JP5003784B2 - Indicators for vehicles - Google Patents

Description

  The present invention relates to a vehicle indicating instrument that displaces a pointer by a step motor.

  Conventionally, there has been known a vehicle indicating instrument that rotates a pointer by applying a drive signal alternating according to an electrical angle to a field winding of a step motor to indicate a vehicle state value according to the rotation position of the pointer. It has been. In such a vehicle indicating instrument, the pointer is returned to the zero position indicating the zero value of the vehicle state value by rotating in the return zero direction. Further, the stopper mechanism stops at a stopper position within a predetermined range from the zero position to the return zero direction, and an electrical angle corresponding to the stopper position is used as a reference for drive signal control.

  In the vehicle indicating instrument of Patent Document 1, an induced voltage generated in the field winding is detected while controlling a drive signal applied to the field winding of the stepping motor so as to rotationally drive the pointer in the nulling direction. ing. As a result, an induced voltage is generated in the field winding while the pointer is rotating, and when the pointer is stopped, the induced voltage generated in the field winding is lowered. Therefore, if the detected voltage of the induced voltage generated in the field winding is below the set value, it is assumed that the pointer has stopped at the stopper position, and the electrical angle corresponding to the stopper position is updated and set. Yes. According to such a series of processing, even if the stepping motor steps out due to disturbances such as vibration before starting the indicator instrument and the rotational position of the pointer is shifted, the drive signal is accurately calculated based on the updated electrical angle. It becomes possible to control.

JP 2002-272190 A

  Some vehicle indicating instruments include noise generating means for generating a magnetic field acting on the field winding. The noise generating means is a flasher device that performs, for example, a turn lamp (hazard lamp), a buzzer, and further a blink control of the lamp and a buzzer that blows in conjunction with the blink of the lamp. In recent years, it has been considered to integrate the system by incorporating the function of the flasher device (flasher function) into a vehicle indicating instrument to reduce the production cost of the vehicle.

  However, when the flasher function is taken into the vehicle indicating instrument, the field winding and the flasher semiconductor switch for blinking the flasher may be close to each other in the vehicle indicating instrument. In order to blink the flasher, it is necessary to turn on and off the semiconductor switch, and a magnetic field is generated from the semiconductor switch by turning on and off the semiconductor switch. For this reason, if the semiconductor switch of the flasher function unit operates during detection of the induced voltage, erroneous detection of the stopper position may occur due to the generated magnetic field, and the stopper position may shift. More specifically, if the pointer does not collide with the stopper but it is determined that it has collided and stopped, and the pointer rotates even though it has stopped colliding with the stopper. It may be misjudged that it is. When such a phenomenon occurs, there is a possibility that a problem that the vehicle state value cannot be correctly indicated can occur.

  Accordingly, the present invention has been made in view of the above-described problems, and provides a vehicle indicating instrument that can reduce the occurrence of an inaccurate indication of a vehicle state value while integrating the system. For the purpose.

  The present invention employs the following technical means in order to achieve the aforementioned object.

  According to the first aspect of the present invention, the pointer rotates along the display surface of the scale plate for displaying the vehicle state value, and indicates the vehicle state value according to the rotation position, and the step for rotationally driving the pointer A step motor including a stator having a field winding that generates a magnetic field when a drive signal is input, and a magnet rotor that is rotatably supported coaxially with the stator and rotates in accordance with the magnetic field; A stopper mechanism that stops the pointer rotating in the zero direction at a stopper position that is within a predetermined range in the return zero direction from the zero position that indicates the zero value of the vehicle state value, and the field winding every time a certain detection interval elapses A detecting means for detecting an induced voltage generated on the wire and a driving control means for controlling a driving signal to be applied to the field winding in accordance with the vehicle state value with reference to a preset zero point. To do Using the induced voltage detected by the detecting means, the zero point stopper position detecting operation is performed to detect the electric angle at which the pointer stops at the stopper position, and the detected electric angle is set to the zero point by executing the zero point stopper position detecting operation. Drive control means for setting, and noise generation means for generating a magnetic field acting on the field winding by being given a noise generation signal over a generation period after the noise generation signal is given, and the detection interval is The drive control means supplies the noise generation signal to the noise generation means so that the generation period is within the detection interval longer than the generation period.

  According to the first aspect of the present invention, the drive control means controls the drive signal applied to the field winding in accordance with the vehicle state value with reference to the set zero point. By controlling the drive signal based on the set zero point, the pointer can be rotated to a position corresponding to the vehicle state value. In addition, the driving means executes a zero-point stopper position detecting operation for detecting an electrical angle at which the pointer stops at the stopper position using the induced voltage detected by the detecting means in order to set the zero point, and the zero-point stopper position detecting operation The electrical angle detected by executing is set as a zero point. The detection means detects the induced voltage every time the detection interval elapses. However, in the vehicle indicating instrument of the present invention, a magnetic field acting on the field winding (hereinafter sometimes referred to as “inductive noise”) is generated. Includes noise generation signal. If there is such a noise generating means, there is a possibility that the induced voltage detected by the detecting means may not be reliable information, so that it is not possible to reliably detect the stop at the stopper position.

