JP4452013B2 - Control device and indicating instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device and an indicating instrument, and more particularly to a control device that controls the rotation of a movement, a pointer driven by the movement, the movement, and an indicating instrument that includes the control device.
[0002]
[Prior art]
As an example of the indicating instrument described above, one shown in FIG. 1 is known. In the figure, the indicator 10 drives a movement 12A for driving a vehicle speed instruction needle 11A, a movement 12B for driving an engine speed instruction needle 11B, and a fuel remaining value instruction needle 11C by rotation. A movement 12C for driving, a movement 12D for driving a pointer 11D for instructing water temperature, and the like. As the above-described movements 12A to 12D, a stepping motor type or a cross coil type is generally known.
[0003]
The indicating instrument 10 includes a control microcomputer 13 (hereinafter, control microcomputer 13) to which a speed sensor 20A, a rotation speed sensor 20B, a fuel remaining amount sensor 20C, a water temperature sensor 20D, and the like are connected. The control microcomputer 13 obtains measurement values such as vehicle speed, engine speed, remaining fuel value, and water temperature based on the outputs from the various sensors 20A to 20D, and the movements 12A to 12D according to the obtained measurement values. By controlling the power supply to each, a movement control operation for controlling the rotation of the movements 12A to 12D is performed so that the hands 11A to 11D indicate the measured values.
[0004]
The control microcomputer 13 receives power from an in-vehicle battery (not shown) via an IGN switch (not shown) and a power supply IC 30 that are turned on when the key position is set to ignition (IGN). The power supply IC 30 steps down the battery voltage V _B to the operating voltage of the control microcomputer 13 and applies it to the control microcomputer 13. Further, the control microcomputer 13 is supplied with an IGN signal S ₁ which becomes H level when the key position becomes IGN. The control microcomputer 13 supplies operating power to the movements 12A to 12D when the IGN signal S1 is supplied.
[0005]
The above-described control microcomputer 13 starts to operate in response to the operation power supplied from the power supply IC 30 and immediately checks the input of the H level IGN signal S ₁ to perform rotation control on all the movements 12A to 12D. At this time, if the engine is not started, the vehicle speed and the engine speed are naturally zero. However, in order to drive the control microcomputer 13 from the initial position of the hands 11A and 11B (minus from the indicated position of the measured value 0) to the measured value 0, the control microcomputer 13 further holds the instruction of the measured value 0 by the hands 11A and 11B. Therefore, even before the engine start is started, power is supplied to the movements 12A and 12B.
[0006]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional indicating instrument 10, if the key position is set to IGN and then the key position is set to the starter, engine start (cranking) is performed by the starter device, resulting in the following problems. That is, when cranking is started, most of the power of the on-vehicle battery is used in the starter device, and the power supplied to the indicator 10 is reduced, and the battery voltage V _B is drastically reduced although it is instantaneous. To do.
[0007]
When the operating voltage supplied from the power supply IC 30 to the control microcomputer 13 falls below the voltage value necessary for the control microcomputer 13 to operate due to the decrease in the battery voltage V _B , the indicating instrument 10 Stops function instantly (reset). Therefore, in order to prevent such a situation, as shown in FIG. 1, backup capacitors C ₁ and C ₂ for supplying the charge stored in advance to the control microcomputer 13 when the battery voltage V _B decreases are provided. It is considered.
[0008]
The time during which the capacitors C ₁ and C ₂ can prevent the indicator 10 from being reset greatly depends on the amount of power used at that time by the indicator 10, and the more power that is used, the more the reset can be prevented. Time is shortened. Further, if the capacitances of the capacitors C ₁ and C ₂ are increased, the time during which the reset can be prevented becomes longer, but the size of the capacitors C ₁ and C ₂ is increased, which is disadvantageous in terms of space and cost. there were.
