JP2009202634A - Vehicle instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle instrument capable of preventing abnormal indication due to variation of drive voltage. <P>SOLUTION: The vehicle instrument equipped with a control means 4 for controlling an indicator 5 so as to indicate vehicle information using a generator as a drive supply comprises a supply voltage detection circuit 3 for detecting whether or not an output potential of the generator is not less than a predetermined value. The control means 4 provides a control signal to the indicator 5 so as to accelerate the termination movement of the indicator 5 when the output potential by the supply voltage detection circuit 3 is less than the predetermined value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicular instrument device including control means for controlling a display so as to display vehicle information using a generator as a driving power source, and displays vehicle information such as a travel speed and a travel distance of the vehicle, for example. It is suitable for a vehicle instrument device.

  Conventionally, a normal vehicle starts an engine by operating a starter with a charging voltage of a vehicle-mounted battery. On the other hand, in vehicles such as motorcycles and snowmobiles, those with a small battery capacity are used, and those that allow engine start operation without using a battery such as kicking or pulling a recoil rope in consideration of battery exhaustion. Yes, for example, it is disclosed in Patent Document 1.

Vehicles that can start the engine without using these batteries are equipped with a generator on the engine rotation shaft, and after starting the engine, the electric power generated by this generator is sent to each electrical component such as an ignition system, pump, and instrument device. It is a batteryless system to supply.
JP 2003-343401 A

  However, in such an instrument device of a batteryless system, the drive voltage value from the generator may be input with a large fluctuation. In this case, the driving voltage is interrupted before the end process such as the return of the pointer indicating position or the liquid crystal display is turned off, and the instrument device stops at the indicated position or display state different from the measured value. This is a problem because there is a possibility of abnormal display.

  Accordingly, an object of the present invention is to provide a vehicle instrument device that has been made paying attention to the above-described problem and can prevent abnormal display due to fluctuations in drive voltage.

  The vehicle instrument device of the present invention is a vehicle instrument device comprising control means for controlling a display so as to display vehicle information using a generator as a driving power source. A power supply voltage detection circuit for detecting whether or not the output potential of the generator is greater than or equal to a predetermined value; and the control means is configured to detect when the output potential is less than a predetermined value by the power supply voltage detection circuit. A control signal for prompting the display device to end is sent to the display device.

  Further, as described in claim 2, in the vehicular instrument device according to claim 1, the control means has a value equal to or higher than a limit voltage value at which the control means may display an abnormality. It is characterized by setting a value.

  Further, as described in claim 3, in the vehicle instrument device according to claim 1, the power supply voltage detection circuit includes a voltage dividing unit for stepping down the output potential to a voltage that can be input by the control means. It is characterized by comprising.

  According to a fourth aspect of the present invention, in the vehicular instrument device according to the first aspect, a step-down circuit for generating a drive voltage of the control means is provided between the generator and the control means. The control means monitors the output potential of the generator between the generator and the step-down circuit using the power supply voltage detection means.

  The present invention is a vehicular instrument device comprising control means for controlling a display so as to display vehicle information using a generator as a driving power source, and can prevent abnormal display due to fluctuations in driving voltage.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments to which the present invention is applied will be described below with reference to the accompanying drawings, taking an example applied to an instrument device mounted on a vehicle.

  FIG. 1 shows an embodiment of the present invention and is a block diagram showing an electrical configuration of a vehicle instrument device. The instrument device includes a power supply input circuit 1, a step-down circuit 2, a power supply voltage detection circuit 3, a control means 4, and a display 5.

  The power supply input circuit 1 is provided with a surge cut portion constituted by an input port for connecting to a generator mounted on a vehicle, a transistor and the like. The generator includes a regulator and a rectifier, and is configured to generate a stable DC voltage that is a drive source for electrical equipment such as an instrument device. In this case, an example in which the driving power of the meter device is obtained only by the power generation of the generator will be described. However, in addition to the generator, a vehicle meter to which power from a battery can be connected may be used.

  The step-down circuit 2 is a circuit for stepping down the output potential from the generator to the optimum drive voltage of the control means 4, and a regulator is suitable. In this case, the step-down circuit 2 is configured to generate a drive voltage of 5 V using the output potential from the generator.

  The power supply voltage detection circuit 3 is a circuit for detecting an output potential from the generator, and is provided with a voltage dividing unit using a resistor. Further, the power supply voltage detection circuit 3 steps down the voltage so that the voltage can be detected by the control unit 4 and outputs the voltage to the control unit 4 as a detection signal corresponding to the output potential.

