JP5391138B2 - Vehicle power supply - Google Patents

Description

  The present invention relates to a vehicular power supply apparatus having a relay that opens and closes a power supply circuit from a power supply to a load, and particularly relates to an apparatus that improves reliability and quietness in a vehicle interior.

For example, it has been proposed that a water pump that circulates engine cooling water of an automobile is stopped to improve fuel efficiency when there is no need to circulate cooling water as in warm-up operation immediately after starting.
Such a water pump includes an electromagnetic clutch that switches between transmission and interruption of driving force from the engine. A circuit for supplying electric power from the battery to the electromagnetic clutch is opened and closed by an electromagnetic relay.

In general, an electromagnetic clutch for a water pump is configured such that the clutch is connected to drive the water pump when not energized, and a normally open relay whose contact is opened when de-energized is used.
However, when such a relay is arranged in the engine room, it is difficult to ensure reliability because the relay is exposed to water and dust. For example, when the relay becomes inoperable when the relay is closed, the water pump cannot be driven, and there is a concern about engine overheating and damage.

In addition, if the relay is arranged in the vehicle interior, it is easy to ensure reliability because it is not exposed to water or dust, but in this case, the quietness of the vehicle interior is impaired by the operating noise of the relay. End up.
As a conventional technique related to the operation sound of such a relay, for example, Patent Document 1 describes that the relay is operated when the engine speed or the vehicle speed becomes high, and the noise of the relay is made difficult to hear due to noise other than the relay. Has been.

JP 2003-175882 A

In a vehicle with good quietness in the passenger compartment, even if the engine speed is high or the vehicle speed is high as in the technique described in Patent Document 1 described above, the operation noise of the relay is caused by other noise. It is difficult to conceal the vehicle, and there is a demand for achieving a higher level of both quietness in the passenger compartment and reliability of the power supply device.
The subject of this invention is providing the power supply device for vehicles which improved the reliability and the quietness of the vehicle interior.

The present invention solves the above-described problems by the following means.
The invention according to claim 1 opens and closes a power supply circuit that supplies power from a power source to a load, opens and closes the first relay disposed outside the vehicle compartment, and the power supply circuit, and arranges the power supply circuit in the vehicle interior. The second relay, an abnormality detecting means for detecting an abnormality of the first relay, and when the first relay is normal, the first relay is opened and closed, and when the first relay is abnormal Is a vehicle power supply device comprising relay control means for opening and closing the second relay.
The invention according to claim 2 is the vehicle power supply device according to claim 1, wherein the first relay is disposed in the vicinity of a suspension strut support portion in an engine room of the vehicle.

According to the present invention, the following effects can be obtained.
(1) The quietness in the passenger compartment can be improved by operating only the first relay arranged outside the passenger compartment at normal times. In addition, by operating the second relay disposed in the vehicle compartment when the first relay is abnormal, it is possible to maintain the same function as the normal function and improve the reliability of the power supply device.
(2) The reliability of the first relay can be improved by disposing the first relay in the vicinity of the suspension strut support portion that is relatively less susceptible to water and dust in the engine room.

It is a schematic circuit diagram of the Example of the power supply device for vehicles to which this invention is applied. It is a figure which shows the mounting position of the 1st relay in the vehicle power supply device of an Example.

  An object of the present invention is to provide a vehicular power supply device with improved reliability and quietness in a vehicle interior. The first relay of normally open disposed in an engine room and a normally closed vehicle disposed in the vehicle interior The problem was solved by connecting the second relay directly and opening the second relay when the first relay is defective.

Embodiments of a vehicle power supply device to which the present invention is applied will be described below. The vehicle power supply device according to the embodiment is mounted on an automobile such as a passenger car, for example.
FIG. 1 is a schematic circuit diagram of the vehicle power supply device of the embodiment.
As shown in FIG. 1, the vehicle power supply device 1 supplies power to an electromagnetic clutch 2 that turns on and off a water pump that circulates engine coolant (not shown), for example.
The electromagnetic clutch 2 enables power transmission from the engine to the water pump when not energized and shuts off when energized. The electromagnetic clutch 2 is disposed in the engine room (outside the passenger compartment).

The vehicle power supply device 1 includes a battery 3, a power line 4, a first relay 5, a second relay 6, an engine control unit (ECU) 7, a voltage monitor line 8, and the like.
The battery 3 is a secondary battery that supplies electric power to various electrical components of the vehicle. The battery 3 is disposed in the engine room (outside the passenger compartment).
The power line 4 is a wiring that supplies power from the positive electrode of the battery 3 to the positive terminal of the electromagnetic clutch 2. The negative pole of the battery 3 and the negative terminal of the electromagnetic clutch 2 are grounded to the vehicle body.

The first relay 5 is an electromagnetic relay that is provided in an intermediate portion of the power line 4 and opens and closes a circuit by a movable contact that is electromagnetically driven.
The first relay 5 is disposed in the engine room (outside the passenger compartment).
The first relay 5 is a normally open relay whose contact is opened at the time of non-excitation.

The second relay 6 is an electromagnetic relay that is provided between the first relay 5 and the electromagnetic clutch 2 in an intermediate portion of the power line 4 and opens and closes a circuit by an electromagnetically driven movable contact.
The second relay 6 is disposed in the vehicle interior.
The second relay 6 is a normally closed relay whose contact is closed when de-energized.

The ECU 7 comprehensively controls the engine and its accessories, and includes an information processing device such as a CPU, a storage device such as a ROM and a RAM, an input / output interface, and the like. ECU7 is arrange | positioned in the vehicle interior.
The ECU 7 has a function of supplying currents for operating the coils of the first relay 5 and the second relay 6, and functions as a relay control means in the present invention. Further, the ECU 7 has a function of detecting an abnormality of the first relay 5 and functions as an abnormality detection means according to the present invention. This point will be described in detail later.
The ECU 7 is connected to a voltage monitor line 8 that detects the voltage of the power line 4 between the second relay 6 and the electromagnetic clutch 2 (potential difference from the vehicle body grounding portion).