  However, in the present invention, when a noise generation signal for operating the noise generation means is given, the drive control means gives the noise generation signal to the noise generation means so that the generation period of the magnetic field falls within the detection interval. Therefore, even if a noise generation signal for operating the noise generation means is given to the drive control means, the drive control means does not immediately operate the noise generation means, but the noise generation means is set so as to satisfy a predetermined condition. Make it work. Since the generation period of the induced noise is shorter than the detection interval, by controlling the generation period within the detection interval, it is possible to prevent the detection time point detected by the detection means from being within the generation period. For example, if a noise generation signal can be given to the noise generation means immediately after being detected by the detection means, even if the generation period ends, the detection interval and the occurrence will occur until the next detection time point detected by the detection means. There is only a period of difference from the period. As a result, no induced noise is generated at the detection time point detected by the detecting means, and therefore the zero point stopper position detecting operation can be executed using an induced voltage that is not affected by the induced noise. Accordingly, since the possibility that an inaccurate zero becomes the reference of the drive signal is reduced, it is possible to reduce the occurrence of an inaccurate indication of the vehicle state value.

  Further, in the invention according to claim 2, when the noise generation signal is given, the noise generation means generates a magnetic field over the generation period every time a preset generation interval elapses, and the drive control means The length is controllable, and the drive control means controls the length of the generation interval so that the generation period falls within the detection interval.

  According to the second aspect of the present invention, when the noise generation signal is given, the noise generation means generates a magnetic field over the generation period every time a predetermined generation interval elapses. Then, even when control is performed so that the generation period is within the detection interval when the noise generation signal is given, there may be a detection time point within the generation period if no control is performed thereafter. However, in the present invention, the drive control means can control the length of the generation interval, and controls the length of the generation interval so that the generation period is within the detection interval. It can be prevented. In other words, even when the noise generating means operates periodically, the zero point stopper position detecting operation can be executed using the induced voltage that is not affected by the induced noise by temporarily shifting the period.

According to a third aspect of the present invention, when a noise generation signal is input from the outside to the drive control unit instead of the noise generation unit, the drive control unit is first induced after the noise generation signal is input to the drive control unit. A noise generation signal is provided to the noise generation means so that the generation period is within a detection interval from a detection time point at which the voltage is detected.

  According to the third aspect of the present invention, when a noise generation signal is input from the outside, the drive control means is generated within a detection interval from a detection time point at which an induced voltage is first detected after the noise generation signal is input. The noise generation signal is given to the noise generation means so that the period is reached. If the period from when the noise generation signal is input to when the noise generation means operates is long, the noise generation means does not operate, and the user may recognize that a problem has occurred in the noise generation means. In the present invention, after the noise generation signal is input, the noise generation signal is given to the noise generation means so that the generation period is within the detection interval from the first detection time point. Therefore, the noise generating means can be operated at an early timing. As a result, the time difference (time lag) from when the noise generating signal is input to when the noise generating means operates can be shortened.

Furthermore, in the invention according to claim 4, the drive control means determines whether or not a noise generation signal is input from the outside to the drive control means instead of the noise generation means every time a predetermined determination interval longer than the detection interval elapses. When it is determined that the noise generation signal is input to the drive control means , the noise generation signal is supplied to the noise generation means so that the generation period is within the detection interval.

According to the invention described in claim 4, the drive control means determines whether or not a noise generation signal is input every time a predetermined determination interval elapses, and determines that the noise generation signal is input. A noise generation signal is given to the noise generation means. Therefore, even if a noise generation signal is input, the drive control unit does not immediately control the noise generation unit, and after the determination, the drive control unit executes processing based on the noise generation signal. By setting the detection interval longer than the determination interval, the drive control unit can reduce the processing load of the drive control unit by periodically determining without monitoring whether the noise generation signal is input. .

  Further, in the invention described in claim 5, the noise generating means includes a semiconductor switch and an operation unit that operates or stops operation by switching control for switching on and off of the semiconductor switch. The semiconductor switch generates noise. When a signal is applied, the semiconductor switch is turned on and off, and the semiconductor switch generates a magnetic field when turned on and off.

  According to the fifth aspect of the present invention, the noise generating means includes a semiconductor switch and an operating unit. The semiconductor switch is an element that generates inductive noise that is switched between on and off in response to a noise generation signal. In other words, inductive noise is generated when the semiconductor switch is turned off from on, and inductive noise is generated even when the semiconductor switch is turned off. Even in a vehicular indicating instrument including such a semiconductor switch, the present invention can reduce the influence of induced noise.

It is a front view showing indicator 1 for vehicles of a 1st embodiment. FIG. 2 is a cross-sectional view seen from a cutting plane line II-II in FIG. 1. It is a block diagram which simplifies and shows the electrical structure of the indicator device 1 for vehicles. It is a perspective view which simplifies and shows the inner machine main body 30a. It is a top view which simplifies and shows the step motor M. It is a characteristic view showing an example of a drive signal applied to field windings 32 and 33. It is a front view which shows the state which the pointer 20 stopped to the stopper position from a front direction. It is a flowchart which shows a ZPD process. It is a flowchart which shows the 1st noise generation function process. It is a flowchart which shows a 2nd noise generation function process. 6 is a timing chart for explaining the operation of the flasher function unit 50.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing a vehicular indicating instrument 1 according to a first embodiment. FIG. 2 is a cross-sectional view seen from the section line II-II in FIG. FIG. 3 is a block diagram showing a simplified electrical configuration of the vehicle indicating instrument 1. The vehicle indicating instrument 1 is installed in front of a driver's seat (not shown) in the vehicle. The vehicular indicating instrument 1 includes an instrument panel 10, a pointer 20, a rotary inner unit 30, a substrate 40, and a control unit 60.