[0009]
Accordingly, the present invention provides a control device that can prevent the power reset of the indicator instrument that occurs due to a decrease in battery voltage, and an indicator instrument that uses the controller, paying attention to the above problems. Is an issue.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a control microcomputer for controlling the rotation of a plurality of movements by controlling power supply to the plurality of movements for driving the hands mounted on the vehicle. And a backup capacitor for supplying the control microcomputer with the charge previously stored when the voltage of the battery that supplies the operating voltage of the control microcomputer decreases, the cranking from the start of cranking Until the engine of the vehicle is started, the power supply to only the movement that drives the indicator of the speedometer and / or the tachometer among the plurality of movements is stopped and the speedometer and / or the rotation of the plurality of movements is stopped. power for the movement for driving the hands of the instrument other than the total of Supply resides in the control apparatus characterized by comprising a supply stop means to continue.
[0011]
According to a third aspect of the present invention, there is provided a pointer mounted on a vehicle, a control microcomputer for controlling rotation of the plurality of movements by controlling power supply to the plurality of movements for driving the pointers, and the control A control device having a backup capacitor for supplying the control microcomputer with a charge stored in advance when the voltage of a battery for supplying the operating voltage of the microcomputer is lowered, the control instrument comprising: The apparatus stops the power supply to only the movement that drives the speedometer and / or the tachometer pointer from the start of cranking to the start of the engine of the vehicle, and the movement of the plurality of movements is stopped . of Mu for driving the hands of the speedometer and / or instrument other than the tachometer Power supply to the instrument resides in the indicating instrument, characterized in that it comprises a supply stop means to continue.
[0012]
According to the first and third aspects of the present invention, the supply stop means stops the power supply to the speedometer and / or the tachometer movement from the start of cranking to the start of the vehicle engine. The power supply to other movements continues . Accordingly, it is possible to reduce the power consumed by the plurality of movements from the start of cranking when the battery voltage is lowered and the charge from the backup capacitor is released to the start of the vehicle engine. In addition, if the movement that drives the hands after starting the engine (for indicating the vehicle speed or indicating the engine speed ) is a part of the movement that stops the power supply, the movement that stops the power supply until the engine starts The driven pointer can instruct the measured value without giving the driver a sense of incongruity.
[0013]
The invention according to claim 2 is the control device according to claim 1, wherein the engine rotation signal corresponding to the engine speed is monitored, and the engine is started based on the monitoring of the engine rotation signal. Start detection means for detecting this, and the supply stop means stops the power supply from the start of cranking until the start of the engine is detected by the start detection means. It exists in the control device.
[0014]
According to the second aspect of the invention, the start detection means monitors the engine rotation signal corresponding to the engine speed, and detects that the engine is started based on the monitoring of the engine rotation signal. The supply stop means stops the power supply from the start of cranking until the start of the engine is detected by the start detection means. Therefore, the engine start can be accurately detected by detecting the engine start based on the engine rotation signal, that is, the engine speed monitor. For this reason, it is possible to accurately stop the power supply from the start of cranking to the start of the engine.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of an indicating instrument incorporating the control device of the present invention. In the figure, the indicator 10 drives a movement 12A for driving a vehicle speed instruction needle 11A, a movement 12B for driving an engine speed instruction needle 11B, and a fuel remaining value instruction needle 11C by rotation. A movement 12C for driving, a movement 12D for driving a pointer 11D for instructing water temperature, and the like. As the above-described movements 12A to 12D, a stepping motor type or a cross coil type is generally known.
[0020]
The indicating instrument 10 includes a control microcomputer 13 (hereinafter, control microcomputer 13) to which a speed sensor 20A, a rotation speed sensor 20B, a fuel remaining amount sensor 20C, a water temperature sensor 20D, and the like are connected. The control microcomputer 13 (= corresponding to the control device) is used in various processing processes in the CPU 13a that operates according to a preset control program, the ROM 13b that is a read-only memory storing the control program of the CPU 13a, and the CPU 13a. A RAM 13c, which is a readable / writable memory having a work area, a data storage area for storing various data, and the like are incorporated, and these are interconnected by a bus line (not shown).
