JP3024521B2 - Resistance temperature fuse - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention applies to a resistance temperature fuse used for overcurrent protection and overheat protection.

[0002]

2. Description of the Related Art As shown in FIGS. 18 and 19, a conventional resistance temperature fuse has a temperature fuse 24 having a lead 23 in which a fusible material is sealed in an outer case, and a lead 25 attached to a resistor. A box-shaped ceramic case 2 having a body 26 and a resistor 26 in which a part of a lead wire 25 is covered with resin is provided with a notch on a pair of opposite side surfaces without an upper surface.
7, the lead wires 23 and 25 are inserted into the respective notches, and the thermal fuse 24 and the body of the resistor 26 are arranged in the case 27.
Are cemented with cement 28. If an abnormality occurs in the device to which the resistance temperature fuse is attached, an overcurrent flows in a circuit in which the resistance 26 is connected in series, and the resistance 26 generates heat.
Upon detecting the heat, the thermal fuse 24 operates, and the circuit in which the thermal fuse 24 is connected in series is cut off.

[0003]

In the resistance temperature fuse having the above-described structure, the position of the fusible element of the temperature fuse 24 varies in the outer case, the resistance 26 is not uniform in the case 27, and the heat generation becomes uneven. Thermal fuse 24
When the resistor 26 is filled with the cement 28 with the cement 28, the resistor 26 and the thermal fuse 24 stick or separate from each other, causing a variation in heat conduction. Further, the heat generated by the heating of the resistor is transmitted to the resin portion of the resistor 26, the cement portion 28, the outer case portion of the thermal fuse 24, the sealed gas portion, and the fusible portion, resulting in poor thermal responsiveness. However, there is a drawback that the thermal fuse 24 does not operate unless the temperature is considerably high.

[0004]

On the first substrate in a plane formed by the ceramic green sheets SUMMARY OF THE INVENTION The pair of electrodes and the first structure provided with a resistor for crosslinking between the electrodes, the ceramic <br/> green sheets Forming a metal layer to form the first structure
Laminated on the first structure so as to cover at least the resistor part of
A second structure in which a fusible body is provided on the plane of the second substrate that is integrally molded by sintering and ceramicized, and at least
And an insulating member for covering a fusible portion of the second structure .

[0005] A first structure in which electrodes and resistors are formed on a first substrate formed of a green sheet, and a second structure in which a pair of metal layers are formed on a second substrate formed of a green sheet. Provide an integrally molded resistance temperature fuse.

[0006] Further, a pair of electrodes, a resistor bridging between the electrodes, a lead wire led out to the outside and an insulating member covering at least the resistor are provided on one surface of the substrate, Provided are a fuse section in which a fusible body is joined to a surface opposite to a substrate and lead wires leading to both ends thereof to the outside, and a resistance temperature fuse provided with an insulating member covering at least the fusible body section.

Another object of the present invention is to provide a resistance temperature fuse in which a resistor is formed in a thick film by screen printing.

Another object of the present invention is to provide a resistance temperature fuse in which a fusible material is formed into a thick film by screen printing.

Further, there is provided a resistance temperature fuse in which a fusible body is formed of a metal foil.

[0010]

