JP4695900B2 - Instrument device - Google Patents

Description

  The present invention relates to an instrument device for indicating a measurement amount by indicating a scale on a dial plate with a pointer fixed to a drive main body (for example, a PM type stepping motor) in which a step out occurs, and in particular, a step out reset of the drive unit. It relates to processing.

  In an instrument device equipped with this type of drive unit, the pointer fixed to the drive shaft end of the drive unit is rotated according to the input signal, and this pointer is compared with the dial plate on which numbers and scales are formed. It is configured to indicate the measurement amount by reading.

  The number of steps is determined by the structure of the PM type stepping motor which is the driving unit. In order to obtain a smooth rotation operation, it is necessary to increase the number of steps or to perform so-called micro-step driving by a drive signal, and these include an allowable size of the stepping motor body and a drive circuit according to use conditions. It is selected by cost. Further, the stepping motor, which performs pulse signal control in accordance with the digitization of the processing circuit by the microcomputer, is also attracting attention as an instrument movement of the instrument device, and is disclosed in, for example, Patent Documents 1 and 2. These instrument devices can be used for automobile speedometers and engine tachometers, as well as fuel meters and thermometers, and various proposals have been made for practical use.

  The stepping motor obtains a change amount of the input signal per predetermined cycle and is driven by this change amount. For example, when the ignition switch of the vehicle is turned on or when the battery power is turned on (when the battery power is connected). Initialize the position of the magnet rotor when the power is turned on or when the power is turned on again, such as when engine cranking occurs (when a voltage drop occurs at the start of the cell starter and the microcomputer stops operating) The starting point initialization process for forcibly returning to the zero position is generally performed, and step driving is performed from the starting point position of the pointer on the dial according to the measurement amount. Due to its structure, the stepping motor has a plurality of stable positions with respect to a predetermined electrical input angle (hereinafter referred to as an electrical angle) of the drive signal, and the stable position rotates by an electrical angle of 2π of the drive signal. Exist at an angular pitch. That is, when the pointer is fixed to the magnet rotor output shaft of the stepping motor, the electrical angle at that time is the same no matter where the multiple stable positions are indicated, and the mechanical rotor is mechanically driven by external vibration to the instrument device. When a rotational force that does not depend on the drive signal is generated due to the influence, there is a possibility that deviation is caused by an integer multiple of an angle pitch corresponding to an electrical angle of 2π from an angular position that is originally driven and controlled by driving from the starting point. Yes, once such an angle deviation (hereinafter referred to as step-out) of the angle pitch that rotates at an electrical angle of 2π occurs, the initial point initialization (electrical angle and mechanical deflection angle (apparently apparent) This is a process to return the magnet rotor equipped with the pointer to the starting position in order to match the deflection angle), and hereinafter referred to as a step-out reset process). It does not indicate the correct angular position, and always indicates an angle that includes a step-out error. Since such step-out occurs at an angular pitch at which the stable position exists, this angular pitch will be described below as “one step-out angle”.

In such a stepping motor type instrument device, it is generally easiest to initialize the starting point at the time of power-on or power-on so as to minimize the indication error due to such step-out. For example, as proposed in Patent Document 3, when the power is turned on, the pointer is stopped at the position where the stopper is formed by rotating an angle corresponding to the maximum graduation angle of the instrument in the starting (zero) direction. It is the structure to make. In addition to the PM-type stepping motor described above, the drive main body where the step-out occurs includes a rotor magnet having a rotating shaft, a housing for housing the rotor magnet and supporting the rotating shaft, and a winding around the housing. There is a movable magnet type instrument provided with a pair of coils, and such a movable magnet type instrument is disclosed in Patent Document 4, for example.
JP-A 61-129575 Japanese Patent Laid-Open No. 1-222312 JP-A-6-38593 JP 2004-125445 A

  In an instrument device using such a stepping motor, a step-out reset process is performed when the ignition switch is turned on, when the battery power is turned on, when the engine is cranked, or when the power is turned on or the power is turned on again. However, the step-out reset processing in all of these cases is to return the pointer to the starting position by applying a reset signal for an angle corresponding to the maximum graduation angle of the dial to the stepping motor. When the battery power is turned on, it is assumed that the instrument device has been attached to or detached from the car, or the car will be left for a long time (even when the ignition switch is turned on) Because it is easy to be affected mechanically by the external vibration to the instrument device and the possibility that the pointer is swung at a wide angle increases, the reset signal for the angle corresponding to more than the maximum scale angle of the dial is stepping motor However, cranking is a phenomenon that occurs after the ignition switch is turned on, and from when the ignition switch is turned on to when cranking occurs. The possibility that the pointer will operate at a wide angle is very low, and it varies depending on the object to be measured. As long as to take into account the deflection of the guidelines.

