JP2007093525A - Pointer-type measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pointer-type measuring instrument capable of carrying out an initialization operation, while keeping performance effects of a pointer at start-up. <P>SOLUTION: The pointer 50 is rotated normally from a zero scale position Pa to a maximum scale side stopper position Pc exceeding the maximum scale position Pb; when an ignition switch is turned on thereafter, an performance operation is carried out thereafter to rotate the pointer 50 from the maximum scale side stopper position Pc to the zero scale position Pa, and the initialization operation is executed to store a count value C in the position into a storage part 91, when the maximum scale side stopper position Pc is reached. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pointer-type instrument that rotates a pointer using a step motor.

Conventionally, in a pointer-type instrument using a step motor, an origin position detection operation, so-called ZPD (zero point detection), is performed at the time of starting the instrument in order to prevent deviation of the indication of the pointer due to a step-out. This is because the pointer position when the pointer is rotated to the zero scale side and reaches the zero scale side stopper provided at a position lower than the zero scale position is set as the reference position (see, for example, Patent Document 1). ).
JP 2003-125599 A

  On the other hand, there is an instrument aiming at an effect on the driver by performing an effect operation in which the pointer is normally rotated to the maximum graduation position at the start and then reversed to the zero graduation position. In an instrument having such an effect operation function, the origin position detection operation and the effect operation are performed at the time of activation. Therefore, after the pointer is once reversed to the zero scale side stopper, the maximum scale side Rotate forward toward, and finally reverse toward zero graduation position.

  However, originally, since the pointer reverse operation was added to the series of pointer operations in which the pointer is rotated forward after being rotated forward, it gives the driver an unnatural impression of the pointer operation, resulting in a production effect. There is a risk of damage.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a pointer-type instrument capable of performing an initialization operation while maintaining the effect of the pointer at the time of activation.

  In order to achieve the above object, according to the first aspect of the present invention, a pointer that swings in accordance with the rotation of the step motor, a maximum scale side stopper that stops the pointer when the pointer swings toward the maximum scale position, and a start signal Control means for driving the step motor to reciprocate the pointer in the range from the zero scale position to the maximum scale side stopper, and when the pointer reaches the maximum scale side stopper, the pointer position initial setting processing is performed. It is characterized by having prepared.

  According to the invention of claim 1, the maximum scale side stopper is provided on the maximum scale position side, and the initial setting process is performed on condition that the pointer has reached the maximum scale side stopper. In this way, since the initialization operation can be included in the production operation performed at the time of starting the instrument, the initialization operation is performed while giving the impression of a natural pointer operation to the driver and maintaining the production effect. It can be carried out.

  The invention according to claim 2 is characterized in that the maximum scale side stopper is installed at an angular position that is separated from the maximum scale position by a predetermined angle.

  In general, a vehicle instrument generally indicates a value obtained by adding a predetermined value to an actual measurement value. Therefore, when the actual measurement value is a value corresponding to the maximum scale, the pointer is positioned more than the maximum scale position. Rotate to an angular position separated by a predetermined angle. In this way, the rotation range of the pointer extends to the angular position beyond the maximum scale position, so installing the maximum scale stopper at a position corresponding to the maximum scale position places a burden on the step motor. It is desirable to install the maximum scale side stopper at an angular position that is farther from the maximum scale position.

  In the invention of claim 3, the control means has position setting means for setting the rotational angle position of the pointer, and when the pointer hits the maximum scale side stopper as an initial setting process, the control means has a predetermined value corresponding to the maximum scale side stopper position. The rotation angle position information is set in the position setting means.

  In this configuration, rotation angle position information when the pointer reaches the maximum scale side stopper position is set in the position setting means. Since the angular position of each scale position and the maximum scale side stopper position have a predetermined relationship, the angular position information of each angular position can be acquired based on the determined angular position information of the maximum scale side stopper position. it can.

  The invention according to claim 4 is characterized in that the activation signal is a signal indicating the start of use of the user.

