JP4009917B2 - Manufacturing method of fuse with sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a fuse with a plug-in sensor mainly used for automobiles, and a current flowing in a fuse blown portion and a fuse is obtained by punching a long fuse material made of one conductive plate. The sensor to be detected is integrally formed.
[0002]
[Prior art]
Conventionally, as a general fuse mounted on a fuse box for an automobile, there is a blade type fuse disclosed in US Pat. No. 4,032,264.
[0003]
As shown in FIG. 5, as shown in FIG. 5, a long fuse material 8 in which a thin portion 7 having a constant width is formed in the longitudinal direction in the center as shown in FIG. The upper half portion including the thin fused portion 1 of the fuse element 4 formed by forming the thin fused portion 1 having a predetermined width corresponding to the current carrying capacity simultaneously with the pair of left and right conductive terminals 2 and cut to a predetermined length is heat resistant. -It is held by an insulating housing 5.
[0004]
Many of the conventional blade-type fuses are used in the electric system of automobiles, but in many cases, the slow blow characteristics (the fuse does not blow out due to instantaneous overcurrent, and if the overcurrent continues for a certain period of time, In other words, it has a function to prevent a danger by fusing when there is a danger such as a fire if an overcurrent continues.
[0005]
For this reason, the fuse blows at the time of a dead short, but the fuse does not blow in a continuous short that is so small that the fuse does not blow or a continuous short for a short time (hereinafter referred to as “rare short”). If this condition persists, a vehicle fire may occur.
[0006]
As means for solving this situation, there has been proposed a fire prevention device for an electric system of an automobile disclosed in Japanese Patent Application Laid-Open No. 60-203551.
[0007]
In the fire prevention device disclosed in Japanese Patent Laid-Open No. 60-203551, a current sensor and a circuit breaker are provided between a battery and a fuse provided in an electric wire connecting each electrical component, and the current sensor An excess current signal as a result of comparing the electric wire current signal from the load current signal from each electrical component operation detection circuit with a comparison circuit is sent to the circuit breaker as an abnormal pulse through the monostable multivibrator, It cuts off and protects the electrical components from being energized.
[0008]
[Problems to be solved by the invention]
However, since the conventional fire prevention device is a system in which a current sensor is installed in the middle of the circuit, it is necessary to secure an installation space for the sensor. However, securing the installation space in recent vehicles has become difficult year by year, and there are cases where the installation location is limited or cannot be installed.
[0009]
Further, as a current sensor provided in the middle of the circuit, Japanese Patent Laid-Open No. 60-203551 discloses a system using a Hall element as an example. However, this Hall element is expensive and is called for cost reduction. However, it is difficult to use.
[0010]
Furthermore, devices that detect current without contact, such as Hall elements, are generally susceptible to noise (such as magnetic noise) present in the vehicle, so it is difficult to obtain true value, and it is necessary to take measures against noise. In addition, in the case of a sensor that is directly connected (connected in series with the circuit), at least two new connection points are required, and a voltage drop due to an increase in contact points or poor contact, or heat generation due to this voltage drop. At present, there are various problems such as occurrence.
[0011]
[Means for Solving the Problems]
In the present invention, the fuse element can be used also as a shunt (sensor) for detecting electric current, and the fuse and the sensor are integrally formed by punching from one conductive plate, and the upper half of the element is formed. A thin male with a voltage drop in the thin fused part of the element (hereinafter referred to as “fused part”) integrated inside the lower half of the conductive terminal of the element. It can be detected by a terminal (hereinafter referred to as “detection terminal”).
[0012]
That is, according to the present invention, the fuse element 8 is punched to a predetermined length while intermittently transporting a long fuse material 8 composed of a single conductive plate having a thin portion 7 having a constant width along the longitudinal direction at the center. In the process of forming 4, the thinned portion 7 is punched out to a predetermined width corresponding to the energization capacity of the fuse so that the upper part between the pair of left and right conductive terminals 2, 2 is connected. A fuse element 4a with a sensor is integrally formed by punching out a pair of left and right detection terminals 3 and 3 parallel to and integrally connected to the conductive terminals 2 and 2 inside the lower half of the conductive terminals 2 and 2 In this method, the upper half part of the fuse element with sensor 4 is inserted and held in the heat-resistant / insulating housing 5.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view of a sensor-equipped fuse 9 formed according to the present invention, and the sensor-fuse 9 is a long shape made of a single zinc (Zn) alloy conductive plate as shown in FIG. A thin-walled portion 7 having a constant width is formed by cutting along the longitudinal direction in the center of the fuse material 8, and the pair of left and right conductive terminals 2 are transferred as shown in FIG. , 2, and a blowout portion 1 corresponding to the energization capacity of the fuse is connected to the thin portion 7 and punched out in the upper half portion, and the detection terminals 3, 3 are provided inside the lower half portions of the conductive terminals 2, 2. A fuse element with a sensor (hereinafter referred to as “element”) 4a as shown in FIG. 1 is formed by integrally connecting and punching out from the thin portion 7, and then the upper half of the element 4a has heat resistance and insulation. Made of transparent resin and flat It is formed by a housing 5 which is formed to be inserted and fixed.
[0014]
A fuse 9 with a sensor formed according to the present invention includes female female terminals 14 and 14 for insertion of a pair of left and right conductive terminals 2 and 2 provided on a terminal block 13 indicated by a two-dot chain line in the lower part of FIG. The pair of left and right thin male terminals 3, 3 are inserted into the signal detecting female terminals 15, 15 which can be inserted.
