockwise from the rotation angle of 0 °, both the left and right vehicle lamps 5 are rotated to the left. On the other hand, in the case of the single swing type, when the steering wheel is rotated clockwise (rightward) from a state where the rotation angle of the steering wheel is 0 °, only the right vehicle lamp 5 is rotated to the right. When the steering wheel is rotated counterclockwise (leftward) from a state in which the rotation angle of the steering wheel is 0 °, only the left vehicle lamp 5 is rotated to the left. Here, the state in which the rotation angle of the steering wheel is 0 ° means that the steering wheel is not rotated in either the left or right direction, and the tire of the vehicle 1 is not rotated in either the left or right direction. That is. In either case of the double swing type or the single swing type, when the rotation angle of the steering wheel is returned to 0 °, the vehicle lamp 5 also faces the front of the vehicle 1 in conjunction therewith. Is rotated.

  The vehicle lamp 5 is rotated by rotating the output shaft 61. That is, in the rotation driving device 4 configured as described above, when the motor 21 is driven by the command pulse signal input from the driver circuit 80, the rotation shaft 27 rotates by a predetermined angle, whereby the drive gear 40 is predetermined. Angle rotated. The rotation of the drive gear 40 is transmitted to the output gear portion 62a while being decelerated by the first to third intermediate gears 51 to 53. When the output gear portion 62a is rotated by the transmitted rotation, the output shaft 61 is rotated together with the output gear portion 62a, and the vehicle lamp 5 is rotated.

  At this time, when the output gear portion 62a is rotated, the transmission gear portion 62b formed integrally with the output gear portion 62a and the output shaft 61 is rotated, and the sensor gear portion 72 is rotated. The rotation transmitted from the transmission gear part 62 b to the sensor gear part 72 is accelerated by the sensor gear part 72. Accordingly, the rotation angle of the output shaft 61 is enlarged by the sensor gear portion 72 and transmitted to the sensor magnet 75. Further, since the outer diameter of the sensor magnet 75 fixed to the magnet fixing portion 73 having an outer diameter larger than that of the sensor gear portion 72 is larger than the outer diameter of the sensor gear portion 72, the rotation transmitted to the sensor gear portion 72. Is rotated by the sensor magnet 75. The Hall IC 83 outputs a sensor signal corresponding to a change in magnetic flux accompanying the rotation of the sensor magnet 75 to the driver circuit 80. The driver circuit 80 recognizes whether the potential level is the H level or the L level by measuring the potential level of the input sensor signal for a predetermined time t. Note that the driver circuit 80 repeatedly performs measurement for recognizing the potential level of the sensor signal. The predetermined time t is set to a time shorter than the cycle of the pulse rate of the command pulse signal, and is close to the cycle of the pulse rate of the command pulse signal in order to prevent hunting in potential level recognition. Is set. The driver circuit 80 recognizes the rotational position of the output shaft 61, that is, the irradiation direction of the vehicle lamp 5 based on the recognized potential level of the sensor signal and the count value of the number of steps of the command pulse signal.

  Next, a process for detecting a failure such as locking of the gears 40, 51 to 53, 60, 70 performed by the driver circuit 80 in the rotation driving device 4 configured as described above will be described. The driver circuit 80 performs three types of failure determination (first to third failure determination) based on the sensor signal in order to detect a failure (mainly a gear failure) of the rotation drive device 4.

First, the first failure determination will be described.
The sensor signal output from the Hall IC 83 includes various errors. For example, in the sensor signal, an assembly variation error that occurs when various components having dimensional errors are assembled to configure the rotation drive device 4, and the temperature of each component changes as the temperature of the rotation drive device 4 changes. It includes a temperature characteristic error caused by the change in the dimensions of each component and a detection error caused by the magnetic flux detection accuracy by the Hall IC 83. Further, for example, an error caused by rattling between the gears 40, 51 to 53, 60, 70 caused by backlash provided between the gears 40, 51 to 53, 60, 70, driving of the rotation driving device 4 is performed. Errors due to durability deterioration caused by wear of the gears 40, 51 to 53, 60, and 70 as they overlap are included. Further, the sensor signal includes an error caused by the rebound caused by the abutting portion 57 rebounding when the abutting portion 57 abuts against the abutted portion 58. These errors that affect the sensor signal are converted into the number of steps as follows.

[1] Assembly variation error ... ± e1 step [2] Temperature characteristic error ... ± e2 step [3] Detection error ... ····· ± e3 step [4] Error due to rattling ····· -e4 step [5] Error due to durability deterioration ····· + e5 step [6] Error due to rebound... ± e6 steps where e1 to e6 are positive numbers. Also, among the error step numbers (first error step numbers) in [1] to [6], the sum of the negative error step numbers is defined as the subtraction side error step number “−E1”, which is positive. Assuming that the sum of the numerical errors is the addition-side error step number “+ E2”, “−E1” and “+ E2” are respectively expressed as follows.

-E1 = -e1-e2-e3-e4-e6
+ E2 = + e1 + e2 + e3 + e5 + e6
Here, E1 and E2 are positive integers, and when the sum of errors of [1] to [6] does not become an integer, the number after the decimal point is raised to an integer. Further, E1 <K1 and (E1 + E2) <N1.

  When there is no failure in the rotation drive device 4 and the errors [1] to [6] do not occur, the output shaft 61 is moved from the abutting position, and the vehicle lamp 5 is located outside the vehicle 1. When the count value is “K1”, the sensor signal is switched from the H level to the L level, when the count value is “K2”, from the L level to the H level, and from “H3” when the count value is “K3”. It switches to the L level, and when it is “K4”, it switches from the L level to the H level. However, considering that the sensor signal includes the errors [1] to [6], the count value when the potential level of the sensor signal is switched is the case where there is no error of [1] to [6]. The count values “K1” to “K4” may be any number within the range from the count value obtained by subtracting “E1” to the count value obtained by adding “E2”. In the present embodiment, the range from (K1−E1) to (K1 + E2) is the first switching range A1, the range from (K2−E1) to (K2 + E2) is the second switching range A2, The range from K3-E1) to (K3 + E2) is referred to as a third switching range A3, and the range from (K4-E1) to (K4 + E2) is referred to as a fourth switching range A4.

  On the other hand, if the count value of the number of steps of the command pulse signal is the number of the range excluding the first to fourth switching ranges A1 to A4, the potential of the sensor signal if there is no failure in the rotation drive device 4. It is thought that the level will not change. Here, in the present embodiment, a range other than the first to fourth switching ranges A1 to A4, that is, a range of 0 or more and less than (K1−E1) is defined as the first signal determination range B1, and (K1 + E2 + 1) or more. A range less than (K2-E1) is defined as a second signal determination range B2. Further, a range from (K2 + E2 + 1) to less than (K3-E1) is defined as a third signal determination range B3, and a range from (K3 + E2 + 1) to less than (K4-E1) is defined as a fourth signal determination range B4. Therefore, if there is no failure in the rotation drive device 4, the sensor signal is at the H level when the count value is a number in the first signal determination range B1, and is a number in the second signal determination range B2. When the number is within the third signal determination range B3, the level is H level. When the number is within the fourth signal determination range B4, the level is L level. The first failure determination is performed when the count value of the step number of the command pulse signal is a number in any one of the first to fourth signal determination ranges B1 to B4. By determining whether or not the output shaft 61 is at a normal level, it is determined whether or not the output shaft 61 is disposed at a normal position. When the count value when the motor 21 is stopped is a number in any one of the first to fourth signal determination ranges B1 to B4, the driver circuit 80, after 1 second from the stop of the motor 21, It is determined whether or not the potential level of the sensor signal is at a normal level. When the driver circuit 80 recognizes that the sensor signal is at the L level when the count value is a number within one of the first signal determination range B1 and the third signal determination range B3, It is determined that the output shaft is not disposed at a normal position, that is, the rotation driving device 4 is out of order. On the other hand, when the driver circuit 80 recognizes that the sensor signal is at the H level when the count value is a number within one of the second signal determination range B2 and the fourth signal determination range B4, the driver circuit 80 It is determined that the dynamic drive device 4 has failed.

