JP2011213228A - Alarm sound generating device of electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the safety of a pedestrian by making the pedestrian in an advancing direction of an electric automobile notice alarm a sound by surely transmitting the alarm sound to the pedestrian.SOLUTION: This alarm sound generating device is mounted to the electric automobile or the electric automobile constituted of a hybrid automobile. The alarm sound generating device includes a sensor for detecting vehicle speed, an electronic control unit connected to the sensor, and a circuit board for generating an alarm sound provided at a tip of a wiring harness having a base end connected to the electronic control unit. In the circuit board, a chip for sound source storage generation, an amplifier connected to the chip and a vibration generation source connected to the amplifier are mounted to a hard printed board or a flexible printed board. The wiring harness is wired in the vehicle and attached in a vehicle body arranged with the circuit board on a vehicle external surface existing on-board parts already mounted to the vehicle body and/or a tire wheel.

Description

  TECHNICAL FIELD The present invention relates to an alarm sound generating device for an electric vehicle, and more particularly to an electric vehicle such as an electric vehicle or a hybrid vehicle that can notify a pedestrian in the traveling direction of the approach of the vehicle.

In this type of electric vehicle, there is no engine noise generated in the engine vehicle, so a pseudo sound similar to the traveling sound generated by the engine vehicle is generated as an alarm sound according to the vehicle speed, so that pedestrians notice the approach of the vehicle It is required to make it.
Various proposals have been made for this type of alarm sound generating device. For example, in Japanese Utility Model Laid-Open Nos. 56-171501 and 7-182587, a speaker is used as a means for generating an alarm sound. .

Japanese Utility Model Publication No. 56-171501 Japanese Patent Laid-Open No. 7-182587

A speaker used as an alarm sound generating device has directivity in sound propagation, and when the speaker is facing forward, it is difficult for a pedestrian in all directions including both sides and back of a car to recognize.
In order for pedestrians in all directions to recognize the approach of a vehicle, it is necessary to increase the volume generated by a warning sound generator such as a speaker. However, increasing the volume causes problems of noise generation and increases the volume. This may threaten pedestrians.

  Therefore, it is preferable that the alarm sound during low-speed driving generated by the electric vehicle is a volume that is small enough to make the pedestrian notice the approach of the vehicle, but as described above, usually one speaker is mounted on the vehicle. Then, when speakers are distributed and arranged in many places, there is a problem that it takes a lot of installation work.

  The present invention has been made in view of the above problems, and it is assumed that the alarm sound to be generated has no directivity in sound propagation, so that pedestrians in all directions are aware of the approach of the vehicle and are safe for pedestrians. The challenge is to make it possible to contribute to

In order to solve the above problems, the present invention is an alarm sound generating device mounted on an electric vehicle or a hybrid vehicle,
A vehicle speed detection sensor; an electronic control unit connected to the sensor; and a circuit board for generating an alarm sound provided at a distal end of a wire harness having a base end connected to the electronic control unit, The circuit board is mounted on a rigid printed board or a flexible printed board with a sound source memory generating chip, an amplifier connected to the chip, and a vibration generating source connected to the amplifier.
The wire harness is routed to the vehicle, and the circuit board is disposed on the outer surface of the vehicle. The vehicle body is already attached to the vehicle body, and / or is attached to the tire wheel.
If the vehicle speed received from the sensor by the electronic control unit during traveling of the vehicle is below a threshold, the electronic control unit transmits an alarm sound generation signal to the circuit board via the wire harness and vibrates at the vibration source. And an alarm sound generating device characterized by generating an alarm sound by the vibration.

