JPH09251904A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electronic component having a fuse function capable of fusing against an abnormal current lower than a rush current against which is usable normally by placing near a heat generating element a temp. fuse function composed of a low-temp. fuse having a current fuse function at a narrow part. SOLUTION: A motor starting circuit 25 has a motor main coil 26 connected in parallel to a series circuit of a motor sub-coil 27 are electronic component 21. When a lower current than that in the rush flows in this series circuit, a positive temp. coefficient thermistor element 2 more heats to a higher temp. than that in the normal to fuse a low-temp. fuse unit 23 away from a terminal member 22, an abnormal current flows, a narrow part 10 gradually heats to result in melt-away. Thus, the terminal member 22 functions as a current fuse at the narrow part 10 after the low-temp. fuse unit 23 functions as a temp. fuse.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component having a function of not interrupting an inrush current and interrupting a circuit against an abnormal current after the inrush current flows.

[0002]

2. Description of the Related Art A conventional electronic component having a fuse function is constructed, for example, as shown in FIGS. The electronic component 1 includes a positive temperature coefficient thermistor element 2, first and second terminal members 3 and 4, and a case 5. More specifically, the PTC thermistor element 2 has electrodes 6 and 7 formed on both main surfaces of a plate-shaped PTC thermistor element body. The first terminal member 3 has an elastic pressing portion 12 having one end 8 electrically contacting the electrode 6 of the positive temperature coefficient thermistor element 2, and the other end 9 serving as an external terminal that can be led out of the case 5. First
As shown in FIG. 12, between the one end 8 and the other end 9 of the terminal member 3, a narrow portion 10 having a narrow width is formed at a part of the other end 9. The second terminal member 4 has an elastic pressing portion 12 that is in electrical contact with the electrode 7 of the positive temperature coefficient thermistor element 2 at one end 11, and an external terminal that can be led out of the case 5 at the other end 13. There is. The case 5 is made of an insulating resin or the like, and accommodates the positive temperature coefficient thermistor element 2 sandwiched between the first and second terminal members 3 and 4.

The electronic component 1 has a positive temperature coefficient thermistor element 2 from the first and second terminal members 3 and 4 via electrodes 6 and 7.
Power is supplied to In this electronic component 1, when an abnormal current larger than the normal current value flows, the narrow width portion 10 provided in the first terminal member 3 is blown and functions as a current fuse.

[0004]

However, the electronic component 1 having the current fuse function described above is used in a degaussing circuit or a motor starting circuit in which an inrush current larger than the abnormal current flows immediately after the power is turned on. Then, due to the rush current, the narrow portion 10 of the first terminal member 3 becomes hot and melts. That is, the electronic component 1 has a problem that it cannot be used in a circuit in which a rush current larger than the abnormal current flows.

The object of the present invention is to eliminate the above-mentioned problems, and an electronic device having a fuse function which can be normally used for an inrush current but can be blown for an abnormal current smaller than the inrush current. It is to provide parts.

[0006]

To achieve the above object, an electronic component of the present invention comprises an electronic component main body and a terminal member electrically connected to a power feeding portion of the electronic component main body, A narrow portion is formed on the terminal member, and the low temperature melt is provided at least in the narrow portion. In particular, it is preferable that the electronic component body is a heating element and further a positive temperature coefficient thermistor element.

More specifically, it is provided with a plate-shaped positive temperature coefficient thermistor element having electrodes formed on both main surfaces, a terminal member, and a case, and is electrically connected to the positive temperature coefficient thermistor element and its electrode. In this state, the terminal member is housed in the case, a narrow portion is formed in the terminal member, and the low temperature melt is provided at least in the narrow portion.

In addition, plate-shaped first and second positive temperature coefficient thermistor elements having electrodes formed on both principal surfaces, and first, second and third
And a case, and the first terminal member is disposed between the first and second positive temperature coefficient thermistor elements and electrically connected to one of the electrodes.
The second and third terminal members are electrically connected to the other electrodes of the first and second PTC thermistor elements, respectively, and are housed in the case, and the first terminal is provided. A narrow portion is formed in the member, and the low temperature melt is provided at least in this narrow portion.

As a result, the electronic component is not blown out by an inrush current, but can be blown out by an abnormal current smaller than the inrush current.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to FIGS. However,
The same parts as those in the above-described conventional example are denoted by the same reference numerals, and detailed description will be omitted. The present invention is characterized in that the low temperature melt is provided in the narrow portion of the terminal member.