  However, in all cases, if the step-out reset process is performed at an angle corresponding to the maximum graduation angle or more, it takes time to execute the step-out reset process especially when cranking occurs, resulting in a normal It takes time to return to the normal display state in which the measurement amount is instructed, and there is a problem that the movement becomes uncomfortable.

  The present invention has been made in view of this problem. By detecting the driving of an electric load such as cranking, the step-out reset process after the occurrence of cranking is changed to the step-out reset process at the time of power-on. Therefore, it is an object of the present invention to provide an instrument device that is restored to a normal display state at an early stage and does not feel uncomfortable.

The present invention, like the instrument apparatus as set forth in claim 1, a meter device for indicating the measured quantity by rotating from the origin position on the dial the pointer by a drive body which step-out occurs, battery power a supply power through the ignition switch connected to the power supply line with power is supplied via the connected fuse to a power supply line, a first detection function for detecting the presence or absence of the fuse, the ignition At least a second detection function for detecting the presence / absence of an input of the switch, and based on the detection results of the first detection function and the second detection function, the ignition switch the first state is whether the input is in the state of there, or the fuse and conditions der both of there of the ignition switch input It is determined whether the second condition, in the first state and said second state, a reset process control means comprising at different step out reset processing for returning the pointer to the start position And the reset process control means is different from the step-out reset process so that the number n of the step-out reset process in the second state is smaller than the number m of the step-out reset process in the first state. It will be made .

Further, the present invention according to claim 2 is an instrument device for indicating a measurement amount by rotating a pointer from a starting position on a dial plate by a drive body in which step-out occurs, and is connected to a power line of a battery power source. A first detection function for detecting the presence / absence of the fuse by supplying power through an ignition fuse and supplying power via an ignition switch connected to the power supply line; and presence / absence of input of the ignition switch A state in which the ignition switch is input without the fuse based on detection results of the first detection function and the second detection function. Whether it is the first state or the second state where both the fuse and the ignition switch input are present Reset processing control means comprising different step-out reset processing conditions for returning the pointer to the starting position between the first state and the second state. In the step-out reset processing, the step-out reset processing is different from the step-out reset processing so that a wide-angle range in which the pointer is operated in the second state is narrower than a wide-angle range in which the pointer is operated in the first state. It will be made .

  The present invention relates to an instrument device that indicates a measurement amount by rotating a pointer from a starting position on a dial plate by a drive main body that causes a step-out, and can reliably detect the occurrence of cranking. In the tone reset process, it is possible to provide an instrument device that does not give a sense of incongruity in displaying the measurement amount by shortening the time.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A vehicle speedometer will be described as an example of an instrument device.

  FIG. 1 is a block diagram showing the basic configuration of a speedometer. The speedometer is mainly composed of a control means 1, a drive circuit 2, and a meter body 3.

  The control means 1 consists of a microcomputer and has a ROM, a RAM, a CPU, an input / output interface, and the like. The control means 1 is supplied with power via a power supply line 4a of the battery power supply 4 and a battery fuse (hereinafter referred to as fuse) 5, and via a power supply line 4a and an ignition switch (hereinafter referred to as IGN switch) 6. Power supply system. In the control means 1, the power supply voltage (+ 13V) from the battery power supply 4 is converted into a drive voltage (+ 5V) for operating the microcomputer by a predetermined circuit (not shown) in the control means 1.

