JPH11273544A - Fuse element provided with layer short-circuit determining function, equivalent fuse, and manufacture of the equivalent fuse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuse provided with a layer short-circuit determining function and comprising a determination part in a fuse element itself. SOLUTION: Upper half parts of a pair of right and left conductive terminals 2a, 2b arranged in a single plane are joined in electrically communicated state by a thin fusible part 1 corresponding to the electric communication capacity of this fuse. Thin connection pieces 3a, 3b are also extended inward in the lower side of the thin fusible part 1. Three terminals; a thin male terminal 4a for electric power source, a thin male terminal 4b for shutting signals, and a thin male terminal 4c for earth; are independently arranged in parallel to one another between lower half parts of the conductive terminals 2a, 2b and under the connection pieces 3a, 3b. Those three thin male terminals 4a, 4b, 4c and the connection pieces 3a, 3b are joined through a determining part 8 for determining layer short circuit to give this fuse element provided with layer short-circuit determining function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in type fuse having a rare short judging function mainly used for automobiles.

[0002]

2. Description of the Related Art A conventional fuse mounted in a fuse box for an automobile is disclosed in US Pat.
There is a blade type fuse disclosed in Japanese Patent No. 023264.

[0003] The conventional blade-type fuses are widely used in electric systems of automobiles, but in many cases, they have a slow blow characteristic (the fuse does not blow due to an instantaneous overcurrent, and the overcurrent continues for a certain period of time). In this case, that is, when there is a danger such as a fire if the overcurrent continues, a function to prevent the danger is provided.

[0004] For this reason, the fuse is blown at the time of a dead short, but a continuous short short enough to prevent the fuse from blowing or an intermittent short for a short time at most (hereinafter, these shorts are referred to as "rare shorts"). Since the fuse is not blown in the area, a vehicle fire may occur if this state continues.

As a means for solving this situation, the present inventor has previously applied for a fuse with a sensor for detecting a rare short (Japanese Patent Application No. 9-303541).

The above-mentioned fuse F with a sensor is as follows.
As shown in FIG. 9, a fuse element connected between the upper halves of a pair of left and right conductive terminals 2 and 2 arranged on the same plane by a fusing portion 1 corresponding to the current carrying capacity of the fuse. In a plug-in fuse whose half is held in the heat-resistant and insulating housing 10, thin male terminals (detection terminals) 3 are provided inside the lower half of a pair of left and right conductive terminals 2, 2.
Numeral 3 is formed parallel to and integral with the conductive terminals 2 and 2.

[0007]

As shown in FIGS. 10A and 10B, the judging unit 8 is disposed between each sensor-equipped fuse F and the relay 17 as shown in FIGS. The voltage drop of the thin fusing section 1 detected by the thin male terminals 3 and 3 is judged by the judging section 8 whether or not there is a rare short circuit, and this signal is sent to the relay 17 to interrupt the circuit. Therefore, it is necessary to provide the judgment unit 8 in the middle of the circuit, but this wiring work is very troublesome.

[0008]

According to the present invention, in order to solve the above-mentioned problem, a terminal for detecting a voltage drop of a fusing portion and a judging portion are integrally provided in a fuse itself. By punching out from the long conductive plate, the blown part of the fuse and the pair of left and right conductive terminals are integrally formed, and a separate terminal for rare short detection is also punched at the same time, and the blown part and the separate terminal are separated. It is characterized by being connected and integrated via a determination unit for determining a rare short.

That is, the first aspect of the present invention is that a conductive state is established between the upper halves of a pair of left and right conductive terminals 2a and 2b arranged on the same plane by a thin-walled fusing portion 1 corresponding to the current carrying capacity of a fuse. The conductive terminals 2 are connected to each other and the thin connecting pieces 3a and 3b are extended inward below the thin-walled fusing portion 1 so as to protrude inward.
a thin power male terminal 4a, a thin cutoff signal male terminal 4b, and a thin earth male terminal 4 between the lower halves of the a and 2b and below the connection pieces 3a and 3b.
c are arranged independently and in parallel, and connected between the three thin male terminals 4a, 4b, 4c and the connection pieces 3a, 3b via a judging unit 8 for judging a rare short. This is a fuse element having a rare short judgment function.

A second aspect of the present invention is an upper end portion 5a of the power male terminal 4a among the three thin male terminals 4a, 4b, 4c in the fuse element with a rare short judging function according to the first invention. Power supply terminal (VDD) of the judgment circuit 8
8a, the upper end 5b of the cut-off signal male terminal 4b is connected to the output terminal (cut-off signal to the relay 17) 8b of the judging unit 8, and the upper end 5c of the earthing male terminal 4c is judged.
, A thin connection piece 3a is connected to one input terminal 8d of the determination section 8, and a connection piece 3b is connected to the other input terminal 8e of the determination section 8.
The upper end 5a of each thin male terminal 4a, 4b, 4c of the book
This is a fuse with a function of judging a rare short-circuit, characterized in that a portion above 5b and 5c is held by a heat-resistant and insulating housing 10.