  Thereby, an initial setting process can be performed with the production | presentation operation | movement performed every time a user starts utilization. Examples of the activation signal include a signal indicating that the ignition switch is turned on, a detection signal from a seat sensor disposed on the seat, or a detection signal from a door courtesy lamp switch.

  The invention according to claim 5 is characterized in that when the start signal is received, the control means performs an initial setting process, and thereafter performs a pointer display process of waving a pointer in accordance with a value to be displayed. In this way, since the initial setting process is performed prior to the pointer display process every time it is started, accurate pointer display can always be performed.

<First Embodiment>
An embodiment in which a pointer-type instrument according to the present invention is applied to a two-wheeled vehicle speedometer will be described with reference to FIGS. In the figure, the direction of the arrow X is the upward direction, the direction of the arrow Ta is the clockwise direction, and the direction of the arrow Tb is the counterclockwise direction. The speedometer according to the present embodiment rotates the pointer 50 on the scale unit 11 using the step motor M as a drive source, and the current value is obtained by rotating the pointer 50 to the scale position corresponding to the detected vehicle speed. It indicates the vehicle speed.

  A scale portion 11 in which a plurality of scales are arranged in an arc shape is formed on the dial face of the dial 10. Of the scales constituting the scale part 11, one on one end is a zero scale 11a indicating a vehicle speed of 0 km / m, and the other one is a maximum scale 11b indicating a vehicle speed of 180 km / h. Note that the dial 10 is provided on the opening 21 a formed in the bottom wall 21 of the annular facing plate 20 from the back side.

  As shown in FIG. 2, the indicating instrument includes a rotary inner unit 30, a wiring board 40, and a pointer 50. The rotating inner unit 30 includes an inner unit main body 30a and a pointer shaft 30b. The internal machine main body 30a incorporates a two-phase step motor M, a reduction gear train G, and a stopper mechanism ST in a casing 30c assembled on the back side of the wiring board 40, and is disposed at a position corresponding to the dial 10. ing. The pointer shaft 30b is rotatably supported on both upper and lower walls of the casing 30c, and is coaxially supported with an output stage gear 34 (described later) of a reduction gear train G that transmits the rotation of the step motor M at a reduced speed. A cage (see FIG. 3 or FIG. 4) extends through the upper wall of the casing 30 c, the wiring board 40 and the through hole 12 of the dial 10 and onto the dial 10.

  Further, the fixed end 51 of the pointer 50 is pivotally supported by the pointer shaft 30b and rotates along the surface of the dial 10, and corresponds to the position corresponding to the zero scale 11a (zero scale position Pa) and the maximum scale. It rotates between the maximum scale-side stopper position Pc that exceeds the position (maximum scale position Pb) and is an angular position that is a predetermined angle away from that position. Here, the angle range from the zero scale position Pa to the maximum scale position P is θ1, and the angle range from the zero scale position Pa to the maximum scale side stopper position Pc is θ2. The pointer 50 is stopped at the zero scale position Pa when the instrument is stopped.

  As shown in FIGS. 3 and 4, the step motor M includes a stator Ms and a magnet rotor Mr. The stator Ms is supported in parallel with the dial 10 in the casing 30c, and the stator Ms includes a yoke 31 and field windings 32 and 33. The yoke 31 includes pole-shaped magnetic poles 31a and 31b and several other magnetic poles. A field winding 32 is wound around the magnetic pole 31a, and a field winding 33 is wound around the magnetic pole 31b. ing.

  Further, the magnet rotor Mr is coaxially supported on a rotating shaft 35a, which will be described later, so as to be located in the yoke 31 and form a magnetic circuit together with the yoke, and on the outer circumferential surface of the magnet rotor Mr, Along the circumferential direction, a large number of N poles and S poles are alternately magnetized. Here, as the magnet rotor Mr rotates, the magnetic poles 31a and 31b of the yoke 31 and the tip surfaces of the other magnetic poles of the yoke 31 face each other through a narrow gap with the N or S pole. However, the rotation of the magnet rotor Mr is made one by one for the number of magnetic poles of the magnet rotor. The rotating shaft 35a is supported on both the upper and lower walls of the casing 30c so as to be parallel to the pointer shaft 30b and to be rotatable.

