JP2011027540A - Initialization driving device for vehicle meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reset a pointer to the origin normally, even if initialization operation of a vehicle meter is performed, while an ignition switch is not in the on-state. <P>SOLUTION: Even when a battery B voltage is lowered to below a reset voltage and microcomputers 21, 43 are circuit-reset, and thereafter the battery B voltage is reset to a reset removal voltage or higher and the microcomputers 21, 43 are initialized (removed from circuit-reset), initialization operation of the pointer 9 is not performed, if the battery B voltage is not maintained at a reference voltage or higher for a prescribed period thereafter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an initialization drive device that returns a pointer of a vehicle meter to an origin, and more particularly to an initialization drive device of a vehicle meter that eliminates a positional deviation of a pointer due to a stepper motor that rotates the pointer. It is.

  Conventionally, in a vehicle meter in which a pointer is driven by a stepper motor, it is known to perform an initialization operation for returning the pointer to the origin at the timing when an ignition switch is turned on (for example, Patent Document 1). When the ignition switch is turned on and the starter switch is turned on at the same time to start the engine, the battery voltage becomes unstable due to large power consumption by the starter motor during cranking. Therefore, it is also known to perform a process for stopping the initialization operation while the voltage of the battery is unstable even when the ignition switch is turned on (for example, Patent Document 2).

  When the starter switch that is turned on at the same time as the ignition switch is turned off after the engine is started, the starter motor is stopped, thereby eliminating the large power consumption. In addition, the alternator is activated by starting the engine and charging of the battery is started. For this reason, the voltage of the battery is stabilized after the starter switch is turned off. Therefore, the pointer can be returned to the normal position by executing the stopped initialization operation when the starter switch is turned off.

JP 2002-58289 A Japanese Patent No. 3846343

  By the way, the initialization operation | movement in the vehicle meter mentioned above may be performed in the state in which an ignition switch is not ON. For example, the controller of the vehicle meter is reset due to the voltage drop of the battery that is the power source of the vehicle meter, and the operation of the vehicle meter is stopped. When the meter is restarted, an initialization operation is performed.

  When the ignition switch is not on, the engine is not running, and the battery is not charged by the alternator. Therefore, when the vehicle meter is restarted in this state, the battery voltage may decrease again due to its own power consumption, and the controller may be reset again. As described above, when the battery voltage is lowered and the controller is reset while the ignition switch is not turned on, the reset release and reset of the controller may be repeated in a short cycle thereafter.

  If the reset and reset release of the controller are repeated in a short cycle while the ignition switch is not turned on, the battery voltage recovered after the reset of the controller decreases again due to the power consumption by the controller after the reset is released. Then, the initialization operation started by the restart of the vehicle meter accompanying the reset release of the controller is stopped halfway by the subsequent reset of the controller.

  When the started initialization operation is stopped halfway, the rotating magnet rotor of the stepper motor rotates for a while due to inertia. Such rotation of the magnet rotor can be grasped by monitoring the induced voltage generated in the unexcited stator coil by the controller if the ignition switch is in the ON state. However, when the ignition switch is not turned on, the rotation due to the inertia of the magnet rotor cannot be grasped by the induced voltage generated in the stator coil.

  Therefore, when the reset controller is subsequently released from reset and the vehicle meter is restarted, the position of the magnetic pole of the magnet rotor rotated by inertia when the initialization operation is stopped halfway due to reset of the controller, There is a case where there is no matching with the excitation pattern of the stator coil by the controller that is released from the reset. When such a reset occurs repeatedly, the magnet rotor is rotated in a direction opposite to the intended direction, and a large step-out may occur in the stepper motor before the initialization operation is normally started. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is, for example, when the initialization operation of the vehicle meter is performed in a state where the ignition switch is not turned on, such as when the vehicle meter is started. A vehicle meter initialization drive device that prevents the stepper motor from stepping out even if the controller is reset before the switch is turned on and can return the pointer to the normal position. It is to provide.

