JP6734675B2 - Vehicle switching device - Google Patents

Description

The present invention relates to a vehicle switching device.

Conventionally, there is a switching device having switching means. Patent Document 1 discloses a technology of a switching power supply that rectifies and smoothes a voltage generated by turning on and off a switching element to obtain a direct current output, and feeds back the output to a PWM control circuit to control the operation of the switching element. Has been done.

JP 2002-369507 A

When a switching device is installed in a vehicle having a communication device, noise may occur in the communication device due to the switching operation of the switching device. It is desired to suppress noise to communication equipment.

An object of the present invention is to provide a vehicle switching device capable of suppressing noise to communication equipment.

A vehicle switching device according to the present invention includes a voltage conversion unit that converts a voltage by on/off control of a switching unit, a control unit that controls the voltage conversion unit, and a detection unit that detects an operating state of a communication device mounted on a vehicle. And the control unit sets the switching frequency of the voltage conversion unit to a frequency different from the frequency band used by the communication device when the communication device is operating.

In the above vehicle switching device, the communication device is a radio receiver, and the control unit, when the radio receiver is in a reception state, sets the switching frequency of the voltage conversion unit to a frequency band used by radio broadcasting. Preferably have different frequencies.

When the communication device is operating, the control unit of the vehicle switching device according to the present invention sets the switching frequency of the voltage conversion unit to a frequency different from the frequency band used by the communication device. According to the vehicle switching device of the present invention, it is possible to suppress the noise to the communication device due to the switching operation of the switching unit.

FIG. 1 is a block diagram showing a configuration of a vehicle switching device according to an embodiment. FIG. 2 is a flowchart showing the operation of the vehicle switching device according to the embodiment. FIG. 3 is an explanatory diagram of a switching frequency determination method in the second modified example of the embodiment.

Hereinafter, a vehicle switching device according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 and 2. The present embodiment relates to a vehicle switching device. FIG. 1 is a block diagram showing a configuration of a vehicle switching device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing an operation of the vehicle switching device according to the embodiment.

As shown in FIG. 1, the vehicle switching device 1 according to the present embodiment includes an input unit 11, a voltage conversion circuit 12, an output unit 13, a switching frequency control circuit 14, a microcomputer 15, and a communication circuit 16. The vehicle switching device 1 of the present embodiment is a DC/DC converter, and is a voltage conversion device that converts the voltage of DC power. The vehicle switching device 1 constitutes a vehicle switching power supply together with the power supply 3.

The input unit 11 is electrically connected to the power supply 3. The power supply 3 of the present embodiment is a power supply device mounted on a vehicle, and is typically a power storage device such as a battery. The voltage conversion circuit 12 is a voltage conversion unit that converts a voltage by on/off control of the switching means 12a. The switching means 12a included in the voltage conversion circuit 12 is, for example, a semiconductor switching element. The voltage conversion circuit 12 may include a plurality of switching means 12a. Further, the voltage conversion circuit 12 may be configured to include an inductor and a capacitor in addition to the switching means 12a. The output unit 13 is connected to an electric load mounted on the vehicle. The electric load is, for example, a power storage device such as a device or a battery operated by electric power supplied from the vehicle switching device 1. The electric load of this embodiment includes the audio device 2.

The switching frequency control circuit 14 is a control circuit that outputs an ON command and an OFF command to the switching means 12a of the voltage conversion circuit 12. The switching frequency control circuit 14 updates the command content for the switching means 12a with the set switching frequency. The switching frequency control circuit 14 of the present embodiment switches the switching means 12a between the ON state and the OFF state so that the duty ratio of the switching means 12a becomes the target duty ratio. The duty ratio of the switching means 12a is the ratio of the cumulative time during which the switching means 12a is in the ON state in a unit time. The vehicle switching device 1 stores in advance, for example, a control pattern that defines an ON/OFF switching schedule of the switching unit 12a according to the duty ratio. The switching frequency control circuit 14 outputs an ON command or an OFF command to the switching means 12a based on this control pattern.