A third aspect of the present invention is to intermittently transfer a long fuse material 18 formed of a single conductive plate having a thin portion 19 having a constant width in the center along the longitudinal direction while transferring the same to a predetermined length. When punching, a pair of left and right conductive terminals 2a, 2b
The thin portion 19 is punched out to a predetermined width corresponding to the current carrying capacity of the fuse so as to connect the upper portion therebetween, thereby forming the thin-walled fusing portion 1, and the thin-walled connection pieces 3 a and 3 b are projected downward inward. At the same time, the thin power male terminal 4a, the thin interrupt signal male terminal 4b, and the thin earth male terminal 4c are connected to the conductive terminals 2a, 2c.
b After punching out from the thin portion 19 between the lower halves, the upper end portions 5a, 5 of the three thin male terminals 4a, 4b, 4c are punched out.
b, 5c and the thin connecting pieces 3a, 3b are connected via a judging part 8 for judging a rare short, and the upper portions 5a, 5b, 5c of the thin male terminals are heat-resistant. After being held by the insulating housing 10, the lower end portions of the pair of left and right conductive terminals 2a and 2b and three thin male terminals 4 are formed.
a, 4b, non-punched portion 19a connecting lower ends of 4c
And a method for manufacturing a fuse with a rare short judgment function.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a fuse with a sensor according to the present invention. As shown in FIG. 8C, the fuse element according to the present invention has a thin portion 19 having a constant width in the center along the longitudinal direction. While intermittently transporting a long fuse material 18 made of a single zinc (Zn) alloy conductive plate formed by cutting
8, as shown in FIG. 8A, as a first step, a thin-walled fusing portion 1 corresponding to the current-carrying capacity of the fuse is connected to the upper half between the pair of left and right conductive terminals 2 a and 2 b and a little. The thin connecting pieces 3a and 3b are punched downward and punched inward, and at the same time, two upper and lower support holes 6 and 6 are punched in the upper half of the conductive terminals 2a and 2b.

As a second step, a pair of left and right conductive terminals 2
From the thin portion 19 between the lower halves a and 2b, a thin power male terminal 4a, a thin cut-off signal male terminal 4b, and a thin earth male terminal 4c (hereinafter collectively referred to as "thin Male terminals 4a, 4b, 4c), the upper ends 5a, 5b, 5c exhibit a square bulge,
Punching is performed except for the lower end so as to provide small holes 7 in the center thereof. (The non-punched portion 19a at the lower end serves to prevent the thin male terminals 4a, 4b, and 4c from being dispersed and to maintain the connection state of the long fuse material 18.)

On the other hand, a judging section 8 provided with a comparison judging circuit for judging a rare short circuit is provided separately. As a third step, this judging section 8 includes the thin connecting pieces 3a, 3
b and the upper ends 5a, 5b, 5c of the three thin male terminals 4a, 4b, 4c to form a fuse element (see FIG. 2).

That is, as shown in FIG.
An input terminal 8 of the comparison circuit 21 includes a comparison circuit 21, a timer 22, a counter 23, and an abnormality determination circuit 24.
d and 8e are connected to the connection pieces 3a and 3b, and the output terminal 8b of the abnormality determination circuit 24 is
b, the power supply terminal 8a of the judging unit 8 is connected to the cut-off signal male terminal 4a, and the ground terminal 8c is connected to the ground male terminal 4c.

The judging section 8 (a) takes the signals (potential differences) detected by the fuse connecting pieces 3a and 3b into the comparison circuit 21 and compares them with the abnormal level stored in the comparison circuit 21. (B) The timer 22 compares the presence or absence of an abnormality at regular intervals, counts the number of signals exceeding the abnormality level, and stores the number in the counter 23. (C) The abnormality determination circuit 24 checks the number of counts within a certain time,
If the count is equal to or more than the predetermined count, it is determined that an abnormality has occurred, and an abnormality signal is output from the output terminal 8b to operate the relay 17.

In FIG. 1, reference numeral 10 denotes a heat-resistant / insulating housing which is separately formed and holds the upper half of the fuse element so as to cover the upper half. As shown in FIG.
Pins 9 and 9 are provided above the inner surface of one housing 10b so that the support holes 6 and 6 in the upper half portions of the conductive terminals 2a and 2b are fitted into the housing 10b. Are the three thin male terminals 4a, 4b, 4c
There are provided three recesses 11 into which the upper rectangular bulging upper ends 5a, 5b, 5c fit, and bosses 12 into which the small holes 7 fit.