In order to achieve the above object, an initialization drive device for a vehicle meter according to the present invention described in claim 1 comprises:
An initialization operation for driving a pointer driven by a stepper motor of a meter powered by a vehicle battery in a reverse rotation direction to return to the origin by contacting a stopper of a driven member interlocked with the pointer is performed by the controller. In an initialization drive device for a vehicle meter that is controlled at a predetermined timing,
Switch state detecting means for detecting whether or not an ignition switch of the vehicle is in an on state;
In a state where the switch state detecting means does not detect the ON state of the ignition switch of the vehicle, the voltage of the battery that has fallen below a reset voltage that resets the controller returns to a reset release voltage that releases the reset of the controller or more. Accordingly, after the meter is restarted, continuation confirmation means for confirming whether the voltage of the battery has been maintained for a predetermined period of time at a reference voltage higher than the reset release voltage,
The continuation confirmation means confirms that the voltage of the battery has been maintained for a predetermined period after the restart of the meter in a state where the switch state detection means does not detect the ON state of the ignition switch of the vehicle. Until the holding means for suspending execution of the initialization operation accompanying the arrival of the predetermined timing,
After the suspension of the execution of the initialization operation by the suspension unit is released, the initialization operation based on the arrival of the predetermined timing is sufficient to return the pointer to the origin and a predetermined predetermined A post-holding execution means to be executed by driving in the reverse rotation direction by an angle;
It is characterized by providing.

  According to the vehicle meter initialization drive device of the present invention as set forth in claim 1, when the ignition switch is not on, the voltage of the battery below the reset voltage for resetting the meter controller cancels the reset of the controller. When the reset voltage exceeds the reset release voltage, the meter is restarted. After the meter is restarted, the initialization operation is suspended and executed even if a predetermined timing arrives until the battery voltage is maintained for a predetermined period higher than the reference voltage higher than the reset release voltage. Not.

  Therefore, when the ignition switch is not on, the battery voltage that is higher than the reset release voltage is not stable, and when the meter is restarted, the reset voltage will fall below the reset voltage. Is not done. For this reason, the initialization operation is stopped halfway due to the reset of the controller, and the position of the magnetic pole of the magnet rotor of the stepper motor does not become inconsistent with the excitation pattern of the stator coil by the controller whose reset is released. Therefore, it is possible to prevent the magnet rotor from rotating in the direction opposite to the intended direction in the next initialization operation, and to drive the pointer normally toward the origin in the initialization operation after the meter is restarted. it can.

  According to a second aspect of the present invention, there is provided the vehicle meter initialization drive apparatus according to the present invention, wherein the switch state detection means is provided on the vehicle. An auxiliary machine controller is provided that is used to control an auxiliary machine that can operate with the battery as a power source even when an on-state of an ignition switch of the vehicle is not detected. Is reset when the voltage falls below the reset voltage, and the reset is released when the voltage of the battery below the reset voltage returns to the reset voltage or higher.

  According to the vehicle meter initialization drive apparatus of the present invention described in claim 2, in the vehicle meter initialization drive apparatus of the present invention described in claim 1, the voltage of the battery that is lower than the reset voltage is reset. When returning to the release voltage or higher, not only the meter controller but also the auxiliary controller is released from reset. Then, the auxiliary machine that is not operated by the resetting of the auxiliary machine controller can be operated again, the battery power consumption by the auxiliary machine is resumed, and the battery voltage may fall below the reset voltage again. However, even if the voltage of the battery returns to the reset release voltage or higher, the initialization operation is not performed in the meter unless a higher reference voltage is maintained for a predetermined period.

  For this reason, the initialization operation is stopped halfway due to the re-reduction of the battery voltage, and the magnetic pole position of the magnet rotor of the stepper motor does not stop matching with the excitation pattern of the stator coil by the controller that has been reset. Therefore, it is possible to prevent the magnet rotor from rotating in the direction opposite to the intended direction in the next initialization operation, and to drive the pointer normally toward the origin in the initialization operation after the meter is restarted. it can.

  According to the vehicle meter initialization drive apparatus of the present invention, even when the initialization operation of the vehicle meter is performed in a state where the ignition switch is not on, the pointer can be normally returned to the origin.