Next, the second failure determination will be described.
In the second failure determination, when the motor 21 is rotated forward, the count value when the potential level of the sensor signal is switched within any one of the first to fourth switching ranges A1 to A4, When the motor 21 is reversed, it is determined whether or not the absolute value of the difference from the count value when the potential level of the sensor signal is switched within the same switching range is equal to or less than the reference step difference Nd. Then, based on the determination result, it is determined whether or not the rotation drive device 4 has failed.

Here, the reference step difference Nd will be described in detail.
In general, once the rotation driving device 4 is constructed by assembling the respective parts, it is considered that no further assembly error occurs during the operation of the rotation driving device 4 thereafter. Further, before and after one reciprocating operation of the rotation drive device 4 (for example, before the steering wheel rotation angle is rotated from 0 ° to one in the circumferential direction and to the other in the circumferential direction, the rotation angle is 0). It is considered that there is no change in temperature after returning to the position where the angle becomes °. Further, the abutting portion 57 does not come into contact with the abutted portion 58 during one operation and one reciprocation operation of the rotation drive device 4. For these reasons, the errors [1], [2], and [6] do not have to be taken into account during the normal reciprocating rotation of the output shaft 61 rotated in accordance with the operation of the steering wheel. That is, the difference between the count value when the motor 21 is rotated forward and the sensor signal potential level is switched and the count value when the motor 21 is reversed and the sensor signal potential level is switched is the output shaft 61. It is considered that only errors that may occur during normal reciprocating rotation are included. Therefore, it is considered that the difference between the two count values includes the number of error steps (second error step number) of [3] to [5] excluding [1], [2], and [6]. . Based on this, the count value when the potential level of the sensor signal is switched in each of the normal rotation and reverse rotation of the motor 21 within each of the first to fourth switching ranges A1 to A4. There is a possibility that the absolute value of the difference of the difference of the maximum sum of the absolute values of the number of error steps [3] to [5] may vary. The reference step difference Nd is obtained by adding a “Ne (positive integer)” step for adjusting the failure detection accuracy to the sum of the absolute values of the number of error steps [3] to [5]. It is expressed as

Nd = + e3 + | −e3 | + | −e4 | + e5 + Ne
If the sum of the number of error steps of [3] to [5] is not an integer, Nd is incremented by a number after the decimal point.

  In the driver circuit 80, the potential level of the sensor signal is switched in two cases, when the motor 21 is rotated forward and when it is reversed within each of the first to fourth switching ranges A1 to A4. It is determined whether or not the absolute value of the count value difference is equal to or smaller than the reference step difference Nd. Then, when the absolute value is a number equal to or smaller than the reference step difference Nd, the driver circuit 80 determines that the rotation drive device 4 has not failed, and the absolute value is larger than the reference step difference Nd. In this case, it is determined that the rotation drive device 4 is out of order.

  For example, if the steering wheel is rotated clockwise and the vehicle lamp 5 is rotated to the right side of the vehicle 1, then the steering wheel is rotated counterclockwise and the vehicle lamp 5 is rotated to the left side of the vehicle 1. To do. At this time, the driver circuit 80 recognizes that the potential level of the sensor signal is switched from the L level to the H level at the count value “K2 + 1” in the second switching range A2 during the normal rotation of the motor 21 and performs reverse rotation. Suppose that it is recognized that the potential level of the sensor signal has been switched from the H level to the L level at the count value “K2-1” in the second switching range A2. Then, the driver circuit 80 calculates the absolute value of the difference between “K2 + 1” and “K2-1” and compares it with the reference step difference Nd.

  The driver circuit 80 stores a count value when the sensor signal at the time of forward rotation and reverse rotation recognized continuously is switched for each of the first to fourth switching ranges A1 to A4. Then, for each of the first to fourth switching ranges A1 to A4, the driver circuit 80 updates the latest count value when the sensor signal at the time of forward rotation is switched and the latest value when the sensor signal at the time of reverse rotation is switched. Using this count value, the second failure determination is performed for the switching range where the sensor signal potential level is switched every time the sensor signal is switched.

  The second failure determination is performed in each of the first to fourth switching ranges A1 to A4 in the count value when the potential level of the sensor signal is switched during the normal rotation of the motor 21 and during the reverse rotation of the motor 21. This cannot be done without the information of the two count values including the count value when the potential level of the sensor signal is switched. Therefore, since it is during the initial operation of the rotation drive device 4, the count when the sensor signal is switched during one-way rotation of the output shaft 61 in the first to fourth switching ranges A1 to A4. When only the value is available, the driver circuit 80 calculates the absolute value using the center value of each of the first to fourth switching ranges A1 to A4 and compares it with the reference step difference Nd. I do.

Next, the third failure determination will be described.
In the third failure determination, it is determined whether or not the count value when the potential level of the sensor signal is switched is a number within each of the first to fourth switching ranges A1 to A4. It is determined whether or not the level has been switched normally. Specifically, the driver circuit 80 counts when the potential level of the sensor signal is switched, and whether the potential level of the sensor signal is switched from the H level to the L level at the count value or from the L level to the H level. It remembers whether it has switched. Then, every time the count value exceeds the first to fourth switching ranges A1 to A4, the driver circuit 80 sets the count value when the potential level of the sensor signal is switched to the first to fourth switching ranges A1. It is determined whether or not the number is within a range of A4 to A4, and it is determined whether or not the sensor potential level is normally switched within each switching range A1 to A4.

  For example, when the driver circuit 80 rotates the motor 21 in the forward direction and the number of steps exceeds the first switching range A1 (that is, when the count value becomes “K1 + E2 + 1”), the potential level of the sensor signal is It is determined whether the count value at the time of switching is a number within the first switching range A1. Furthermore, the driver circuit 80 determines whether or not the potential level of the sensor electrode has been switched normally according to the rotation direction of the motor 21. When the number of steps when the potential level of the sensor signal is switched is the number in the first switching range A1, and the potential level of the sensor signal is switched from the H level to the L level, the driver The circuit 80 determines that the rotation driving device 4 has not failed. On the other hand, if the count value when the potential level of the sensor signal is switched is not a number within the first switching range A1, the driver circuit 80 determines that the rotation driving device 4 has failed. When the potential level of the sensor signal is switched from the L level to the H level, the driver circuit 80 determines that the rotation drive device 4 is out of order. Note that the case where the count value when the potential level of the sensor signal is switched is not a number within the first switching range A1, for example, the count value when the potential level of the sensor signal is switched is, for example, the first value. Or the potential level of the sensor signal does not switch even though the count value exceeds the first switching range A1.

  On the other hand, when the motor 21 is rotated in the reverse direction, the driver circuit 80, when the number of steps exceeds the first switching range A1 (that is, when the count value becomes “K1-E1-1”), It is determined whether or not the count value when the potential level of the sensor signal is switched is a number within the first switching range A1. Furthermore, the driver circuit 80 determines whether or not the potential level of the sensor signal has been switched normally according to the rotation direction of the motor 21. When the count value when the potential level of the sensor signal is switched is a number in the first switching range A1, and the potential level of the sensor signal is switched from the L level to the H level, the driver The circuit 80 determines that the rotation driving device 4 has not failed. On the other hand, even if the count value when the potential level of the sensor signal is switched is not a number within the first switching range A1, or the count value exceeds the first switching range A1, the sensor signal The driver circuit 80 determines that the rotation driving device 4 is out of order. When the potential level of the sensor signal is switched from the H level to the L level, the driver circuit 80 determines that the rotation drive device 4 is out of order.

  The driver circuit 80 detects the potential level of the sensor signal when the count value exceeds the second to fourth switching ranges A2 to A4, similarly to when the count value exceeds the first switching range A1. It is determined whether or not the count values at the time of switching are numbers within the second to fourth switching ranges A2 to A4, respectively. Similarly, the driver circuit 80 determines whether or not the potential level of the sensor signal has been switched normally according to the rotation direction of the motor 21. The count value when the potential level of the sensor signal is switched is a number in the corresponding second to fourth switching ranges A2 to A4, and the potential level of the sensor signal is normally changed from L level to H level. Alternatively, when the level is switched from the H level to the L level, the driver circuit 80 determines that the rotation driving device 4 has not failed.

