JP2014043152A - Vehicle measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle measuring instrument capable of driving a power supply circuit in an optimum drive mode corresponding to a load state even in a vehicle requiring a low current mode.SOLUTION: A vehicle measuring instrument comprises: display means 2 displaying vehicle information; control means 3 inputting various information from a vehicle, generating a control signal prompting display of the vehicle information and outputting the control signal to the display means 2; and a power supply circuit 1 generating prescribed voltage from a battery power source mounted in the vehicle and outputting the prescribed voltage to a load including the display means 2 and the control means 3. The power supply circuit 1 is provided so as to be switchable to a pulse width modulation system and a pulse frequency modulation system for the driving when generating the prescribed voltage. The control means 3 outputs a switch signal prompting to switch each modulation system to the power supply circuit 1 on the basis of an operation state of the load.

Description

  The present invention relates to a vehicular instrument including a power supply circuit that generates a predetermined voltage from a battery power supply mounted on a vehicle and outputs the voltage to a load, and particularly generates a drive voltage for a load by a power supply circuit using a DC-DC converter. It is suitable for a vehicle instrument.

  As a conventional control device such as a vehicle instrument, there is one that uses a DC-DC converter to absorb a difference between a battery power source mounted on a vehicle and a driving voltage required for various control devices (loads). Patent Document 1 discloses this.

Japanese Utility Model Publication No. 7-4207

  However, the power supply circuit using these DC-DC converters is optimal in both cases because the voltage conversion efficiency and heat generation state differ greatly when the load current (current consumption) is large (normal operating state) and when it is small. It was difficult to construct a simple power supply circuit.

  In particular, even after the vehicle transitions from the operating state to the stopped state, it is limited to specific functions such as time measurement and security device operation, and when it is necessary to operate the vehicle instrument in the low current mode, Thus, when the efficiency of voltage conversion by the power supply circuit decreases, the current on the input side increases, which increases the battery power consumption even though the load current is small, which is disadvantageous as a low current mode. There was a problem.

  Therefore, the object of the present invention is to pay attention to the above-mentioned problem, and even in a vehicle that requires a low current mode, the power supply circuit is set in an optimum drive mode corresponding to the load state. It is to provide a vehicle instrument that can be driven.

  The vehicle meter according to the present invention includes display means for displaying vehicle information, control means for inputting various information from the vehicle, generating a control signal for prompting display of the vehicle information, and outputting the control signal to the display means, and the vehicle And a power supply circuit that generates a predetermined voltage from a battery power source mounted on the battery and outputs the predetermined voltage to a load having the display means and the control means. The power supply circuit generates the predetermined voltage. For switching, a pulse width modulation method and a pulse frequency modulation method are provided so as to be switchable, and the control means sends a switching signal for urging to switch each modulation method based on an operating state of the load. It is characterized by being output to.

  Further, the control means controls the power supply circuit to be driven using the pulse width modulation method when performing display by the display means, and the pulse frequency modulation method when stopping the display means. And controlling to drive the power supply circuit.

  The present invention relates to a vehicular instrument including a power supply circuit that generates a predetermined voltage from a battery power supply mounted on a vehicle and outputs a predetermined current to a load even when the vehicle requires a low current mode. The power supply circuit can be driven in various drive modes.

The figure which shows the electrical structure in embodiment of this invention. The figure which shows the process sequence of the control means in embodiment same as the above.

  Embodiments to which the present invention is applied will be described below with reference to the accompanying drawings.

  A vehicle instrument according to the present invention mounted on a two-wheeled vehicle will be described as an example. As shown in FIG. 1, the vehicle meter A includes a power supply circuit 1, a display unit 2, and a control unit 3.

  The power supply circuit 1 is provided with a DC-DC converter 11 that converts a battery voltage that changes in the vicinity of 12V into a predetermined voltage (for example, 5V) by on / off driving by a switching means (not shown), and display means 2 mounted on the vehicle. And the driving voltage of the electronic component such as the control means 3 is output. The power supply circuit 1 is configured to be able to be driven by the pulse frequency modulation method and the pulse width modulation method when the on / off driving is performed, and is provided with an input terminal 12 for switching the modulation method. .

  The display means 2 is an interface for notifying the vehicle user of vehicle information based on a control signal from the control means 3 in the vehicle meter A provided at a position where the vehicle user can visually recognize the vehicle. It is. The display means 2 includes a so-called analog instrument, a liquid crystal display or a so-called analog instrument that includes a pointer that rotates in accordance with various types of information on the vehicle, a scale plate that is an instruction target of the pointer, and the like so that the measured amount can be read in comparison Numerical values and bars can be displayed using a display panel such as an organic EL.

  The display means 2 displays measured values such as the vehicle running speed, engine speed, remaining fuel amount, and fuel consumption information based on various types of vehicle information when the ignition switch (start switch) S is on. I can do it. The display means 2 is also provided with an electronic component (load) such as an illumination light source that can be operated by a driving voltage supplied from the power supply circuit 1 and that allows vehicle information to be visually recognized even at night.

  The control means 3 includes a power supply circuit 1, a display means 2, an electric signal line connected to an operation switch or sensor for inputting various information from the vehicle, or a communication cable using a CAN (Controller Area Network). Connected to the wiring, etc. The control means 3 can be a microcomputer that drives using the output from the power supply circuit 1 as a drive source, and performs arithmetic processing for controlling the display means 2 based on the various information.