It is a front view of the meter for vehicles concerning one embodiment of the present invention to which the initialization drive device of the present invention is applied. It is explanatory drawing which shows schematic structure of the stepper motor of the vehicle meter shown in FIG. It is explanatory drawing which shows the relationship between the stopper and stopper piece of a stepper motor shown in FIG. It is a block diagram which shows the electric constitution of the meter for vehicles shown in FIG. 6 is a flowchart showing a pointer movement control process executed by the microcomputer of FIG. 4 according to a program stored in an internal ROM. 6 is a flowchart showing a pointer movement control process executed by the microcomputer of FIG. 4 according to a program stored in an internal ROM. It is explanatory drawing which shows the positional relationship of the stator coil and magnet rotor of the stepper motor shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of an initialization drive device for a vehicle meter according to the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a vehicle meter according to an embodiment of an initialization drive device of the present invention. A tachometer denoted by reference numeral 1 in FIG. 1 relates to an embodiment of a vehicle meter to which an initialization drive device according to the present invention is applied, and a combination meter unit together with a speedometer, a shift indicator, a warning lamp, etc. (not shown). (Not shown). This combination meter unit is mounted on the instrument panel of the vehicle, and the tachometer 1 displays the engine speed of the vehicle.

  The tachometer 1 has a dial plate 5 whose periphery is covered with a dial plate 3, and a light emitting pointer 9 that is arranged in front of the dial plate 5 and indicates a scale 7 that indicates the engine speed of the dial plate 5. ing. The pointer 9 is rotationally driven by a stepper motor 11 (see FIG. 2) described later.

  As shown in FIG. 2, the stepper motor 11 transmits two stator coils 11 a and 11 b, a magnet rotor 11 c in which NS poles are alternately magnetized in three poles, and rotation of the stator coils 11 a and 11 b to the pointer 9. Gears 11d and 11e (see FIG. 3) are provided.

  As shown in FIG. 3, the gear 11 e rotates integrally with the pointer 9. A stopper pin 11f as a driven member that interlocks with the pointer 9 protrudes from the side surface of the gear 11e, and can be engaged with the stopper pin 11f on the movement locus of the stopper pin 11f as the gear 11d rotates. A stopper 11g is fixed. The stepper motor 11 rotates the pointer 9 in a direction in which the indicated value increases by rotating in the forward direction, and rotates the pointer 9 in a direction in which the indicated value decreases by rotating in the reverse direction. Then, when the stopper 11g comes into contact with the stopper pin 11f, the pointer 9 stops at the origin where the zero indicating value is indicated.

  Next, the electrical configuration of the tachometer 1 of the present embodiment will be described with reference to the block diagram of FIG. FIG. 4 is a block diagram showing an electrical configuration of a vehicle combination meter (not shown) including the tachometer 1 shown in FIG. Reference numeral 31 in FIG. 4 is a meter ECU (electronic control unit) that controls the operation of the combination meter. The meter ECU 31 includes a stepper motor 11 for the tachometer 1, a stepper motor for a speedometer and a fuel gauge, and a microcomputer to which these stepper motors 11 are connected (corresponding to the controller in the claims, hereinafter referred to as "microcomputer" Abbreviated to ".) 21.

  The microcomputer 21 includes a CPU 21a, a RAM 21b used as a work area used for processing of the CPU 21a, and a ROM 21c that stores a control program executed by the CPU 21a. The microcomputer 21 is supplied with stabilized power from a power source 23 connected to a battery B of a vehicle (not shown) regardless of whether the ignition switch IGN of the vehicle is on or off. The microcomputer 21 has a function of digitally converting and monitoring the voltage from the battery B by a built-in A / D converter (not shown).

  Further, an interface (I / F) 25 is connected to the microcomputer 21 in order to detect the on / off state of the ignition switch IGN. The microcomputer 21 that has detected the on / off state of the ignition switch IGN using the interface 25 controls the operation of the control target such as the stepper motor 11 with the content corresponding to the position of the ignition switch IGN. The microcomputer 21 having such a configuration performs the driving process of the hands 9 according to the control program stored in the built-in ROM 21c.

