WO2020137718A1

WO2020137718A1 - Vehicle-use sound outputting device

Info

Publication number: WO2020137718A1
Application number: PCT/JP2019/049501
Authority: WO
Inventors: 石川　貴之; 淑石川
Original assignee: 日本精機株式会社
Priority date: 2018-12-25
Filing date: 2019-12-18
Publication date: 2020-07-02

Abstract

The present invention enables detection of an open abnormality in the wiring between a drive unit and a sound emitting body, without causing the sound emitting body to sound. Provided is a vehicle-use sound outputting device that includes: a sound emitting body; a drive unit that generates a drive signal for causing the sound emitting body to sound; wiring which is formed between the sound emitting body and the drive unit, and through which the drive signal propagates; and an open abnormality detection unit that is electrically connected to the wiring and that detects an open abnormality in the wiring, in a state where the drive signal is not propagating in the wiring.

Description

Sound output device for vehicle

The present disclosure relates to a vehicle sound output device.

A vehicle instrument that detects an abnormal state such as a failure or disconnection of a drive circuit of a sounding body is known (for example, see Patent Document 1).

JP, 2016-141383, A

However, the above-described conventional technique detects an abnormal state based on a pulse signal (control signal) for ringing the sounding body, and therefore, in a situation where the control signal is generated (that is, the sounding body is ringing). The abnormal condition can be detected only under the condition of causing it.

Therefore, the present disclosure aims to detect an open abnormality in the wiring between the drive unit and the sounding body without the sounding of the sounding body.

In one aspect, with a sounder,
A drive unit for generating a drive signal for ringing the sounding body;
A wire formed between the sounding body and the drive section, through which the drive signal flows,
A vehicle sound output device is provided that includes an open abnormality detection unit that is electrically connected to the wiring and that detects an open abnormality related to the wiring when the drive signal does not flow in the wiring.

According to the present disclosure, it is possible to detect an open abnormality in the wiring between the drive unit and the sounding body without the sounding of the sounding body.

FIG. 3 is a diagram showing an example of mounting an on-vehicle instrument in the first embodiment. FIG. 3 is a diagram showing an in-vehicle instrument according to the first embodiment. FIG. 3 is a diagram showing a configuration of an in-vehicle instrument according to the first embodiment. 5 is an explanatory diagram of an open abnormality detection unit according to the first embodiment. FIG. It is explanatory drawing of an open abnormality. It is explanatory drawing of the detection principle of an open abnormality. It is explanatory drawing of a preferable execution timing of an open detection process. FIG. 9 is an explanatory diagram of an open abnormality detection unit according to the second embodiment.

Each embodiment will be described in detail below with reference to the accompanying drawings.

[Example 1]
FIG. 1 is a diagram illustrating an example of mounting an on-vehicle instrument (vehicle instrument) A according to the first embodiment. FIG. 2 is a diagram showing an in-vehicle instrument A in this embodiment. FIG. 3 is a diagram showing the configuration of the on-vehicle instrument A in this embodiment.

As shown in FIG. 1, an in-vehicle instrument A (an example of a vehicle sound output device) is incorporated and mounted in an instrument panel B provided on the front side of a driver's seat in a vehicle. The display of the in-vehicle instrument A can be visually confirmed via the, and measurement information such as the traveling speed of the vehicle can be confirmed.

As shown in FIGS. 2 and 3, the in-vehicle instrument A functions as a complex instrument, and includes a display 1, an input unit 2, a microcomputer (abbreviation of microcomputer) 3A, a drive circuit 3B, and a sounding body ( Drive body) 4. These components are electrically connected via a circuit board, wiring, etc., and are housed in a case (housing) K made of synthetic resin or the like. The case K includes a transparent case made of a transparent synthetic resin such as acrylic and a storage case made of a light-shielding synthetic resin for holding the circuit board, the sounding body 4 and the like so that the display of the display 1 can be seen. Together, they are fixed using hooks, screws, etc. not shown.

As shown in FIG. 2, the display 1 indicates a display panel (display means) 11 that switches between transmission and non-transmission to form a display image, and an indicator unit such as a scale or a numerical value by rotating a motor that is a drive source. The pointer type display unit 12 may be included.

The display device 1 displays desired vehicle information such as the traveling speed and traveling distance of the vehicle, the remaining capacity of the on-vehicle battery, and an alarm in a power-on state (operating state) of the vehicle such as during normal traveling based on a control signal from the microcomputer 3A. To display.