  As shown in FIG. 1, the instrument panel 10 has a vehicle speed display unit 11 for displaying a vehicle speed value on a display surface 10 a, and the display surface 10 a is arranged toward the driver's seat side. The vehicle speed display unit 11 has a plurality of vehicle speed values (0 km / h, 20 km / h,..., 160 km / h) from a zero value (0 km / h) as a reference of the vehicle speed value to an upper limit value (180 km / h). 180 km / h) is displayed in an arc shape. The vehicle speed value corresponds to the vehicle state value described in the claims, and the instrument panel 10 corresponds to the scale plate described in the claims.

  As shown in FIG. 1 and FIG. 2, the pointer 20 is connected to the pointer shaft 30 b of the rotary inner unit 30 on the base end 21 side, and the zero return direction X and the opposite zero direction are the opposite directions. Y can be rotated along the display surface 10 a of the instrument panel 10. The pointer 20 indicates a value corresponding to the rotational position among the vehicle speed values displayed on the vehicle speed display unit 11 by rotating in the nulling direction X or the zeroing direction Y. The pointer 20 can be returned to the zero position indicating the zero value by rotating in the return zero direction X. In the present embodiment, the zero return direction X is a direction from the upper limit value toward the zero value, and the zero separation direction Y is the direction from the zero value toward the upper limit value.

  As shown in FIG. 2, the rotating inner unit 30 includes an inner unit main body 30a, a pointer shaft 30b, and a casing 30c. The internal unit main body 30 a is disposed on the back side of the substrate 40 substantially parallel to the instrument panel 10. FIG. 4 is a perspective view schematically showing the internal unit main body 30a. The internal machine main body 30a incorporates a two-phase step motor M, a reduction gear mechanism G, and a stopper mechanism S in a casing 30c. The pointer shaft 30 b is supported by a casing 30 c fixed to the back surface of the substrate 40, and supports the proximal end portion 21 of the pointer 20 through the substrate 40 and the instrument panel 10. The internal machine main body 30a rotationally drives the pointer shaft 30b coaxially with the output stage gear 34 of the reduction gear mechanism G and consequently the pointer 20 by the reduction rotation of the reduction gear mechanism G interlocking with the rotation of the step motor M.

  FIG. 5 is a plan view schematically showing the step motor M constituting the internal unit main body 30a. As shown in FIGS. 4 and 5, the step motor M is configured by combining a stator Ms and a magnet rotor Mr. The stator Ms has a yoke 31 and two-phase field windings 32 and 33. The yoke 31 has a pair of magnetic poles 31a and 31b having a pole shape, and an A-phase field winding 32 is wound around the magnetic pole 31a, while a B-phase field winding 33 is wound around the magnetic pole 31b. It is wound. The magnet rotor Mr is coaxially fixed to the rotation shaft 35a of the reduction gear mechanism G. N poles and S poles as magnetic poles are alternately formed in the rotation direction on the outer peripheral surface of the magnet rotor Mr that forms a gap between the tip surfaces of the magnetic poles 31a and 31b of the yoke 31.

  FIG. 6 is a characteristic diagram illustrating an example of a drive signal applied to the field windings 32 and 33 of the step motor M. In the step motor M having such a configuration, as shown in FIG. 6, an AC A-phase drive signal whose voltage alternates in a cosine function according to the electrical angle is applied to the A-phase field winding 32. On the other hand, an alternating B-phase drive signal whose voltage alternates in a sine function according to the electrical angle is applied to the B-phase field winding 33. When such A-phase and B-phase drive signals that are 90 degrees out of phase with each other are applied, an alternating magnetic flux is generated in each of the field windings 32 and 33, and the generated alternating magnetic flux is converted into the yoke 31 and the magnet rotor Mr. Pass between the magnetic poles. The magnet rotor Mr rotates in accordance with the voltage change of the A-phase and B-phase drive signals according to the electrical angle.

  As shown in FIG. 4, the reduction gear mechanism G has a plurality of gears 34 to 37 made of spur gears. The output stage gear 34 is coaxially connected to the pointer shaft 30b, and the input stage gear 35 is coaxially fixed to the rotary shaft 35a supported by the casing 30c. The intermediate gears 36 and 37 are coaxially supported by a rotating shaft 36a fixed to the casing 30c, so that they can rotate integrally. The intermediate gear 36 meshes with the output stage gear 34, and the intermediate gear 37 meshes with the input stage gear 35.

  With this configuration, the reduction gear mechanism G reduces the rotation of the magnet rotor Mr of the step motor M and transmits the reduced rotation to the pointer 20. Therefore, when the rotational position of the magnet rotor Mr changes according to the change of the A-phase and B-phase drive signals according to the electrical angle, the rotational position of the pointer 20 also changes. In the present embodiment, the direction in which the electrical angle is decreased corresponds to the zero return direction X of the pointer 20, and the direction in which the electrical angle is increased corresponds to the zeroing direction Y of the pointer 20.

  As shown in FIG. 4, the stopper mechanism S includes a contact member 38 and a stopper member 39. The abutting member 38 is formed in a strip plate shape protruding from the output stage gear 34, and can rotate integrally with the gear 34. The stopper member 39 is formed in an L shape that protrudes inward from the casing 30 c, and the protruding end 39 a is on the side corresponding to the return zero direction X with respect to the contact member 38 on the rotation track of the contact member 38. Is located.