  A network LAN is connected to the microcomputer 21 described above via an interface 27. The network LAN is connected to an air conditioner ECU 33 and other ECUs (not shown) in the vehicle. The air conditioner ECU 33 controls the operation of the auxiliary machine 41 such as a fan and a throttle valve used for adjusting the air volume and temperature of the air conditioner that uses the battery B as a power source, and a blower duct switching valve for switching the blower mode. Equivalent to the auxiliary machine controller in the middle). Similar to the microcomputer 21 of the meter ECU 31, the microcomputer 43 has a CPU, a RAM, and a ROM.

  Further, an interface (I / F) 45 is connected to the microcomputer 43 of the air conditioner ECU 33 in order to detect the switch state of the ignition switch IGN. The microcomputer 43 that has detected the switch state of the ignition switch IGN using the interface 45 controls the operation of the auxiliary machine 41 with the content corresponding to the position of the ignition switch IGN. Further, a network LAN is connected to the microcomputer 43 via an interface 47. The microcomputer 43 having such a configuration performs an operation process of the auxiliary machine 41 in accordance with a control program stored in a built-in ROM (not shown).

  The above-described microcomputer 43 of the air conditioner ECU 33 operates regardless of whether the ignition switch IGN is turned on or off in response to the supply of power from the stabilized power supply from the power supply 49 connected to the battery B. Further, the microcomputer 43 has a function of digitally converting and monitoring the voltage from the battery B by a built-in A / D converter (not shown). When the voltage of the battery B to be monitored falls below the reset voltage, the microcomputer 43 resets the circuit and stops the operation control of the auxiliary machine 41. Thereafter, when the voltage of the battery B, which has fallen below the reset voltage, returns to the reset release voltage or higher, the microcomputer 43 releases the circuit reset and is initialized, and resumes the operation control of the auxiliary machine 41.

  Next, an outline of the pointer movement control process that the microcomputer 21 causes the CPU 21a to execute according to the control program stored in the built-in ROM 21c will be described with reference to the flowcharts of FIGS.

  First, as shown in FIG. 5, the microcomputer 21 is accompanied by the fact that the voltage of the battery B being monitored has returned to the reset release voltage or higher (including the case where the battery B is connected to the microcomputer 21) (step S1). ), Initialize itself (release the circuit reset) (step S3). Subsequently, the microcomputer 21 checks whether or not the voltage of the battery B being monitored has maintained a reference voltage higher than the reset release voltage over a predetermined period (step S5).

  When the voltage of the battery B has not maintained the reference voltage or higher for a predetermined period (NO in step S5), the voltage of the battery B is continuously monitored for a certain time on the assumption that the voltage of the battery B is lower than the reference voltage. (Step S7). Then, it is confirmed whether or not the voltage of the battery B being monitored has returned to the reference voltage or higher (step S9). If the voltage has returned to the reference voltage or higher (YES in step S9), the process returns to step S5. If the voltage has not returned to the reference voltage or higher (NO in step S9), the process shifts to the low power consumption mode (step S11).

  In step S5, when the voltage of the battery B is maintained above the reference voltage for a predetermined period (YES), excitation output to the stator coils 11a and 11b of the stepper motor 11 is started (step S13), and the pointer An initialization operation process for returning 9 to the origin is started (step S15). Subsequently, it is confirmed whether or not the pointer 9 has been returned to the origin (origin return end) (step S17).

  In step S15, the completion of the return to origin is confirmed by rotating the stepper motor 11 in the reverse direction by a predetermined angle sufficient to return to the origin regardless of the rotation position of the pointer 9. It can be executed depending on whether or not 9 is rotated toward the origin. If the pointer 9 has not been returned to the origin (NO in step S17), step S17 is repeated, and if the return has been completed (YES in step S17), whether or not the ignition switch IGN is on. Is confirmed (step S19).

  When the ignition switch IGN is not on (NO in step S19), the process shifts to the low power consumption mode (step S11). If the ignition switch IGN is on (YES in step S19), normal meter instruction operation processing is started (step S21).