  When the driver circuit 80 determines in each of the first to third failure determinations that the rotation drive device 4 has failed, the driver circuit 80 indicates to the AFS-ECU 6 that the rotation drive device 4 has failed. Output a fault signal. In addition, when the driver circuit 80 determines that the rotation driving device 4 is out of order, the driver circuit 80 immediately stops the motor 21.

Next, initialization of the output shaft 61 in the rotation drive device 4 of the present embodiment will be described.
When the ignition switch of the vehicle 1 is turned on, the driver circuit 80 performs initialization to rotate the output shaft 61 to an initial position where the vehicle lamp 5 faces the front of the vehicle 1. Further, the driver circuit 80 drives the motor 21 to place the output shaft 61 at the initial position when the vehicle speed of the vehicle 1 becomes a predetermined value or less. The vehicle speed of the vehicle 1 is detected by, for example, a vehicle speed sensor (not shown) mounted on the vehicle 1. The driver circuit 80 divides the initialization process according to whether the rotational driving device 4 is used in the double swing type or the single swing type.

  When the ignition switch of the vehicle 1 is turned on, the AFS-ECU 6 indicates an initial command pulse signal indicating the number of steps (initial position step number) necessary for rotating the output shaft 61 from the abutting position to the initial position. The position signal is output to the driver circuit 80. In the present embodiment, the number of steps of the command pulse signal necessary for rotating the output shaft 61 from the abutting position to the initial position is set to “Nr” step in the double swing type rotation driving device 4, and the single swing type In the rotation driving device 4, the “Nk” step is used. Nr and Nk are positive integers, and Nr> Nk. Further, when the motor 21 is rotated forward by the “Nr” step and the output shaft 61 is rotated in the positive direction in which the abutted portion 58 and the abutting portion 57 move away from the abutting position, the count value becomes the second value. The number is within the signal determination range B2. Further, when the motor 21 is rotated forward by “Nk” steps and the output shaft 61 is rotated in the positive direction in which the abutted portion 58 and the abutting portion 57 are moved away from the abutting position, the count value becomes the first value. The number is within the signal determination range B1.

  Hereinafter, the initialization process performed by the driver circuit 80 will be described with reference to FIGS. 8 and 9. In the description of the initialization process, the direction in which the output shaft 61 is rotated to rotate the vehicle lamp 5 toward the outside of the vehicle 1 is defined as a positive direction, and the vehicle lamp 5 is directed toward the inside of the vehicle 1. The direction in which the output shaft 61 is rotated so as to be rotated is the reverse direction. The direction in which the abutted portion 58 and the abutting portion 57 are separated from the abutting position by moving away from the abutting position is the positive direction, and the output shaft 61 is directed to the abutting position, whereby the abutted portion 58 The direction in which the abutment portion 57 approaches is the reverse direction. Further, when the motor 21 is rotated forward, the output shaft 61 is rotated in the forward direction, and when the motor 21 is rotated reversely, the output shaft 61 is rotated in the reverse direction.

  As shown in FIG. 8, in step S101, the driver circuit 80 determines whether or not an initial position signal has been received from the AFS-ECU 6. When the initial position signal is received, the process proceeds to step S102. On the other hand, if the initial position signal has not been received, step S101 is repeated.

  In step S <b> 102, the driver circuit 80 determines based on the initial position signal whether the rotation driving device 4 is used in the double swing type or the single swing type. That is, when the number of steps indicated by the initial position signal is larger than “Nk”, the driver circuit 80 determines that the rotation driving device 4 is used in the double swing type, and proceeds to step S103. On the other hand, when the number of steps indicated by the initial position signal is equal to or less than “Nk”, the driver circuit 80 determines that the rotation driving device 4 is used in a swinging manner, and proceeds to step S201 shown in FIG. To do.

  In step S103 shown in FIG. 8, the driver circuit 80 determines whether or not the potential level of the sensor signal output from the Hall IC 83 is L level. Since the driver circuit 80 drives the motor 21 to place the output shaft 61 at the initial position when the vehicle speed of the vehicle 1 becomes a predetermined value or less, the output shaft 61 is brought to the initial position when the ignition switch is turned off. Should have been placed. Therefore, the sensor signal in step S103 should be L level. Therefore, the driver circuit 80 simply determines whether or not the output shaft 61 is disposed at the initial position by determining whether or not the potential level of the sensor signal output from the Hall IC 83 is L level. Judgment. Then, the driver circuit 80 proceeds to step S104 when the sensor signal is at the L level, and proceeds to step S116 when the sensor signal is at the H level.

  In step S104, the driver circuit 80 issues a command whose pulse rate is R1 [pps] to rotate the vehicle lamp 5 toward the inside of the vehicle 1 until the potential level of the sensor signal is switched from the L level to the H level. A pulse signal is output to the motor 21 and the motor 21 starts to reversely move to step S105. Incidentally, in step S104, the driver circuit 80 starts reverse rotation of the motor 21 to rotate the output shaft 61 to the abutting position, that is, to bring the abutting portion 57 into contact with the abutted portion 58.

  In step S105, the driver circuit 80 determines whether or not the number of steps from the start of output in step S104 is equal to or less than the “N2” step. For example, if any of the gears 40, 51 to 53, 60, 70 is locked and the output shaft 61 is not rotatable, the sensor signal is changed from the L level to the H level no matter how many steps are input to the motor 21. Does not switch to level. Therefore, step S105 is provided in order to prevent step S106 described later from being repeated infinitely. In the present embodiment, “N2” is “N2 = Ks−K3 + E1-1”. “N2” is set in this way because the sensor signal has two count value ranges in which the potential level is L level, so that the count value is larger than “K1” and smaller than “K2”. In this case, even if the number is larger than “K3” and smaller than “K4”, it is considered that if the motor 21 is reversed by “N2” step, the potential level of the sensor signal is switched from L level to H level. is there. In step S105, the driver circuit 80 proceeds to step S106 if the number of steps from the start of output in step S104 is equal to or smaller than the “N2” step, and proceeds to step S106 if larger than the “N2” step. The process proceeds to S116.

  In step S106, the driver circuit 80 determines whether or not the potential level of the sensor signal has become H level. That is, the driver circuit 80 determines whether or not the potential level of the sensor signal is the same as that in the state where the output shaft 61 is in the abutting position. If the driver circuit 80 recognizes that the potential level of the sensor signal is H level, the driver circuit 80 proceeds to step S107. On the other hand, when recognizing that the potential level of the sensor signal is L level, the driver circuit 80 proceeds to step S105.

  In step S107, the driver circuit 80 outputs a command pulse signal having a pulse rate of R1 [pps] to the motor 21, reverses the motor 21, and starts rotating the output shaft 61 toward the inside of the vehicle 1 in step S108. Migrate to Incidentally, also in step S107, as in step S104, the driver circuit 80 reverses the motor 21 in order to rotate the output shaft 61 to the abutting position.

  In step S108, the driver circuit 80 determines whether or not the sensor signal is at the H level. If the output shaft 61 is normally located at the initial position when the ignition switch is turned off, the sensor signal may be at the L level even if the motor 21 is reversed after the sensor signal is at the H level in step S106. No. Therefore, this determination is performed in order to detect that the output shaft 61 is not arranged at the position where it should be arranged in the initialization process when the sensor signal is switched to the L level. Then, the driver circuit 80 proceeds to Step S109 when the potential level of the sensor signal is H level, and proceeds to Step S116 when the potential level of the sensor signal is L level.

  In step S109, the driver circuit 80 determines whether or not the number of steps from the start of output in step S107 has reached the “N3” step. “N3” is “N3 = K1-E1-2”. Therefore, even when the potential level of the sensor signal is switched from the L level to the H level at the count value “K1-E1”, the rotation drive device 4 is abutted against the abutted portion 58 as long as the rotation drive device 4 has not failed. One step is surely left before the portion 57 comes into contact. Then, the driver circuit 80 repeats step S108 and step S109 until the number of steps from the start of output in step S107 reaches the “N3” step, and the number of steps from the start of output in step S107 becomes the “N3” step. When it is detected that it has become, the process proceeds to step S110.