  FIG. 7 is a front view showing the state in which the pointer 20 is stopped at the stopper position from the front. As shown in FIG. 7, the pointer 20 has a predetermined range from the zero position to the zero return direction X in a state where the contact member 38 is locked to the tip end portion 39 a of the stopper member 39 by the rotation in the zero return direction X. It stops at the inner stopper position. In the present embodiment, in the ZPD process described later, the electrical angle corresponding to the stopper position is updated and set as the zero point θ0 (0 degree). Incidentally, the stopper position is set within a range of, for example, 450 degrees in terms of the electrical angle of the stepping motor M from the zero position of the pointer 20 to the zero return direction X when the vehicle indicating instrument 1 is manufactured.

  As shown in FIG. 3, the vehicle indicating instrument 1 includes a flasher function unit 50 having an indicator 51, a flasher semiconductor switch 52, a buzzer 53, and a buzzer semiconductor switch 54.

  Among these, the indicator 51 is an operating unit, is disposed on the display surface 10 a (not shown in FIG. 1), and is connected to the control unit 60 via the flasher semiconductor switch 52. When the flasher semiconductor switch 52 is controlled to be switched from OFF to ON, the indicator 51 is lit (operated) when power is supplied from the control unit 60, while the flasher semiconductor switch 52 is controlled to be switched from ON to OFF. In this case, the power supply from the control unit 60 is shut off and turned off (stopped). Then, the control unit 60 performs switching control for switching the flasher semiconductor switch 52 between on and off, so that the indicator 51 blinks.

  The buzzer 53 is an operating unit and is connected to the control unit 60 via the buzzer semiconductor switch 54. When the buzzer semiconductor switch 54 is turned on, the buzzer 53 blows (operates) when power is supplied from the control unit 60, while the buzzer 53 starts from the control unit 60 when the buzzer semiconductor switch 54 is turned off. The power of the unit is cut off and does not sound (stop operation). The control unit 60 controls the on / off of the buzzer semiconductor switch 54 in conjunction with the on / off of the flasher semiconductor switch 52, so that the buzzer 53 sounds in conjunction with the indicator 51.

  Note that the indicator 51 is illustrated as a single indicator in FIG. 3 for the sake of convenience, but actually, the right turn blinks in synchronization with the blinking of a turn lamp for right turn (not shown) to indicate that the vehicle turns right. And a left turn indicator that blinks in synchronization with blinking of a left turn turn lamp (not shown) for indicating that the vehicle makes a left turn. The indicator 51 corresponds to a flasher.

  Next, the control unit 60 will be described. The control unit 60 is mainly composed of a microcomputer having a memory 61, and is mounted on the substrate 40 (see FIG. 2). The memory 61 stores an execution program for executing a later-described ZPD process, and also stores the latest zero point θ0 set (updated) by executing the ZPD process. In addition, the memory 61 has a storage area for a ZPD flag indicating that the ZPD processing has been executed while the control unit 60 is being activated.

  The control unit 60 includes a flasher function unit 50, a vehicle door sensor 70, a vehicle speed sensor 71, a vehicle side device (not shown), an ignition switch IG, a battery power source B, a drive circuit 80, a zero position detection circuit 81, and an input means 82. And are electrically connected. The control unit 60 is activated by direct power supply from the battery power supply B when the door sensor 70 detects the opening of the vehicle door or when an unlock signal or a lock signal is input from the vehicle side device. In addition, when the ignition switch IG is turned on until a set time (for example, 2 minutes) elapses after activation, the control unit 60 maintains the activation state by power supply from the battery power supply B, and thereafter the ignition unit IG When the switch IG is turned off, it sleeps. On the other hand, the control unit 60 sleeps when the ignition switch IG is not turned on until the set time elapses after activation, and restarts when the ignition switch IG is turned on after the sleep. The restart after the sleep may be performed, for example, when the vehicle door is opened or when the brake pedal is depressed, in addition to when the ignition switch IG is turned on. The control unit 60 sets the ZPD flag when the ZPD process is executed during the activation, and resets the ZPD flag immediately before going to sleep.

  The control unit 60 gives the drive circuit 80 a drive command for controlling the rotation of the magnet rotor Mr. The drive circuit 80 applies the A-phase drive signal and the B-phase drive signal to the field windings 32 and 33 based on the drive command given from the control unit 60. As a result, the magnet rotor Mr rotates in accordance with the voltage change of the A-phase and B-phase drive signals according to the electrical angle.

  The zero position detection circuit 81 is detection means, detects an induced voltage generated in the field windings 32 and 33 every time a preset detection interval elapses, and transmits information indicating the detected induced voltage to the control unit. 60.

  Next, ZPD processing (zero position detection processing) of the control unit 60 will be described with reference to FIG. FIG. 8 is a flowchart showing the ZPD process. When a predetermined stopper position detection operation execution condition is satisfied, the control unit 60 executes the pointer swinging-up operation and the zero-point stopper position detecting operation following the pointer swinging-up operation. The stopper position detection operation execution condition is that the control unit 60 is activated. The control unit 60 is, for example, when the vehicle door is opened, the ignition switch IG is turned on, or the brake pedal is depressed. to start. The flowchart shown in FIG. 8 is started when the stopper position detection operation execution condition is satisfied, and the process proceeds to step s11.