As described above, in the present invention, since the sound source memory generating chip, the amplifier, and the vibration generating source are collectively arranged on one circuit board, the alarm sound generating means can be miniaturized. In addition, since the circuit board is connected to and attached to the tip of a wire harness having a base end connected to an electronic control unit (hereinafter abbreviated as ECU) for alarm sound generation control, The circuit board for generating an alarm sound can be easily installed at an arbitrary position of the vehicle.
Therefore, in order to make it easy for people around the vehicle to notice the circuit board, the vehicle body to be arranged on the outer surface of the vehicle, the on-vehicle parts already mounted on the outer surface or the inner surface of the vehicle body, and any installation place such as a tire wheel Can be easily arranged.
The in-vehicle parts already mounted on the outer surface or inner surface of the vehicle body refer to the in-vehicle components already mounted on the conventional vehicle, and are attached to the bumper, license number plate, lamp cover, door molding, door inner surface. Door trims and the like.

The vibration generating source mounted on the circuit board is composed of a linear drive motor or eccentric drive motor including a voice coil motor, a piezoelectric element including a piezoelectric element, a mechanism using a giant magnetostrictive material,
The vehicle body to which the circuit board is attached, the on-vehicle components attached to the vehicle body, the tire wheel is vibrated to generate an alarm sound, or the vibration source of the vibration source is brought into contact with the vehicle body, the wheel or the vehicle-mounted product. An alarm sound is generated.
The piezoelectric element changes its dimensions when a voltage is applied. Specifically, for example, a piezoelectric ceramic vibrator is used. The giant magnetostrictive material is dimensionally deformed by a change in magnetic flux, and a vibrator made of the giant magnetostrictive material is used.

The alarm sound to be generated does not generate a stored alarm sound source through a speaker, but amplifies it with an amplifier, vibrates the vibration source with the amplified sound source signal, and the vibration is generated in the vehicle body, on-vehicle parts or tire wheel. It is propagated and vibrated to generate an alarm sound. Alternatively, a vibration is generated by directly striking the vehicle body with a vibrator in a vibration generating unit constituting a vibration generating source, and an alarm sound is generated.
Therefore, compared with the case where an alarm sound is generated through a speaker, the sound propagation is not directional, and an alarm sound is transmitted to pedestrians around the omnidirectional vehicle to notice the approach of the car. Can do.
Further, the vibration generating source can be easily obtained because it is simple, small and inexpensive and is a general-purpose component. If the voice coil motor in which the member (vibrator) to be vibrated is linearly driven among the vibration generating sources is used, an alarm sound can be easily generated by hitting the vehicle body when the vibrator moves forward. The vibration generation source is not limited, and other appropriate vibration generation sources may be used.

When the vehicle speed received from the sensor by the ECU during driving is less than or equal to a threshold value set in a range of 10 km to 30 km per hour, a sound generation signal is transmitted from the electronic control unit to the circuit board to generate an alarm sound, It is preferable that the generation of the alarm sound is stopped when the threshold value is exceeded. The threshold is preferably about 20 km / hour.
In addition, not only when driving at low speed, it may be set so as to generate an alarm sound similar to the driving sound generated by the engine car according to the vehicle speed during medium speed driving and high speed driving.

  Furthermore, a human sensor for detecting a person around the automobile may be installed in the automobile, and an alarm sound may be generated only when a human in the traveling direction of the automobile is detected by the human sensor.

It is preferable that the vibration sound generated by the vibration of the vibration generation source has a volume and tone color equivalent to a running sound generated in an engine automobile.
Thus, if it is a pseudo sound of the running sound of the engine car, it is possible to make the pedestrian notice the approach of the car without a sense of incongruity.

  In the alarm sound generating device of the present invention having the above-described configuration, an IC chip and an amplifier for generating an alarm sound source are provided on one circuit board (board) provided at the distal end of a wire harness whose base end is connected to an ECU for alarm sound generation control. Since the vibration generating sources are integrated and mounted, the wire harness can be routed in the vehicle, and the circuit board at the tip thereof can be easily attached to the vehicle body or the like disposed on the outer surface of the vehicle.

  In addition, the vibration source installed on the circuit board is vibrated, and the vibration is propagated to the vehicle body arranged on the outer surface of the vehicle, the on-vehicle components attached to the vehicle body, the tire wheel, and the vibration is amplified to generate an alarm sound. Alternatively, the alarm sound is generated by hitting the vehicle body or the member with the vibration member of the vibration generation source. In this way, since the alarm sound to be generated has no directivity of propagation, even if the number of installed alarm generators is a small number such as one, pedestrians who surround the car are all You can notice the approach.