  Further, the control means 1 includes a vehicle speed pulse from each input port for confirming the presence / absence of the fuse 5 (whether it is removed) and the presence / absence of the input of the IGN switch 6 (ON / OFF), and a rotation sensor (not shown). Are input ports. When a vehicle speed pulse signal proportional to the travel speed, which is a measured quantity, is input from the input port, the control means 1 detects the rise or fall of the input signal and counts it at a predetermined gate time (gate time method). Or by counting another high-frequency clock signal with the input signal (period measurement method), calculating the ever-changing running speed as digital data, and outputting this digital data to the drive circuit 2, 3 pointers are operated, and processing operations to be described later are executed.

  The drive circuit 2 converts the digital data obtained by the control means 1 into an instruction angle signal (voltage value) for operating the instrument body 3. The drive circuit 2 stores an instruction angle signal corresponding to the digital data obtained by the control means 1, and this instruction angle signal corresponds to an instruction area from MIN to MAX of the digital data corresponding to the measurement amount. The number of data is determined according to the resolution. For example, it is composed of indication angle data in units of 0.5 degrees with respect to an indication angle of 0 degrees (MIN) to 360 degrees (MAX). The drive circuit 2 generates a command angle signal from a two-phase signal that is arbitrarily set according to the number of teeth and the pitch of the tooth yoke that drives the stepping motor that is the drive unit of the meter body 3, and generates a command angle signal of 360 degrees. The command angle signal corresponding to the digital data of all corresponding drive waveforms is stored. The indicated angle signal is determined by the comb pitch of the comb yoke of the stepping motor, and is composed of a waveform signal for smoothly operating the pointer by so-called micro-step driving of the mechanical step operation. Actually, it consists of SIN and COS waveforms composed of digital fine staircase waveforms.

  Although the above-mentioned indication angle signal may have 360 degree data, it stores the indication angle signal corresponding to the digital data for 60 degrees that is 1/6 of 360 degrees, and this digital data is stored in each angle region. It is possible to reduce the memory capacity by using a method of expanding and using.

  For example, a PM type stepping motor is used as the driving main body in which the instrument main body 3 is stepped out. As shown in FIGS. 2 and 3, a dial 3b for giving an instrument instruction is fixed to a PM-type stepping motor main body (drive unit) 3a as shown in FIGS. 2 and 3, and the scale 3b1 and the number 3b2 of the dial 3b are used as pointers. The measured amount is displayed by instructing by 3c. The stepping motor main body 3a supports the rotating shaft 3a2 of the magnet rotor 3a1 to which the pointer 3c is fixed by the upper and lower bearings of the motor, and the upper and lower phase comb teeth yokes 3a3 and 3a4 are wound around the resin bobbin 3a5. Excitation is performed by each of the excitation coils 3a6, and the magnet rotor 3a1 is sequentially rotated to the excitation position in its magnetic balance. Reference numeral 3a7 denotes a plate made of a nonmagnetic material such as aluminum, and the plate 3a7 prevents magnetic interference between the upper and lower phases.

  In addition, a starting point P of the pointer 3c is defined on the dial 3b of the meter body 3. Specifically, a protrusion 3d1 is provided on a part of the magnet rotor 3a1 of the stepping motor main body 3a, and a contact portion 3d2 that contacts the protrusion is provided on the plate 3a7, so that the vehicle speed on the dial 3b as shown in FIG. A position of 0 km / h is set as a starting position P of the pointer 3c, and a pointer rotating area 3e1 is configured to rotate from the starting position P to a predetermined angle (for example, 315 degrees). It becomes area 3e2.

  Next, the step-out reset process by the control means 1 will be described in detail with reference to FIGS.

  First, the control means 1 determines whether or not engine cranking has occurred under the conditions described later, and is a return operation after the cranking has occurred (step S1). In other words, as shown in FIG. 5, the control unit 1 performs the cranking based on the connection state (1) of the battery power source 4, the state (2) of the IGN switch 6, and the state (3) of the fuse 5. The control means 1 determines whether or not the step-out reset processing (pointer position initialization processing) after the occurrence has occurred, but the control means 1 uses the start operation by the cell starter when the engine cranking occurs. Is unstable and drops to a voltage at which the microcomputer cannot operate, but after the engine is started, the determination process in step S1 is executed after the drive voltage is stably supplied to the microcomputer. .