  In the step motor M configured as described above, when a cosine wave drive voltage and a sine wave drive voltage having a phase of 90 degrees are applied to the corresponding field windings 32 and 33, each of the field windings 32 and 33 is applied. Cosine and sinusoidal magnetic fluxes are generated in the corresponding magnetic poles 31 a and 31 b by the current flowing in the magnetic field, and the magnet rotor Mr forms a magnetic circuit between the yoke 31 and rotates forward (reversely). This forward rotation (reverse rotation) corresponds to rotation in the clockwise direction Ta (counterclockwise direction Tb).

  The reduction gear train G includes the above-described output stage gear 34, input stage gear 35, and intermediate gears 36, 37. Each of the output stage gear 34, input stage gear 35, and intermediate gears 36, 37 includes a step motor M. The reduction gear train G is meshed so as to give a reduction ratio that reduces the rotational speed of the motor to a predetermined low speed.

  The stopper mechanism ST includes a strip-shaped ridge 38 and an L-shaped maximum scale side stopper 39. The ridge 38 is formed to protrude from the center of the surface of the output stage gear 34 directly below the pointer 50 so as to extend in the radial direction. The stopper 39 extends from the lower wall of the casing 30c in parallel to the pointer shaft 30b, and is L-shaped immediately below the longitudinal direction of the pointer 50 when the tip 39a is at the maximum scale side stopper position Pc. It extends toward the surface of the output stage gear 34. Here, the receiving side end surface 39 b of the tip end portion 39 a corresponds to the maximum scale side stopper position Pc of the pointer 50. Therefore, when the pointer 50 reaches the maximum scale side stopper position Pc by forward rotation of the step motor M, the locking end surface 38a of the ridge 38 is locked to the receiving side end surface 39b of the arm 39.

  As shown in FIG. 5, the electrical configuration of the present embodiment includes a step motor M, a switch unit 60, a vehicle speed sensor 70, a drive circuit unit 80, and a controller unit 90 (control means). Since the configuration of the step motor M is as described above, the description thereof is omitted.

  The switch unit 60 detects that the driver starts using the vehicle. For example, the switch unit 60 includes an ignition switch, and when the switch is turned on, the detection signal S (activation signal) is transmitted to the controller. Output to the unit 90. The vehicle speed sensor 70 detects the traveling speed of the vehicle, and outputs a detection signal Ss corresponding to the detected vehicle speed to the controller unit 90.

  The drive circuit unit 80 applies a cosine wave drive voltage and a sine wave drive voltage to the field windings 32 and 33 of the step motor M based on the control signal Sc from the controller unit 90, and rotates the step motor M forward or backward. The pointer is rotated by reversing the operation. Further, the induced voltage generated in the field windings 32 and 33 is detected, and the detected value D is output to the controller unit 90.

  The controller unit 90 transmits a control signal Sc for normal rotation or reverse rotation of the pointer 50 to a predetermined angular position (scale position) to the drive circuit 80. The control signal Sc calculates the deflection angle of the pointer when the zero scale position Pa is set as the reference position, and rotates the pointer 50 forward or backward in accordance with the angle difference between the current deflection angle and the target deflection angle. It is a signal for. Specifically, from the counter value C of the maximum scale side stopper position Pc set in the initial setting process described later, the counter value C of each angular position is calculated based on the angular position relationship with the maximum scale side stopper position Pc. Since the pulse signal sequence determined according to the difference between the counter value C of the current angular position (deflection angle) and the counter value C of the target angular position (deflection angle) is transmitted to the drive circuit unit 80. is there.

  In addition, a storage unit 91 (position information setting means) is provided inside the controller unit 90, and an area for storing the count value C (angle position information) of the maximum scale side stopper position Pc described above is provided. It is secured.