The electronic component 21 is a positive temperature coefficient thermistor element 2
And the first and second terminal members 22, 4 and the case 5. The first terminal member 22 is one in which the low temperature melt 23 is provided in the narrow portion 10 of the terminal member 3 shown in FIG. The low-temperature melt 23 is made of a metal that melts at a low temperature, such as solder, and includes the narrow portion 10 and the first terminal member 2
2 is joined from one end 8 to the other end 9 and is located inside the case 5 of the electronic component 21.

The operation of the electronic component 21 having such a configuration when used in the motor starting circuit 25 as shown in FIG. 3 will be described. The motor starting circuit 25 is configured by connecting the motor main coil 26 in parallel to a series circuit of the motor auxiliary coil 27 and the electronic component 21. When the motor starting circuit 25 is powered on to start the motor, a large inrush current flows through the main coil 26 and the series circuit of the auxiliary coil 27 and the electronic component 21. At this time, the electronic component 21 includes the narrow portion 10 of the first terminal member 22.
The low-temperature melt 23 provided at the position serves as a bypass for the inrush current to suppress current concentration in the narrow portion 10 and prevent melting. Further, when a current flows through the PTC thermistor element 2, the PTC thermistor element 2 has a high temperature and a high resistance, and the current flowing through the PTC thermistor element 2 is small and held at a predetermined temperature.

However, the auxiliary coil 27 and the electronic component 21
If an abnormal current, that is, a current that is larger than normal and smaller than inrush, flows in the series circuit of and, the positive temperature coefficient thermistor element 2 further heats up to a temperature higher than a predetermined temperature during normal operation, and then melts at a low temperature. The body 23 melts. The melted low-temperature melt 23 separates from the terminal member 22, and an abnormal current concentrates and flows in the narrow portion 10 which is a current passage path, gradually heats the narrow portion 10, and eventually the narrow portion 10 melts. . That is, in the terminal member 22, the low temperature melt 23 functions as a thermal fuse, and then the narrow portion 10 functions as a current fuse. Table 1 shows the relationship between the current value and the temperature of the positive temperature coefficient thermistor element 2 at the time of rushing, during normal operation, and during abnormal operation.

[0014]

[Table 1]

The low-temperature melt 23 may have a melting point higher than the medium temperature shown in Table 1 and lower than the high temperature shown in Table 1, and is composed of, for example, solder having a predetermined melting point. Further, the low-temperature melting body 23 may be formed by joining a metal piece having a high melting point to the narrow width portion 10 using solder having a predetermined melting point or the like.
When the electronic component body used for the electronic component 21 is the positive temperature coefficient thermistor element 2, the melting point of the low temperature melt 23 is 150 to 250.
C is preferred.

The material of the terminal member 22 is the narrow portion 10
In order to stop the heat generated in the above and facilitate the fusing, it is preferable that the thermal conductivity is 0.1 cal / cm · sec · ° C. or less, as typified by stainless steel having a low thermal conductivity. Further, in the case where the positive temperature coefficient thermistor element 2 is a resistance heating element or the like having no electrode, the terminal members 22 and 4 may be electrically connected to a power supply section instead of the electrode.

Next, another embodiment of the present invention will be described with reference to FIGS. Electronic component 3
Reference numeral 1 denotes the first and second positive temperature coefficient thermistor elements 32 and 33, which constitute the electronic component body, and the first, second and third terminal members 3
4, 35, 36 and a case 37. 1st, 2nd
The positive temperature coefficient thermistor elements 32 and 33 are plate-shaped and have the first, second, third and fourth electrodes 3 on their respective principal surfaces.
8, 39, 40 and 41 are formed.

The first terminal member 34 is made of a flat metal plate and has one end 42 disposed between the first and second positive temperature coefficient thermistor elements 32 and 33, respectively. It is electrically connected to the electrodes 38 and 40. First terminal member 3
The other end 43 of 4 is made conductive with the outside of the case 37.
A narrow width portion 44 having a narrow width is formed in a part of the other end 43 of the first terminal member 34, and the narrow width portion 44 is provided with a low temperature melt 45. The low-temperature melt 45 is made of a metal that melts at a low temperature, such as solder, and has a narrow width portion 4.
The one end 42 and the other end 43 including 4 are joined.

