JP2018070081A - Vehicular instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a proper measured value even in a case where different signals indicating the same measured value are input from multiple input means.SOLUTION: A vehicular instrument 1 according to the invention includes: display means 10 which displays a measured value; a first input circuit 12 into which a first signal indicating the measured value is input from first input means 2; a second input circuit 13 into which a second signal indicating the measured value is input from the second input means 3; and control means 11 to which the first signal and the second signal are input from a measured value input part 11a and which causes the display means 10 to display the measured value. The vehicular instrument 1 has: detection means 11c which detects connection of the first input means 2; and block means 15 which blocks input of the second signal to the second input circuit 13 when the detection means 11c detects the connection of the first input means 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an input circuit for a vehicle meter.

  A conventional instrument for a vehicle is disclosed in Patent Document 1. This vehicle instrument captures a detection signal from a speed sensor and displays the traveling speed of the vehicle on a display panel.

  In recent vehicles, an ABS unit that controls the braking operation of the vehicle based on the detection signal of the speed sensor may be mounted. In this case, the speed sensor is connected to the ABS unit, and the ABS unit is configured to output a detection signal obtained by performing predetermined waveform shaping to the detection signal of the speed sensor to the vehicle instrument.

  Therefore, it is necessary to have two different input circuits in order to cope with both the specification without the ABS unit and the specification with the ABS unit.

JP-A-6-109487

  However, when signals are simultaneously input from both the ABS unit and the speed sensor, there is a possibility that the signals may interfere with each other and an accurate measurement value cannot be calculated.

  The present invention has been made in view of the above-described problems, and provides a vehicle instrument capable of displaying appropriate measurement values even when different signals representing the same measurement value are input from a plurality of input means. Objective.

The vehicle instrument according to the present invention is:
Display means for displaying measured values;
A first input circuit for inputting a first signal representing the measurement value from a first input means;
A second input circuit for inputting a second signal representing the measurement value from a second input means;
Control means for inputting the first signal and the second signal from a measurement value input unit and displaying the measurement value on the display means;
Detecting means for detecting connection of the first input means;
And a blocking means for blocking the input of the second signal to the second input circuit when the detecting means detects the connection of the first input means.

In addition, the vehicle meter according to the present invention,
A power output unit for supplying power to the first input means;
The detection means detects connection of the first input means based on an output voltage of the power output unit.
It is preferable to configure as described above.

Further, the first input means of the vehicle meter according to the present invention is a sensor,
The second input means outputs the second signal based on the first signal.
It is preferable to configure as described above.

  According to the present invention, it is possible to provide a vehicle instrument that can display appropriate measurement values even when different signals representing the same measurement value are input from a plurality of input means.

The electrical block diagram of the meter for vehicles which is embodiment of this invention.

  A vehicle instrument 1 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

  The vehicle instrument 1 has a display means 10, a control means 11, a first input circuit 12, a second input circuit 13, a history effect circuit 14, and a cutoff circuit 15, and the first input circuit 12 or the second input circuit 13 includes It is an instrument that displays the traveling speed of the vehicle on the display means 10 based on the input signal.

  The vehicle meter 1 has a power input unit P1, a power output unit P2, a first signal input unit P3, and a second signal input unit P4 as interfaces connected to external devices.

  The vehicular meter 1 has an ignition power supply connected to the power input unit P1, and takes in the ignition power supply.

  In the vehicle meter 1, a vehicle speed sensor (first input means) 2 can be connected to the power output unit P2 and the first signal input unit P3. When the vehicle speed sensor 2 is connected, the vehicle meter 1 supplies the ignition power source taken in from the power input unit P1 to the vehicle speed sensor 2 from the power output unit P2 to operate the vehicle speed sensor 2. The vehicle instrument 1 inputs a pulse signal (first signal) representing the rotation of the wheel detected by the activated vehicle speed sensor 2 from the first signal input unit P3.

  In the vehicular meter 1, an ABS unit (second input means) 3 can be connected to the second signal input portion P4. The ABS unit 3 receives the first signal of the vehicle speed sensor 2 and outputs a pulse signal (second signal) representing the rotation of the wheel obtained by performing a predetermined waveform shaping on the first signal. When the ABS unit 3 is connected, the vehicle instrument 1 inputs the second signal from the second signal input unit P4.

  The display means 10 is, for example, a liquid crystal display that displays an image, a dial plate on which an index scale is formed, and a pointer that indicates the index scale of the dial, and displays the traveling speed of the vehicle.

  The control means 11 is, for example, a microcontroller having an interface of a measurement value input port 11a, a display control signal output port 11b, a detection signal input port 11c, and a cutoff signal output port 11d, and a CPU that controls the interface.

  The control means 11 calculates the travel speed of the vehicle based on the signal input from the measured value input port 11a, and outputs a display control signal to the display means 10 from the display control signal output port 11b to display the travel speed of the vehicle. It is displayed on the means 10.