  The configuration of the present embodiment is as described above, and the operation will be described focusing on the processing of the controller unit 90. When the driver turns on an ignition switch provided in the vehicle, the detection signal S is received by the controller unit 90, and the controller unit 90 executes a rendering operation / initial setting process as shown in FIG. S10) After that, a pointer display process for instructing the vehicle speed is executed (step S20). Each process is terminated when the ignition switch is turned off, and the processes are executed in the above order each time the ignition switch is turned on.

  In the effect operation / initial setting process shown in FIG. 7, first, a control signal Sc is set so that the deflection angle of the pointer 50 is θ1, and the pointer 50 is rotated forward from the zero scale position Pa to the maximum scale position Pb (step S110, Arrow (1) in FIG. Subsequently, a control signal Sc for normal rotation of the pointer 50 is transmitted, and it is determined whether or not the pointer 50 has reached the maximum scale side stopper position Pc (steps S120 and S130). Specifically, the determination of reaching the maximum scale side stopper position Pc is performed as follows. That is, it is determined that the maximum scale side stopper position Pc has been reached on condition that the detected value D of the induced voltage output from the drive circuit 80 is lower than a predetermined threshold value. This is because when the pointer 50 continues to rotate forward without reaching the maximum scale side stopper position Pc, a predetermined induced voltage is generated in the field windings 32 and 33, while the pointer 50 has the maximum scale side stopper. When the position Pc is reached and no forward rotation is possible, the induced voltage on the field windings 32 and 33 becomes approximately 0V. Thus, it is detected that the maximum scale side stopper position Pc has been reached on condition that the induced voltage is lower than the threshold value. For example, the threshold value is set to a value that is half of the induced voltage that is generated during forward rotation of the pointer.

  In step S120, the frequency of the pulse signal train transmitted to the drive circuit 80 may be made lower than the frequency in step S110 to reduce the rotation speed of the pointer 50. Thereby, the burden (impact) when the pointer 50 abuts on the maximum scale side stopper position Pc can be reduced.

  Therefore, in this process, the control signal Sc is transmitted until the pointer 50 reaches the maximum scale side stopper position Pc (until the deflection angle θ2 is reached) (No in Step S120 and Step S130), and the maximum scale side stopper position Pc. When reaching, transmission of the control signal Sc is stopped (Yes in step S130, arrow (2) in FIG. 8A). Then, a count value C is set at the stopper position Pc, and this is stored in the storage unit 91 (step S140, corresponding to “initial setting process” in the claims).

  Thereafter, a control signal Sc for setting the deflection angle to 0 ° is transmitted to reverse the pointer 50 from the maximum scale side stopper position Pc to the zero scale position Pa (step S150, arrow (3) in FIG. 8A). ).

  When the above process is completed, a pointer display process for transmitting a control signal Sc to the drive circuit unit 80 in order to rotate the pointer 50 forward or reverse to the corresponding scale position based on the detection signal Ss output from the vehicle speed sensor 70 is performed. Execute (Step S20).

  Therefore, in this embodiment, when the ignition switch is turned on, the pointer 50 rotates forward from the zero scale position Pa to the maximum scale side stopper position Pc beyond the maximum scale position Pb, and then from the maximum scale side stopper position Pc. An initialization operation is performed together with an effect operation of reversing to the zero scale position Pa (see FIG. 8B), and then an instruction display for instructing the vehicle speed by rotating the pointer to a swing angle corresponding to the vehicle speed Operation is performed.

  According to this embodiment, the maximum scale side stopper 39 is provided at an angular position larger than the maximum scale position Pb, and the initial setting process is performed when the pointer 50 reaches the maximum scale side stopper position Pc. In this way, since the initialization operation can be included in the production operation performed at the time of starting the instrument, the initialization operation is performed while giving the impression of a natural pointer operation to the driver and maintaining the production effect. It can be carried out.