  After shifting to the low power consumption mode in step S11, as shown in FIG. 6, whenever a certain period elapses (YES in step S23), it wakes up (step S25) and the voltage of battery B is reset. It is confirmed whether or not the voltage is lower (step S27). If the voltage is not lower than the reset voltage (NO in step S27), the process returns to step S11. If the voltage is lower than the reset voltage (YES in step S27), the circuit is reset (step S29), and a series of processes is performed. finish.

  In addition, after the meter instruction operation process is started in step S21, the pointer 9 is rotated to a position where an instruction value corresponding to the engine speed input from another ECU via the network LAN is instructed (step S31). . Then, every time a certain period elapses (YES in step S33), it is confirmed whether or not the voltage of the battery B is lower than the reset voltage (step S35). If the voltage is not lower than the reset voltage (NO in step S35), the process returns to step S21. If the voltage is lower than the reset voltage (YES in step S35), the circuit is reset (step S29), and a series of processes is performed. finish.

  In step S9, when the voltage of the battery B being monitored has not returned to the reference voltage or higher (NO), or when the ignition switch IGN is not turned on in step S19 (NO), the low consumption in step S11 In the power mode, although not shown, the voltage of the battery B is periodically monitored. If the voltage is lower than the reset voltage, the circuit is reset and the process is terminated.

  Incidentally, the reset release voltage described above may be the same potential as the reset voltage, or may have a slightly higher potential than the reset voltage with hysteresis in order to avoid frequent resets and release.

  As is clear from the above description, in this embodiment, step S19 in the flowchart of FIG. 5 is a process corresponding to the switch state detecting means in the claims. Further, in the present embodiment, step S5 in FIG. 5 executed after circuit reset is performed in step S29 in the flowchart of FIG. 6 is a process corresponding to the continuation confirmation means in the claims.

  Furthermore, in this embodiment, step S7 and step S9 in FIG. 5 are processing corresponding to the holding means in the claims. Further, in the present embodiment, steps S13 to S17 in FIG. 5 executed after the voltage of the battery B is returned to the reference voltage or higher in step S9 in FIG. 5 correspond to post-hold execution means in the claims. It is processing to do.

  As described above, according to the tachometer 1 of the present embodiment, after the voltage of the battery B is lower than the reset voltage and the microcomputers 21 and 43 are reset, the voltage of the battery B returns to the reset release voltage or higher. Even if the microcomputers 21 and 43 are initialized (circuit reset is released), the initialization operation of the pointer 9 is not performed unless the voltage of the battery B thereafter maintains the reference voltage or higher for a predetermined period.

  Accordingly, the voltage of the battery B, which has been lowered until the ignition switch IGN is not turned on, falls below the reset voltage, returns to the reset release voltage or more, and the microcomputers 21 and 43 are initialized. Even if the voltage drops below the reset voltage again, the initialization operation of the pointer 9 once started by the initialization of the microcomputer 21 is not stopped halfway by the circuit reset of the microcomputer 21 thereafter.

  If the initialization operation of the pointer 9 once started is stopped in the middle, the magnet rotor 11c continues to rotate for a while due to inertia even if the excitation of the stator coils 11a and 11b is stopped. For example, as shown in FIG. 2, even if the initialization operation is stopped when the magnet rotor 11c is located at the rotational position where the N pole faces the right stator coil 11b, the stator coil 11b is in FIG. As shown, there may be a case where the S pole rotates to a position where it faces and stops.

  In this case, when the initialization operation is resumed by the restoration of the voltage of the battery B, the magnet rotor 11c that originally has to rotate in the direction of the arrow in FIG. 2 (counterclockwise direction) in order to restore the pointer 9 to the origin. However, since it does not match the excitation pattern of the stator coils 11a and 11b, it may rotate in the direction of the arrow (clockwise direction) in FIG.

  However, in the tachometer 1 of the present embodiment, the initialization operation does not stop halfway due to the circuit reset of the microcomputer 21, and therefore the magnet rotor 11c rotates in the direction opposite to the intended rotation direction during the initialization operation. There is nothing to do. For this reason, in the circuit reset of the microcomputer 21 and the initialization operation after the release, the pointer 9 can be normally rotated toward the origin.