  In step S110, the driver circuit 80 outputs a command pulse signal having a pulse rate of R2 [pps] to the motor 21, reverses the motor 21, and starts rotating the output shaft 61 toward the inside of the vehicle 1 in step S111. Migrate to Note that R2 [pps] is a value smaller than R1 [pps]. In step S111, as in step S104, the driver circuit 80 reverses the motor 21 to rotate the output shaft 61 to the abutting position.

  In step S111, the driver circuit 80 determines whether or not the sensor signal is at the H level as in step S108. Then, the driver circuit 80 proceeds to Step S112 when the potential level of the sensor signal is H level, and proceeds to Step S116 when the potential level of the sensor signal is L level.

  In step S112, the driver circuit 80 determines whether or not the number of steps from the start of output in step S110 is the “N4” step. “N4” is “N4 = K1 + E2−N3”. If the output shaft 61 is normally positioned at the initial position when the ignition switch is turned off, the count value when the sensor signal potential level is switched to the H level in step S106 is “K1 + E2” at the maximum. Accordingly, when the output shaft 61 is normally located at the initial position when the ignition switch is turned off, the driver circuit 80 recognizes that the potential level of the sensor signal has been switched to the H level in step S106. When the output shaft 61 is rotated in the reverse direction by “K1 + E2” steps, the abutting portion 57 always comes into contact with the abutted portion 58. That is, the output shaft 61 is disposed at the abutting position. However, in step S109, the driver circuit 80 inputs N3 steps to the motor 21. Therefore, when the output shaft 61 is normally disposed at the initial position when the ignition switch is turned off, the number of steps after starting output in step S107 in this step S112 becomes “N4” step. If detected, the output shaft 61 should be placed at the abutting position. Then, the driver circuit 80 repeats steps S111 and S112 until the number of steps from the start of output in step S110 reaches the “N4” step, and the number of steps from the start of output in step S110 becomes the “N4” step. When it is detected that the count has reached, the count value is set to zero (reset), and the process proceeds to step S113.

  In step S113, the driver circuit 80, in the swing-type rotation drive device 4, has a pulse rate equal to the number of steps necessary to rotate the output shaft 61 from the abutting position to the initial position, that is, “Nr” steps. A command pulse signal (a part of the second command pulse signal) is output to the motor 21 so that the motor 21 is normally rotated. Then, after outputting the “Nr” step, the driver circuit 80 proceeds to Step S114.

  In step S114, the driver circuit 80 determines whether or not the potential level of the sensor signal is L level. If the abutting portion 57 is in contact with the abutted portion 58 in the previous step S112, the output shaft 61 is rotated to the initial position in step S113, so that the potential level of the sensor signal becomes the L level. Should be. Therefore, this determination is for detecting that the initialization is not normally performed when the sensor signal is at the H level when the number of steps is “Nr”. Then, the driver circuit 80 proceeds to step S115 when the potential level of the sensor signal is L level, and proceeds to step S116 when the potential level of the sensor signal is H level.

  In step S115, the driver circuit 80 determines whether or not the number of steps output until the potential level of the sensor signal is switched from the H level to the L level during the output of the “Nr” step in step S113 is less than “N5”. judge. “N5” is set to a positive integer smaller than “K1 + E2” and larger than “K1”. In the present embodiment, there are two ranges in which the potential level of the sensor signal is L level within the entire rotation range of the output shaft 61. Therefore, in step S113, there is a possibility that the output shaft 61 is arranged in a range far from the abutting position, that is, a range not including the initial position, out of the two ranges where the potential level of the sensor signal is L level. There is. When the output shaft 61 is arranged in a range far from the abutting position, the motor 21 is rotated forward by “K1 + E2” steps after the sensor signal becomes H level in step S106. Only occasionally the potential level of the sensor signal should be L level. On the other hand, when the output shaft 61 is disposed in a range closer to the abutting position among the two ranges in which the potential level of the sensor signal is L level, the output shaft 61 is between steps S110 to S112. Since the motor 21 is normally rotated by the number of steps smaller than “K1 + E2” and larger than “K1”, the potential level of the sensor signal should be L level. Therefore, this step S115 confirms whether or not the output shaft 61 has been abutted between steps S110 to S112, and includes the initial position of the two ranges in which the potential level of the sensor signal is L level. This is provided in order to prevent the initialization from being terminated when the output shaft 61 is arranged in a non-existing range. When the number of steps output until the potential level of the sensor signal is switched from the H level to the L level during the output of the “Nr” step in step S113 is less than “N5”, the driver circuit 80 Assuming that the output shaft 61 is disposed at the initial position, the initialization process is terminated. On the other hand, when the number of steps output until the potential level of the sensor signal is switched from the H level to the L level during the output of the “Nr” step in step S113 is “N5” or more, the driver circuit 80 The process proceeds to step S116.

  In step S116, the driver circuit 80 determines that the output shaft 61 is not arranged at the position where it should be arranged in the initialization process, that is, an abnormality has occurred in the initialization process, and proceeds to step S117. .

  In step S117, the driver circuit 80 outputs a command pulse signal having a pulse rate of R2 [pps] to the “N6” step, after rotating the output shaft 61 in the reverse direction by rotating the motor 21 in the reverse direction. Then, the count value is set to zero and the process proceeds to step S118. In step S117, as in step S104, the driver circuit 80 reverses the motor 21 in order to rotate the output shaft 61 to the abutting position. The “N6” step is a number of steps sufficient to rotate the entire rotation range of the output shaft 61, and is set to a number larger than “Ks”. Therefore, if the motor 21 is reversed by “N6” step, the abutting portion 57 contacts the abutted portion 58 as long as there is no failure such as the gears 40, 51 to 53, 60, 70 being locked. That is, the output shaft 61 is rotated to the abutting position.

  In step S118, the driver circuit 80 causes the pulse rate of the number of steps necessary to rotate the output shaft 61 from the abutting position to the initial position, that is, the “Nr” step, in the swing-type turning drive device 4. A command pulse signal with R1 [pps] is output to the motor 21 to cause the motor 21 to rotate forward. As a result, if there is no failure such as the gears 40, 51 to 53, 60, 70 being locked, the output shaft 61 is rotated to the initial position, and the rotation drive device 4 used in the swing type is initialized. This process ends.

  As shown in FIG. 9, in step S201, the driver circuit 80 determines whether or not the potential level of the sensor signal output from the Hall IC 83 is H level. Since the driver circuit 80 drives the motor 21 to place the output shaft 61 at the initial position when the vehicle speed of the vehicle 1 becomes a predetermined value or less, the output shaft 61 is brought to the initial position when the ignition switch is turned off. Should have been placed. Therefore, the sensor signal in step S201 should be H level. Therefore, the driver circuit 80 simply determines whether or not the output shaft 61 is disposed at the initial position by determining whether or not the potential level of the sensor signal output from the Hall IC 83 is L level. Judgment. The driver circuit 80 proceeds to step S202 when the sensor signal is at the H level, and proceeds to step S209 when the sensor signal is at the L level.

  In step S202, the driver circuit 80 outputs a command pulse signal having a pulse rate of R2 [pps] to rotate the output shaft 61 toward the inside of the vehicle 1 until the output shaft 61 is disposed at the abutting position. It outputs to the motor 21, begins to reverse the motor 21, and proceeds to step S203.

  In step S203, the driver circuit 80 determines whether or not the sensor signal is at the H level. In this determination, if the output shaft 61 is normally placed at the initial position when the ignition switch is turned off, the sensor signal does not become L level even if the motor 21 is reversed. This is for detecting that the output shaft 61 is not arranged at the position where the output shaft 61 should be arranged in the initialization process when the level is switched. Then, the driver circuit 80 proceeds to step S204 when the potential level of the sensor signal is H level, and proceeds to step S209 when the potential level of the sensor signal is L level.

  In step S204, the driver circuit 80 determines whether or not the number of steps from the start of output in step S202 is “N8”. “N8” is “N8 = K1 + E2”, and when the output shaft 61 is normally placed at the initial position when the ignition switch is turned off, the output shaft 61 is reversely moved by “K1 + E2” steps. The abutting portion 57 always comes into contact with the abutted portion 58. That is, the output shaft 61 is disposed at the abutting position. Then, the driver circuit 80 repeats step S203 and step S204 until the number of steps from the start of output in step S202 reaches the “N8” step, and the number of steps from the start of output in step S202 becomes the “N8” step. When it is detected, the count value of the number of steps is set to zero (reset), and the process proceeds to step S205.