  Specifically, the control means 1 is configured such that the battery power state is “ON” when the battery power is connected (hereinafter referred to as (1) state), and the state of the IGN switch 6 (hereinafter referred to as (2) state) is “OFF”. When the fuse 5 state (hereinafter referred to as the state (3)) is “ON”, the maximum deflection angle of the pointer 3c (the rotation corresponding to the pointer turning region 3e1) The number of steps out of reset (corresponding to the step angle) is set to m times (for example, 7 times) corresponding to the moving angle). Further, the control means 1 indicates that the pointer is in the second determination condition that the state of (1) is “ON”, the state of (2) is “ON”, and the state of (3) is “Yes” (ON). The number is set to n times (for example, 3 times) smaller than the number of step-out reset times m times corresponding to the maximum deflection angle of 3c (m> n). In addition, the control means performs the third determination condition when the state of (1) is “OFF”, the state of (2) is “ON”, and the state of (3) is “none” (OFF). Similarly to the determination condition 1, the step-out reset count corresponding to the maximum deflection angle of the pointer 3c (the rotation angle corresponding to the pointer rotation area 3e1) is set to m times. In the following description, it is assumed that the maximum deflection angle of the pointer 3c is an integral multiple of the single step-out angle described in the conventional example. Further, when assuming a speedometer as in the embodiment of the present invention in the number of steps out of reset, since the pointer 3c is less likely to swing after the IGN switch 6 is turned on, the number of steps out of reset n is set to be small. For example, in the case of a tachometer that displays the engine speed, the deflection angle of the pointer increases after the IGN switch 6 is turned on. It is desirable to change appropriately in various instrument devices.

  The first determination condition is based on the assumption that the engine of the vehicle is stopped and left for a long time (when the IGN switch 6 is turned off and the IGN switch 6 is turned on again). It is assumed that a rotational force that does not depend on the drive signal is likely to occur due to a mechanical influence on the magnet rotor 3a1 due to external vibration. Further, the second determination condition assumes that the vehicle engine is started by a cell starter, a voltage drop of the drive voltage occurs at that time, and then the drive voltage is restored and immediately performs normal operation. It is assumed that a rotational force that does not depend on the drive signal is unlikely to occur due to a mechanical influence on the magnet rotor 3a1. The third determination condition assumes that the engine is started by the IGN switch 6 without the fuse 5, and the rotation does not depend on the drive signal due to the mechanical influence on the magnet rotor 3a1. It is assumed that force is likely to be generated.

  Next, when the control means 1 determines that cranking has not occurred, the control means 1 sets the number of step-out resets to m times corresponding to the maximum deflection angle of the pointer 3c (step S2), and sets the internal counter C to m times. A writing process (“C ← m”) is executed (step S3).

  Then, the control means 1 executes a process of returning to the pointer start position by one step-out angle (hereinafter referred to as one step-out reset process), and moves the pointer 3a (magnet rotor 3a1) in the direction of the start position P. (Step S4), the internal counter C is decremented by "-1" (Step S5), and then it is determined whether or not the internal counter C is "0" (Step S6). Until it becomes “0”, the processing from step S4 to step S6 is repeatedly executed, and when the internal counter C becomes “0” (“C = 0”), the normal pointer operation (speed display operation) ) Is executed (step S7).

  When it is determined in step S1 that the cranking has occurred according to the above-described determination condition, the control unit 1 sets the number of step-out resets n times less than m times corresponding to the maximum deflection angle of the pointer 3c. Is set (step S8), and a process of writing n times in the internal counter C is executed in step S3 ("C ← n"). Then, similarly to the above-described process, the control unit 1 executes the step-out reset process and repeatedly executes the processes from step S4 to step S6 until the internal counter C becomes “0”. is there.

  The instrument main body 3 relates to an instrument that indicates a measurement amount by rotating a pointer 3c fixed to the rotation shaft 3a2 of the stepping motor main body 3a from a starting position P on the dial plate 3b. 4 having at least a first detection function for detecting the presence / absence of the battery fuse 6 connected to 4 and a second detection function for detecting the presence / absence of the input of the IGN switch 6, wherein the first detection function and the first detection function 2 based on the detection result of the detection function 2, whether the battery is disconnected from the battery power supply 4, whether the IGN switch 6 is turned on (first state), or whether the engine It is determined whether or not the state of the return operation from the state where the ranking has occurred (second state), and the number of step-out reset processings is made different between the former state and the latter state.