The second and third terminal members 35 and 36 are electrically connected to the second and fourth electrodes 39 and 41 of the first and second positive temperature coefficient thermistor elements 32 and 33, respectively, and supply power to them. Since it is the same as the terminal member 4 of FIG. 1, detailed description thereof will be omitted.

The case 37 is an insulator made of an insulating resin or the like, and the second and third terminal members 35 and 36 have the first positive temperature coefficient thermistor element 32, the first terminal member 34 and the second terminal member 34. The positive temperature coefficient thermistor element 33 is housed in the state of being sandwiched in order. Therefore, the electronic component 31 is
From the second and third terminal members 34, 35, 36 to the first, second, third and fourth electrodes 38, 39, 40, 4.
1 through the first and second positive temperature coefficient thermistor elements 32,
Power is supplied to 33.

The operation of the electronic component 31 having such a configuration when used in the degaussing circuit 47 as shown in FIG. 6 will be described. In the degaussing circuit 47, the first PTC thermistor element 32 and the series circuit of the second PTC thermistor element 33 and the degaussing coil 48 are connected in parallel. When the degaussing circuit 47 is powered on, a large inrush current flows in the series circuit including the first PTC thermistor element 32 and the second PTC thermistor element 33. At this time, in the electronic component 31, the low temperature melt 45 provided in the narrow width portion 44 of the first terminal member 34 serves as a bypass for the inrush current, and the current is not concentrated in the narrow width portion 44 and is melted. To prevent. After the inrush current flows, the first and second PTC thermistor elements 32 and 33 generate heat to keep the current small. Further, in the second PTC thermistor element 33, the current is narrowed down by the heat of the first PTC thermistor element 32, and the current flowing through the coil 48 is made smaller.

However, the first positive temperature coefficient thermistor element 3
2, or when an abnormal current, that is, a current larger than normal and smaller than inrush flows in the series circuit of the degaussing coil 48 and the second positive characteristic thermistor element 33, the first positive characteristic thermistor element 32 or the second Positive temperature coefficient thermistor element 3
3 heats up to a temperature higher than a predetermined temperature during normal operation, and the low temperature melt 45 melts. When the low-temperature melt 45 is melted, the first terminal member 34 is formed in the same manner as the electronic component 21 described above.
The electric current is concentrated in the narrow width portion 44 and melts. That is, the first
The terminal member 34 functions as a thermal fuse and a current fuse.

Next, modified examples of the narrow portions 10, 44 of the terminal members 22, 34 and the low temperature melts 23, 45 will be described with reference to FIGS. However, the terminal member is shown as a main portion including a narrow portion, and the same functional portions as those of the terminal member 22 shown in FIG. 3 are denoted by the same reference numerals and detailed description thereof will be omitted.

In FIG. 7, the terminal member 22a is the narrow portion 1
A low temperature melt 23a is provided from one end 8a to the other end 9a so as to straddle 0a. When an inrush current flows through the narrow portion 10a, the low-temperature melt 23a serves as a bypass for the inrush current to prevent the narrow portion 10a from melting, and when an abnormal current flows, a low temperature The melted body 23a is melted, and the current is further concentrated and melted in the narrow portion 10a.

In FIG. 8, the narrow portion 1 of the terminal member 22b.
0b has a slot 10c formed therein, and the low temperature melt 23b is joined to a part of the narrow portion 10b. When a rush current flows through the narrow portion 10b, the low-temperature melt 23b serves as a heat sink and a heat radiator to prevent the narrow portion 10b from being heated to a high temperature, to prevent melting, and to prevent abnormalities. When electric current flows, low temperature melt 2
3b is melted, and the current is further concentrated and melted in the narrow portion 10b.

In FIG. 9, the narrow portion 1 of the terminal member 22c.
0b has the slot 10c formed similarly to the terminal member 22b shown in FIG. 8, and the low temperature melt 23c is joined to one part of the narrow portion 10b. When an inrush current flows through the narrow portion 10b, the low temperature melt 23c functions as a heat sink or a radiator as in the case of the terminal member 22b, and the narrow portion 10b is prevented from being heated to a high temperature and blown. When the abnormal current flows, the low temperature melt 2
3c is melted, and the current is further concentrated and melted in the narrow portion 10b.