The display panel 11 may be, for example, a liquid crystal display panel including a backlight 11a including a light source such as a light emitting diode. In this case, the display panel 11 generates and outputs a display screen according to the control signal from the microcomputer 3A, and also changes the output brightness of the backlight 11a based on the control signal from the microcomputer 3A.

The input means 2 may be a trip switch for switching and displaying the total traveled distance, the section traveled distance, etc. of the in-vehicle instrument A. The input means 2 may also be used as a dimming switch for setting the illumination brightness of the vehicle-mounted instrument A including the display 1. The input means 2 outputs an operation signal corresponding to the pressing operation of the vehicle user to the microcomputer 3A. The input means 2 can be used together with or replaced with the steering switch C1.

The microcomputer 3A includes a storage unit 31 which is used as a storage area for storing a predetermined program and various data and a calculation, a CPU for performing calculation processing according to the predetermined program, an input/output interface and the like. To input an operation signal from the input means 2 and vehicle information based on various sensors of the vehicle through a dedicated communication cable (multiplex communication line), and to control the display 1 and the sounding body 4 according to these signals. The control signal of is generated and output. In this case, the electronic control unit D and the main switch unit E are provided so as to be able to communicate with each other via a communication cable.

The microcomputer 3A can switch the display screen of the display panel 11 according to the operation of the input means 2 by starting the vehicle-mounted instrument A by turning on the main switch (start switch) of the main switch unit E.

The main switch unit E includes a switch for starting or ending the operation of the vehicle, and may be a button type or a key type. When the vehicle is an electric vehicle (electric vehicle or hybrid vehicle), when the main switch is turned on, a state in which electric power can be supplied from a high voltage battery (not shown) to the vehicle drive motor (not shown), When the main switch is turned off, a state in which the power supply is impossible is formed. Further, when the vehicle is a non-electric type (vehicle equipped with only an engine as a drive source), when the main switch is turned on, the ignition switch is turned on, and when the main switch is turned off, the ignition switch is turned off. In the following, as an example, it is assumed that the vehicle is a non-electric type and the on/off state of the main switch is linked to the on/off state of the ignition switch.

The drive circuit 3B is, for example, in the form of a voice IC (Integrated Circuit). The drive circuit 3B drives the sounding body 4 based on the control signal from the microcomputer 3A. The drive circuit 3B drives the sounding body 4 by applying a drive signal according to the control signal from the microcomputer 3A to the sounding body 4. In addition, in the present embodiment, the microcomputer 3A and the drive circuit 3B form an example of a “drive unit” that generates a drive signal for causing the sounding body 4 to ring.

The drive circuit 3B transits between the reset release state after the reset release and the non-reset release state. The drive circuit 3B shifts to the non-reset release state when reset in the reset release state, and shifts to the reset release state when reset is released in the non-reset release state.

In the non-reset release state, the drive circuit 3B makes a transition between the ringing drive state in which the sounding body 4 rings and the non-ringing drive state. The drive circuit 3B applies a constant voltage of 2.5 V to the sounding body 4 in the non-sounding drive state, and applies, for example, a sinusoidal drive signal to the sounding body 4 in the sounding drive state.

The sounding body 4 is a buzzer that sounds based on the control signal of the microcomputer 3A (and the drive signal based on it). The sounding body 4 can prompt the vehicle user to warn the vehicle in synchronization with the alarm state, the vehicle state, and the display output by the display 1, based on the vehicle information from the various electronic control units D and various sensors.

Note that the on-vehicle instrument (vehicle instrument) A described above is merely an example, and other configurations are arbitrary as long as the configuration includes the microcomputer 3A, the drive circuit 3B, and the sounding body 4.

FIG. 4 is an explanatory diagram of the open abnormality detection unit 7, and is a diagram showing an example of a circuit configuration including the microcomputer 3A, the drive circuit 3B, and the sounding body 4. FIG. 5 is a diagram schematically showing a state in which an open abnormality related to the wiring 90 has occurred in the circuit configuration of FIG. FIG. 6 is an explanatory diagram of the voltage V(P2) that changes according to the presence/absence of an open abnormality, and is a diagram showing a time-series waveform of the voltage V(P2). Further, FIG. 6 shows the time series waveform of the voltage V(P2), the time series of the state of the terminal AD (“HIGH” or “LOW”) and the open state of the wiring 90 (whether there is an open abnormality). Changes are shown.