1 is a schematic perspective view of an electric automobile showing a first embodiment of the present invention. It is a schematic block diagram of the alarm sound generator of 1st embodiment. It is drawing which shows the voice coil motor used as a vibration generation source, (A) is a whole block diagram, (B) is a principal part expanded sectional view. It is drawing which shows the structure of ECU. It is drawing which shows the experimental apparatus which measures the sound volume generate | occur | produced with the vibration source of 1st embodiment. It is the schematic of 2nd embodiment. It is the schematic of 3rd embodiment. It is the schematic of 4th embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment.
An electric vehicle 1 composed of an electric vehicle or a hybrid vehicle is equipped with an electronic control unit (ECU) 2 for alarm sound generation control, and a base end of a wire harness 4 is connected to the ECU 2 via a connector 3. An alarm sound generating circuit board 5 made of a hard board printed circuit board is connected to the tip of the wire harness 4 via a connector 6.
When the vehicle speed sensor 8 is connected to the ECU 2 and the speed received from the vehicle speed sensor 8 during traveling is a low speed equal to or lower than a set value, a drive signal is transmitted from the ECU 2 to the circuit board 5 to generate vibrations, thereby The alarm sound is generated.
The wire harness 4 that connects the ECU 2 and the circuit board 5 converges the electric wires of the power supply circuit w1, the signal circuit w2, and the ground circuit w3.

  The circuit board 5 includes a sound source generation chip (melody IC) 11, an amplifier 12 connected to the melody IC 11, and a vibration source 13 connected to the amplifier 12 mounted on a conductor 15 of the printed board 10. The melody IC 11 is connected to the ECU 2 via the conductor 15 and the connector 3.

As the vibration source 13, in this embodiment, as shown in FIG. 3, a voice coil motor 40 that vibrates by reciprocatingly moving a bobbin of a voice coil in a linear direction is used. The voice coil motor 40 has a yoke 42 fixed to the inner surface of the unit frame 41. The yoke 42 includes a bottom wall 42a, a peripheral wall 42b protruding from the bottom wall 42a, and a central shaft portion 42c surrounded by a space in the peripheral wall 42b. A magnet 43 is fixed to the inner peripheral surface of the peripheral wall 42b of the yoke 42, a bobbin 44 is interposed in the magnetic field between the magnet 43 and the central shaft portion 42c, and a coil 45 is wound around the outer periphery of the bobbin 44. By passing a current through the coil 45, the coil 45 and the bobbin 44 integrated with the coil 45 are moved according to Fleming's left-hand rule. A tip 44 a of the bobbin 44 is protruded outward from the opening of the unit frame 41.
The connector at the tip of the coil 45 is connected to the connector mounted on the circuit board 5. With this configuration, the vibration generating source 13 including the voice coil motor 40 is integrally provided on the circuit board 5 and accommodated in the case 20.

  A bracket 20a for fixing the vehicle body is projected in advance on the outer surface of the case 20 housing the circuit board 5, so that the bracket 20a can be fixed to the inner surface of the vehicle body B arranged on the outer surface of the vehicle. The tip 44a of the bobbin 44 of the voice coil motor 40 accommodated in the case 20 is brought close to the vehicle body B in a fixed state to the vehicle body B. Thus, when the coil 45 of the voice coil motor 40 is energized, the bobbin 44 moves forward or backward to strike the vehicle body B, and an alarm sound is generated using the vehicle body B as a sound source by a so-called vibration method.

  In this embodiment, the vehicle body B hit by the bobbin 44 of the voice coil motor 40 is a vehicle body formed of a partition panel that surrounds the engine placement portion. The sound generated in the engine room can resonate in the space in the engine room to increase the volume. In addition, the alarm sound generated by hitting the vehicle body B has low directivity of sound propagation compared to the sound generated from the speaker, and can be resonated from front to back and from side to side. In addition, the volume and timbre of the sound to be generated can be controlled by the amount of movement and the number of movements of the bobbin 44.

