Patent Application
20050045405
This application is based on Applications No. 2002-160824 filed in Japan on May 31, 2002, the content of which is incorporated hereinto by reference.
The present invention relate to a power device for an automotive vehicle, especially to a power device for an automotive vehicle interrupting an output circuit by a crash sensor and an interlock switch.
In a conventional power device for an automotive vehicle shown in
Further, the interlock switch 21 is provided in the power device of
Furthermore, a delay circuit 27 is provided in such a conventional power device in order to prevent a malfunction of the interlock relay 23. The delay circuit 27 is provided between the interlock switch 21 and the interlock relay 23 so as not to turn the interlock relay 23 OFF from ON by a momentary interrupting signal outputted from the interlock switch 21. The interlock switch 21 can momentarily output an interrupting signal, when chattering occurs caused by vibrations of an automotive vehicle etc. If the interlock relay 23 is turned OFF from ON in this state, the contactor 24 is turned OFF even it is unnecessary to turn it OFF. If the contactor 24 is turned OFF, the output circuit of a power device is interrupted, so that an automotive vehicle cannot run normally. It is important to prevent from turning the interlock relay 23 OFF from ON for a safety run, when it is unnecessary. To achieve this, the delay circuit 27 is provided.
However, the power device shown in
The present invention is developed to solve the above problems. It is an important object of the present invention to provide a power device for an automotive vehicle, which can quickly interrupt an output circuit corresponding to a interrupting signal of a crash sensor and can slowly interrupt corresponding to a interrupting signal of an interlock switch, capable of interrupting an output circuit in ideal time corresponding to both of a crash sensor and an interlock switch.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
A power device for an automotive vehicle according to the present invention comprises an interlock switch; a crash sensor for detecting impact of an automotive vehicle; an interlock relay controlled and turned ON and OFF by the interlock switch; and a contactor for interrupting an output circuit when the interlock relay is turned OFF. In the power device, when the interrupting signal for interrupting the output circuit is outputted from the crash sensor, or when the interlock switch is turned OFF from ON, the contactor is turned OFF to interrupt the output circuit. Further, the power device comprise a switching element connected to an exciting coil of the contactor in series and turned ON and OFF by an interrupting signal of the crash sensor. When the crash sensor outputs the interrupting signal, the switching element is turned OFF, and the contactor is turned OFF by interrupting a current of the exciting coil in the contactor.
The power device for an automotive vehicle of the above construction has the feature that the power device can quickly interrupt the output circuit corresponding to the interrupting signal of the crash sensor and can slowly interrupt corresponding to the interrupting signal of the interlock switch, capable of interrupting the output circuit in ideal time corresponding to both of the crash sensor and the interlock switch. Here is the reason. When the crash sensor outputs the interrupting signal, the contactor is quickly turned OFF by turning the switching element, which is connected to the exciting coil of the contactor, OFF from ON. While, when the interlock switch outputs the interrupting signal, the contactor is turned OFF not via the switching element, which quickly operates, but via the interlock relay.
The switching element connected to the exciting coil of the contactor in series can be an FET or a transistor. An exciting coil of the interlock relay, which is connected to the interlock switch via a delay circuit, can turn the interlock relay OFF from ON after predetermined time determined by the delay circuit when the interlock switch is turned OFF.
A positive side contactor for interrupting a positive output of the output circuit and a negative side contactor for interrupting a negative output of the output circuit can be provided as the contactor. In the power device, each of exciting coils of the positive side contactor and the negative side contactor is connected to the contact of the interlock relay, and is connected to the switching element controlled and turned ON and OFF by the crash sensor. In the power device, when the crash sensor outputs the interrupting signal, both of the switching elements are turned OFF and the positive side contactor and the negative side contactor are turned OFF from ON.
The delay circuit can include an FET, whose gate is connected to the interlock switch, connected to the exciting coil of the interlock relay, and a delay capacitor connected therein. In the delay circuit, when the interlock switch is turned OFF and the gate voltage of the FET starts to drop, the delay capacitor can delay the drop in the gate voltage so as to delay turning the FET OFF from ON.
The crash sensor can include a switch, which is turned OFF from ON when detecting impact. The exciting coil of the interlock relay can be connected to a power supply circuit via the crash sensor.
A power device for an automotive vehicle shown in
In addition, in the power device of
The interlock switch 1 keeps the output circuit 110N in a normal use state of the power device. On the other hand, the interlock switch 1 turns the output circuit 11 OFF when it is necessary to interrupt the output circuit 11 in order to conduct work safely, for example, at maintenance of the power device, or when a case of the power device is opened, or when the power device is removed from an automotive vehicle. The power device of
The interlock switch 1 of
Additionally, a normally off switch can also be used as the interlock switch. This interlock switch performs ON/OFF control of the FET or the transistor of the delay circuit 7 via an inverting circuit. In the interlock switch with a normally off switch, all switches are connected in parallel, and the interlock switch detects that any of switches is turned OFF.