  In step S205, the driver circuit 80 sends a command pulse signal (second pulse rate) having a pulse rate of R1 [pps] to rotate the output shaft 61 in the positive direction until the potential level of the sensor signal is switched from the H level to the L level. Command pulse signal) is output to the motor 21, and the motor 21 starts to rotate normally, and the process proceeds to step S206.

  In step S206, the driver circuit 80 determines whether or not the number of steps from the start of output in step S205 is less than “N5”. The driver circuit 80 proceeds to step S207 when the number of steps from the start of output in step S205 is less than “N5”, and proceeds to step S209 when it exceeds “N5”.

  In step S207, the driver circuit 80 determines whether or not the potential level of the sensor signal has become L level. If the driver circuit 80 recognizes that the potential level of the sensor signal is L level, the driver circuit 80 proceeds to step S208. On the other hand, when recognizing that the potential level of the sensor signal is H level, the driver circuit 80 proceeds to step S209. Incidentally, the steps S206 and S207 are provided to confirm whether or not the output shaft 61 is disposed at the abutting position by performing steps S202 to S204. By performing steps S202 to S204, when the output shaft 61 is disposed at the abutting position, the motor 21 is rotated forward by the number of steps smaller than “K1 + E2”, that is, “N8” and larger than “K1”. Then, the potential level of the sensor signal should be L level. Therefore, in step S206 and step S208, it is determined whether or not the number of steps from the start of output in step S205 is less than “N5” and the potential level of the sensor signal becomes L level.

  In step S208, the driver circuit 80 reversely rotates the motor 21 until the count value of the number of steps of the command step signal becomes “Nk”. As a result, if there is no failure such as the gears 40, 51 to 53, 60, 70 being locked, the output shaft 61 is rotated to the initial position, and the rotation drive device 4 used in a swinging manner is initialized. The process ends.

  In step S209, the driver circuit 80 determines that the output shaft 61 is not disposed at the position where the output shaft 61 is to be disposed in the initialization operation, that is, an abnormality has occurred in the initialization process, and proceeds to step S210. .

  In step S210, the driver circuit 80 outputs a command pulse signal having a pulse rate of R2 [pps] to the “N6” step, outputs the motor 21 to the motor 21, reverses the motor 21, and rotates the output shaft 61 in the reverse direction. The count value is set to zero and the process proceeds to step S211. In step S210, the driver circuit 80 reverses the motor 21 to rotate the output shaft 61 to the abutting position. When the motor 21 is reversed by the “N6” step, the output shaft 61 is rotated to the abutting position as long as there is no failure such as the gears 40, 51 to 53, 60, 70 being locked.

  In step S211, the driver circuit 80 causes the pulse rate to be R1 by the number of steps, that is, by “Nk” steps, in the swing drive device 4 for swinging type to rotate the output shaft 61 from the abutting position to the initial position. A command pulse signal of [pps] is output to the motor 21 and the motor 21 is rotated forward. As a result, if there is no failure such as the gears 40, 51 to 53, 60, 70 being locked, the output shaft 61 is rotated to the initial position, and the rotation drive device 4 used in a swing manner is initialized. This process ends.

As described above, the present embodiment has the following effects.
(1) Unlike the conventional magnetic sensor that linearly outputs a voltage signal according to the rotational position of the pair of magnets, the Hall IC 83 outputs a sensor signal that is a pulse signal corresponding to the rotational position of the sensor magnet 75. Is. For this reason, even if the Hall IC 83 and the sensor magnet 75 are arranged close to each other, the rotational position of the output shaft 61 does not adversely affect the detection accuracy. Therefore, a magnet other than rare earth can be used for the sensor magnet 75. Further, since the Hall IC 83 outputs a sensor signal that is a pulse signal, it is possible to use one sensor magnet 75 in which N poles and S poles are alternately magnetized in the circumferential direction. Therefore, compared to the conventional case where a pair of magnets are arranged symmetrically with high accuracy in order to correctly reflect the rotation angle of the output shaft in the output voltage output from the magnetic sensor, the labor required for magnet assembly is reduced. It is possible to reduce the cost required to arrange the pair of magnets with high accuracy. For these reasons, the configuration for detecting the rotational position of the output shaft 61 can be configured at low cost, and the manufacturing cost of the rotation drive device 4 can be reduced.

  (2) The gears 40, 51 to 53, 60, 70 are assembled so that the potential level of the sensor signal is switched when the count value of the number of steps of the command pulse signal becomes “K1” to “K4”. Yes. In other words, “K1” to “K4” are target values when the potential level of the sensor signal is switched. The first to fourth signal determination ranges B1 to B4 are the first to fourth switching ranges obtained by adding or subtracting the error step numbers “E1” and “E2” to “K1” to “K4”. Since it is a range other than A1 to A4, if the output shaft 61 is normally rotated, if the count value is a number within the first to fourth signal determination ranges B1 to B4, the sensor signal It is considered that the potential level does not switch. Therefore, if the output shaft 61 rotates normally, if the count value is a number within the first to fourth signal determination ranges B1 to B4, the potential level of the sensor signal output from the Hall IC 83 is Even if the count value changes, the potential does not change from one of the H level and L level in each of the first to fourth signal determination ranges B1 to B4. Further, when the count value is a number in the first to fourth signal determination ranges B1 to B4, whether the potential level of the sensor signal is the H level or the L level depends on the output shaft 61 and the sensor. It can be specified in advance from the positional relationship with the magnet 75 for use. Therefore, when the count value is a number in any one of the first to fourth signal determination ranges B1 to B4, the potential for determining whether or not the output shaft 61 is disposed at a normal position. Levels can be preset. As a result, the driver circuit 80 performs the first failure determination when the count value is a number in any one of the first to fourth signal determination ranges B1 to B4, so that the output shaft is normal. It is possible to easily determine whether or not the rotation drive device 4 is disposed, that is, whether or not the rotation drive device 4 has failed.

  (3) If there is no failure in the rotation drive device 4, the sensor signal is at the L level regardless of the count value in any of the first signal determination range B1 and the third signal determination range B3. Become. If there is no failure in the rotation drive device 4, the sensor signal is at the H level regardless of the count value in any of the second signal determination range B2 and the fourth signal determination range B4. . Therefore, for example, when the count value is a number in the first signal determination range B1, the output shaft 61 is locked, and the count value becomes a number in the third signal determination range B3 without rotating the output shaft 61. In this case, in the first failure determination, it is determined that the potential level of the sensor signal is normal. Thus, when only the first failure determination is performed, the potential level of the sensor signal in the first to fourth switching ranges A1 to A4 is not easily reflected in the determination result, and the sensor signal is determined in the first failure determination. Even if it is determined that the potential level is normal, there is a possibility that the rotation drive device 4 is broken. On the other hand, in the second failure determination, the number is in the first to fourth switching ranges A1 to A4, and when the motor 21 is normally rotated and the potential level of the sensor signal is switched from one level to the other level. And the absolute value of the difference between the count value when the motor 21 is reversed and the potential level of the sensor signal is switched from the other level to the one level. Is used. Therefore, when the second failure determination is performed in addition to the first failure determination, whether the output shaft 61 is rotating normally at the potential level of the sensor signal in the first to fourth switching ranges A1 to A4. The result can be reflected in the determination result.

