JP2542473Y2 - Electronic fuses for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Especially for fuses used for vehicles, the fuses into which the power lines of the vehicles are inserted are digitized, and the fuses are provided with self-recovery and self-diagnosis functions to improve serviceability. Means for electronically setting the fuse rating so as to be in a vehicle-specific mode, and means for detecting the magnitude of a current flowing through a switching semiconductor element and a line connected to the semiconductor element. Means for judging whether or not the detected current is equal to or higher than a predetermined rated current; and, when the detected current is equal to or higher than the rated current, a current flowing through the line is a certain value. An electronic fuse for a vehicle including means for controlling the switching semiconductor element so as not to become the above, and a vehicle determination signal indicating a type of the vehicle. Output means, a setting means for outputting a rating setting signal for determining the rated current, and storage means for storing information corresponding to the rating setting signal, and output from the vehicle signal output means. The vehicle determination signal is compared with the information stored in the storage means, and if the comparison result does not match, the setting means does not output the rating setting signal.

[Industrial applications]

 The present invention relates to fuses, particularly fuses for vehicles.

[Conventional technology]

Conventionally, an alloy fuse has been used as this type of fuse. Once blown, such alloy fuses cannot be used again.

Therefore, even if the user accidentally short-circuits the load for a moment, the fuse remains open, and it is necessary to check the entire line until the user notices, and it is necessary to check all of the lines. Will be.

At present, automotive fuses have various ratings such as 5, 10, 15, and 25 A. However, since the fuses have the same shape and can be replaced freely by the user, a current exceeding the rating flows through the harness (wire bundle). In many cases (that is, adding a load without changing the harness and replacing the fuse with one with a higher rating). Alternatively, when a fuse having a sufficient margin with respect to the maximum current that can flow through the harness is used, the fuse cannot cut the line for an abnormal current in a range where the fuse cannot be blown. Therefore, there is also a risk that a vehicle fire accident may occur due to these.

[Problems to be solved by the invention]

The present invention has been made to solve the above-described problems. The fuse itself is self-recovered (that is, once the fuse is blown, it is automatically recovered once the fault is repaired) and self-diagnosis is performed in order to improve serviceability to the user. (That is, whether or not an abnormality such as a short circuit has occurred) is provided.

In addition, a box with a vehicle-specific set value is provided to prevent the current exceeding the rating from flowing to the load and to make it easy for the user to replace the fuse in the event of a fuse failure. This is done with precision. Further, the fuse rating can be set only for the vehicle, thereby preventing an accident due to replacement of the fuse by a manual operation.

[Means for solving the problem]

According to the present invention, there is provided a switching semiconductor element, means for detecting a magnitude of a current flowing through a line connected to the semiconductor element, and a method of setting the detected current to a predetermined rated current. Means for determining whether or not the above is true, and means for controlling the switching semiconductor element so that the current flowing through the line does not exceed a certain value when the detected current is equal to or more than the rated current. An electronic fuse for a vehicle, comprising: vehicle signal output means for outputting a vehicle determination signal indicating the type of the vehicle; setting means for outputting a rating setting signal for determining the rated current; and the rating setting signal. Storage means for storing corresponding information; comparing the vehicle determination signal output from the vehicle signal output means with the information stored in the storage means; Electronic fuse for vehicles that do not output the rated setting signal from the setting unit is provided to be.

Here, as a means for controlling the switching semiconductor element so that the current flowing through the line does not exceed a certain value, a duty control or a current limiting means as described later may be used. The switching semiconductor element may be turned off when there is.

[Action]

According to the above configuration, the fuse itself can have a self-recovery function. Moreover, if the stored information is different from the type of the vehicle, it is possible not to set the rating setting signal corresponding to the information and to set the wrong rated current. It is possible to prevent an accident or the like caused by setting the rated current.

〔Example〕

FIG. 1 is a diagram showing a circuit connection of an electronic fuse for a vehicle as one embodiment of the present invention, FIG. 2 is a diagram illustrating a circuit connection of a rating setting box connected to the electronic fuse for a vehicle, FIG. FIG. 4 is a diagram showing the interrelationship of the whole system connected to the electronic fuse for vehicle of the present invention. In FIG. 3, reference numeral 1 denotes a vehicle electronic fuse box, reference numeral 2 denotes a rating setting box for the fuse, and reference numeral 3 denotes a vehicle control computer as vehicle signal output means.

A vehicle determination signal (a signal indicating the type of the vehicle) is sent from the vehicle control computer 3 as the vehicle signal output means to the rating setting box 2. Here, the second
In the circuit connection shown in the figure, the vehicle determination signal is sent as a serial signal to the shift register 21 in the rating setting box 2 through one line. The vehicle determination signal set in the shift register 21 in this way and the vehicle information set in the vehicle information memory 22 as storage means in the rating setting box 2 are input to the EOR circuit 23. .