In FIG. 10, the terminal member 22d is formed with a narrow width portion 10a, and the side surface of the narrow width portion 10a extends from one end 8d to the other end 9d. The wedge-shaped low-temperature melt 23d is joined. When an inrush current flows through the narrow portion 10a, the low temperature melt 23d serves as a bypass and heat sink for the inrush current to prevent the narrow portion 10a from melting, and when an abnormal current flows, a low temperature The melted body 23d is melted, and the narrow portion 10a is further melted.
The current concentrates on and melts. Moreover, the low-temperature melt 23d can simply close the gap S between the case 5 and the terminal member 22d due to the wedge-shaped thickness.

In the above embodiments, the positive characteristic thermistor element is used for the electronic component body, but the invention is not limited to this, and a heating element such as a resistance heating element whose heating temperature rises as the current increases. May be Further, the low-temperature melt provided in the narrow portion need not be provided on only one side of the terminal member, and may be provided on both sides of the terminal member.

[0029]

As described above, in the electronic component according to the present invention, the temperature fuse function made of the low temperature melt is arranged in the narrow portion having the current fuse function in the vicinity of the heating element, so that the electronic component at the time of rushing in can be provided. It has a fuse function that can withstand a large current, but can protect the circuit against an abnormal current that is smaller than the inrush current and larger than normal.

[Brief description of drawings]

FIG. 1 is an electronic component 21 according to one embodiment of the present invention.
FIG. 4 is a side view of FIG.

FIG. 2 is a front view of a terminal member 22 shown in FIG.

3 is a motor starting circuit diagram in which an electronic component 21 is used. FIG.

FIG. 4 is a side view of an electronic component 31 according to another embodiment of the present invention, in which a case 37 is cut away.

5 is a front view of the first terminal member 34 in FIG.

FIG. 6 is a degaussing circuit diagram in which an electronic component 31 is used.

7A and 7B show a first modification of the terminal member 22, FIG. 7A is a front view of relevant parts corresponding to FIG. 5, and FIG. 7B is a side view.

FIG. 8 is a front view of a main part corresponding to FIG. 5, showing a second modification of the terminal member 22.

9 is a front view of the principal part corresponding to FIG. 5, showing a third modification of the terminal member 22. FIG.

FIG. 10 shows a fourth modification of the terminal member 22, (a)
Is a front view of relevant parts corresponding to FIG. 5, and FIG.

FIG. 11 is a side view of the conventional electronic component 1, showing a case 5;
It is the figure which cut | disconnected.

12 is a front view of the terminal member 3 in FIG.

[Explanation of reference numerals] 2 PTC thermistor element (main body of electronic component) 4, 22 Terminal member 5, 37 Case 6, 7 Electrode (feeding portion) 10, 44 Narrow width portion 21, 31 Electronic component 23, 45 Low temperature melt 32 , 33 1st, 2nd positive characteristic thermistor element 34 1st terminal member 35, 36 2nd, 3rd terminal member 38, 39, 40, 41 1st-4th electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayo Katsuki 2 26-10 Tenjin Tenjin, Nagaokakyo, Kyoto Prefecture Murata Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. An electronic component main body, and a terminal member electrically connected to a power feeding portion of the electronic component main body, wherein a narrow width portion is formed in the terminal member, and a low temperature melt is formed at least in the narrow width portion. An electronic component characterized by being provided with. 2. The electronic component according to claim 1, wherein the electronic component body is a heating element. 3. The electronic component according to claim 2, wherein the heating element is a positive temperature coefficient thermistor element. 4. A plate-shaped positive temperature coefficient thermistor element having electrodes formed on both main surfaces, a terminal member, and a case, wherein the positive temperature coefficient thermistor element and the terminal are electrically connected to the terminal. An electronic component, wherein a member is housed in the case, a narrow portion is formed in the terminal member, and a low temperature melt is provided at least in the narrow portion. 5. A plate-shaped first electrode having electrodes formed on both main surfaces,
A second PTC thermistor element, first, second and third terminal members, and a case are provided, and the first terminal member is arranged between the first and second PTC thermistor elements. Is provided and electrically connected to one of the electrodes, and the second and third terminal members are electrically connected to the other electrodes of the first and second PTC thermistor elements. And is housed in the case in a state where the first terminal member is formed with a narrow width portion,
An electronic component characterized in that a low-temperature melt is provided at least in this narrow portion.