JP6565566B2 - Contact protection device - Google Patents

Description

  The present invention relates to a contact protection device, and more particularly, to a contact protection device which removes an oxide film generated by aging of a switch or relay having a mechanical contact and prevents contact failure.

In a vehicle, when an emergency call device speaker is also used as a vehicle-mounted speaker, a speaker relay circuit for switching sound output is required.
Normally, the contact on the emergency notification device side of the relay circuit is not energized, so that an oxide film is formed and a conduction failure occurs.
In order to prevent the conduction failure due to the aging of the contact of the relay circuit, it is necessary to periodically pass a current in order to remove the oxide film on the contact of the relay circuit.
In patent document 1 mentioned later, the technical content which destroys the oxide film produced in the switch contact by applying a direct current is disclosed.

JP-A-6-96637

By the way, in the conventional contact protection device, there are a direct current and an alternating current. However, as described in Patent Document 1 described above, when a direct current is passed, a load is applied to the speaker coil, causing a failure. There is a fear.
In Patent Document 1, there is no description regarding the alternating current and the frequency band of the alternating current.
In addition, when an alternating current is passed through the contact point of the relay circuit for the speaker, a sound corresponding to the alternating current is output, so that there is an inconvenience that the passenger senses it.

  An object of the present invention is to remove an oxide film generated in a switch or relay having a mechanical contact, and to prevent a contact failure.

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention includes a relay circuit having a mechanical contact and capable of switching between a first circuit that is always energized during normal operation and a second circuit that is energized in an emergency. And a current supply means for removing the oxide film generated at the contact of the relay circuit by always passing an excessive current more than the usual, wherein the relay circuit supplies a signal of a speaker that outputs sound. And a control means for controlling the current supply means so that an AC signal having a predetermined frequency or higher is output to the relay circuit, while being connected to a line and temporarily switching the relay circuit to the second circuit. It is characterized by that.
The contact protection device includes a switch having a mechanical contact, and a current supply unit that removes an oxide film generated at the contact of the switch by flowing an excessive current more than usual. A control means connected to a signal supply line of a speaker that outputs sound, and controls the current supply means so that an alternating current signal having a predetermined frequency or higher is output to the switch while temporarily closing the contact of the switch. It is provided with.

According to the present invention, by outputting a high-frequency signal (signal other than the audible frequency) of a predetermined frequency or higher, it is possible to prevent sound from being heard from the speaker during execution of the oxide film removal control.
The oxide film can be removed without causing discomfort to the occupant, and poor energization of relay contacts with low energization frequency can be prevented.
Further, by outputting a high-frequency signal (signal other than the audible frequency) of a predetermined frequency or higher, it is possible to prevent sound from being heard from the speaker during execution of the oxide film removal control.
The oxide film can be removed without causing discomfort to the occupant, and a failure in energization of the switch contacts can be prevented.

FIG. 1 is a schematic explanatory diagram showing a relay circuit during normal operation in the contact protection device. Example 1 FIG. 2 is a schematic explanatory view showing an emergency relay circuit in the contact protection device. Example 1 FIG. 3 is a schematic explanatory view showing a switch in a contact open state in the contact protection device. (Example 2)

  Embodiments of the present invention will be described below in detail with reference to the drawings.

1 and 2 show Embodiment 1 of the present invention.
1 and 2, reference numeral 1 denotes a contact protection device.
The contact protection device 1 includes a relay circuit 2 that can be switched between a normal operation and an emergency, and a current supply means 3 that removes an oxide film generated in the relay circuit 2 by flowing an excessive current more than usual. And a control means 4 for controlling the current supply means 3.
The contact protection device 1 is connected to an audio 5 so as to function as a speaker that outputs sound and to be connected to a signal supply line 10 to be described later to serve as both an emergency speaker and an in-vehicle speaker. Yes.
In addition, the relay circuit 2 is energized in a first circuit 6 that is always energized during normal operation as shown in FIG. 1 and in an emergency (which can also be referred to as “relay failure diagnosis”) as shown in FIG. 2. A circuit, that is, a second circuit 7 that is a circuit that is less energized than the first circuit 6.
At this time, the first circuit 6 has mechanical first contacts 8a and 8b, while the second circuit 7 also has mechanical second contacts 9a and 9b.
The audio 5 includes a driver-side speaker 11 connected to the audio 5 via a signal supply line 10 and a passenger-side speaker 12 connected to the audio 5 by the first circuit 6 of the relay circuit 2 during normal operation. And a rear seat right speaker 13 and a rear seat left speaker 14.
The signal supply line 10 includes a first signal supply line 10x that connects the relay circuit 2 and the driver's seat side speaker 11, and a second signal that connects the first contacts 8a and 8b of the first circuit 6 to the audio 5 side during normal operation. It comprises a signal supply line 10y and a third signal supply line 10z for connecting the second contacts 9a, 9b of the second circuit 7 to the current supply means 3 side in an emergency.
Therefore, during normal operation, as shown in FIG. 1, the first contacts 8 a and 8 b of the first circuit 6 of the relay circuit 2 pass through the first signal supply line 10 x and the second signal supply line 10 y of the signal supply line 10. The driver's seat side speaker 11 is connected to the audio 5 side.
In an emergency, as shown in FIG. 2, the control circuit 4 controls the relay circuit 2 to be switched to the second circuit 7, and the second contact points 9 a and 9 b of the second circuit 7 of the relay circuit 2 control the signal supply line 10. The driver's seat side speaker 11 is connected to the current supply means 3 side via the first signal supply line 10x and the third signal supply line 10z.