  The ECU 2 that transmits a vibration generation signal or a vibration stop signal to the vibration source 13 including the voice coil motor 40 via the amplifier 12 and the melody IC chip 11 detects the detection signal from the vehicle speed sensor 8 as shown in FIG. Is connected to the circuit board 5 via a wire harness 4, and a processing unit 2d is provided in a circuit 2c that conducts the input unit 2a and the output unit 2b. The processing unit 2d includes a determination unit 2d1 that determines whether the vehicle speed is equal to or lower than a threshold value for generating an alarm sound, an alarm sound adjustment unit 2d2 that adjusts the volume and tone of the alarm sound to be generated, and the like.

The processing unit 2d of the ECU 2 sets a threshold value within the range of 10 km / h to 30 km / h of the vehicle speed received from the vehicle speed sensor 8, and transmits a drive signal to the vibration source 13 when the vehicle speed is below the threshold during traveling. It is set to generate sound. In the present embodiment, a speed of 20 km / h is set as a threshold, an alarm sound is generated at a speed of 20 km / h or less, and the alarm sound is stopped when the speed exceeds 20 km / h.
Further, the volume and tone color of the alarm sound generated by the vibration of the vibration source 13 is the same volume and tone color as the traveling sound at the low speed of the engine automobile. It should be noted that other timbres and melodies may be used as long as the pedestrian recognizes that the sound is a sound that makes an electric vehicle approach.

In an electric vehicle equipped with the alarm sound generator configured as described above, if the vehicle speed is less than or equal to a threshold value (less than 20 km / h) during travel, an alarm generation signal is transmitted from the ECU 2 to the circuit board 5 via the wire harness 4, The coil 45 of the voice coil motor 40 of the vibration source 13 is energized on the substrate 5. As a result, the bobbin 44 moves back and forth to strike the vehicle body B and vibrate the vehicle body B to generate an alarm sound.
Since the vehicle body B is a partition plate in the engine room as described above, the vibration generated from the vehicle body B resonates in the space in the engine room and propagates outside the vehicle with a large volume. It should be noted that, in a state where the sound volume is resonated in the engine room and the sound volume becomes high, the sound volume is set to the same level as the traveling sound generated when the engine automobile is 20 km per hour.

"Experimental example"
A voice coil motor as a vibration source was created with the following settings to generate sound.
The configuration of the whistle coil motor used in the experiment was the same as that shown in FIG. 3, and a diaphragm 50 was fixed to the tip of the bobbin of the voice coil motor as shown in FIG. A microphone 51 was installed at a position 10 cm away from the diaphragm 50, and the generated sound was measured.
Coil wound around the outer periphery of the bobbin: diameter 7 mm, length 27 mm, number of turns: 77 turns Inner gap between the inner peripheral surface of the bobbin and the outer peripheral surface of the central shaft portion of the yoke: 1 mm
Outer cap between the outer peripheral surface of the bobbin and the inner peripheral surface of the peripheral wall of the yoke: 4 mm
In FIG.
B: Magnetic velocity density
I: Current (A)
L: Length of coil wire in magnetic field (m)
F (force that the bobbin moves (N)): B × I × L
Input: 50 mW Frequency 7 kHz (peak voltage 1.58 V, peak current 0.38 A) The sound volume collected by the microphone 51 installed at a position 10 cm away from the voice coil motor was 58 dBA.
In addition, the running sound at 20 km / hour of the engine car measured by the present inventors was 50 to 60 dBA. Therefore, it was possible to generate a traveling sound similar to that of an engine vehicle.

In the embodiment, the circuit board 5 is attached to the vehicle body B surrounding the engine room. However, the circuit board 5 may be fixed to the inner surface of the lamp cover of the headlamp disposed on the outer surface of the vehicle body B and the rear surface of the license plate. Furthermore, you may attach the case 20 which accommodated the said circuit board 5 in the center position of a tire wheel.
Further, the tip of the bobbin of the voice coil motor may be contactless without hitting the vehicle body or the vehicle-mounted product, and vibration may be propagated to vibrate the vehicle body or the vehicle-mounted product to generate an alarm sound.