  (4) There is no error between the count value when the potential level of the sensor signal is switched when the motor 21 is rotated forward and the count value when the potential level of the sensor signal is switched when the motor 21 is reversed. For example, any count value should be the same value of any one of “K1” to “K4”. Even when there is an error, the count value when the potential level of the sensor signal is switched when the motor 21 is rotated forward and the potential level of the sensor signal is switched when the motor 21 is reversed. Any count value should be a number within the same range of the first to fourth switching ranges A1 to A4. When the motor 21 is rotated forward and backward, for example, the errors [1], [2], and [6] can be ignored or canceled by performing forward and reverse rotation. Or Thus, when the motor 21 is rotated forward and backward, there is an error that can be ignored or canceled by performing forward and reverse rotation. Therefore, within the same switching range, the count value when the potential level of the sensor signal is switched when the motor 21 is rotated forward and the potential value of the sensor signal when the motor 21 is reversed are switched. When comparing with the count value, the error of [1], [2], [6] need not be considered. Therefore, as in the second failure determination, the absolute value of the count value when the sensor signal potential level switches during forward rotation of the motor 21 and the count value when the sensor signal potential level switches during reverse rotation is calculated. If this absolute value is compared with the reference step difference Nd set based on the number of error steps [3] to [5] that occurs only when the motor 21 is rotated forward and backward, an error to be taken into account is determined. Therefore, the failure of the rotation drive device 4 can be detected with higher accuracy.

  (5) If the output shaft 61 is rotating normally, the count value when the potential level of the sensor signal is switched is a number in any one of the first to fourth switching ranges A1 to A4. . Therefore, in the third failure determination, it is determined whether or not the count value when the potential level of the sensor signal is switched is a number in any one of the first to fourth switching ranges A1 to A4. It is possible to determine whether or not the output shaft is disposed at a normal position simply by doing so. Further, for example, when the rotation driving device 4 is operated, an external force is applied to the output shaft 61 so that the output shaft 61 cannot be rotated, or a foreign object is sandwiched between the gears 40, 51 to 53, 60, 70. Furthermore, if the Hall IC 83 fails, the absolute value for comparison with the reference step difference Nd may not be calculated in the second failure determination. As described above, when the absolute value cannot be calculated, the second failure determination cannot be performed. However, since the third failure determination can be performed if one count value is obtained when the potential level of the sensor signal is switched, the determination time is limited compared to the second failure determination. It is hard to be done.

  (6) In the initialization process, if the potential level of the sensor signal output from the Hall IC 83 is equal to the potential level of the sensor signal when the abutting portion 57 contacts the abutted portion 58, the maximum Thus, if the motor 21 is rotated by the number of steps obtained by adding “+ E2” on the addition side error step number to “K1” and the output shaft 61 is rotated in the reverse direction, the abutting portion 57 is brought into contact with the abutted portion 58. There is a possibility of contact. When the abutting portion 57 actually contacts the abutted portion 58, the motor 21 is rotated by the number of steps smaller than “K1 + E2” and larger than “K1” to thereby adjust the output shaft 61 correctly. When rotating in the direction, the potential level of the sensor signal is switched. Therefore, when the potential level of the sensor signal is equal to the potential level of the sensor signal output from the Hall IC 83 when the abutting portion 57 comes into contact with the abutted portion 58, the driver circuit 80 performs the “K1 + E2” step. By reversing the motor 21 only by this, the abutting portion 57 can be brought into contact with the abutted portion 58. At the same time, when the motor 21 is rotated forward, the driver circuit 80 reduces the potential level of the sensor signal from the H level to the L level when the number of steps is smaller than “K1 + E2” and less than the number of steps “N5” larger than “K1”. By determining whether or not the level has been switched, it can be determined whether or not the abutting portion 57 has contacted the abutted portion 58. Therefore, in the swing-type turning drive device 4, when the driver circuit 80 recognizes that the potential level of the sensor signal is the same H level as in the state where the output shaft 61 is in the abutting position in S 106, the step is performed. In total from S107 to S110, the command pulse signal (first command pulse signal) of the “N3 + N4” step, that is, the “K1 + E2” step is output to reverse the motor 21. On the other hand, in the swing drive device 4 of the single swing type, when the driver circuit 80 recognizes in S201 that the potential level of the sensor signal is the same H level as the state where the output shaft 61 is at the abutting position, Between S202 and S204, the command pulse signal (first command pulse signal) of the “N8” step, that is, the “K1 + E2” step is output to reverse the motor 21. After that, the driver circuit 80 reverses the motor 21 and rotates the motor 21 in both the swing type and the single swing type, and is smaller than “K1 + E2” and larger than “K1”. If the number of steps is less than “N5”, it is determined whether or not the potential level of the sensor signal is switched from the H level to the L level. As a result, since the abutting portion 57 is actually arranged at a position close to the abutted portion 58, the sensor signal potential level when the abutting portion 57 abuts against the abutted portion 58 is detected. When the signal level is equal to the potential level, the output shaft 61 is rotated more than the command pulse signal having the number of steps sufficient to rotate the entire rotation range of the output shaft 61 in order to rotate the output shaft 61 to the contact position. The time required for initialization can be shortened.

  (7) When the driver circuit 80 detects that the output shaft 61 is not disposed at the position where it should be disposed in the initialization process, the double swing type rotation driving device 4 proceeds to step S116. In the swing type rotation driving device 4, the process proceeds to step S209. Then, regardless of the swing drive device 4 of the double swing type or the single swing type, the command pulse signal of the “N6” step (the third command pulse signal that can rotate the entire rotation range of the output shaft 61). ), The abutting portion 57 can be brought into contact with the abutted portion 58 regardless of the position where the output shaft 61 is disposed.

  (8) The driver circuit 80 causes the output shaft 61 to rotate forward when the output shaft 61 is reversely rotated to bring the abutting portion 57 into contact with the abutted portion 58 (steps S110, S117, S202, S210). In such a case, the motor 21 is rotated at a pulse rate R2 [pps] that is smaller than the pulse rate R1 [pps] of the command pulse signal when there is no possibility that the abutting portion 57 contacts the abutted portion 58. Yes. Therefore, when the abutting portion 57 comes into contact with the abutted portion 58, the abutting portion 57 is prevented from bouncing against the abutted portion 58. As a result, the amount by which the output shaft 61 is pushed back in the forward direction by the bounce can be reduced, and the number of error steps due to the bounce of [6] can be reduced.

  (9) The driver circuit 80 drives the motor 21 to place the output shaft 61 at the initial position when the vehicle speed of the vehicle 1 becomes a certain value or less. Further, the number of initial position steps is different between the swing-type turning drive device 4 and the swing-type turning drive device 4. For this reason, the minimum number of steps required to bring the abutting portion 57 into contact with the abutted portion 58 differs between the swing-type rotation driving device 4 and the one-side swing type rotation driving device 4. In this embodiment, since the position where the vehicle lamp 5 faces the front of the vehicle 1 is the initial position of the output shaft 61, the output shaft 61 is arranged at the initial position even before the initialization. In most cases, the abutting portion 57 can be brought into contact with the abutted portion 58 by rotating the output shaft 61 in the reverse direction by the number of initial position steps. Accordingly, in order to bring the abutting portion 57 into contact with the abutted portion 58, the initialization process is different depending on whether the initial position step number is “Nr” or “Nk”. By varying the number of steps of the input command pulse signal, the time required for initialization can be further shortened when the number of initial position steps is “Nk”. In addition, when the number of initial position steps is “Nr” and “Nk”, the initialization process is different, so that the single position swing is different from the double swing type rotation drive device 4. The amount of rotation of the output shaft 61 at the time of initialization in the rotary drive device 4 can be reduced.

  (10) The time t for measuring the potential level of the sensor signal so that the driver circuit 80 recognizes the potential level of the sensor signal is set to be shorter than the cycle of the pulse rate of the command pulse signal. Accordingly, the time from when the Hall IC 83 outputs the sensor signal until the driver circuit 80 recognizes the potential level of the sensor signal can be suppressed within the time of one step of the command pulse signal.

  (11) The predetermined time t is set to be shorter than the cycle of the pulse rate of the command pulse signal, and is close to the cycle of the pulse rate of the command pulse signal in order to prevent hunting in potential level recognition. Is set to Therefore, hunting can be prevented in recognition of the potential level of the sensor signal in the driver circuit 80, and the accuracy of various determinations performed by the control means can be increased.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the time t for measuring the potential level of the sensor signal so that the driver circuit 80 recognizes the potential level of the sensor signal is set to a time shorter than the cycle of the pulse rate of the command pulse signal. At the same time, the time is set close to the cycle of the pulse rate of the command pulse signal in order to prevent hunting in the recognition of the potential level. However, the predetermined time t is not limited to the time that satisfies the above conditions, and may be changed as appropriate.