The inner surface of the other housing 10a is
As shown in FIG. 2, the conductive terminals 2a, 2b and the thin male terminals 4a, 4
The square bulging upper ends 5a, 5b, 5c of b, 4c and the judging section 8 are formed so as to be clamped between one housing 10b without backlash. As a fourth step,
The housings 10a and 10b are joined and held so as to cover the upper half of the fuse element.

As a final step, a pair of left and right conductive terminals 2
a, 2b and three thin male terminals 4a, 4b,
The non-punched portion 19a connecting the lower end of 4c is punched and separated, and finished as a fuse 20 with a rare short judgment function as shown in FIG. 8C.

The fuse 20 with the rare short judging function according to the present invention is a terminal block 1 shown by a two-dot chain line in the lower part of FIG.
3 is provided with fuse female terminals 14a and 14b into which a pair of left and right conductive terminals 2a and 2b
A power supply female terminal 15a, a signal detection female terminal 15b, into which the thin male terminals 4a, 4b, 4c can be inserted;
It is inserted into the grounding female terminal 15c.

FIG. 4 shows an electric circuit of an automobile using a fuse having a rare short judgment function according to the present invention. A relay 17 is installed immediately after a battery 16 and a rare short circuit is provided between each of the loads A on the downstream side. Fuse 20 with judgment function
In the case of this circuit, if a dead short circuit occurs between the fuse 20 having the rare short determination function and each load A, the fuse 20 having the rare short determination function will be provided similarly to the conventional fuse. And the circuit is cut off.

In addition, the connection pieces 3a, 3
b, the signal is always output, and the signal is
Is always entered.

Therefore, when the judging section 8 judges an abnormality such as a rare short, an abnormal signal (a signal for turning on the relay) is output, and the relay 17 installed immediately after the battery 16 is output.
Is turned off and the circuit is cut off.

FIG. 5 shows a fuse 20 having a rare short judgment function and a relay 17 corresponding to each load A.
Are arranged as a pair, and in this circuit,
If a dead short occurs between the fuse 20 with the rare short determination function and the load A, the thin-walled fusing portion 1 of the fuse 20 with the rare short determination function is blown and the circuit is cut off as in the conventional fuse. The circuit can be interrupted by the relay 17 even when a rare short circuit occurs.

FIGS. 6 and 7 show circuits in which the loads A, B and C are arranged in parallel in the circuits of FIGS. 4 and 5. In FIG. 6, a relay 17 is installed immediately after the battery 16.
Fuses 20a, 20b, and 20c with a rare short determination function are arranged between the loads A, B, and C on the downstream side, and the entire circuit is cut off by the relay 17 when a rare short occurs.

On the other hand, in FIG. 7, fuses 20 each having a rare short-circuit judgment function correspond to each load A, B, C.
a, 20b, and 20c and the relays 17a, 17b, and 17c are arranged in parallel as a pair, so that when a rare short circuit occurs, only the circuit in which an abnormality has occurred can be cut off.

It should be noted that the configuration, arrangement, and logic for judging a rare short shown in the above-described embodiment are not particularly limited, and it goes without saying that there are various kinds of logic.

[0028]

According to the present invention, at the time of dead short, the thin blown portion 1 of the fuse element is blown similarly to the conventional fuse, and when the fuse element is not blown, the thin blown portion 1 of the fuse element is blown. It functions as a current detection sensor and inputs a current (actually, a voltage applied to both ends of the fuse element) flowing through the thin-walled fusing section 1 of the fuse element to the determination section 8, and determines whether or not the abnormality is abnormal. In the case of an abnormality, an abnormal signal is output and the relay 17 shuts off.

The fuse is stipulated to be blown at a constant current and within a fixed time as specified in JASO D612. The variation in the resistance value is also ± 3%, and the fuse element according to the present invention can be sufficiently used as a current detection sensor.

[0030]

According to the present invention, a fuse having a rare short-circuit judging function can be provided by integrally providing a fuse function and a judging unit for judging a rare short circuit into one fuse. There is no need to install a simple judgment unit (judgment circuit).

Furthermore, the use of the fuse element, which originally functions as a fuse, as a current detection sensor eliminates the need for a special current sensor.

In addition, since the detection terminal is provided in the empty space of the conventional fuse (inside the lower half of the conductive terminal), there is no waste in removing material when forming the fuse element. Since it is provided in parallel with the fuse element, it can be manufactured in a dimension slightly thicker than the external dimensions of the conventional fuse,
It can be accommodated almost in the conventional fuse mounting space and does not require any special space.