The microcomputer 15 is a device that outputs a control target for the voltage conversion circuit 12. In the vehicle switching device 1 of the present embodiment, the switching frequency control circuit 14 and the microcomputer 15 function as a control unit. The microcomputer 15 of the present embodiment outputs the target switching frequency and duty ratio to the switching frequency control circuit 14. The switching frequency control circuit 14 determines the period for updating the command content for the switching means 12a based on the target switching frequency acquired from the microcomputer 15. Further, the switching frequency control circuit 14 determines the command content for the switching means 12a based on the target duty ratio acquired from the microcomputer 15. The switching frequency control circuit 14 refers to the control pattern and updates the command content (ON command/OFF command) to the switching means 12a every time the update cycle elapses. The switching means 12a switches to an on state or an off state according to the content of the command from the switching frequency control circuit 14.

The communication circuit 16 is a circuit that communicates with the audio device 2. The communication circuit 16 of the present embodiment communicates with the audio device 2 information regarding the operating state of the audio device 2.

The audio device 2 of this embodiment includes a radio receiver. The audio device 2 has a function as an AM radio receiver that receives an AM radio broadcast and a function as an FM radio receiver that receives an FM radio broadcast. The audio device 2 of the present embodiment operates by the electric power supplied from the vehicle switching device 1.

The information about the operating state of the audio device 2 includes information about power-on/off of the audio device 2, information about whether or not a radio broadcast is being received, and the radio broadcast being received is AM radio broadcast or FM broadcast. It includes information about which of the radio broadcasts is being received, information about the frequency of the radio broadcast being received, and the like. The audio device 2 of the present embodiment digitally sets the received frequency. The audio device 2 sends the information about the received frequency and the like as a digital signal to the communication circuit 16. The communication circuit 16 outputs the information acquired from the audio device 2 to the microcomputer 15. The communication circuit 16 has a function as a detection unit that detects an operating state of a communication device mounted on the vehicle.

In the vehicle switching device 1 of the present embodiment, when the audio device 2 is in a reception state in which it receives a radio broadcast as a radio receiver, the switching frequency of the voltage conversion circuit 12 is different from the frequency band used by the radio broadcast. Frequency. As a result, the vehicle switching device 1 can suppress the generation of radio noise.

The operation of the vehicle switching device 1 according to the present embodiment will be described with reference to FIG. The control flow shown in FIG. 2 is repeatedly executed at predetermined intervals, for example. In step S10, the microcomputer 15 determines whether or not radio reception (listening) is in progress. The microcomputer 15 determines whether or not the audio device 2 is receiving a radio broadcast based on the information acquired from the communication circuit 16. As a result of the determination, if it is determined that the radio is being received (step S10-Y), the process proceeds to step S20, and if not (step S10-N), the process proceeds to step S30.

In step S20, the microcomputer 15 acquires the frequency of the reception band. The microcomputer 15 acquires the frequency band of the radio broadcast currently received by the audio device 2 based on the information acquired from the communication circuit 16. In the present embodiment, when the broadcast received by the audio device 2 is AM radio broadcast, the frequency band used as AM radio broadcast is acquired. This frequency band is, for example, a usable frequency band (526.5 to 1,606.5 [kHz]) between the upper limit and the lower limit defined by the Broadcast Law. When the broadcast received by the audio device 2 is FM radio broadcast, the frequency band (76 to 90 [MHz]) used as FM radio broadcast is acquired. When step S20 is executed, the process proceeds to step S40.

In step S40, the microcomputer 15 changes the operating frequency. The microcomputer 15 determines the target switching frequency based on the frequency band acquired in step S20. When the frequency band acquired in step S20 is the frequency band of AM radio broadcasting (hereinafter, simply referred to as "AM band"), the microcomputer 15 sets the target switching frequency to a frequency different from the AM band, in other words, an AM band. The frequency is not included. When the audio device 2 receives an AM radio broadcast, the microcomputer 15 of the present embodiment sets the target switching frequency to a frequency on the low frequency side of the AM band, for example, a frequency of 100 kHz or less. The target switching frequency is preferably a frequency that allows the efficiency of the vehicle switching device 1 to be as high as possible within a selectable range.