  In step s11, a rotation process is executed, and the process proceeds to step s12. The rotation process is a process of rotating the pointer 20, and specifically performs a needle swinging operation and a needle swinging operation. The outline of the needle swinging operation is as follows: A and B phases applied to the field windings 32 and 33 of the step motor M so that the pointer 20 once stops in the zero-separating direction Y and stops. This is an operation for controlling the drive signal. The outline of the needle swinging operation will be described below. After the needle swinging operation is finished, A applied to the field windings 32 and 33 of the step motor M so that the pointer 20 rotates in the return zero direction X. This is an operation to control the phase and B phase drive signals.

  In step s12, sampling of the induced voltage is started, and the process proceeds to step s13. In step s12, the zero position detection circuit 81 is controlled so that the detection voltage supplied from the zero position detection circuit 81 is detected (sampled) at predetermined detection points when the pointer swinging operation in step s11 is performed. Then, the process proceeds to step s13. Therefore, the control unit 60 is provided with information on the induced voltage from the zero position detection circuit 81 for each detection time point.

  In step s13, threshold determination is performed, and this flow is terminated. The threshold determination is a process for determining whether the induced voltage detected by induced voltage sampling is equal to or less than a set value. When the induced voltage is equal to or lower than the set value, it is estimated that the pointer 20 has stopped at the stopper position (detection of stopping at the stopper position). The control unit 60 sets (updates) the electrical angle corresponding to the stopper position detected by the threshold determination as the zero point θ0.

  The above-described zero stopper position detection operation is the A phase applied to the field windings 32 and 33 of the step motor M so that the pointer 20 continues to rotate in the return zero direction X after the end of the pointer swinging operation. When the detection voltage applied from the zero position detection circuit 81 is equal to or lower than the set value while controlling the drive signal for B and B, it is estimated that the pointer 20 has stopped at the stopper position (detection of stopping at the stopper position is detected). ) Operation.

  In step s13 of the ZPD process shown in FIG. 8 described above, the control unit 60 executes a zero point setting operation that is an operation for setting (updating) the electrical angle corresponding to the detected stopper position as the zero point θ0. Thus, the needle swinging operation, the zero point stopper position detecting operation, and the zero point setting operation are also referred to as ZPD processing. Then, the control unit 60 gives a drive command to the drive circuit 80 using the zero point θ0 set by executing the ZPD process as a reference, and sends the drive signals of the A phase and the B phase from the drive circuit 80 to the field of the step motor M. Applied to the magnetic windings 32 and 33. Therefore, the control unit 60 corresponds to drive control means.

  The control unit 60 controls the drive command given to the drive circuit 80 based on the zero point θ0 of the electrical angle stored in the memory 61 in the start-up state after the ZPD process is executed, so that the detected vehicle speed value of the vehicle speed sensor 71 is obtained. The pointer 20 is instructed.

  Further, the control unit 60 determines whether or not a predetermined flasher driving condition based on a manual operation of the user is satisfied, and when determining that the flasher driving condition is satisfied, the control unit 60 responds to the flasher driving condition determined to be satisfied. In order to blink the flasher in this manner, the on / off control of the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 is controlled. Therefore, it is determined that the flasher driving condition is satisfied when an operation signal (switching control signal) for operating the flasher function unit 50 is input by the input unit 82.

  Specifically, in the flasher driving condition, a right turn turn lamp arranged on the right side in the forward direction of the vehicle on which the vehicle indicating instrument 1 is mounted blinks, or a left turn turn arranged on the left side in the forward direction of the vehicle. A combination lever (not shown) for blinking the lamp is set to a turn lamp blinking position (a position shifted by a predetermined angle in the vertical direction from the reference position). Therefore, the combination lever has a function as input means 82 to which an operation signal is input.

  In addition, the flasher driving condition includes a hazard of flashing both a right turn turn lamp disposed on the right side in the forward direction of the vehicle on which the vehicle indicating instrument 1 is mounted and a left turn turn lamp disposed on the left side in the forward direction of the vehicle. It includes that the lamp switch is set to the hazard blinking position (position pushed from the reference position). Therefore, the hazard lamp switch has a function as input means 82 to which an operation signal is input.

  Further, the flasher driving condition includes that a command signal is input to the control unit 60 from a portable device (not shown) that remotely controls the vehicle using wireless communication with the vehicle. Specifically, in the portable device, an unlock button for unlocking the vehicle door, a lock button for locking the vehicle door, and the like are arranged, and when these unlock button and lock button are pushed, An unlock signal and a lock signal indicating that are transmitted from the portable device. These unlock signals and lock signals are received by a vehicle-side device (not shown) mounted on the vehicle and input to the control unit 60. The flasher driving condition includes that such an unlock signal or lock signal is input to the control unit 60. Therefore, the portable device has a function as input means 82 to which an operation signal is input.

  Then, when the combination lever is set at a position where the right turn turn lamp blinks, the control unit 60 flashes so that the right turn indicator blinks and the buzzer 53 sounds in conjunction with the blinking of the right turn turn lamp. On / off control of the semiconductor switch 52 and the buzzer semiconductor switch 54 is controlled. Similarly, when the combination lever is set at a position where the left turn turn lamp blinks, the control unit 60 causes the left turn indicator to blink in conjunction with the blinking of the left turn turn lamp and the buzzer 53 to sound. On / off control of the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 is controlled. Further, when the hazard lamp switch is set to the on state, the control unit 60 flashes so that the indicator 51 blinks and the buzzer 53 sounds in conjunction with blinking of both the right turn turn lamp and the left turn turn lamp. On / off control of the semiconductor switch 52 and the buzzer semiconductor switch 54 is controlled. In addition, when an unlock signal or a lock signal is input from the portable device, the control unit 60 interlocks with blinking of both the right turn turn lamp and the left turn turn lamp to indicate to the user that these signals have been input. Thus, a so-called answerback is performed in which the on / off control of the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 is controlled so that the indicator 51 blinks and the buzzer 53 sounds.