Also, since it has the function of a conventional fuse, it can operate effectively even in the case of a short-circuit failure of a relay, a semiconductor relay, or the like, so that the circuit can be protected.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a fuse with a rare short judgment function according to the present invention.

FIGS. 2A and 2B show a fuse having a rare short-circuit judging function according to the present invention, wherein FIG. 2A is a vertical sectional front view, and FIG.

FIG. 3 is an example of a judgment logic of a judgment unit in a fuse with a rare short judgment function according to the present invention.

FIG. 4 is an example of an electric circuit of an automobile using one fuse with a rare short judgment function according to the present invention.

FIG. 5 is another example of an electric circuit of an automobile using one fuse with a rare short judgment function according to the present invention.

FIG. 6 is an example of an electric circuit of an automobile using a plurality of fuses having a rare short judgment function according to the present invention.

FIG. 7 is another example of an electric circuit of an automobile using a plurality of fuses with a rare short judgment function according to the present invention.

8A and 8B show a manufacturing process of a fuse with a rare short judgment function according to the present invention, wherein FIG.
(B) is a plan view of a completed product, and (C) is a partial perspective view of a fuse material.

FIG. 9 is an exploded perspective view of a conventional fuse with a sensor.

FIG. 10 shows an example of an electric circuit of an automobile using a conventional fuse with a sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thin fusing part 2a, 2b Conductive terminal 3a, 3b Connection piece 4a Power supply male terminal 4b Cutoff signal male terminal 4c Grounding male terminal 5a Power supply male terminal 5b Upper end of disconnection signal male terminal 5c Ground Upper end of male terminal for use 6 Support hole 7 Small hole 8 Judgment part 9 Pin 10a, 10b Housing 11 Depression 12 Boss 13 Terminal block 17 Relay 18 Long fuse material 19 Thin part 19a Non-punched part 20 With rare short judgment function fuse

Claims (3)

[Claims] An upper half of a pair of left and right conductive terminals 2a and 2b arranged on the same plane is connected in a conductive state by a thin fusing portion 1 corresponding to a current carrying capacity of a fuse, and the thin fusing is performed. The thin connecting pieces 3a, 3b are extended inward below the portion 1, and a thin power supply is provided between the lower halves of the conductive terminals 2a, 2b and below the connecting pieces 3a, 3b. The three male terminals 4a, 4b, 4 are arranged independently and in parallel with each other, the male terminal 4a, the thin-walled male terminal 4b for the cutoff signal, and the thin-walled male terminal 4c for the ground.
A fuse element having a rare short-circuit judging function, wherein the fuse element and the connection pieces are connected via a judging section for judging a rare short-circuit. 2. The three thin male terminals 4a, 3 in the fuse element with rare short judgment function according to claim 1.
4b, 4c, the upper end 5a of the power male terminal 4a is connected to the power supply terminal (VDD) 8a of the judging circuit 8, and the upper end 5b of the cutoff signal male terminal 4b is connected to the relay 8b of the judging unit 8.
The upper end 5c of the earthing male terminal 4c is connected to the earth terminal (GND) 8c of the judging unit 8, the thin connecting piece 3a is connected to one input terminal 8d of the judging unit 8, 3b is connected to the other input terminal 8e of the judging unit 8, and the upper end 5 of each of the three thin male terminals 4a, 4b, 4c is connected.
a, 5b, 5c, heat-resistant and insulating housing 10
A fuse with a rare short judgment function, which is held by 3. A pair of right and left long fuse materials 18 formed of a single conductive plate having a thin portion 19 having a constant width formed in the center thereof in a longitudinal direction while being intermittently transported and punched to a predetermined length. The thin portion 19 is punched out to a predetermined width corresponding to the current carrying capacity of the fuse so that the upper portions between the conductive terminals 2a and 2b are connected to each other to form the thin fusing portion 1 and the thin connecting pieces 3a and 3b thereunder. The thinner male terminal 4a for power supply, the thinner male terminal 4b for cut-off signal, and the thinner male terminal 4c for grounding are simultaneously connected between the lower halves of the conductive terminals 2a and 2b. After punching from the thin portion 19 of each of the three thin male terminals 4
The upper ends 5a, 5b, 5c of a, 4b, 4c and the thin connecting pieces 3a, 3b are connected via a judging unit 8 for judging a rare short, and the upper end of each of the thin male terminals. Heat-resistant and insulating housing 1 above 5a, 5b, 5c
After holding at 0, punching and separating the non-punched portion 19a connecting the lower ends of the pair of left and right conductive terminals 2a, 2b and the lower ends of the three thin male terminals 4a, 4b, 4c. Characteristic method of manufacturing fuse with rare short judgment function.