When the frequency band acquired in step S20 is the frequency band of FM radio broadcasting (hereinafter, simply referred to as “FM band”), the microcomputer 15 sets the target switching frequency to a frequency different from the FM band, in other words, the FM band. The frequency is not included. When the audio device 2 is receiving the FM radio broadcast, the microcomputer 15 of the present embodiment sets the target switching frequency to a frequency lower than the FM band, for example, a frequency of 1 MHz or less. The target switching frequency is preferably a frequency that allows the efficiency of the vehicle switching device 1 to be as high as possible within a selectable range.

The microcomputer 15 outputs the determined target switching frequency to the switching frequency control circuit 14. The switching frequency control circuit 14 updates the command content for the switching means 12a with the acquired target switching frequency. When step S40 is executed, this control flow ends.

In step S30, the microcomputer 15 optimizes the operating frequency. Since the audio device 2 is not receiving the radio broadcast, the switching frequency can be determined without considering the radio noise. The microcomputer 15 determines the optimum frequency as the operating frequency (switching frequency) of the voltage conversion circuit 12. The optimum frequency is, for example, a frequency at which the vehicle switching device 1 can operate most efficiently based on the target value of the output voltage. The microcomputer 15 outputs the determined optimum frequency to the switching frequency control circuit 14 as a target switching frequency. The switching frequency control circuit 14 updates the command content for the switching means 12a with the acquired optimum frequency. When step S30 is executed, this control flow ends.

As described above, the vehicle switching device 1 of the present embodiment includes the voltage conversion circuit 12 that converts the voltage by the on/off control of the switching means 12a, the switching frequency control circuit 14 and the microcomputer 15 that control the voltage conversion circuit 12. And a communication circuit 16 for detecting the operating state of the audio device 2 mounted on the vehicle. When the audio device 2 is operating, the switching frequency control circuit 14 and the microcomputer 15 set the switching frequency of the voltage conversion circuit 12 to a frequency different from the frequency band used by the audio device 2. Therefore, the vehicle switching device 1 of the present embodiment can reduce the radio noise of the audio device 2.

In order to make the vehicle switching device 1 highly efficient and compact, it is effective to operate the switching means 12a at a high frequency. However, when the switching means 12a is operated at a high frequency, there is a possibility that noise may be generated in communication equipment such as a radio receiver mounted on the vehicle. The vehicle switching device 1 of the present embodiment can operate with high efficiency by optimizing the switching frequency when the communication device is not operating. On the other hand, the vehicle switching device 1 suppresses noise to the communication device and improves communication quality by setting the switching frequency to a frequency different from the frequency band used for communication when the communication device is operating. be able to.

According to the vehicle switching device 1 of the present embodiment, it is possible to reduce the number of parts for noise reduction in the communication device.

The vehicle switching device 1 is not limited to the DC/DC converter, and may be another voltage conversion device or another switching device. The power supply source of the audio device 2 may not be the vehicle switching device 1. The vehicle switching device 1 of the present embodiment can suppress not only the noise transmitted through the electric wire but also the influence of the radiation noise on the audio device 2.

The communication device mounted on the vehicle is not limited to the audio device 2 including the function of the radio receiver. The communication device may be a communication device that performs inter-vehicle communication, a communication device that performs road-to-vehicle communication, or the like. In this case, the microcomputer 15 sets the switching frequency of the voltage conversion circuit 12 to a frequency that does not overlap with the frequency band used by the communication device when the communication device is operating.

[First Modification of Embodiment]
A first modified example of the embodiment will be described. In the above-described embodiment, the changed target switching frequency in step S40 is set to a frequency on the lower frequency side than the frequency band of radio broadcasting. Alternatively, the changed target switching frequency may be a frequency higher than the frequency band of radio broadcasting. For example, when the audio device 2 receives an AM radio broadcast, the changed target switching frequency may be a frequency on the higher frequency side than the AM band, for example, a frequency of 1700 kHz or higher or a frequency of 2 MHz or higher. When the audio device 2 is receiving the FM radio broadcast, the changed target switching frequency may be a frequency on the higher frequency side than the FM band, for example, a frequency of 108 MHz or higher.