  Here, in the vehicle indicating instrument 1 of the present embodiment, the field windings 32 and 33 constituting the step motor M are disposed on the substrate 40 and the flasher semiconductor switch 52 constituting the flasher function unit 50. The buzzer semiconductor switch 54 is also disposed on the same substrate 40, and is disposed on the same substrate 40.

  In the vehicular indicating instrument 1 according to the present embodiment, the same control unit 60 executes ZPD processing and on / off switching control of both the flasher semiconductor switch 52 and the buzzer semiconductor switch 54.

  By integrating the flasher function unit 50 into the vehicle indicating instrument 1 in this way, the system cost of the vehicle can be reduced. The field windings 32 and 33, the flasher semiconductor switch 52, and the buzzer semiconductor switch 54 are arranged in close proximity.

  When the field windings 32 and 33 are disposed in a state where the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 are close to each other, when the flasher function unit 50 is operated during the ZPD processing of the step motor M, the flasher semiconductor switch 52 is operated. Inductive noise is generated by the on / off switching control of the buzzer semiconductor switch 54. In other words, the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 are inductions that are magnetic fields that reduce the detection accuracy of the induced voltage detected by the zero position detection circuit 81 when the on / off switching is controlled by the operation signal. Noise generating means for generating noise. Therefore, the operation signal corresponds to a noise generation signal. Inductive noise is a magnetic field that acts on the field winding. Specifically, the flasher function unit 50 includes a flasher semiconductor switch 52 and a buzzer semiconductor switch 54 that are semiconductor switches. Such a semiconductor switch is an element that generates inductive noise when an operation signal is given and the switching mode is switched. In other words, inductive noise is generated when the semiconductor switch is turned off from on, and inductive noise is generated even when the semiconductor switch is turned off. Such induced noise is continuously generated over a generation period (for example, 2 ms) after the operation signal is given to the flasher function unit 50. Due to such induction noise, erroneous detection of the stopper position may occur and the stopper position may shift. As a result, there is a possibility that the vehicle speed value cannot be correctly indicated.

  Therefore, the control unit 60 controls the detection time point for detecting the induced voltage in step s12 shown in FIG. 8 and the operation start time point for operating the flasher function unit 50. Specifically, the operation start time is controlled so that the generation period falls within the detection interval. Specific control timing will be described with reference to FIGS. FIG. 9 is a flowchart showing the first noise generation function process. FIG. 10 is a flowchart showing the second noise generation function process. FIG. 11 is a timing chart for explaining the operation timing of the flasher function unit 50.

  First, the first noise generation function process will be described. The first noise generation function process shown in FIG. 9 is executed by the control unit 60. The first noise generation function process is a process that is repeatedly executed in a short time while the ZPD process shown in FIG. 8 is being executed. When the flow is started, in step s21, it is determined whether or not it is a determination time point. If it is the determination time point, the process proceeds to step s22. If it is not the determination time point, the flow ends. The determination time point is a time point for determining whether or not an operation signal for operating the flasher function unit 50 is given at predetermined determination intervals. In other words, it is determined whether or not the determination interval has elapsed since the previous determination. Such a determination interval is set to be longer than the detection interval for detecting the induced voltage.

  In step s22, since it is a determination time point, it is determined what information the current operation signal is, and this flow is ended. It is determined whether the specific determination content is different from the content determined at the previous determination time. For example, in the determination at the previous determination time, the operation signal of the flasher function unit 50 is L (low), whereas in the current determination, the operation signal is different between the previous time and the current time in H (high). Therefore, in such a case, it is necessary to give an operation signal to the flasher function unit 50. As described above, the control unit 60 has a function as a determination unit that determines whether or not an operation signal is given every time a predetermined determination interval elapses.

  Next, the second noise generation function process will be described. The second noise generation function process shown in FIG. 10 is executed by the control unit 60. The second noise generation function process is a process that is repeatedly executed in a short time while the ZPD process shown in FIG. 8 is being executed. When the flow is started, in step s31, it is determined whether or not it is an operation start time. If it is the operation start time, the process proceeds to step s32. If the operation start time is not reached, the flow ends. The operation start time is a time when the start time of the generation period in which the induced noise is generated is after the start time of the detection interval, and the end time of the generation period is before the end time of the detection interval. In other words, the operation signal time point is a time point when there is no detection time point between the operation signal time point and the generation period. In the present embodiment, the operation start time is set immediately after the detection time (for example, 0.1 ms after the detection time).

  In step s32, since it is the operation start time, the determination result is output based on the determination result of the first noise generation function processing described above, and this flow is ended. When the determination result is output is information indicating that the operation signal needs to be given to the flasher function unit 50, the operation signal is given so that the flasher function unit 50 operates. If the information does not require the operation signal to be supplied to the flasher function unit 50, the flasher function unit 50 is not controlled at all. Thus, when an operation signal for operating the flasher function unit 50 is given by a user operation, the operation signal is not immediately supplied to the flasher function unit 50, but the flasher function unit 50 is operated immediately after the detection time point. The operation timing is controlled so that By operating the flasher function unit 50 immediately after the detection time in this way, the generation period ends from the operation start time until the next detection time, that is, until the detection interval elapses. The presence of the detection time can be suppressed.