When an overcurrent flows due to an abnormality in a device to which the resistance temperature fuse is attached, the resistor generates heat. The heat is transmitted through the substrate that is in close contact with the resistor to the fusible member that is also in close contact with the substrate. When the temperature of the fusible reaches the melting point or more due to the heat of the resistor, the fusible melts and cuts off the circuit. The resistor, the substrate and the fusible element are formed in close contact with each other, there is no room for heat to escape between them, the heat of the resistor is efficiently and accurately transmitted to the fusible element, and the resistance temperature fuse operates with high precision to operate the circuit. Cut off.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway perspective view of the resistance temperature fuse according to the present invention, FIG. 2 is a plan view of the first structure of the resistance temperature fuse as viewed from above, and FIG.
4 is a plan view of the second structure, FIG. 5 is a side view of FIG. 4, FIG. 6 is a plan view of another second structure, FIG. 7 is a side view of FIG. 6, and FIG. FIG. 9 is a plan view of a portion of the fuse excluding the resin portion, and FIG. 9 is a side view of FIG. FIG. 1 shows an external view of a first embodiment according to the present invention. Since the structure is a laminated structure, each structure is disassembled into layers and the structure will be described according to a manufacturing procedure. As shown in FIGS. 2 and 3, a pair of conductive electrodes 2 and 2 are formed on a first substrate 1 made of, for example, ceramic green sheet by screen printing, for example, a paste of silver or silver palladium or copper. as well as the shape formed, at both ends between the electrodes 2 and 2 resistor 3 formed so as to overlap a portion of electrodes 2, for example made of ruthenium oxide resistive paste formed by screen printing. Also, as shown in FIGS. 4 and 5,
For example, a pair of metal layers 6 and 6 are formed on a second substrate 5 made of a ceramic green sheet, for example, by silver, silver palladium, or copper.
The paste is formed by screen printing. Then,
One substrate 1 and the second substrate 5 are connected to each other.
It is laminated so as to cover the resistor 3 of the plate 1 and integrally molded by sintering.
You. Thereafter, you prepare and outer end of the first substrate 1 of the electrodes 2, the first structure to fix the lead wire 4, 4 electrically connected to the outside by soldering or conductive paste (not shown) . Also,
As shown in FIGS. 4 and 5, the metal layers 6 and 6 of the second substrate 5
The fusible member 7 is placed so that both ends of the fusible member 7 overlap with each other, and the ends of the lead wires 8, 8 that conduct to the outside are overlapped and fixed on the upper surfaces of both ends of the fusible member 7. At this time, to produce a second structure by fixing at for example the two ends of the fusible element 7 pressurized heat melted to the metal layer 6 and the lead wire 8 or fixing the fusible element 7, or solder or a conductive paste. FIGS. 6 and 7 show another embodiment of the second structure shown in FIGS. 4 and 5, which is characterized in that the end faces of the lead wires 8a and 8a are provided on both end faces of the fusible member 7a on the second substrate 5a. The melt-bonded structure is fixed with, for example, an adhesive to form a second structure. 8 and 9 are a plan view and a side view of a portion of the resistance temperature fuse excluding the resin portion. As illustrated, the completion of the resistance temperature fuse of the present invention, the second structure i.e. on the first substrate 1 in FIG. 2 on the first structure <br/>, second substrate 5 (or the diagram of FIG. 4 the second substrate 5a) the I weight of 6, the fusible element 7
In addition, a part of the lead wires 8, 8 and a joint between the lead wires 4, 4 and the electrodes 2, 2 are covered with a resin 22 as shown in FIG.

A second embodiment of the present invention will be described. FIG. 10 is a plan view of a substrate portion of the resistance temperature fuse, and FIG.
Is a sectional view taken along the line BB 'of FIG. 10, and FIG. 12 is another embodiment of the first structure of the substrate of FIG. A first structure in which a pair of electrodes 10 and 10 and a resistor 11 bridging between the electrodes 10 and 10 are provided on a plane of a first substrate 9 shown in FIGS. And a second structure composed of a second substrate 13 having a cutout provided to expose the electrodes 10 of the first substrate 9 is superposed and integrally molded and sintered. Hereinafter, similarly to the first embodiment, the fusible material and the lead wire are fixed on the metal layers 12 and 12 of this structure, and the lead wire is fixed on the electrodes 10 and 10, and then the fusible material and the lead wire are fixed. Is covered with resin to complete a resistance temperature fuse. FIG. 12 is a view showing an example in which inverted L-shaped electrodes 10a, 10a are provided on a first substrate 9a instead of the first substrate 9 shown in FIG.
Another embodiment of the first structure in which the position of the resistor 11 is directly below the fusible body of the second substrate 13 shown in FIG. 10 is shown.

A third embodiment of the present invention will be described. FIG. 13 is a plan view of the resistance temperature fuse, and FIG.
15 is a cross-sectional view of FIG. 13 viewed from the lower surface side, and FIG. 16 is a cross-sectional view of FIG. As shown in FIGS. 13 to 16, a fusible body 15 is provided on one plane of the substrate 14, and lead wires 16, 1 are provided at both ends of the fusible body 15.
6 is attached and covered with an insulating member 17 such as a resin. On the back surface of the substrate 14, a pair of electrodes 1
8, 18 and the resistor 1 bridging between the electrodes 18, 18
The lead wires 20, 20 are fixed to the electrodes 18, 18 by soldering or resistance welding or a conductive paste, and at least the surface of the resistor 19 is covered with an insulating member 21 such as a glass coat or a resin. FIG. 17 shows another embodiment in place of FIG. 15, in which the opposing portions of the L-shaped electrodes 18a, 18a are extended at a right angle, a resistor 19 is bridged at the tip thereof, and the resistor 19 is Is provided at a position where the fusible member 15 shown in FIG.