In FIG. 4, a wiring 90 between the drive circuit 3B and the sounding body 4 is shown. A drive signal or the like from the drive circuit 3B is passed through the wiring 90. The wiring 90 includes two

lines

91 and 92. The line 91 has one end electrically connected to the sounding body 4 and the other end electrically connected to the connection point P0. The connection point P0 is located between the output terminal SPP and the resistor R0, and one end of the resistor R0 is electrically connected to the ground. The line 92 has one end electrically connected to the sounding body 4 and the other end electrically connected to the output terminal SPM. The voltage applied to the output terminals SPP and SPM is controlled by the drive circuit 3B. In the present embodiment, as an example, the drive circuit 3B applies a voltage of 2.5 V to the output terminals SPP and SPM in the reset release state (and the non-sounding drive state). In the ringing drive state, the drive circuit 3B applies a negative-phase sine wave voltage (a voltage oscillating around 2.5 V) as a drive signal to the output terminals SPP and SPM.

Further, in FIG. 4, the wiring 90 includes a connector 80. The connector 80 includes a sounding body side connector portion 81 and a board side connector portion 82. The sounding body side connector portion 81 and the board side connector portion 82 are electrically connected. In FIG. 4, circuit parts other than the circuit part from the sounding body side connector part 81 to the sounding body 4 are formed on the same circuit board.

In the present embodiment, the in-vehicle instrument A includes an open abnormality detection unit 7 that detects an open abnormality related to the wiring 90. The open abnormality related to the wiring 90 is typically caused by the disconnection of the wiring 90. The disconnection of the wiring 90 may occur due to disconnection of the connector 80 (disconnection between the sounding body side connector section 81 and the board side connector section 82) (see FIG. 5).

The open abnormality detection unit 7 performs processing for detecting an open abnormality related to the wiring 90 (hereinafter, referred to as “non-reset release state”) in a state where no voltage is applied to the output terminals SPP and SPM (hereinafter, referred to as “non-reset release state”). This is referred to as "open detection processing").

As shown in FIG. 4, the open abnormality detection unit 7 includes a pull-up circuit unit 401 (an example of a first circuit unit) and a pull-down circuit unit 402 (an example of a second circuit unit).

The pull-up circuit unit 401 is electrically connected to a connection point P1 on the line 91 (an example of a first connection point). Further, the pull-up circuit unit 401 is electrically connected to the microcomputer 3A (see terminal P in FIG. 4).

The pull-up circuit unit 401 is controlled by the microcomputer 3A. The microcomputer 3A controls the pull-up circuit unit 401 to switch between a state in which the predetermined voltage V0 is applied to the connection point P1 and a state in which the predetermined voltage V0 is not applied to the connection point P1. Specifically, when the microcomputer 3A turns on the transistor TR2, the base current of the transistor TR1 increases and the transistor TR1 turns on. When the transistor TR1 is turned on, a predetermined voltage V0 is generated at the connection point P1. Further, when the transistor TR2 is turned off, the base current of the transistor TR1 is reduced and the transistor TR1 is turned off. When the transistor TR1 is turned off, the connection point P1 is electrically disconnected from the power supply voltage 400 (a state in which the predetermined voltage V0 is not applied to the connection point P1 is formed).

The pull-up circuit unit 401 applies a predetermined voltage V0 to the connection point P1 in the non-reset released state under the control of the microcomputer 3A. The predetermined voltage V0 is an arbitrary voltage greater than 0, but in the present embodiment, as an example, it is a voltage between 4V and 5V (about 4.33V). Specifically, the pull-up circuit unit 401 is electrically connected to the power supply voltage 400 of 5V, and includes transistors TR1 and TR2 (an example of switching means), resistors R1, R2, R4, and the like.

The pull-down circuit unit 402 is electrically connected to a connection point P2 (an example of a second connection point) on the line 92. Further, the pull-down circuit unit 402 has a connection point P3, which is electrically connected to the microcomputer 3A via the resistor R3 (see terminal AD in FIG. 4) and also connected to the ground via the resistor R6. Electrically connected to. In this case, assuming that the voltage generated at the connection point P2 is V(P2), a voltage corresponding to the voltage V(P2) is generated at the terminal AD. In this way, the pull-down circuit unit 402 has a function of acquiring voltage information according to the voltage V(P2).