[Second Modification of Embodiment]
A second modification of the embodiment will be described with reference to FIG. FIG. 3 is an explanatory diagram of a method of determining a switching frequency in the second modified example of the embodiment. There may be a plurality of frequency bands used by communication devices, such as a case where a vehicle is equipped with a plurality of communication devices. For example, it is assumed that another communication device is mounted on the vehicle in addition to the audio device 2. Examples of other communication devices include communication devices that perform inter-vehicle communication, communication devices that perform road-to-vehicle communication, and the like. As shown in FIG. 3, it is assumed that the frequency band FR1 used by another communication device and the AM band FR2 used by the audio device 2 do not overlap.

The vehicular switching device 1 of the second modified example has a detection unit that detects an operating state of another communication device. The microcomputer 15 sets the switching frequency of the voltage conversion circuit 12 to a frequency different from the frequency bands FR1 and FR2 used by each communication device when the other communication device and the audio device 2 are operating to perform communication. The microcomputer 15 selects the target switching frequency from the frequency band FRX between the frequency band FR1 and the AM band FR2, for example. The microcomputer 15 may employ an intermediate frequency in the frequency band FRX as the target switching frequency.

The microcomputer 15 may set a frequency on the high frequency side of the AM band FR2 or a frequency on the low frequency side of the frequency band FR1 as the target switching frequency. That is, when a plurality of communication devices are operating, the microcomputer 15 preferably sets the frequency that is not included in any of the frequency bands used by these communication devices as the target switching frequency.

[Third Modification of Embodiment]
A third modified example of the embodiment will be described. The microcomputer 15 may select, as the switching frequency, a frequency different from the frequency band used by the receiving broadcasting station. For example, when the audio device 2 selects the A1 broadcasting station for AM radio broadcasting, the switching frequency of the voltage conversion circuit 12 is a frequency different from the frequency band used by the A1 broadcasting station. In this case, of the AM band, frequency bands other than the frequency band used by the A1 broadcasting station are also candidates for switching frequencies. When the tuning is switched from the A1 broadcasting station to another broadcasting station, the switching frequency is appropriately changed so as not to overlap with the frequency band used by the broadcasting station after the switching. With this configuration, it is possible to maintain the switching frequency of the voltage conversion circuit 12 at a high frequency and suppress a decrease in efficiency of the vehicle switching device 1.

The contents disclosed in the above-described embodiments and modified examples can be appropriately combined and executed.

1 Vehicle Switching Device 2 Audio Equipment 3 Power Supply 11 Input Section 12 Voltage Converter (Voltage Converter)
12a switching means 13 output section 14 switching frequency control circuit (control section)
15 Microcomputer (control unit)
16 Communication circuit (detection unit)

Claims (4)

A voltage conversion unit that converts the voltage by on/off control of the switching means and supplies power to the communication device mounted on the vehicle,
A control unit for controlling the voltage conversion unit,
A detection unit that detects an operating state of the communication device,
Equipped with
When the communication device is operating, the control unit sets the switching frequency of the voltage conversion unit to a frequency that can operate with high efficiency in a frequency range different from the frequency band used by the communication device ,
The communication device includes a radio receiver,
The control unit includes a frequency band excluding a frequency band of a broadcast received by the radio receiver in a band of a radio broadcast, as a switching frequency candidate of the voltage conversion unit. .. The control unit determines a frequency at which the operation can be performed with high efficiency, based on a target value of the output voltage of the voltage conversion unit.
The vehicle switching device according to claim 1. A voltage conversion unit that converts the voltage by on/off control of the switching means and supplies power to the communication device mounted on the vehicle,
A control unit for controlling the voltage conversion unit,
A detection unit that detects an operating state of the communication device,
Equipped with
When the communication device is operating, the control unit sets the switching frequency of the voltage conversion unit to a frequency that can operate with high efficiency in a frequency range different from the frequency band used by the communication device,
The control unit determines a frequency at which the operation can be performed with high efficiency, based on a target value of the output voltage of the voltage conversion unit.
A vehicle switching device characterized by the above. The communication device includes a radio receiver and a second communication device different from the radio receiver,
The second communication device is a communication device for performing vehicle-to-vehicle communication or a communication device for performing road-to-vehicle communication,
When the radio receiver is in a receiving state and the second communication device is communicating, the control unit controls the switching frequency of the voltage conversion unit to be a frequency band used by radio broadcasting and the second frequency. The vehicle switching device according to any one of claims 1 to 3, wherein the frequency is different from any of frequency bands used by the communication device.

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