  The control means 3 stores a CPU for performing arithmetic processing based on various input signals, a readable / rewritable RAM for temporarily storing arithmetic processing results in the CPU, a control program and control data. A storage unit including a ROM, and an input / output interface connected by a bus for exchanging the various signals, control signals, clock signals, and the like. The control means 3 can measure the time using the clock signal in the low current mode described later.

  The power supply circuit 1, the display means 2, and the control means 3 of the vehicle meter A described above are housed and held in the same casing, and are connected to the ignition switch S and the battery B via wiring and connectors.

  Next, the processing procedure of the control means 3 will be described with reference to FIG.

  The control means 3 is connected to the ignition switch S of the vehicle via a resistance element (not shown) and the like, and is input from the input terminal 31 as a state signal to monitor the on / off state (step S1). The control means 3 performs the following processing in order to switch the display / non-display by the display means 2 according to the state of the ignition switch S.

  When the ignition switch S shifts from the off state to the on state, the control unit 3 uses a pulse width modulation method as a normal operation mode in order to perform voltage conversion corresponding to a large load such as the display unit 2. A switching signal that prompts the power supply circuit 1 to be driven is output to the power supply circuit 1 (step S2), and thereafter, vehicle information that changes due to traveling or the like is displayed on the display means 2 based on the various signals that are input. Normal calculation processing (step S3) is performed.

  Further, when the ignition switch S shifts from the on state to the off state by the determination process described above, the process of stopping the display output by the display unit 2 (step S4) is performed as the low current mode, and then the pulse frequency modulation is performed. A switching signal that prompts the power supply circuit 2 to drive using the method is output to the power supply circuit 1 (step S5), and a predetermined function calculation process (step S6) that performs only a specific function such as time measurement or a security function is performed.

  Through the above processing, the vehicle meter A can not only drive the power supply circuit 1 with the optimum modulation method according to the state of the display means 2 which is one of the loads, but also can automatically switch the modulation method. This can be realized with a simple configuration without providing a configuration for detecting the current consumption.

  The vehicle meter A includes a display unit 2 that displays vehicle information, a control unit 3 that inputs various information from the vehicle, generates a control signal that prompts display of the vehicle information, and outputs the control signal to the display unit 2; A power supply circuit 2 that generates a predetermined voltage from a battery power supply mounted on a vehicle and outputs the predetermined voltage to a load having the display means 2 and the control means 3, and the power supply circuit 1 is configured to drive the predetermined voltage. The control means 3 is provided so as to be able to switch between a pulse width modulation method and a pulse frequency modulation method, and outputs a switching signal for urging to switch each modulation method to the power supply circuit 1 based on the operating state of the load.

  Therefore, it becomes a vehicle meter using a power supply circuit that can support both the normal operation mode and the low current mode. In particular, the vehicular instrument A having the above-described configuration is advantageous because a small standby power is required even in a vehicle such as a two-wheeled vehicle that does not have a large and large-capacity battery. The above-described configuration is advantageous because it does not require a complicated configuration such as a plurality of power supply circuits (DC-DC converters) and a switch circuit for disconnecting the power supply circuit and the battery in the low power consumption mode. is there.

  The control means 3 controls the power supply circuit 1 to be driven using the pulse width modulation method when performing display by the display means 2, and the pulse frequency modulation method when the display means 2 is stopped. By controlling so that the power supply circuit 1 is driven using, a modulation method corresponding to the display state of the display means 2 can be selected, so that an optimum modulation method corresponding to the load state can be selected. Since the pulse frequency modulation method is not used in the normal operation mode, noise generation due to high frequency switching can be suppressed. Further, by driving with a pulse frequency modulation method at low load (low current mode), it is possible to cope with a smaller current output than when driving with a pulse width modulation method.

  Although the vehicular instrument of the present invention has been described as an example in the configuration of the above-described embodiment, the present invention is not limited to this, and other configurations depart from the gist of the present invention. It goes without saying that various improvements and design changes can be made without departing from the scope. For example, the display state of the display unit 2 is changed according to the ON / OFF operation of the ignition switch S. In addition to this, it is determined whether the driver is getting on or off, and the display state of the display unit It can also be configured to switch modes.

  The present invention relates to a vehicle instrument, and can be applied as, for example, a vehicle instrument mounted on a moving body including an automobile, a motorcycle, an agricultural machine, or a construction machine.

DESCRIPTION OF SYMBOLS 1 Power supply circuit 2 Display means 3 Control means A Vehicle meter B Battery S Ignition switch

Claims (2)

Display means for displaying vehicle information;
Control means for inputting various information from the vehicle, generating a control signal for prompting display of the vehicle information, and outputting the control signal to the display means;
A vehicle meter comprising a power supply circuit that generates a predetermined voltage from a battery power supply mounted on the vehicle and outputs the predetermined voltage to a load having the display means and the control means,
The power supply circuit is provided to be able to switch between a pulse width modulation method and a pulse frequency modulation method for driving when generating the predetermined voltage,
The vehicle instrument characterized in that the control means outputs a switching signal for urging to switch each modulation method to the power supply circuit based on an operating state of the load. The control means controls to drive the power supply circuit using the pulse width modulation method when performing display by the display means,
The vehicular instrument according to claim 1, wherein when the display means is stopped, the power supply circuit is controlled to be driven using the pulse frequency modulation method.

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