  Specifically, the control means 1 is set so that the step-out reset processing number n in the latter state is smaller than the step-out reset processing number m in the former state, and is caused by external vibration to the instrument body 3. The step-out reset frequency is varied by determining whether or not a rotational force that does not depend on the drive signal is likely to occur due to a mechanical influence on the magnet rotor 3a1.

  That is, the control means 1 determines whether the possibility that a rotational force independent of the drive signal is applied to the magnet rotor 3a1 is large or small by the first detection function and the second detection function. The first detection function is a case where “the possibility is high”, the number of one-step reset is set to m times corresponding to the maximum deflection angle of the pointer 3c, and the second detection function is “possibility” The step-out reset count is set to n times less than m times corresponding to the maximum deflection angle of the pointer 3c. Therefore, it is possible to reliably detect that cranking has occurred even after the microcomputer has returned after cranking has occurred (after the microcomputer's drive voltage has stabilized), and in step-out reset processing after cranking has occurred. Since the return time to the normal display state can be shortened, it is possible to solve the problem that the measurement amount instruction is delayed after cranking occurs.

  In the embodiment of the present invention, the step-out reset process at the time of cranking is performed by switching the number of times that is an integral multiple of one step-out angle. The wide angle range is set to the maximum deflection angle of the pointer 3c to operate the pointer 3c when it is removed or the IGN switch 6 is turned on. If the wide-angle range is set to be narrower than the wide-angle range in the above-described state in order to operate the pointer 3c in this case, it is not always necessary to switch the number of times that is an integral multiple of one step-out angle.

It is a block diagram which shows the structure of the speedometer in embodiment of this invention. It is principal part sectional drawing of the speedometer of embodiment same as the above. It is a top view of the speedometer of embodiment same as the above. It is a figure explaining the step-out reset process of embodiment same as the above. It is a figure explaining the step-out reset process of embodiment same as the above.

Explanation of symbols

A Speedometer (instrument device)
P starting position 1 control means (reset processing control means)
2 Drive circuit 3 Instrument body 3a Stepping motor body (drive body)
3a1 Magnet rotor 3a2 Rotating shaft 3b Dial 3b1 Scale 3c Pointer 3d1 Projection 3d2 Abutting part 3e1 Pointer rotation area 3e2 Pointer non-rotation area 4 Battery power supply 5 Battery fuse 6 Ignition switch

Claims (2)

An instrument device that indicates a measurement amount by rotating a pointer from a starting position on a dial plate by a drive main body in which step-out occurs.
A first detection function for supplying power through a fuse connected to a power supply line of a battery power supply and supplying power through an ignition switch connected to the power supply line to detect the presence or absence of the fuse; At least a second detection function for detecting the presence / absence of an input to the ignition switch, and based on detection results of the first detection function and the second detection function, the ignition is performed without the fuse. it is determined whether the second condition whether a first state input of the switch is in the state of there, or both of said fuse and the ignition switch input is the state of presence, the first in one state and said second state, a reset process control means comprising at different step out reset processing for returning the pointer to the start position For example, the reset process control means varies the first said out-reset processing frequency m the out-reset process, as also reduced the number n of the step-out reset process in the second state than in the state of meter apparatus characterized by comprising by. An instrument device that indicates a measurement amount by rotating a pointer from a starting position on a dial plate by a drive main body in which step-out occurs.
A first detection function for supplying power through a fuse connected to a power supply line of a battery power supply and supplying power through an ignition switch connected to the power supply line to detect the presence or absence of the fuse; At least a second detection function for detecting the presence / absence of an input to the ignition switch, and based on detection results of the first detection function and the second detection function, the ignition is performed without the fuse. It is determined whether or not the first state is a state where a switch input is present, or whether the second state is a state where both the fuse and the ignition switch input are present, Reset process control means for differentiating the step-out reset process for returning the pointer to the starting position between the first state and the second state; In the step-out reset process, the reset process control means is configured so that a wide angle range in which the pointer is operated in the second state is narrower than a wide angle range in which the pointer is operated in the first state. An instrument device characterized by different step-out reset processing .

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