FIG. 6 shows a second embodiment.
In the second embodiment, the alarm sound generation circuit board is not a printed board of a rigid board, but a flexible printed circuit (FPC), and the FPC is also used as a wire harness 4 for connecting the ECU 2 to the ECU 2. A melody IC 11, an amplifier 12, and a vibration source 13 are mounted on the other end of the FPC to which one end is connected.

  The FPC 30 is provided with wiring conductors 30a for the power circuit w1, the signal circuit w2, and the ground circuit w3, and the base end of the FPC 30 is connected to the ECU 2 through a connector. The tip of the wiring conductor 30a of the FPC 30 is used as a circuit board portion 55 for generating an alarm sound, and the melody IC11, the amplifier 12 connected to the melody IC11, and the vibration generating source 13 connected to the amplifier 12 are mounted on the circuit board portion 55. is doing.

The circuit board portion 55 at the tip of the FPC 30 is housed in a case as in the first embodiment, and the case is fixed to a vehicle body or a vehicle-mounted component that is fixed to the vehicle body.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.

FIG. 7 shows a third embodiment using a piezoelectric element made of piezoelectric ceramics as the vibration source 13.
The piezoelectric ceramic 60 has a cylindrical shape, is connected to a power supply circuit controlled by the ECU 2, and, like the bobbin of the first embodiment, the piezoelectric ceramic 60 reciprocates in the axial direction to vibrate, and hits the vehicle body at its tip. ing.

FIG. 8 shows a fourth embodiment using a giant magnetostrictive material as a vibration source.
As the giant magnetostrictive material, for example, a vibrator 70 made of terphenol D (magnetic anisotropy compensating alloy Tbr Dy1-xFe2) is used, and the vibrator 70 is reciprocated in the axial direction so as to hit the vehicle body. Yes.

  In addition, this invention is not limited to the said embodiment, All the embodiments of the range which does not deviate from the summary of this invention are included.

1 Electric vehicle 2 ECU
4 Wire harness 5 Circuit board 8 Vehicle speed sensor 10 Printed board 11 Sound source generation chip (melody IC)
12 Amplifier 13 Vibration source 30 FPC
40 Voice coil motor 44 Bobbin 45 Coil B Body

Claims (4)

An alarm sound generating device mounted on an electric vehicle or a hybrid vehicle,
A vehicle speed detection sensor; an electronic control unit connected to the sensor; and a circuit board for generating an alarm sound provided at a distal end of a wire harness having a base end connected to the electronic control unit, The circuit board is mounted on a rigid printed board or a flexible printed board with a sound source memory generating chip, an amplifier connected to the chip, and a vibration generating source connected to the amplifier.
The wire harness is routed to the vehicle, and the circuit board is disposed on the outer surface of the vehicle. The vehicle body is already attached to the vehicle body, and / or is attached to the tire wheel.
If the vehicle speed received from the sensor by the electronic control unit during traveling of the vehicle is below a threshold, the electronic control unit transmits an alarm sound generation signal to the circuit board via the wire harness and vibrates at the vibration source. And generating an alarm sound by the vibration.   2. The electric vehicle alarm sound according to claim 1, wherein the vibration source is selected from a linear drive motor or an eccentric drive motor including a voice coil motor, or a mechanism using a piezoelectric element or a giant magnetostrictive material including a piezoelectric element. Generator.   When the vehicle speed received by the electronic control unit from the sensor is less than or equal to a threshold value set in the range of 10 km / h to 30 km / h, the vibration control signal is transmitted from the electronic control unit to the vibration source to alert The alarm sound generating device for an electric vehicle according to claim 1 or 2, wherein a sound is generated and an alarm sound generation stop signal is transmitted when the threshold value is exceeded.   The alarm sound generating device for an electric vehicle according to any one of claims 1 to 3, wherein the vibration sound generated by the vibration of the vibration generation source has a volume equivalent to a running sound generated in an engine vehicle.

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