Therefore, in the circuit shown in FIG. 2, if the vehicle determination signal and the vehicle information match, the output of the EOR circuit 23 becomes "0" as normal and the NOR circuit 2
The setting output from the setting table 24 as setting means is input to the setting input terminal in the electronic fuse shown in FIG. The setting input input to the terminal is converted into an analog signal by the D / A converter 13, and the reference voltage setting circuit (V _R ) 14 is converted by the analog signal.
A predetermined reference voltage is set therein.

On the other hand, if the vehicle determination signal does not match the vehicle information, it is determined that an abnormality has occurred and the output of the EOR circuit 23 is "1".
As a result, the setting output from the setting table 24 is not output by the NOR circuit 25. As described above, in the case of the abnormality, the setting output from the setting table 24 is prevented from being input to the electronic fuse side, and the collation is performed so as not to cause an incorrect rating setting.

Next, in the electronic fuse shown in FIG. 1, reference numeral 11 denotes a switching semiconductor element (power MOS transistor), and a predetermined voltage is applied to its gate so as to be normally turned on.

Reference numeral 110 denotes a current detection terminal provided on the semiconductor element 11, and the resistor 12 is connected to the terminal 110. As a result, the current flowing through the resistor 12 and thus the voltage drop across the resistor 12 is proportional to the current I flowing through the semiconductor element 11 to the fuse output.

When the current I increases and the voltage drop across the resistor 12 exceeds a predetermined reference voltage set in the reference voltage setting circuit 14, the output voltage of the comparator (COMP) 15 is inverted. Oscillator 16 is activated by the inverted output of comparator 15, thereby turning on / off logic circuit.
Numeral 18 controls the duty so that the semiconductor element 11 is turned on and off at a predetermined duty ratio. Reference numeral 17 denotes a booster circuit for supplying a gate drive voltage.

The inverted output of the comparator 15 is supplied from a diagnostic terminal (a terminal having a failure diagnosis function) to a rating setting box 2.
Side, the delay timer 28 is set by the signal, the alarm indicator 27 is operated through the amplifier 26, and a fault is indicated. When the current I returns to a normal value, the output voltage of the comparator 15 returns to the original value, the oscillator 16 does not operate, and the semiconductor element 11 enters a normal ON state.

In the above embodiment, as means for controlling the semiconductor element so that the current I flowing through the line does not exceed a certain value,
Although the duty control is used, a current limit may be performed instead of the duty control.

In this case, a gate voltage control circuit is provided in place of the oscillator 16 and the on / off logic circuit 18 provided on the output side of the comparator 15, thereby controlling the gate voltage of the semiconductor element 11. Here, for example, by making the output of the comparator low when the current I increases, the gate drive voltage supplied from the booster circuit 17 is reduced by the gate voltage control circuit, and as a result, the current I is reduced. Lower. If the current I decreases in this way, the output of the comparator returns to high, and the gate drive voltage is increased by the gate voltage control circuit to increase the current I, and eventually operate stably at a certain current value. Become like

Further, as means for controlling the semiconductor element, in addition to duty control and current limiting, the semiconductor element may be turned off when there is an abnormality at least once. In this case, the oscillator 16 is replaced with a latch circuit, and when an abnormality occurs once or more, the inverted output of the comparator 15 at that time is latched and the semiconductor element 11 is turned off.

[Effect of the invention]

According to the present invention, the fuse itself can be provided with a self-recovery function, and if the stored information is different from the type of the vehicle, the rating setting signal corresponding to the information is not set so that an incorrect rating is set. It is possible to prevent the setting of the current, and it is possible to prevent an accident or the like due to an incorrect setting of the rated current due to, for example, an artificial work. Therefore, it is possible to set an appropriate rated set value for each harness, and it is not possible to add a load with a fuse having a larger rating than necessary, thereby preventing a vehicle fire accident due to an artificial work or the like. You can also.

[Brief description of the drawings]

FIG. 1 is a circuit connection diagram of a vehicle electronic fuse as one embodiment of the present invention, FIG. 2 is a diagram illustrating a circuit connection of a rating setting box connected to the vehicle electronic fuse, and FIG. FIG. 5 is a diagram showing the interrelationship of the whole system connected to the inventive electronic fuse for a vehicle. (Description of Signs) 1 ... Electronic fuse box for vehicle, 2 ... Rating setting box, 3 ... Computer for vehicle control, 11 ... Switching semiconductor element, 14 ... Reference voltage setting circuit, 15 ... Comparator, 18 ... ON-OFF logic circuit, 27 ... Alarm indicator.

Claims (1)

(57) [Scope of request for utility model registration] 1. A switching semiconductor device, means for detecting the magnitude of a current flowing through a line connected to the semiconductor device, and determining whether the detected current is equal to or greater than a predetermined rated current. And a means for controlling the switching semiconductor element so that the current flowing through the line does not exceed a predetermined value when the detected current is higher than the rated current. Vehicle signal output means for outputting a vehicle determination signal indicating the type of vehicle; setting means for outputting a rating setting signal for determining the rated current; and storage means for storing information corresponding to the rating setting signal. And comparing the vehicle determination signal output from the vehicle signal output unit with the information stored in the storage unit. If the comparison result does not match, the setting unit determines An electronic fuse for a vehicle, which does not output the rating setting signal.