[0015]
FIG. 7 is an electric circuit of an automobile using the sensor-equipped fuse 9 formed according to the present invention. A relay 11 is installed immediately after the battery 10 and sensors corresponding to the loads A, B, and C are provided downstream of the battery. Attached fuses 9a, 9b, 9c are arranged in parallel, and the female terminals for fuses 14, 14 are connected to the relay 11 side and the loads A, B, C side arranged upstream of the battery 10, respectively, The detection female terminals 15 and 15 are connected to a determination unit 12 connected to the relay 11.
[0016]
In the case of this circuit, if a dead short occurs between the fuses 9a, 9b, 9c with sensors and each of the loads A, B, C, the element fuse of the fuse 9 with sensors is blown in the same manner as the conventional fuse. The part 1 is melted and only the circuit is cut off.
[0017]
Further, a signal is always output from the detection terminals 3 and 3 with respect to the current flowing through the element fusing portion 1 of the fuse 9 with sensor, and the signal is always input to the determination portion 12.
[0018]
When an abnormality such as a rare short circuit is determined between each sensor fuse 9a, 9b, 9c and each load A, B, C, an abnormality signal (relay ON signal) is output to the determination unit 12 and immediately after the battery 10. The installed relay 11 is turned off (OFF), and all circuits are cut off.
[0019]
FIG. 8 shows a pair of sensor-equipped fuses 9a, 9b and 9c and relays 11a, 11b and 11c arranged in parallel corresponding to the loads A, B and C, respectively. In this case, if a dead short occurs between the fuses 9a, 9b, 9c with sensors and any one of the loads A, B, C, the fuse 9 with sensors is installed in the same manner as the conventional fuse. The circuits are individually cut off, and when a rare short occurs, unlike the case of FIG. 7, only the circuit in which an abnormality has occurred can be cut off.
[0020]
[Action]
In the fuse with a sensor formed according to the present invention, the fused part 1 of the element is blown in the same manner as the conventional fuse in the case of a dead short, and further, the blown part 1 of the element functions as a shunt (sensor) for current detection in the case of a rare short. The current flowing through the element fusing portion (actually, the voltage applied to both ends of the element) can be output from the detection terminals 3 and 3 provided integrally with the conductive terminals 2 and 2 of the element.
[0021]
In addition, as specified in JASO D612, the fuse is specified to be blown at a constant current within a fixed time. In general, the standard width is determined and managed, and the distribution of the resistance value is a normal distribution as shown in FIG. 6, and the resistance variation in a general shunt is ± 0.1 depending on the class. The variation in resistance in the fuse is ± 3%, and the variation is large compared to the shunt, but the judgment level of the abnormal current only needs to have a capability of ± 1A at most. Can be used as a shunt.
[0022]
【The invention's effect】
According to the present invention, while a long fuse material made of a single zinc (Zn) alloy conductive plate in which a thin portion having a constant width is previously formed in the center in the longitudinal direction is intermittently transferred, Since the fuse element with a sensor in which the fusing part is connected to the upper half between the conductive terminals and the detection terminal is integrally connected to the inner side of the lower half can be formed by punching, the manufacturing efficiency is high.
[0023]
According to the fuse with a sensor formed by the present invention, a compact fuse with a sensor can be provided by combining the fuse function and the sensor function in one element.
[0024]
Furthermore, no special current sensor is required by using an element (melting part) that originally functions as a fuse as a shunt (sensor) for current detection.
[0025]
In addition, since the detection terminal is provided in the space where the conventional fuse is vacant (inside the lower half of the conductive terminal), it can be manufactured within the external dimensions of the conventional fuse. There is no waste, and it can be accommodated in the conventional fuse mounting space, so no special space is required.
[0026]
In addition, since the conventional fuse function is also provided, the circuit can be protected by a conventional method even in the case of a relay failure (short circuit failure).
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a sensor-equipped fuse according to the present invention.
FIG. 2 is a partial perspective view of a long fuse material according to the present invention.
FIG. 3 is a front view showing material removal of a fuse with a sensor according to the present invention.
FIG. 4 is a front view showing material removal of a conventional blade type fuse.
FIG. 5 is an exploded perspective view of a conventional blade-type fuse.
FIG. 6 is a distribution diagram of fuse resistance values;
FIG. 7 shows an example of an electric circuit of an automobile using a sensor-equipped fuse according to the present invention.
FIG. 8 shows another example of an electric circuit of an automobile using the fuse with sensor according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Thin fused part 15 Signal detection female terminal 2 Conductive terminal 3 Thin male terminal 4 Fuse element 4a Fuse element with sensor 5 Housing 7 Thin part 8 Long fuse material 9 Fuse with sensor 10 Battery 11 Relay 12 Judgment part 13 Terminal block 14 Female terminal for fuse

Claims (1)

In the process of forming the fuse element 4 by punching out to a predetermined length while intermittently transferring a long fuse material 8 made of a single conductive plate having a thin portion 7 having a constant width along the longitudinal direction at the center. The thin-walled portion 7 is punched out to a predetermined width corresponding to the current carrying capacity of the fuse so that the upper part between the pair of left-right conductive terminals 2 and 2 is connected, and at the same time, the pair of left-right conductive terminals 2 The fuse element 4a with a sensor is integrally formed by punching a pair of left and right thin male terminals 3 and 3 parallel to and integrally connected to the conductive terminals 2 and 2 inside the lower half of the lower half. A method for manufacturing a fuse with a sensor, comprising: forming and holding an upper half of the fuse element with a sensor 4a in a heat-resistant and insulating housing 5.

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