  The control means 11 monitors the output voltage of the power output unit P2 at the detection signal input port 11c, determines that the vehicle speed sensor 2 is connected when the power output unit P2 is equal to or higher than a predetermined output voltage, A cutoff signal is output from the output port 11d. Further, the control means 11 determines that the vehicle speed sensor 2 is not connected unless the power output unit P2 is equal to or higher than a predetermined output voltage, and does not output a cutoff signal from the cutoff signal output port 11d.

  The first input circuit 12 is a waveform shaping circuit that performs a predetermined waveform shaping on the first signal input from the first signal input unit P <b> 3 and outputs the waveform to the history effect circuit 14.

  The second input circuit 13 is a waveform shaping circuit that performs a predetermined waveform shaping different from that of the first input circuit 12 on the second signal input from the second signal input unit P4 and outputs the waveform to the history effect circuit 14.

  The history effect circuit 14 is a Schmitt trigger in which the output state output to the control means 11 changes with hysteresis in response to changes in the input potentials input from the first input circuit 12 and the second input circuit 13. The history effect circuit 14 has two thresholds for the input signal, and outputs the output H when the potential of the input signal exceeds the high first threshold, and outputs when the potential of the input signal falls below the low second threshold. L is output, and when the input signal is between the first threshold value and the second threshold value, the previous output is held. This reduces the influence of noise due to fluctuations in the input signal on the displayed traveling speed of the vehicle.

  The cutoff circuit 15 is a transistor provided on a signal path for transmitting the second signal from the ABS unit 3 to the second input circuit 13. When a cutoff signal is input from the cutoff signal output port 11d of the control means 11, the cutoff circuit 15 blocks the signal path through which the second signal is transmitted. In other words, the blocking circuit 15 is in a state in which the second signal can be transmitted from the ABS unit 3 to the second input circuit when the blocking signal is not input from the control means 11.

As described above, the vehicle instrument 1 according to the present invention includes a display means 10 for displaying a measured value, a first input circuit 12 for inputting a first signal representing the measured value from the first input means 2, and a first input circuit 12. A second input circuit 13 for inputting a second signal representing the measurement value from the two input means 3; and a control means for inputting the first signal and the second signal from the measurement value input section 11a and displaying the measurement value on the display means 10. 11 for detecting the connection of the first input means 2 to the second input circuit 13 when the detection means 11c detects the connection of the first input means 2. And a blocking means 15 for blocking the input of the second signal.
With this configuration, even when the first input means 2 and the second input means 3 are connected at the same time, the second signal input from the second input means 3 is cut off. Since the measurement value is obtained only by the first signal input from the input unit 2, an appropriate measurement value can be displayed even when different signals representing the same measurement value are input from the plurality of input units.

  The present invention is not limited by the above-described embodiment (including the contents of the drawings), and modifications (including deletion of components) can be added to the above-described embodiment within the scope of the gist of the present invention.

  In the above embodiment, the present invention is applied to the vehicle speed sensor 2 that outputs a pulse signal representing the rotation of the wheel related to the traveling speed of the vehicle and the ABS unit 3, but the present invention is not limited to this and may be applied to various measurement values. For example, the present invention can be applied to a vehicular instrument to which a rotation sensor that outputs a pulse signal representing the engine speed and an ECU unit that outputs a signal obtained by performing a predetermined waveform shaping on the pulse signal output from the rotation sensor.

  In the above-described embodiment, the connection of the vehicle speed sensor 2 is detected by the detection signal input port 11c of the control means 11, but a configuration having a separate detection circuit may be employed. For example, the same effect as the above-described embodiment can be obtained by incorporating a circuit for turning on / off the cutoff circuit 15 according to the voltage of the power output unit P2. In this case, the processing program of the control means 11 can be simplified.

DESCRIPTION OF SYMBOLS 1: Instrument for vehicles 10: Display means 11: Control means 11a: Measurement value input port 11b: Display control signal output port 11c: Detection signal input port (detection means)
11d: shut-off signal output port 12: first input circuit 13: second input circuit 14: history effect circuit 15: shut-off circuit (shut-off means)
P1: Power input unit P2: Power output unit P3: First signal input unit P4: Second signal input unit IGN: Ignition power supply

Claims (3)

Display means for displaying measured values;
A first input circuit for inputting a first signal representing the measurement value from a first input means;
A second input circuit for inputting a second signal representing the measurement value from a second input means;
Control means for inputting the first signal and the second signal from a measurement value input unit and displaying the measurement value on the display means;
Detecting means for detecting connection of the first input means;
And a blocking means for blocking the input of the second signal to the second input circuit when the detection means detects the connection of the first input means.
A vehicle instrument characterized by that. A power output unit for supplying power to the first input means;
The detection means detects connection of the first input means based on an output voltage of the power output unit.
The vehicle instrument according to claim 1. The first input means is a sensor;
The second input means outputs the second signal based on the first signal.
The vehicular instrument according to claim 1 or 2, characterized by the above-mentioned.

Images