  The control timing of the noise generation function process shown in FIGS. 9 and 10 will be described with reference to FIG. At time t0, the operation signal for operating the flasher function unit 50 is in the L state. The determination time is a time when a predetermined determination interval T1 (for example, 50 ms) has elapsed from the previous determination time. Immediately after the determination time has elapsed, the first noise generation function process shown in FIG. 9 is executed. As a result, the determination of the operation signal is executed every time the determination interval T1 elapses.

  The detection time is a time when a preset detection interval T2 (for example, 10 ms) has elapsed from the previous detection time. Immediately after the detection time has elapsed, the induced voltage is detected. As a result, the detection of the induced voltage is executed at every detection interval T2. Such a detection interval T2 is set to be shorter than the determination interval T1. The induction noise generation period T3 is started when an operation signal is given to the flasher function unit 50. The generation period T3 (for example, 2 ms) is shorter than the detection interval T2.

  At time t1 after time t0, the operation signal is changed from L to H. Therefore, the time point t1 is a time point when an operation signal for operating the flasher function unit 50 is input by the user. Then, the first noise generation function process is executed at the time t2, which is the latest determination time after the time t1. Actually, the time point t2 is the determination time point, but there is a time lag until the first noise generation function process is executed, so the first noise is immediately after the time point t2 (for example, 0.1 ms later). Generation function processing is executed. At the time t3, the operation signal is different from the previous time, so that the determination result is that the signal has changed from L to H. The induced voltage is detected at time t4, which is the latest detection time after time t3. Actually, the time point t4 is the detection time point, but there is a time lag until the detection process is executed. Therefore, the induced voltage is detected immediately after the time point t4 (for example, 0.1 ms later). At this time, since the flasher function unit 50 is not operating at all, it is not affected by the induced noise. The second noise generation function process is executed at the operation start time point t6 immediately after the detected time point t5. At time t6, since it is necessary to operate the flasher function unit 50 based on the determination result, an operation signal is given to the flasher function unit 50. When an operation signal is given to the flasher function unit 50, inductive noise is generated over a generation period T3 from time t6 to time t7. Since the induction noise generation period T3 is shorter than the detection interval T2, no induction noise is generated until the next detection time t8.

  Since the processing is repeated at such processing timing, for example, even when the operation signal is switched from H to L at time t9, the first noise generation function is similarly performed at time t11 immediately after the most recent determination time t10. The process is executed, and an operation signal is given to the flasher function unit 50 at the latest operation start time t12. Eventually, since there is no next detection time t14 within the generation period T3 from time t12 when the operation signal is applied to time t13, no induced noise is generated at the detection time t14.

  Therefore, when the flasher function unit 50 operates periodically, in other words, even when the generation period and the generation interval where no induction noise occurs alternately, the control unit 60 or the operation start time is controlled. Therefore, it is possible to control the length of the generation interval, and therefore, by controlling the length of the generation interval so that the generation period is within the detection interval, it is possible to prevent the detection time point from being within the generation period. Can do. In other words, even when the flasher function unit 50 operates periodically, the zero point stopper position detection operation can be executed using an induced voltage that is not affected by induced noise by temporarily shifting the cycle. . The case where the flasher function unit 50 operates periodically is, for example, an operation of blinking the indicator 51.

  The detection interval T1 will be described in more detail. The detection interval T1 is greater than the sum of the induction noise generation period T3 and the period (not shown) from the start of the detection process to the end of the second noise generation function process. , Set to a large value. The period from the start of the induced voltage detection process at the time of detection to the end of the second noise generation function process is extremely shorter than the induction noise generation period T3 and may be omitted.

  As described above, in the vehicular indicating instrument 1 according to the present embodiment, when an operation signal for operating the flasher function unit 50 is input, the start time of the induction noise generation period T3 is after the start time of the detection interval T2. In addition, an operation signal is given to the flasher function unit 50 by the control unit 60 at an operation start point in which the end point of the generation period T3 is before the end point of the detection interval T2. Therefore, even if an operation signal for operating the flasher function unit 50 is input, the control unit 60 does not immediately operate the flasher function unit 50, but the flasher function unit 50 is activated at an operation start point that satisfies a predetermined condition. Make it work. Since the generation period T3 of the flasher function unit 50 is shorter than the detection interval T2, the start time of the generation period T3 is after the start time of the detection interval T2, and the end time of the generation period T3 is the end time of the detection interval T2. When the operation is performed at the previous operation start time, the detection time detected by the zero position detection circuit 81 is prevented from being within the generation period T3. As a result, no induced noise (inductive noise) is generated at the detection time point detected by the zero position detection circuit 81. Therefore, the zero point stopper position detection operation can be performed using an induced voltage that is not affected by the induced noise. it can. Therefore, the possibility that an inaccurate zero point becomes the reference of the drive signal is reduced, and it is possible to reduce the occurrence of an inaccurate indication of the vehicle speed value.

  In other words, in the present embodiment, paying attention to the period length of the induced noise and the periodic control method of zero position detection, by intentionally generating the induced noise in the detection interval, the noise from the zero point stopper position detecting operation is detected. Can be excluded.