  In the above embodiment, in step S105, the driver circuit 80 determines whether or not the number of steps from the start of output in step S104 is “N2” or less. “N2” is set to “N2 = Ks−K3 + E1-1”. However, if there is no failure in the rotation drive device 4, the potential level of the sensor signal is switched if at least “N1” step input is made to the motor 21, so that “N2” is set to a number greater than “N1”. Just do it.

  In the above embodiment, in step S117 and step S210, the driver circuit 80 outputs a command pulse signal of R2 [pps]. However, when the potential level of the sensor signal is L level, the abutting portion 57 does not come into contact with the abutted portion 58. Therefore, in step S117 and step S210, the driver circuit 80 determines that the potential level of the sensor signal is When it is at the L level, the pulse rate of the command pulse signal may be set to R1 [pps]. In this way, the time required for steps S117 and S210 can be shortened compared with the case where the motor 21 is driven at all N6 steps at R2 [pps], and thus the time required for initialization of the output shaft 61 is further reduced. can do.

  In the above embodiment, after receiving the initial position signal in step S101, the driver circuit 80 determines in step S102 whether or not the rotation drive device 4 is used in a swinging manner. However, when it is known that the rotation drive device 4 is used only in either the double swing type or the single swing type, step S102 may be omitted. In this case, in the case of the swing type rotation drive device 4, the driver circuit 80 proceeds from step S101 to step S103. On the other hand, in the case of the one-down type drive device 4 for rotation, the driver circuit 80 moves from step S101 to step S201.

  In the above embodiment, the abutting portion 57 is provided in the third intermediate gear 53, but any one of the drive gear 40, the first and second intermediate gears 51, 52, the output gear 60, and the sensor gear 70. It may be provided on the gear. In this case, the abutted portion 58 is provided in the case 13 according to the position of the abutting portion 57.

  In the above embodiment, the gears 40, 51 to 53, 60, and 70 are assembled so that the potential level of the sensor signal becomes H level when the output shaft 61 is in the abutting position. However, the gears 40, 51 to 53, 60, and 70 may be assembled so that the potential level of the sensor signal becomes L level when the output shaft 61 is in the abutting position. In this case, when the output shaft 61 is rotated so that the vehicle lamp 5 faces the outside of the vehicle 1 from the abutting position, the sensor signal is switched from the L level to the H level when the count value is “K1”. When it is “K2”, it switches from the H level to the L level, when it is “K3”, it switches from the K level to the H level, and when it is “K4”, it switches from the H level to the L level. And when performing the 1st-3rd failure determination and the initialization process, the electric potential level of the sensor signal used for each determination becomes reverse to the said embodiment.

  In the above embodiment, the sensor magnet 75 has an annular shape, and four north and south poles are alternately magnetized in the circumferential direction. However, the sensor magnet 75 may be formed by alternately magnetizing five or more N poles and the same number of S poles in the circumferential direction.

  In the above embodiment, the subtraction-side error step number “−E1” and the addition-side error step number “+ E2” are set in consideration of the errors [1] to [6]. However, the number of error steps “−E1” and “+ E2” may be set in consideration of errors other than [1] to [6]. In addition, when there are errors in [1] to [6] that are expected to have little effect on the sensor signal, the error step numbers “−E1” and “+ E2” are set excluding the error. May be.

In the above embodiment, the reduction gear group 50 is composed of the three first to third intermediate gears 51 to 53, but may be composed of at least one gear.
In the above embodiment, the rotation drive device 4 is used to rotate the vehicle lamp 5 in the left-right direction, but may be used to rotate other than the vehicle lamp 5. .

The technical ideas that can be grasped from each of the above embodiments and each of the above modifications are described below.
Outputs a command pulse signal for driving the (b) before SL motor to the motor, a control means for counting the number of steps output by the command pulse signal, said control means, said number of steps counted value Is a range other than the switching range obtained by adding or subtracting the first error step number considering an error to a reference count value set in advance as a target count value when the potential level of the sensor signal is switched. When the number is within the signal determination range, if it is recognized that the potential level of the sensor signal is not one of the predetermined H level and L level, the output shaft is arranged at a normal position. When the first failure determination is made and the motor is rotated forward, the potential level of the sensor signal is at one level within the switching range. When the sensor signal potential level is switched from the other level to the one level within the same range as the switching range when the motor is reversed from the count value when switching from the other level to the other level The absolute value of the difference from the count value is compared with a reference step difference that is set based on a second error step number that takes into account an error that occurs during forward and reverse rotation of the motor, and the absolute value is greater than the reference step difference. And the count value when the potential level of the sensor signal is switched is determined by the second failure determination that determines that the output shaft is not disposed at a normal position. If the number is not within the range, at least one failure determination is performed among the third failure determinations that determine that the output shaft is not disposed at a normal position, and at least once, When the force shaft is determined not to be disposed in a normal position, characterized by stopping the motor.

The perspective view of the vehicle carrying a vehicle headlamp device. Sectional drawing of the headlamp apparatus for vehicles. Sectional drawing of the drive device for rotation. The schematic block diagram of the drive device for rotation. The perspective view of the drive device for rotation. The schematic diagram which shows the arrangement | positioning relationship between an output gear and a sensor gear. Explanatory drawing for demonstrating the waveform of a sensor signal. The flowchart which shows the process of initialization which a driver circuit performs. The flowchart which shows the process of initialization which a driver circuit performs.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... Drive apparatus for rotation, 13 ... Case, 21 ... Motor, 27 ... Rotary shaft, 40 ... Drive gear, 51 ... 1st intermediate gear as an intermediate gear, 52 ... 2nd intermediate gear as an intermediate gear, 53 ... Third intermediate gear as an intermediate gear, 57 ... abutting portion, 58 ... abutted portion, 60 ... output gear, 61 ... output shaft, 62 ... gear portion, 75 ... sensor magnet as a rotational position detecting portion , 80... Driver circuit as control means, 83. Hall IC as rotational position detector, A1... First switching range as switching range, A2... Second switching range as switching range, A3. A third switching range, A4... A fourth switching range as a switching range, B1... A first signal determination range as a signal determination range, B2... A second signal determination range as a signal determination range, B3. Size Third signal determination range as a range, B4 ... Fourth signal determination range as a signal determination range, -E1 ... Subtraction side error step number as an error step number, + E2 ... Addition side error step number, K1 ... First Reference count value and count value as reference count value, K2 to K4 ... count value as reference count value, Nk ... initial position step number as first initial position step number, Nd ... reference step difference, Nr ... The initial position step number as an initial position step number of 2, t ... a predetermined time.

Claims (8)