Next, the arrangement of the first relay 5 described above will be described.
FIG. 2 is a schematic perspective view showing a vehicle body structure at the front portion of the vehicle on which the first relay 5 is mounted, and shows a so-called white body state in which an engine, auxiliary equipment, lights, a vehicle outer plate, etc. are not mounted. ing.
The vehicle body 10 has a monocoque structure in which, for example, steel press panels are joined by spot welding or the like. The vehicle body 10 includes a bulkhead 11, a main side frame 12, an upper side frame 13, an apron 14, a strut tower 15, and the like.

The bulkhead 11 is a partition wall that is provided at a front end portion of a passenger compartment (not shown) and partitions the passenger compartment and the engine compartment.
The main side frame 12 is a beam-like member that is provided on each of the left and right sides of an engine (not shown) and extends in the longitudinal direction of the vehicle. A subframe (not shown) to which the engine and the front suspension are attached is coupled to the main side frame 12. The rear end portion of the main side frame 12 is connected to the lower portion of the bulkhead 11.

The upper side frame 13 is a beam-like member disposed so as to protrude forward from the left and right end portions of the upper end portion of the bulkhead 11. The upper side frame 13 is disposed substantially along a side end portion (an upper end portion of the fender) of a front hood (not shown).
The apron 14 is a panel-like member disposed between the left and right main side frames 12 and the upper side frame 13. A part of the apron 14 is provided with a wheel house that is formed in a bulge shape to the inside of the engine room in order to accommodate a front wheel (not shown).

The strut tower 15 supports a strut upper end portion of a strut type front suspension (not shown). The strut tower 15 is provided in the upper part of the wheel house part of the apron 14.
The strut tower 15 is formed in a tunnel shape extending substantially along the vertical direction, and the upper portion of the strut is accommodated therein. The strut upper mount provided at the upper end portion of the strut is fastened to the upper surface portion of the strut tower with a bolt or the like.

As shown in FIG. 2, the first relay 5 is attached to the front surface portion of the right strut tower 15, for example.
Such an arrangement is an example, and the first relay 5 may be attached to the side surface portion, the rear surface portion of the strut tower 15, or the apron 14 adjacent to the strut tower 15.

In the present embodiment, in the normal state where the first relay 5 operates normally, the ECU 7 maintains the closed state without energizing the second relay 6 and operates only the first relay 5 to operate the electromagnetic clutch 2. Switching between connection and disconnection.
Specifically, during the warm-up operation of the engine, the first relay 5 is energized (excited), electric power is supplied to the electromagnetic clutch 2, the electromagnetic clutch 2 is disconnected, and the water pump is stopped.
Thereafter, when the warm-up of the engine is finished, the ECU 7 stops energization (excitation) of the first relay 5 and stops the power supply to the electromagnetic clutch 2. As a result, the electromagnetic clutch 2 is connected, the water pump is operated, and the cooling water circulates in the engine.

The ECU 7 monitors the detected voltage of the voltage monitor line 8, and determines that the first relay 5 is abnormal when the voltage does not decrease despite stopping the energization of the first relay 5. As described above, when a failure that cannot open the contact of the first relay 5 occurs, the water pump cannot be driven as it is, and the circulation of the engine cooling water is stopped. Is concerned about engine damage.
In such a case, the ECU 7 energizes (excites) the second relay 6 to open the contact point of the second relay, stop the power supply to the electromagnetic clutch 2, and operate the water pump.
At this time, the ECU 7 urges a user such as a driver to inspect and repair, for example, by turning on a warning light on an instrument panel (not shown).

According to the present embodiment described above, the following effects can be obtained.
(1) The quietness in the passenger compartment can be improved by operating only the first relay 5 disposed in the engine compartment outside the passenger compartment at normal times. Moreover, when ECU7 determines the abnormality of the 1st relay 5, the reliability of the vehicle power supply device 1 can be improved by operating the 2nd relay 6 arrange | positioned in a vehicle interior.
(2) The reliability of the first relay 5 can be improved by disposing the first relay 5 on the front surface of the strut tower 15 which is relatively less susceptible to water and dust in the engine room.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) In the embodiment described above, the electric load supplied with electric power by the vehicle power supply device is, for example, an electromagnetic clutch of a water pump. However, the present invention is not limited to this, and electric power to other electric loads is used. It can also be applied to supply.
(2) Although the normally open first relay and the normally closed second relay are directly connected in the embodiment, the combination of relay types and the connection method are not particularly limited. Further, three or more relays may be used in combination.

DESCRIPTION OF SYMBOLS 1 Vehicle power supply device 2 Electromagnetic clutch 3 Battery 4 Power line 5 1st relay 6 2nd relay 7 Engine control unit (ECU) 8 Voltage monitor line 10 Car body 11 Bulkhead 12 Main side frame 13 Upper side frame 14 Apron 15 Strut tower

Claims (2)

Opening and closing a power supply circuit for supplying power from a power source to a load, and a first relay disposed outside the vehicle compartment;
Opening and closing the power supply circuit, and a second relay disposed in the vehicle interior;
An abnormality detecting means for detecting an abnormality of the first relay;
A vehicle power supply device comprising: relay control means for opening and closing the first relay when the first relay is normal, and opening and closing the second relay when the first relay is abnormal. 2. The vehicle power supply device according to claim 1, wherein the first relay is disposed in the vicinity of a suspension strut support portion in an engine room of the vehicle.

Images