  For example, a microcomputer can be applied to the control means 4, and various information including measurement values from various sensors provided in the vehicle via a cable or the like is input, and the various information is displayed on the display 5. A control signal is generated and output to the display 5. In this case, the control means 4 is operated by a drive voltage obtained via the step-down circuit 2 and inputs various information such as a detection signal from the power supply voltage detection circuit 3 and a traveling speed of the vehicle and an engine speed. CPU that performs arithmetic processing for generating a control signal for display based on information, RAM that can be read and rewritten to temporarily store arithmetic processing results, and the like, and that stores a control program and control data The ROM and an input / output interface for connecting to the power supply voltage detection circuit 3 and the display 5 are connected using a bus. Note that the control means 4 can also be used in combination with a navigation guidance display based on position information, map information, vehicle travel information, etc. obtained via a cable or the like.

  Moreover, the control means 4 inputs the detection signal from the power supply voltage detection circuit 3, and determines whether the output potential from a generator is more than predetermined value (for example, 4.5V). When it is determined by this determination that the value is equal to or greater than the predetermined value, the control unit 4 generates a control signal that prompts the display 5 to display based on the measurement value, and outputs the control signal to the display 5. In addition, when it is determined by the determination that the value is less than the predetermined value, the control unit 4 outputs a control signal that prompts the display 5 to perform an end process (end operation) described later. In this case, the control means 4 is normally driven optimally at a drive voltage of 5 V, and malfunctions or stops when the drive voltage is less than 4 V (the limit voltage value that the control means may display abnormally). It is a specification that may end up.

  The indicator 5 includes, for example, a so-called analog instrument that includes a pointer that rotates based on a control signal from the control unit 4 and an index unit that is an instruction target of the pointer, and that can read and interpret the measured value at the indicated position of the pointer. A liquid crystal display panel that displays a display image based on the control signal can be used. Further, when the control unit 4 inputs a control signal for prompting an end process that is generated when the output potential of the generator is determined to be less than a predetermined value as determined by the control means 4, the indicator 5 indicates that the indicated position of the pointer is the initial position. And a process of stopping the drive signal of the liquid crystal display panel.

  Even if the output potential from the generator serving as the power source varies due to the above-described configuration and other devices cannot operate, the normal display of the instrument device is possible as long as the appropriate drive voltage of the control means 4 is ensured. Therefore, the instrument device can display a stable measurement value. In addition, it is possible to prevent an abnormal display in which the driving voltage is interrupted before the operation by the above-described termination process is terminated, and the instrument device is stopped at the indicated position or display state different from the measured value.

  Such a vehicular instrument device is a vehicular instrument device comprising control means 4 for controlling the display 5 so as to display vehicle information using a generator as a driving power source, and the output potential of the generator is A power supply voltage detection circuit 3 is provided for detecting whether or not the value is equal to or greater than a predetermined value, and the control means 4 terminates the display 5 when the output potential is less than the predetermined value by the power supply voltage detection circuit 3. A control signal for prompting to operate is issued to the display 5. Further, the control unit 4 sets the predetermined value at a value (in this case, 4.5 V) that is equal to or higher than a limit voltage value (in this case, 4 V) that the control unit 4 may display abnormally.

  Therefore, even when the output potential from the generator slightly varies, a stable display is performed, and the output potential varies rapidly, so that the drive voltage falls below the limit value (allowable value) and the control means 4 Even if the process ends, an appropriate end operation can be promoted before malfunctioning, and the vehicle instrument device prevents abnormal display.

  Although the vehicular instrument device of the present invention has been described by way of example in the configuration of the embodiment described above, the present invention is not limited to this, and the gist of the present invention can be achieved in other configurations. It goes without saying that various improvements and design changes can be made without departing from the scope. For example, the control means 4 can more reliably perform the end operation of the display device 5 using power such as a backup capacitor.

The block diagram which shows the outline of the instrument device for vehicles of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply input circuit 2 Step-down circuit 3 Power supply voltage detection circuit 4 Control means 5 Display

Claims (4)

A vehicle instrument device comprising control means for controlling a display so as to display vehicle information using a generator as a driving power source,
A power supply voltage detection circuit for detecting whether the output potential of the generator is a predetermined value or more;
The control device emits a control signal for prompting the display device to end when the output potential is less than a predetermined value by the power supply voltage detection circuit. apparatus.   2. The vehicular instrument device according to claim 1, wherein the control unit is configured to set the predetermined value at a value equal to or higher than a limit voltage value that the control unit may cause an abnormal display.   2. The vehicle instrument device according to claim 1, wherein the power supply voltage detection circuit includes a voltage dividing unit for stepping down the output potential to a voltage that can be input by the control means. A step-down circuit for generating a drive voltage of the control means between the generator and the control means;
2. The vehicular instrument device according to claim 1, wherein the control means monitors the output potential of the generator between the generator and the step-down circuit using the power supply voltage detection means. .

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