  In the present embodiment, an example in which the initialization operation of the pointer 9 is performed under the control of the microcomputer 21 as the circuit reset of the microcomputers 21 and 43 is released regardless of the on / off state of the ignition switch IGN. Explained. However, in the present invention, for example, when the ignition switch IGN is turned on and the initialization operation of the pointer 9 is performed under the control of the microcomputer 21, the microcomputer 21 and 43 has a timing other than the circuit reset release. The present invention can also be applied to the case where the pointer 9 is initialized by the control 21.

  When the initialization operation of the pointer 9 is performed under the control of the microcomputer 21 as the ignition switch IGN is turned on, the rotation of the pointer 9 in the origin direction in the initialization operation is not performed by the stator coil that is not excited. The induced voltage generated at 11a and 11b may be monitored and the actual rotation amount of the pointer 9 may be grasped.

  In the present embodiment, the microcomputers 21 and 43 each independently monitor the voltage of the battery B. When the monitored voltage of the battery B falls below the reset voltage, the microcomputers 21 and 43 perform the circuit reset operation by themselves. did. However, when it is notified from the outside via the network LAN that the voltage of the battery B is lower than the reset voltage, the microcomputers 21 and 43 that have received the notification may perform a circuit reset operation.

  Furthermore, in the present embodiment, the tachometer 1 that displays the engine speed of the vehicle by the indicated position of the pointer 9 has been described as an example. However, the present invention is widely applicable to an initialization drive device for a vehicle meter that displays a measurement amount that changes from moment to moment according to the indicated position of the pointer, such as a speedometer that displays the traveling speed of the vehicle according to the indicated position of the pointer. Applicable.

  The present invention is particularly suitable for a vehicle meter in which an initialization operation is performed in a state where the ignition switch is not turned on.

1 Tachometer (vehicle meter)
3 Dial plate 5 Dial 7 Scale 9 Pointer 11 Stepper motor 11a Stator coil 11b Stator coil 11c Magnet rotor 11d Gear 11e Gear 11f Stopper pin (driven member)
11g stopper 21 microcomputer (controller, switch state detection means, continuation confirmation means, hold means, post-hold execution means)
21a CPU
21b RAM
21c ROM
23 Power supply 25 Interface 27 Interface 31 Meter ECU
33 Air conditioner ECU
41 Auxiliary machine 43 Microcomputer (Auxiliary machine controller)
45 Interface 47 Interface 49 Power supply B Battery IGN Ignition switch LAN Network

Claims (2)

An initialization operation for driving a pointer driven by a stepper motor of a meter powered by a vehicle battery in a reverse rotation direction to return to the origin by contacting a stopper of a driven member interlocked with the pointer is performed by the controller. In an initialization drive device for a vehicle meter that is controlled at a predetermined timing,
Switch state detecting means for detecting whether or not an ignition switch of the vehicle is in an on state;
In a state where the switch state detecting means does not detect the ON state of the ignition switch of the vehicle, the voltage of the battery that has fallen below a reset voltage that resets the controller returns to a reset release voltage that releases the reset of the controller or more. Accordingly, after the meter is restarted, continuation confirmation means for confirming whether the voltage of the battery has been maintained for a predetermined period of time at a reference voltage higher than the reset release voltage,
The continuation confirmation means confirms that the voltage of the battery has been maintained for a predetermined period after the restart of the meter in a state where the switch state detection means does not detect the ON state of the ignition switch of the vehicle. Until the holding means for suspending execution of the initialization operation accompanying the arrival of the predetermined timing,
An initializing drive device for a vehicle meter, comprising:   The vehicle is provided with an auxiliary machine controller used for controlling an auxiliary machine that can operate with the battery as a power source even when the switch state detecting means does not detect the ON state of the ignition switch of the vehicle. The auxiliary machine controller is reset when the voltage of the battery is lower than the reset voltage, and is reset when the voltage of the battery that is lower than the reset voltage returns to the reset voltage or higher. The initialization drive apparatus of the meter for vehicles of Claim 1.

Images