When performing the open detection processing, the microcomputer 3A turns on the transistor TR2 of the pull-up circuit unit 401 in the non-reset release state, thereby forming a state in which the predetermined voltage V0 is applied to the connection point P1. Then, in this state, the microcomputer 3A detects the presence or absence of the open abnormality related to the wiring 90 based on the voltage (voltage information corresponding to the voltage V(P2)) appearing at the terminal AD. When the open detection process is completed, the microcomputer 3A turns off the transistor TR2 of the pull-up circuit unit 401 to electrically disconnect the power supply voltage 400 and the connection point P1.

Here, when the open abnormality related to the wiring 90 does not occur, when the transistor TR2 of the pull-up circuit unit 401 is turned on in the non-reset release state, the voltage V(P2) changes to the voltage (about 4.33V), and the state of the terminal AD becomes "HIGH".

On the other hand, when the open abnormality related to the wiring 90 occurs, when the transistor TR2 of the pull-up circuit unit 401 is turned on in the non-reset release state, the voltage V(P2) becomes the voltage of the output terminal SPM of the drive circuit 3B. The corresponding voltage (that is, 0 V) is obtained, and the state of the terminal AD becomes "LOW".

Specifically, referring to FIG. 6, in FIG. 6, until the time t10, the open abnormality related to the wiring 90 has not occurred, and the voltage V(P2) is the voltage corresponding to the predetermined voltage V0 (about 4.33V). However, if the connector 80 is disconnected at time t10, the voltage V(P2) becomes 0V. As a result, the state (“HIGH” or “LOW”) of the terminal AD changes from “HIGH” to “LOW” at time t10.

Thus, in this embodiment, the wiring 90 is related based on the state of the terminal AD (“HIGH” or “LOW”), that is, the voltage (voltage information corresponding to the voltage V(P2)) appearing at the terminal AD. Open abnormality can be detected. That is, when the voltage appearing at the terminal AD is 0 V instead of the voltage (about 4.33 V) corresponding to the predetermined voltage V0, the open abnormality related to the wiring 90 can be detected. Therefore, for example, the microcomputer 3A detects the open abnormality related to the wiring 90 when the state of the terminal AD is “LOW” while the transistor TR2 of the pull-up circuit unit 401 is turned on in the non-reset release state. You can

Note that when the microcomputer 3A detects an open abnormality related to the wiring 90, it may output information informing that fact. For example, the microcomputer 3A may output information indicating the abnormality of the sounding body 4 on the display 1.

Next, a preferable execution timing of the open detection process will be described with reference to FIG.

FIG. 7 is an explanatory diagram of a preferable execution timing of the open detection process, in which the ignition switch (indicated as “IGN” in the figure) is turned on/off, the state of the microcomputer 3A (wakeup/sleep state), The state of the drive circuit 3B (indicated as "voice IC" in the figure) (reset release state/non-reset release state), the output terminal SPP, the voltage of the SPM (0 V/2.5 V), and the state of the open detection process (FIG. Then, the execution state is expressed as “open detection”) in chronological order.

In FIG. 7, the ignition switch is turned on at time t0, and accordingly, the wake-up signal is input to the microcomputer 3A at time t1. When the wake-up signal is input to the microcomputer 3A, the open detection process is put into the execution state. The open detection processing execution state continues until time t2. Therefore, the open detection processing period ΔT1 is a period from time t1 to time t2. The length of the open detection processing period ΔT1 is set to the minimum length capable of detecting the presence or absence of the open abnormality related to the wiring 90, as described above. For example, the length of the open detection processing period ΔT1 is set within the range of 40 ms to 100 ms as the time required to capture the voltage information (“HIGH” or “LOW”) appearing at the terminal AD. For example, 40 ms considers a sampling time of 10 ms and absorption of chattering four times.

At time t2, the reset release is executed for the drive circuit 3B, and the drive circuit 3B shifts from the non-reset release state to the reset release state. In this way, in this embodiment, the reset release is not executed for the drive circuit 3B at the same time when the wakeup signal is input to the microcomputer 3A, but after the wakeup signal is input to the microcomputer 3A, After the open detection processing period ΔT1 has elapsed, the reset release is executed for the drive circuit 3B. As a result, the open detection process can be executed in the non-reset released state. When the drive circuit 3B reaches the reset release state, the voltage of the output terminals SPP and SPM is fixed to 2.5V from the time t3.