  Usually, the instrument generally indicates a value obtained by adding a predetermined value to an actual measurement value. Therefore, when the actual measurement value is a value corresponding to the maximum scale, the pointer 50 is set to a predetermined value from the maximum scale position. Rotate to an angular position that is away from the angle. As described above, since the rotation range of the pointer 50 extends to an angular position exceeding the maximum scale position Pb, if the maximum scale side stopper 39 is installed at a position corresponding to the maximum scale position Pb, a load is applied to the step motor M. As in this embodiment, it is desirable to install the maximum scale side stopper 30 at an angular position farther from the maximum scale position Pb.

  Further, in the present embodiment, the counter value C when the pointer 50 reaches the maximum scale side stopper position Pc is stored in the storage unit 91. Since the angular position of each scale position and the maximum scale side stopper position Pc have a predetermined relationship, the counter value C of each angular position is determined based on the stored counter value C of the maximum scale side stopper position Pc. be able to.

  In addition, since the above initial setting process is performed by turning on the ignition switch by the driver, the initial setting process can be performed together with the rendering operation performed each time the use is started. In addition to the ignition switch, the effect operation / initial setting process may be executed based on a detection signal from a sheet sensor arranged on the seat. Moreover, when applying the meter of this embodiment to a four-wheeled vehicle, you may make it perform the said process based on the detection signal (door opening signal) of a door courtesy lamp switch, for example.

  In the present embodiment, since the initial setting process is performed and the pointer display process is performed thereafter, the counter value C is set (initial setting process) prior to the pointer display process every time it is started. , It is possible to always display an accurate pointer.

  In the present embodiment, the stopper 39 is installed at an angular position that is separated from the maximum scale position Pb by a predetermined angle, and the initial setting process is performed on condition that the pointer 50 has reached the maximum scale side stopper position Pc. However, the stopper 39 may be installed at the same position as the maximum scale position Pb, and the initial setting process may be performed on condition that the pointer 50 has reached the maximum scale position Pb.

It is a front view which shows one Embodiment of the speedometer of this embodiment. It is a fragmentary sectional view in the AA line of a speedometer. It is a perspective view of a step motor and a stopper mechanism built in the rotating inner unit. It is a top view of a step motor. It is the conceptual diagram which showed the electrical structure of the speedometer. It is the flowchart which showed the processing content of the controller part. It is the flowchart which showed the contents of production operation / initial setting processing. (A) is the figure which showed the operation | movement of the needle | hook at the time of presentation operation and initial setting process. (B) is a time chart showing the time change of the deflection angle (angular position) of the pointer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Scale part 11a ... Zero scale 11b ... Maximum scale 30 ... Turning inner machine 30a ... Inner machine main body 30b ... Pointer shaft 38 ... Strip-shaped convex 39 ... Maximum scale side stopper 50 ... Pointer 60 ... Switch part 70 ... Vehicle speed sensor 80 ... Drive circuit unit 90 ... Controller unit 91 ... Storage unit S ... Detection signal Pa ... Zero scale position Pb ... Maximum scale position Pc ... Maximum scale side stopper position

Claims (5)

A guide that swings according to the rotation of the step motor,
A maximum scale side stopper for stopping the pointer when the pointer swings toward the maximum scale position;
When the start signal is received, the step motor is driven to reciprocate the pointer within the range from the zero scale position to the maximum scale side stopper, and when the pointer reaches the maximum scale side stopper, the pointer position is initialized. A pointer-type instrument comprising control means for performing processing.   The pointer-type instrument according to claim 1, wherein the maximum scale side stopper is installed at an angular position that is separated from the maximum scale position by a predetermined angle.   The control means includes position setting means for setting a rotation angle position of the pointer, and when the pointer hits the maximum scale side stopper as the initial setting process, a predetermined rotation corresponding to the maximum scale side stopper position is performed. The pointer type instrument according to claim 1 or 2, wherein angular position information is set in the position setting means.   The pointer-type meter according to any one of claims 1 to 3, wherein the activation signal is a signal indicating the start of use by a user.   5. The control unit according to claim 1, wherein the control unit performs the initial setting process upon receiving the activation signal, and then performs a pointer display process of waving the pointer in accordance with a value to be displayed. This is a pointer-type instrument described in Crab.

Images