[0021]
The control microcomputer 13 receives power from an on-vehicle battery (not shown) via an IGN switch (not shown) that is turned on when the key position is set to IGN and the power supply IC 30. The power supply IC 30 steps down the battery voltage V _B to the operating voltage of the control microcomputer 13 and applies it to the control microcomputer 13. Further, the control microcomputer is supplied with an IGN signal S ₁ which becomes H level when the 12 key position becomes IGN. Then, the control microcomputer 13 supplies operating power to the movement 12A~12D when IGN signal S ₁ is supplied. Further, backup capacitors C ₁ and C ₂ are connected to the power supply IC 30 in parallel.
[0022]
The operation of the indicating instrument configured as described above will be described below with reference to the time chart shown in FIG. First, when the key position is set to IGN by the driver, the IGN switch is turned on, and power from the in-vehicle battery is supplied to the control microcomputer 13 via the power supply IC 30 (FIG. 2A).
[0023]
When the key position is set to IGN by the driver, the IGN switch is turned on, and the IGN signal S1 is supplied to the CPU 13a in the control microcomputer 13. Check the supply of IGN signals S _1, CPU 13a based on the output from the fuel level sensor 20C and the water temperature sensor 20D, the fuel quantity value, determine the water temperature, obtained fuel remaining amount value, depending on the water temperature Movement By controlling the power supply to 12C and 12D, the first movement control operation for controlling the rotation of the movements 12C and 12D so that the pointer 11C indicates the remaining fuel value and the pointer 11D indicates the water temperature. Start (see FIG. 2C). At this time, the CPU 13a functions as a supply stop unit and does not supply power to the movements 12A and 12B.
[0024]
Thereafter, when the key position is changed to a starter by the driver, cranking is started and the battery voltage V _B is lowered. When the operating voltage supplied to the control microcomputer 13 decreases due to the decrease in the battery voltage V _B (see FIG. 2A), the backup capacitors C ₁ and C ₂ charge the control microcomputer 13. Is released. This prevents the control microcomputer 13 from being reset due to a decrease in the battery voltage V _B.
[0025]
Further, CPU 13a in microcomputer 13, when confirming the supply of the IGN signal S _1, serves as the starting detection means monitors the engine speed signal output from the speed sensor 20B, based on the monitoring result, the engine start To detect. The engine speed signal is a pulse signal having a period corresponding to the engine speed (see FIG. 2B), and the CPU 13a indicates that the engine has started when the period of the pulse signal is equal to or less than a predetermined period. To detect.
[0026]
When it is detected that the engine has started, the CPU 13a in the control microcomputer 13 performs the vehicle speed and engine rotation based on the outputs from the speed sensor 20A and the rotational speed sensor 20B in addition to the rotational control of the movements 12C and 12D. By determining the number and controlling the power supply to the movements 12A and 12B in accordance with the determined vehicle speed and engine speed, the pointer 11A indicates the vehicle speed and the pointer 11D indicates the engine speed. A second movement control operation for controlling the rotations of the movements 12A and 12B is started (see FIG. 2D).
[0027]
According to the above indicating instrument, the movement of the vehicle speed instruction 12A and the engine for driving the pointer 11A after the engine starts and the vehicle starts to move from the start of cranking to the start of the engine of the vehicle. After starting, the power supply to the engine speed instruction movement 12B for driving the hands 11B is stopped. More specifically, since the movement 12A and the movement 12B are driven from the initial position of the hands 11A and 11B (minus from the indicated position of the measured value 0) to the measured value 0, the measured value 0 by the hands 11A and 11B is further decreased. The power supply for holding the instruction is not performed.
[0028]
Therefore, the power consumed by the plurality of movements 12A to 12D from the start of cranking when the battery voltage V _B decreases and the electric charge from the backup capacitors C ₁ and C ₂ is released to the start of the vehicle engine. Can be reduced. For this reason, the time which can prevent the power reset of the indicating instrument by the backup capacitors C ₁ and C ₂ can be further prolonged, and the power reset of the indicating instrument caused by the battery voltage drop can be prevented.