After that, the ignition switch is turned off at time t4. At this time point t4, the microcomputer 3A is maintained in the wake-up state, and the open detection process at the time of turning off the ignition switch described later can be executed. At time t5 after time t4, the voltages of the output terminals SPP and SPM are changed from 2.5V to 0V. That is, the output of 2.5 V is stopped.

Then, at the time t6, when the drive circuit 3B shifts from the reset release state to the non-reset release state, the open detection process becomes the execution state. The execution state of the open detection process continues until time t7. Therefore, the open detection processing period ΔT2 is a period from time t6 to time t7. The length of the open detection processing period ΔT2 may be the same as the open detection processing period ΔT1 when the ignition switch is turned on. At time t7, the sleep signal is input to the microcomputer 3A, and the microcomputer 3A shifts from the wakeup state to the sleep state.

As described above, according to the example shown in FIG. 7, the microcomputer 3A executes the open detection process triggered by each of the operation start (ignition switch on event) and the operation end (ignition switch off event) of the vehicle. .. As a result, the open detection process can be executed without waiting for the timing of ringing the sounding body 4. Further, by using the start and end of operation of the vehicle, it is possible to minimize the influence on other functions due to the open detection process.

According to the present embodiment described above, the following excellent effects are achieved.

First, according to the present embodiment, as described above, the open abnormality detection unit 7 performs the open detection process in the state where the drive signal is not generated by the drive circuit 3B (that is, the sounding body 4 is not sounded). Execute. Thus, the open abnormality in the wiring 90 between the drive circuit 3B and the sounding body 4 can be detected without the sounding of the sounding body 4. More specifically, according to the present embodiment, the open abnormality detection unit 7 uses the predetermined voltage V0 generated by the pull-up circuit unit 401 without using the drive signal from the drive circuit 3B and detects the open state. Execute the process. Thus, the open abnormality in the wiring 90 between the drive circuit 3B and the sounding body 4 can be detected without the sounding of the sounding body 4. Therefore, according to the present embodiment, it is possible to detect the presence or absence of the open abnormality related to the wiring 90 even when the ringing condition of the sounding body 4 is not satisfied.

Further, in the present embodiment, the microcomputer 3A executes the open detection process triggered by the start of operation of the vehicle, so that it is possible to check whether or not the sounding body 4 can be sounded at the start of operation of the vehicle. In this case, the ringing possible state thereafter (in FIG. 7, a state in which 2.5 V is applied to the output terminals SPP and SPM in the non-ringing state, including a trip state in which the vehicle is operable) Since it is possible to detect in advance whether or not the sounding body 4 can be sounded, it is possible to notify the user of the abnormality in advance. In this case, it is possible to reduce the inconvenience caused by the inability to ring the sounding body 4 in the ringable state. That is, the state in which the user does not perform repair or the like in response to the advance notice of abnormality can be said to be a state in which the user does not expect information notification (alert) by the sounding of the sounding body 4. It is possible to reduce the user's uncomfortable feeling that the sounding body 4 has not been sounded at the timing when the sounding 4 should be sounded.

In the present embodiment, the microcomputer 3A executes the open detection process triggered by the start and end of operation of the vehicle, but the present invention is not limited to this. That is, the microcomputer 3A may execute the open detection process triggered by only one of the operation start and the operation end of the vehicle. For example, the microcomputer 3A may execute the open detection process with only the start of operation of the vehicle as the start or end of operation of the vehicle.

Further, in the present embodiment, as described above, the pull-up circuit unit 401 of the open abnormality detection unit 7 includes the transistors TR1 and TR2, so that the predetermined voltage V0 is applied to the connection point P1 and the connection point P1. It is possible to selectively form a state where the power supply voltage 400 and the power supply voltage 400 are electrically disconnected. Therefore, it is possible to form the state in which the predetermined voltage V0 is applied to the connection point P1 only in the execution state of the open detection process, so that the power supply voltage 400 and the connection point P1 are always electrically conducted, and the open detection process is executed. Power consumption can be reduced as compared with a configuration in which the power supply voltage 400 and the connection point P1 are electrically conducted in a period other than the period. However, in a modified example, the pull-up circuit unit 401 may be a circuit that does not include the transistors TR1 and TR2 and the like, and always electrically connects the power supply voltage 400 to the connection point P1. According to such a modified example as well, similar to the above-described embodiment, the open detection process can be executed to detect the presence or absence of an open abnormality in the wiring 90.