[0014]

As described above, according to the resistance temperature fuse of the present invention, the resistor is made of a ceramic green sheet.
Formed in close contact with the first substrate
Forming a metal layer on a second substrate made of a sheet,
Laminated on a plate, molded integrally by sintering and ceramic
Since the fusible body is formed in close contact with the second substrate, the distance between the resistor and the fusible body is constant, and heat is generated between the resistor, the second substrate and the fusible body . There is no room for escape, the heat of the resistor is efficiently and accurately conducted to the fusible element, and the resistance temperature fuse operates with high accuracy to cut off the circuit. Therefore, there is no variation in heat conduction and thermal response between the fusible element and the resistor, and a highly accurate resistance temperature fuse can be provided. In addition, the resistor and the fusible element are
Therefore, since it is electrically insulated, special insulation means
do not need. In addition, a resistor on a ceramic insulating substrate
Form antibodies and glaze glass over this resistor
Prints an insulating film and forms a fusible material on it
Insulation substrate fabrication and glass
Different products such as insulating film formation by slaze printing
Method and the ceramic green sheet
On the first substrate with antibody and ceramic green sheet
Laminated with a second substrate with a metal layer and integrated by sintering
As well as ceramics,
As well as the first base consisting of flat green sheets
Forming an electrode and a metal layer on the plate and the second substrate, respectively;
As a result, metal layers and metal layers can be formed easily and accurately.
You. Furthermore, the fusible material is a substantially planar second substrate.
Various types such as easy to form
Has the effect of

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a resistance temperature fuse according to a first embodiment of the present invention.

FIG. 2 is a plan view of the first structure of FIG. 1 as viewed from above.

FIG. 3 is a sectional view taken along line A-A ′ of FIG. 2;

FIG. 4 is a plan view of the second structure shown in FIG. 1 as viewed from above.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a plan view of another embodiment of FIG. 4;

FIG. 7 is a side view of FIG. 6;

8 is a plan view of a portion of the resistance temperature fuse of FIG. 1 excluding a resin part.

9 is a side view of FIG.

FIG. 10 is a plan view of a substrate of a resistance temperature fuse according to a second embodiment of the present invention.

11 is a sectional view taken along the line B-B 'of FIG.

FIG. 12 is a plan view of another embodiment of the first structure of FIG. 10;

FIG. 13 is a plan view of a resistance temperature fuse according to a third embodiment of the present invention.

14 is a sectional view taken along the line C-C 'of FIG.

FIG. 15 is a plan view seen from the lower surface side of FIG. 13;

16 is a sectional view taken along line D-D 'of FIG.

FIG. 17 is a plan view of another embodiment of the substrate of FIG. 15;

FIG. 18 is a perspective view of a conventional resistance temperature fuse.

FIG. 19 is a perspective view showing a state where a filler is removed from FIG. 18;

[Explanation of symbols]

1, 9, 9a First substrate 2, 10, 10a, 18, 18a Electrode 3, 11, 19 Resistor 4, 8, 8a, 16, 20 Lead wire 5, 5a, 13 Second substrate 6, 12 Metal layer 7 , 7a, 15 fusible 14 substrate 17, 22 an insulating member (resin) 21 insulating member (Garasuko DOO, resin)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-174678 (JP, A) JP-A-63-185002 (JP, A) JP-A-2-153513 (JP, A) JP-A-60-1985 221923 (JP, A) JP-A-60-221921 (JP, A) JP-A-59-11695 (JP, A) JP-A-59-61508 (JP, U) JP-A-62-193647 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 37/76 H01H 69/02 H01H 85/00-87/00

Claims (1)

(57) [Claims] 1. A formed on the first substrate plane formed by the ceramic green sheet and a pair of electrodes and the first structure provided with a resistor for crosslinking between the electrodes, a metal layer and a ceramic green sheet And at least the resistance of the first structure
Laminated on the first structure to cover the body and integrated by sintering
A second structure having a fusible element on a second substrate plane and ceramic together with molded, soluble in at least a second structure
A resistance temperature fuse characterized by comprising an insulating member covering a body part .