  Further, in the present embodiment, when the operation signal is input, the control unit 60, at the operation start time from the detection time when the induced voltage is first detected after the operation signal is input until the detection interval T2 elapses, An operation signal is given to the flasher function unit 50. If the period from when the operation signal is input to when the operation starts is long, the user may recognize that a failure has occurred. In the present embodiment, after the operation signal is input, the operation signal is given to the flasher function unit 50 until the detection interval T2 elapses from the first detection time point. Therefore, the detection time point may be influenced by induction noise. The flasher function unit 50 can be operated at an early point. As a result, the time difference from when the operation signal is input to when the flasher function unit 50 operates can be shortened.

  Further, in the present embodiment, the control unit 60 determines whether or not an operation signal is given every time a predetermined determination interval T1 elapses. When the control unit 60 determines that the operation signal is given, the control unit 60 gives the operation signal to the flasher function unit 50 at the start of the operation, assuming that the operation signal is inputted. Therefore, even if an operation signal is input, the control unit 60 executes processing based on the operation signal after the determination interval T1 has elapsed. By setting the detection interval T2 to be longer than the determination interval T1, it is possible to reduce the processing load on the control unit 60 by periodically determining whether or not the control unit 60 has always received an operation signal. Can do.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the first embodiment described above, both the field windings 32 and 33 and both the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 are arranged on the same substrate 40. The configuration is not limited, and only one of the field windings 32 and 33 and only one of the flasher semiconductor switch 52 and the buzzer semiconductor switch 54 may be arranged on the same substrate 40.

  In addition, as for the driving signals of each phase, if the signals alternate with each other with a phase difference of 90 degrees, other than the signal whose voltage changes in a cosine function shape or a sine function shape, for example, a signal that changes in a trapezoidal wave shape, a triangular wave shape, etc. It may be. Further, the vehicle state value instructed by the pointer 20 may be, for example, the coolant temperature or the like as long as it is a value relating to various vehicle states. Therefore, the lower limit value is not limited to the zero value, and may be a negative value, and can be appropriately set according to the vehicle state value.

  The vehicle on which the vehicle indicating instrument 1 is mounted is not limited to a passenger car, and the present invention is applied to various vehicle indicating instruments used in buses, trucks, motorcycles, and other various indicating instruments. Also good.

DESCRIPTION OF SYMBOLS 1 ... Indicator instrument for vehicles 10 ... Instrument board 10a ... Display board 20 ... Pointer 30 ... Turning inner machine 30a ... Inner machine main body 32, 33 ... Field winding 50 ... Flasher function part (noise generating means)
51. Indicator (noise generating means, operating part)
52. Flasher semiconductor switch (noise generating means, semiconductor switch)
53 ... Buzzer (noise generating means, operating part)
54 ... Buzzer semiconductor switch (noise generating means, semiconductor switch)
60. Control unit (drive control means)
61 ... Memory 80 ... Drive circuit (drive control means)
81 ... Zero position detection circuit (detection means)
82 ... Input means G ... Reduction gear mechanism M ... Step motor Ms ... Stator S ... Stopper mechanism

Claims (5)

A pointer that rotates along a display surface of a scale plate for displaying a vehicle state value, and indicates the vehicle state value according to a rotation position;
A step motor for rotationally driving the pointer, comprising a stator having a field winding for generating a magnetic field when a drive signal is input, and being rotatably supported coaxially with the stator in accordance with the magnetic field A step motor comprising a rotating magnet rotor;
A stopper mechanism that stops the pointer that rotates in the zero return direction at a stopper position that falls within a predetermined range in the return zero direction from a zero position that indicates the zero value of the vehicle state value;
Detecting means for detecting an induced voltage generated in the field winding every time a constant detection interval elapses;
Drive control means for controlling the drive signal to be applied to the field winding in accordance with the vehicle state value with reference to a preset zero point, which is detected by the detection means to set the zero point A zero point stopper position detecting operation for detecting an electrical angle at which the pointer stops at the stopper position is performed using the induced voltage, and the zero angle detected by executing the zero point stopper position detecting operation is detected as the zero point. Drive control means set as:
Noise generation means for generating a magnetic field acting on the field winding by being given a noise generation signal over a generation period after the noise generation signal is given,
The detection interval is longer than the occurrence period,
The vehicle control instrument, wherein the drive control means gives the noise generation signal to the noise generation means so that the generation period falls within the detection interval. When the noise generation signal is given, the noise generation unit generates the magnetic field over the generation period every time a predetermined generation interval elapses,
The drive control means can control the length of the generation interval;
2. The vehicular indicating instrument according to claim 1, wherein the drive control unit controls the length of the generation interval so that the generation period falls within the detection interval. When the noise generation signal is input from the outside to the drive control unit instead of the noise generation unit, the drive control unit first detects an induced voltage after the noise generation signal is input to the drive control unit. 3. The vehicular indicating instrument according to claim 1, wherein the noise generation signal is supplied to the noise generation unit so that the generation period is within the detection interval from a detection time point. It said drive control means determines each time the long constant determined intervals from the detection intervals whether or not the input to the drive control unit rather than the noise signal from outside the noise generating means has passed, the noise 4. The noise generation signal is supplied to the noise generation unit so that the generation period falls within the detection interval when it is determined that a signal is input to the drive control unit . The indicating instrument for vehicles as described in one. The noise generating means is
A semiconductor switch;
An operation unit that operates or stops operation by switching control in which the semiconductor switch is switched on and off, and
The semiconductor switch is switched between on and off when the noise generation signal is given,
5. The vehicular indicating instrument according to claim 1, wherein the semiconductor switch generates the magnetic field when the on and the off are switched. 6.

Images