[Example 2]
Next, a second embodiment will be described. With regard to the present embodiment, constituent elements that may be the same as those in the above-described first embodiment may be assigned the same reference numerals and description thereof may be omitted.

The vehicle-mounted instrument (vehicle instrument) (not shown) in the second embodiment is different from the vehicle-mounted instrument A according to the first embodiment described above in that the open abnormality detection unit 7 is replaced by the open abnormality detection unit 7A.

FIG. 8 is an explanatory diagram of the open abnormality detection unit 7A according to the second embodiment.

The open abnormality detecting unit 7A according to the present embodiment differs from the open abnormality detecting unit 7 according to the first embodiment described above in that the pull-down circuit unit 402 is replaced by the pull-down circuit unit 402A.

The pull-down circuit unit 402A is different from the pull-down circuit unit 402 of the open abnormality detecting unit 7 according to the first embodiment described above in that one end is connected to the pull-up circuit unit 401. Specifically, in FIG. 8, the pull-down circuit unit 402A is electrically connected not to the connection point P3 between the connection point P2 and the resistance R6 but to the connection point P4 between the resistance R4 and the connection point P1. It Also in this case, the presence or absence of the open abnormality related to the wiring 90 can be detected based on the voltage appearing at the terminal AD, as in the first embodiment described above.

Specifically, in the non-reset released state, when the transistor TR2 of the pull-up circuit unit 401 is turned on, when the open abnormality related to the wiring 90 occurs, the voltage appearing at the terminal AD depends on the resistor R0. On the other hand, when the open abnormality related to the wiring 90 does not occur, the voltage appearing at the terminal AD is a value corresponding to the combined resistance of the resistor R0 and the internal resistance of the sounding body 4 and the resistor R6. Becomes Therefore, in the second embodiment, the presence or absence of the open abnormality related to the wiring 90 can be detected based on such a change in the voltage appearing at the terminal AD.

Although the pull-down circuit unit 402A is electrically connected between the resistor R4 and the connection point P1 in FIG. 8, it may be electrically connected between the transistor TR1 and the resistor R4.

Although each embodiment has been described in detail above, the invention is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the claims. Further, it is possible to combine all or a plurality of the constituent elements of the above-described embodiments.

In the above-described embodiment, the open abnormality detecting unit 7 is provided outside the drive circuit 3B and the microcomputer 3A, but the present invention is not limited to this. For example, part of the open abnormality detection unit 7 may be realized in the drive circuit 3B.

DESCRIPTION OF SYMBOLS 1 display 2 input means 3A microcomputer 3B drive circuit 4 sounding body 7 open abnormality detecting section 7A open abnormality detecting section 11 display panel 12 pointer type display section 31 storage section 80 connector 81 sounding body side connector section 82 board side connector section 90 wiring 91 Line 92 Line 400 Power supply voltage 401 Pull-up circuit unit 402 Pull-down circuit unit 402A Pull-down circuit unit A In-vehicle instrument (vehicle instrument)

Claims

With a sounding body,
A drive unit for generating a drive signal for ringing the sounding body;
A wire formed between the sounding body and the drive section, through which the drive signal flows,
A sound output device for a vehicle, comprising: an open abnormality detection unit that is electrically connected to the wiring and that detects an open abnormality related to the wiring when the drive signal does not flow through the wiring.
The open abnormality detection unit,
A first circuit portion electrically connected to a first connection point of the wiring and capable of applying a predetermined voltage to the first connection point;
A second circuit portion electrically connected to a second connection point different from the first connection point in the wiring,
The vehicle sound output device according to claim 1, wherein the open abnormality is detected between the first connection point and the second connection point based on the second circuit unit.
The first circuit unit includes switching means for switching between a state in which the predetermined voltage is applied to the first connection point and a state in which the predetermined voltage is not applied to the first connection point,
The vehicle sound according to claim 2, wherein the open abnormality detecting unit detects the open abnormality based on the voltage of the second circuit unit in a state where the predetermined voltage is applied to the first connection point. Output device.
4. The open abnormality detection unit executes the process for detecting the open abnormality, triggered by at least one of the operation start and the operation end of the vehicle, according to any one of claims 1 to 3. Sound output device for vehicles.