A motor having a rotating shaft;
A drive gear attached to the rotating shaft;
An intermediate gear for reducing the rotation of the drive gear;
An output gear having a gear portion meshed with the intermediate gear and rotated by the rotation transmitted from the intermediate gear; and an output shaft rotating integrally with the gear portion;
A sensor gear that is provided downstream of the output gear and rotates at a speed higher than the rotation of the gear portion;
A rotational position detector provided to rotate together with the sensor gear and detect a rotational position of the output shaft;
A rotational position detector that outputs a sensor signal that is a pulse signal that switches the potential level to H level or L level according to the rotational position of the rotated position detector;
Detecting means for detecting a rotational position of the output shaft based on the pulse signal;
A control means for outputting a command pulse signal for driving the motor to the motor and counting the number of steps of the output command pulse signal;
Equipped with a,
The control means adds or subtracts a first error step number considering an error to a reference count value set in advance as a target count value when the potential level of the sensor signal is switched when the motor is rotated forward. Within the switching range determined in this way, the count value when the potential level of the sensor signal is switched from one level to the other level and the same range as the switching range when the motor is reversed. Then, the absolute value of the difference from the count value when the potential level of the sensor signal is switched from the other level to the one level is based on the second error step number in consideration of the error that occurs during forward / reverse rotation of the motor. When the absolute value is larger than the reference step difference, the output shaft is not arranged at a normal position. Rotation drive device and wherein the determining. A motor having a rotating shaft;
A drive gear attached to the rotating shaft;
An intermediate gear for reducing the rotation of the drive gear;
An output gear having a gear portion meshed with the intermediate gear and rotated by the rotation transmitted from the intermediate gear; and an output shaft rotating integrally with the gear portion;
A sensor gear that is provided downstream of the output gear and rotates at a speed higher than the rotation of the gear portion;
A rotational position detector provided to rotate together with the sensor gear and detect a rotational position of the output shaft;
A rotational position detector that outputs a sensor signal that is a pulse signal that switches the potential level to H level or L level according to the rotational position of the rotated position detector;
Detecting means for detecting a rotational position of the output shaft based on the pulse signal;
A control means for outputting a command pulse signal for driving the motor to the motor and counting the number of steps of the output command pulse signal ;
With
The control means includes
The count value when the potential level of the sensor signal is switched is added to or subtracted from the reference count value set in advance as a target count value when the potential level of the sensor signal is switched by adding a first error step number considering an error. When the number is not within the switching range obtained as described above, it is determined that the output shaft is not disposed at a normal position ,
When the potential level of the sensor signal is switched, if the switching of the potential level is not in accordance with the rotation direction of the motor, it is determined that the output shaft is not disposed at a normal position. Dynamic drive device. A motor having a rotating shaft;
A drive gear attached to the rotating shaft;
An intermediate gear for reducing the rotation of the drive gear;
An output gear having a gear portion meshed with the intermediate gear and rotated by the rotation transmitted from the intermediate gear; and an output shaft rotating integrally with the gear portion;
A sensor gear that is provided downstream of the output gear and rotates at a speed higher than the rotation of the gear portion;
A rotational position detector provided to rotate together with the sensor gear and detect a rotational position of the output shaft;
A rotational position detector that outputs a sensor signal that is a pulse signal that switches the potential level to H level or L level according to the rotational position of the rotated position detector;
Detecting means for detecting a rotational position of the output shaft based on the pulse signal;
A command pulse signal for driving the motor is output to the motor, and the number of steps of the output command pulse signal is counted, and the plurality of gears, the rotated position detection unit, and the rotation In order to rotate the output shaft to the abutting position where the abutting part formed on any one of the plurality of gears is brought into contact with the abutting part provided in the case accommodating the position detecting part After outputting the command pulse signal, the command pulse signal is output by the number of preset initial position steps, and the output shaft is moved to the initial position in the positive direction in which the abutting part is separated from the abutted part. Control means for performing initialization to rotate the number of steps and place the output shaft at an initial position ;
With
When the control means performs the initialization, the potential level of the sensor signal is output from the rotational position detection unit when the level of the sensor signal comes into contact with the contacted part. When it is recognized that the level is equal to the level, when the output shaft is rotated in the forward direction from the abutting position, the first reference count value which is a target count value when the potential level of the sensor signal is first switched is set. On the other hand , a first command pulse signal having a step number obtained by adding an addition-side error step number including an error step number due to rebound generated when the abutting part hits the abutted part is output to the motor and the abutting part. Is less than the number of steps of the first command pulse signal after rotating the output shaft in the opposite direction opposite to the forward direction approaching the abutted portion. A second command pulse signal having a number of steps larger than a reference count value is output to the motor to rotate the output shaft in the positive direction, and the positive direction of the output shaft based on the second command pulse signal When recognizing that the potential level of the sensor signal is switched during rotation, it is determined that the abutting portion is in contact with the abutted portion during the reverse rotation of the output shaft based on the first command pulse signal. A rotating drive device characterized by that. A motor having a rotating shaft;
A drive gear attached to the rotating shaft;
An intermediate gear for reducing the rotation of the drive gear;
An output gear having a gear portion meshed with the intermediate gear and rotated by the rotation transmitted from the intermediate gear; and an output shaft rotating integrally with the gear portion;
A sensor gear that is provided downstream of the output gear and rotates at a speed higher than the rotation of the gear portion;
A rotational position detector provided to rotate together with the sensor gear and detect a rotational position of the output shaft;
A rotational position detector that outputs a sensor signal that is a pulse signal that switches the potential level to H level or L level according to the rotational position of the rotated position detector;
Detecting means for detecting a rotational position of the output shaft based on the pulse signal;
A command pulse signal for driving the motor is output to the motor, and the number of steps of the output command pulse signal is counted, and the plurality of gears, the rotated position detection unit, and the rotation In order to rotate the output shaft to the abutting position where the abutting part formed on any one of the plurality of gears is brought into contact with the abutting part provided in the case accommodating the position detecting part After outputting the command pulse signal, the command pulse signal is output by the number of preset initial position steps, and the output shaft is moved to the initial position in the positive direction in which the abutting part is separated from the abutted part. Control means for performing initialization to rotate the number of steps and place the output shaft at an initial position;
With
When the control means performs the initialization, the potential level of the sensor signal is output from the rotational position detection unit when the level of the sensor signal comes into contact with the contacted part. When it is recognized that the level is equal to the level, when the output shaft is rotated in the forward direction from the abutting position, the first reference count value which is a target count value when the potential level of the sensor signal is first switched is set. A first command pulse signal having the number of steps added with the number of error steps on the addition side is output to the motor so that the abutting portion approaches the abutted portion in the opposite direction opposite to the forward direction. , A second command pulse signal having a number of steps smaller than the number of steps of the first command pulse signal and larger than the first reference count value is sent to the motor. When the output shaft is rotated in the forward direction to recognize that the potential level of the sensor signal is switched during the forward rotation of the output shaft based on the second command pulse signal, the first command pulse is detected. And determining that the abutting part is in contact with the abutted part during reverse rotation of the output shaft based on the signal,
The control means outputs the first command pulse signal to the motor and rotates the output shaft in the reverse direction, and then outputs the second command pulse signal to the motor to correct the output shaft. If it is not recognized that the potential level of the sensor signal has been switched even when the sensor shaft is rotated in the direction, the abutting portion is in contact with the abutted portion when the output shaft rotates in the reverse direction based on the first command pulse signal. A third command pulse signal having a number of steps sufficient to rotate the output shaft over the entire rotation range of the output shaft, and outputs the third command pulse signal to the motor and rotates the output shaft in the reverse direction. A rotating drive device characterized by that. In the rotation drive device according to claim 3 or 4 ,
When the control means rotates the output shaft in the reverse direction to bring the abutting portion into contact with the abutted portion, the potential level of the sensor signal is applied to the abutting portion. Is equal to the potential level of the sensor signal output from the rotational position detector when the sensor is in contact, the potential level of the sensor signal is in contact with the contacted portion. The rotation drive device characterized in that the pulse rate of the command pulse signal is reduced compared to the case where the potential level of the sensor signal output from the rotational position detection unit is sometimes different. In rotation drive device according to any one of claims 3 to 5,
The control means includes
Immediately before the initialization, the count value is the same as the count value when the output shaft is rotated in the positive direction by the initial position step number from the state where the abutting portion is in contact with the abutted portion. The command pulse signal is output to rotate the motor so as to be a number,
Steps required for rotating the output shaft in the positive direction from the state in which the abutting portion is in contact with the abutted portion until immediately before the potential level of the sensor signal is switched for the initial position step number. In the case of the first initial position step number smaller than the number, when performing the initialization, the first command pulse signal is output to the motor to rotate the output shaft in the reverse direction,
When the initial position step number is a second initial position step number that is larger than the first initial position step number, when the initialization is performed, the abutting part is placed on the abutted part. The command pulse signal is output to the motor to rotate the output shaft in the reverse direction until the position where the potential level of the sensor signal is switched first when the output shaft is rotated in the forward direction from the contact state, After recognizing that the potential level of the sensor signal output from the rotational position detector is equal to the potential level of the sensor signal when the abutting portion is in contact with the abutted portion, the first The rotation drive device is characterized in that the command pulse signal is output to the motor to rotate the output shaft in the reverse direction. In rotation drive device according to any one of claims 1 to 6,
The control means recognizes the potential level of the sensor signal by measuring the potential level of the sensor signal for a predetermined time,
The rotation driving device characterized in that the predetermined time is shorter than a cycle of a pulse rate of the command pulse signal. In the rotation drive device according to claim 7 ,
The rotation driving device according to claim 1, wherein the predetermined time is set to a time close to a cycle of the pulse rate in order to prevent hunting in recognition of the potential level of the sensor signal.

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