[0029]
Moreover, after the engine is started and the vehicle starts to move, the speed instruction movement 12A that needs to move the pointer 11A is a part of the movement in which the power supply is stopped. Even if the power supply is stopped until the start, the speed can be instructed without giving the driver a sense of incongruity.
[0030]
Further, by setting the movement 12B for instructing the engine speed that needs to move the pointer 11B after the engine is started to be a movement in which the power supply is stopped, the power supply is stopped from the cranking start to the engine start. The engine speed can be instructed without giving the driver a sense of incongruity.
[0031]
Furthermore, according to the above indicator, the engine start can be accurately detected by detecting the engine start based on the engine rotation signal, that is, the monitoring of the engine speed. For this reason, it is possible to accurately stop the power supply from the start of cranking to the start of the engine.
[0032]
In the above-described embodiment, when the engine start is detected based on the monitoring of the engine rotation signal, power is supplied to the movements 12A and 12B. However, for example, power supply is performed after a predetermined period of time from when cranking is started to which the engine is predicted to start, and power supply is stopped from cranking to engine start. It is also possible.
[0033]
【The invention's effect】
As described above, according to the first and third aspects of the present invention, the battery voltage is lowered and the plurality of times from the start of cranking when the charge from the backup capacitor is released until the vehicle engine starts. The electric power consumed by the movement can be reduced. In addition, if the movement that drives the hands after starting the engine (for indicating the vehicle speed or indicating the engine speed ) is a part of the movement that stops the power supply, the movement that stops the power supply until the engine starts With the driven pointer, it is possible to obtain a control device and an indicating instrument that can instruct the measured value without causing the driver to feel uncomfortable.
[0034]
According to the second aspect of the present invention, the engine start can be accurately detected by detecting the engine start based on the engine rotation signal, that is, the monitoring of the engine speed. For this reason, since the power supply can be stopped accurately from the start of cranking to the start of the engine, the power supply to some movements can be started before the engine starts, It is possible to obtain a control device capable of avoiding a situation in which power supply to some of the movements is stopped until after starting.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of an indicating instrument incorporating a control device of the present invention.
FIG. 2 is a time chart for explaining the operation of the indicating instrument in FIG. 1;
[Explanation of symbols]
10 indicating instruments 11A to 11D pointers 12A to 12D movement 13 microcomputer for control (control device)
13a CPU (supply stop means, start detection means)

Claims (3)

Control microcomputer for controlling rotation of a plurality of movements by controlling power supply to a plurality of movements for driving hands mounted on a vehicle, and a voltage drop of a battery for supplying an operating voltage of the control microcomputer In a control device comprising a backup capacitor that supplies the control microcomputer with the charge that has been stored in advance in advance,
During the period from the start of cranking to the start of the engine of the vehicle, power supply to only the movement that drives the speedometer and / or the tachometer of the plurality of movements is stopped and the speed of the plurality of movements is A control device comprising supply stop means for continuing power supply to a movement that drives a pointer of a meter other than a meter and / or tachometer . The control device according to claim 1,
The engine further comprises start detection means for monitoring an engine rotation signal corresponding to the number of rotations of the engine and detecting that the engine is started based on the monitoring of the engine rotation signal.
The supply stop unit stops the power supply from the start of the crank until the start of the engine is detected by the start detection unit. A control microcomputer for controlling the rotation of the plurality of movements by controlling power supply to the pointers mounted on the vehicle, and the plurality of movements that drive the pointers, and an operating voltage for the control microcomputer A control device having a backup capacitor for supplying a charge stored in advance to the control microcomputer when the battery voltage drops, and an indicating instrument comprising:
The control device stops supplying power to only the movements that drive the hands of the speedometer and / or the tachometer from the start of cranking to the start of the engine of the vehicle and the plurality of movements . The indicator instrument characterized by having the supply stop means which continues the power supply with respect to the movement which drives the pointer | guide of instruments other than the said speedometer and / or tachometer among movements .

Images