The crash sensor 2 detects a crash of an automotive vehicle etc., and can be an inertia sensor detecting an inertia force, an impact sensor, and a G sensor. In addition, a sensor detecting that an automotive vehicle becomes deformed can be also used as the crash sensor 2. The crash sensor 2 is a normally on switch. The crash sensor 2 is turned OFF from ON and outputs the interrupting signal in case of an emergency that impact or the like is detected. As shown in
The crash sensor 2 of
The crash sensor, which outputs a pulse signal as the interrupting signal, includes a latching circuit, which switches output to “Low” from “High” based on the pulse signal as the interrupting signal. The latching circuit normally outputs “High” to keep the switching elements connected to the interlock relay and the exciting coils ON so that a direct current can be discharged in a normal state. In this state, when a pulse signal as the interrupting signal is outputted from the crash sensor, the latching circuit switches its output to “Low” from “High” and retains “Low”. The “Low” signal turns the interlock relay OFF and keeps it OFF. While, the “Low” signal switches the input sides of the switching elements connected to the exciting coils of the contactors to “Low” from “High”, and turns them OFF from ON, and keeps them OFF. Therefore, the exciting coils of the contactors are kept in the state that a current is not applied. The contactors keep the OFF state and interrupt the output circuit 11 of the battery.
The crash sensors 2 of
The interlock relay 3 is controlled by both the crash sensor 2 and the interlock switch 1. The interlock relay 3 is turned OFF from ON, when the interrupting signal for interrupting the output circuit 11 is inputted from any of the crash sensor 2 and the interlock switch 1. This interlock relay 3 controls the contactors 4, and interrupts the output circuit 11 of a battery 5 in the OFF state. In the interlock relay 3 of
The delay circuit 7 includes the FET, whose source and drain are connected in series between the exciting coil 3a of the interlock relay 3 and a ground. The delay capacitor 9 is connected between the gate of FET and a ground. The delay capacitor 9 delays a drop in the gate voltage. This delay circuit 7 delays a drop in the gate voltage by the delay capacitor 9, when the interlock switch 1 is turned OFF from ON and the output of the interlock switch 1 turns “Low” from “High”. For this reason, even if the “Low” signal, which is the interrupting signal, is inputted from the interlock switch 1, the FET is not immediately turned OFF from ON, but is turned OFF after the gate voltage drops lower than a shut-off voltage of the FET. Increasing the capacitance of the delay capacitor 9 can adjust the delay time of the delay circuit 7 to be longer. The delay capacitor 9 is set a capacitance so that the delay time is about 100 msec-3 sec.
The power device of
One end of each of exciting coils 4a of the positive side contactor 4A and negative side contactor 4B is connected to the contact of the interlock relay 3, so that the positive side contactor 4A and negative side contactor 4B are simultaneously controlled and are turned ON and OFF. Each another end of exciting coil 4a of each of contactors 4 is connected to each of the switching elements 6, which are controlled and turned ON and OFF by the crash sensor 2. Each switching element 6 is connected between each exciting coil 4a and a ground. The switching element 6 is an FET, however, a transistor also can be used.
The gate of each of FETs, which are the switching elements 6, is connected to the crash sensor 2. When a transistor is used as the switching element 6, the base of the transistor is connected to the crash sensor via a bias resistor. The switching element 6 is turned OFF from ON, when the interrupting signal is inputted from the crash sensor 2. The switching element 6 does not have a mechanical movable part such as a relay, which moves its contact in order to turn ON and OFF, and can electrically turn ON and OFF. Therefore, the switching element 6 is quickly turned OFF from ON as compared with a relay. Although the time that the switching element 6 is turned ON and OFF depends on a type of the switching element 6, generally, it is time of the order of less than microsecond. Accordingly, the time is very short, and is almost a negligible amount of time as compared with turning time of a relay.
In the power device of
The switching element 6 is controlled only by the crash sensor 2, and is not controlled by the interlock switch 1. For this reason, even if the interlock switch 1 outputs the interrupting signal and is turned OFF from ON, the switching element 6 is not turned OFF from ON. Therefore, even if the interlock switch 1 outputs the interrupting signal, the switching element 6 does not turns a contactor 4 OFF from ON.
1. Interlock Relay
After the operating time (T3) of the interlock relay 3, the interlock relay is turned OFF from ON.
2. Contactor
The contactor 4 is immediately turned OFF from ON after the operating time (T1) of the contactor 4 by the switching element 6, which is turned OFF from ON by the interrupting signal of the crash sensor 2, without taking time that the interlock relay 3 becomes turned-OFF.
1. Interlock Relay
After the delay time of the delay circuit 7 and the operating time (T3) of the interlock relay 3, the interlock relay is turned OFF from ON. The reason is that the interrupting signal of the interlock switch 1 is delayed by the delay circuit 7 and then the interlock relay 3 is turned OFF from ON. For this reason, the interlock relay 3 is turned OFF from ON after the time that is the sum of the delay time (T2) of a delay circuit 7 and the operating time (T3) of the interlock relay 3.
2. Contactor
After the interlock switch 1 is turned OFF from ON, the interlock relay 3 is turned OFF from ON, that is, after the time that is the sum of the operating time (T1) of a contactor 4, the delay time (T2) of a delay circuit 7, and the operating time (T3) of the interlock relay 3, the contactor is turned OFF from ON.
As mentioned above, in the power device of
Furthermore, although not shown in the drawings, the power device of the present invention can also control the contactor by a signal from an ECU, which controls ON/OFF of the power device. In this power device, when detecting abnormal conditions of the battery, the ECU outputs an abnormal signal and turns the contactor OFF to interrupt the output circuit. The abnormal signal from the ECU can be inputted into the switching element connected to the contactor, and can turns the contactor OFF. However, another circuit, which turns the contactor OFF by the abnormal signal from the ECU, can be provided to control the contactor.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within meets and bounds of the claims, or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 160824/2002 | May 2002 | JP | national |