At this time, the control means 4 of the contact protection device 1 temporarily controls the relay circuit 2 to be switched to the second circuit 7 and current supply means 6 so that an AC signal having a predetermined frequency or higher is output to the relay circuit 2. It is set as the structure which controls.
More specifically, the control means 4 of the contact protection device 1 periodically, that is, during the execution of the oxide film removal control of the second contacts 9a and 9b of the second circuit 7, as in the case of an emergency. The relay circuit 2 is temporarily switched from the first circuit 6 to the second circuit 7, and the first signal supply line 10x of the signal supply line 10 and the second contacts 9a and 9b of the second circuit 7 of the relay circuit 2 are controlled. The driver's seat side speaker 11 is connected to the current supply means 3 side via the third signal supply line 10z.
Then, the current supply means 3 is controlled by the control means 4 of the contact protection device 1 so that an AC signal having a predetermined frequency or more is output from the current supply means 3 side to the relay circuit 2.
Note that the “predetermined frequency or more” refers to a frequency that exceeds the audible frequency, and generally the audible frequency range is 20 Hz to 20000 Hz (also referred to as “20 KHz”). Assumes a frequency of 20000 Hz (“20 KHz”) or higher.

As a result, the control circuit 4 of the contact protection device 1 periodically switches the relay circuit 2 from the first circuit 6 to the second circuit 7 periodically, and the second contact 9a of the second circuit 7 of the relay circuit 2 is controlled. , 9b by controlling the current supply means 3 so as to output a high-frequency signal (signal other than the audible frequency) of a predetermined frequency or more, so that the driver seat can be used during the execution of the oxide film removal control of the second contacts 9a, 9b. It is possible to prevent sound from being heard from the side speaker 11.
The oxide film on the second contacts 9a and 9b can be removed without causing discomfort to the occupant, and it is possible to prevent poor energization of the second contacts 9a and 9b of the second circuit 7 of the relay circuit 2 with low energization frequency.
Further, when compared with a configuration in which a direct current is passed, the driver seat side speaker 11 can be reduced.

  FIG. 3 shows Embodiment 2 of the present invention.

  The feature of the second embodiment is that the contact protection device 21 does not use the above-described audio.

That is, the contact protection device 21 includes a switch 22, a current supply unit 24 that removes an oxide film generated at the mechanical contact 23 of the switch 22 by flowing an excessive current, and the current supply unit 24. A control means 25 for controlling and a speaker 26 for outputting sound are provided.
The current supply means 24 and the speaker 26 are connected via a signal supply line 27. A switch 22 that is in an open state during normal operation and temporarily closes in the middle of the signal supply line 27. The contact 23 is provided.
At this time, the signal supply line 27 includes a first signal supply line 27x that connects the current supply unit 24 and the contact 23 of the switch 22, and a second signal supply line 27y that connects the contact 23 of the switch 22 and the speaker 26. It consists of.
In the second embodiment, a single signal supply line 27 will be described in order to simplify the configuration and facilitate understanding.
During normal operation, the contact 23 of the switch 22 is kept open as shown in FIG.
The control means 25 of the contact protection device 21 is configured to temporarily close the contact 23 of the switch 22 and to control the current supply means 24 so that an AC signal having a predetermined frequency or higher is output to the switch.
That is, the control means 25 of the contact protection device 21 temporarily closes the contact 23 of the switch 22 by the control means 25 at the time of execution of the removal control of the oxide film on the contact 23 of the switch 22.
Then, the speaker 26 is connected to the current supply means 24 side via the first signal supply line 27x and the second signal supply line 27y of the signal supply line 27 by the contact 23 of the switch 22 in the closed state.
At this time, the current supply means 24 is controlled by the control means 25 of the contact protection device 21 so that an AC signal having a predetermined frequency or higher is output from the current supply means 24 side to the contact 23 of the switch 22.

Then, the control means 25 of the contact protection device 21 periodically closes the contact 23 of the switch 22 by the control means 25, and the contact 23 of the switch 22 has a high frequency signal (other than an audible frequency) higher than a predetermined frequency. The current supply means 24 is controlled so that the sound signal is output from the speaker 26 during the execution of the removal control of the oxide film on the contact 23.
The oxide film on the contact 23 can be removed without causing discomfort to the occupant, and a failure in energization of the contact 23 of the switch 22 can be prevented.
Moreover, when compared with a configuration in which a direct current is passed, reduction to the speaker 26 can be achieved.

DESCRIPTION OF SYMBOLS 1 Contact protection apparatus 2 Relay circuit 3 Current supply means 4 Control means 5 Audio 6 1st circuit 7 2nd circuit 8a, 8b 1st contact 9a, 9b 2nd contact 10 Signal supply line 10x 1st signal supply line 10y 2nd signal Supply line 10z Third signal supply line 11 Driver seat side speaker 12 Passenger seat side speaker 13 Rear seat right speaker 14 Rear seat left speaker 21 Contact protector 22 Switch 23 Contact 24 Current supply means 25 Control means 26 Speaker 27 Signal supply line 27x First signal supply line 27y Second signal supply line

Claims (2)

  A relay circuit that has a mechanical contact and can be switched between a first circuit that is always energized during normal operation and a second circuit that is energized in an emergency, and an oxide film that is generated at the contact of this relay circuit. And a current supply means for removing the current by passing an excessive current, wherein the relay circuit is connected to a signal supply line of a speaker that outputs sound, and the relay circuit is temporarily connected to the first circuit. A contact protection device comprising a control means for controlling the current supply means so that an AC signal having a predetermined frequency or higher is output to the relay circuit while switching to two circuits.   A contact protection device comprising: a switch having a mechanical contact; and a current supply means for removing an oxide film generated at the contact of the switch by flowing an excessive current more than usual. Control means connected to the signal supply line of the speaker to be output, controls the current supply means so that an alternating current signal having a predetermined frequency or higher is output to the switch, while temporarily closing the contact of the switch. A contact protection device characterized by that.

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