WO2019117153A1

WO2019117153A1 - Temperature-sensitive pellet-type thermal fuse

Info

Publication number: WO2019117153A1
Application number: PCT/JP2018/045530
Authority: WO
Inventors: 栄吾岸; 晃中西; 保若林; 吉川　時弘
Original assignee: ショット日本株式会社
Priority date: 2017-12-12
Filing date: 2018-12-11
Publication date: 2019-06-20
Also published as: CN111247613A; CN111247613B

Abstract

A temperature-sensitive pellet-type thermal fuse (10) comprises: an electroconductive envelope (11) that has an opening at a first end thereof; a temperature-sensitive device that is accommodated within the envelope and that thermally responds at a predetermined temperature; a first lead (14) that is attached to the opening of the envelope so as to be electrically insulated from the envelope, and that has a fixed contact (13); a second lead (15) that is connected to a second end of the envelope; a movable contact (16) that is accommodated in the envelope and that is pressed by the temperature-sensitive device so as to abut the fixed contact; and a weak compression spring (17) that is accommodated in the envelope and that presses the movable contact in a direction away from the fixed contact. The temperature-sensitive device comprises: a cylindrical case (100) that has at least an opening end on the first lead side; a temperature-sensitive material (101) that is accommodated in the cylindrical case and that melts at a predetermined operation temperature; and a strong compression spring (102) that presses the temperature-sensitive material and brings the fixed contact (13) into contact with the movable contact (16).

Description

Temperature sensitive pellet type thermal fuse

The present disclosure relates to a temperature-sensitive pellet-type thermal fuse that detects an overheat of an electric device or the like to shut off an electric circuit.

Thermal fuses are used in home appliances and industrial electrical devices and electronic devices. The thermal fuse is a protective component that senses the temperature of the device and quickly shuts down the circuit when it overheats abnormally. Thermal fuses are incorporated in products such as home appliances, portable devices, communication devices, office equipment, in-vehicle devices, AC adapters, chargers, motors, and batteries, for example.

Generally, there are various types of thermal fuses whose rated current value is approximately 0.5 A to approximately 15 A. Especially for high rated current of 6 A or more, a temperature sensitive pellet type thermal fuse is suitably used. As one of the temperature sensitive pellet type thermal fuses, for example, there is a temperature sensitive pellet type thermal fuse shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 01-154422).

The temperature-sensitive pellet type thermal fuse disclosed in Patent Document 1 includes a cylindrical metal case (hereinafter referred to as an envelope) having a hollow portion inside, and one end and the other end of the envelope, respectively. The first and second leads disposed, the temperature-sensitive pellet disposed in contact with the second lead, and the first lead are in contact with the first lead via the temperature-sensitive pellet, and are always urged in the opening direction. And a movable contact. The temperature-sensitive pellet melts or softens when the temperature of the mounted electric device reaches a predetermined temperature or more. As a result, the movable contact is separated from the first lead by the biasing force, thereby breaking the circuit.

The temperature sensitive pellet type thermal fuse is connected in series to the electric device, and supplies and distributes electric power through the temperature sensitive pellet type thermal fuse. The temperature sensitive pellet type thermal fuse is disposed at a position where it is desired to detect an abnormal temperature rise of the electric device.

The temperature sensitive pellet is solid at normal temperature, and at this time, the movable contact is pressed against and brought into contact with the end of the first lead by the biasing force. Therefore, the first lead, the movable contact, the envelope, and the second lead are held in the conductive state. When the temperature of the installation site rises to the operating temperature of the temperature-sensitive pellet-type thermal fuse due to abnormal energization such as a short circuit of the electric device, the temperature-sensitive pellet melts. When the temperature sensitive pellet melts, the biasing force that presses the movable contact against the end of the first lead reduces and releases. When the force decreases, the movable contact is separated from the end of the first lead, and a non-conductive state is established between the first lead and the second lead. As a result, the supply and distribution to the electric device is stopped to prevent the temperature rise of the electric device, and it is possible to prevent the accident such as the overheat damage of the electric equipment or the ignition caused thereby.

JP 01-154422 A JP 2005-158681 A Japanese Patent Application Publication No. 2003-147461

For example, as described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-158681), the above-mentioned temperature-sensitive pellet type thermal fuse uses the melting point or deformation temperature of the organic material exclusively for the temperature-sensitive material, We used what was processed into pellet form. On the other hand, for example, Patent Document 3 (Japanese Patent Application Laid-Open No. 2003-147461) describes a fusible alloy thermal fuse using an inorganic material as a temperature sensitive material. A conductive metal such as solder is used as the temperature sensitive material of the inorganic material. When this is used for a temperature sensitive pellet type thermal fuse having a cylindrical metal envelope, it can be used because the temperature sensitive material flows in the metal envelope after operation and interferes with contact opening. It was not.

An object of the present disclosure is to provide a highly reliable temperature-sensitive pellet-type thermal fuse.

According to a temperature-sensitive pellet-type thermal fuse according to the present disclosure, a temperature-sensitive thermal-sensitive temperature sensor, which is housed in an electrically conductive envelope having an opening at a first end and housed inside the envelope, is provided. A device, a first lead electrically isolated from the envelope and mounted in the opening of the envelope and having a fixed contact, and a second lead connected to the second end of the envelope 2 lead, a movable contact accommodated in the envelope and pressed by the temperature-sensitive device to abut the fixed contact, accommodated in the envelope, and the movable contact being separated from the fixed contact And a weak compression spring for pressing in the direction of movement. The temperature-sensitive device presses the temperature-sensitive material which is melted at a predetermined operating temperature housed in the cylindrical case, the cylindrical case having an opening end at least on the first lead side, and the temperature-sensitive material, It has a strong compression spring which makes a fixed contact and the above-mentioned movable contact contact.

In the temperature sensitive pellet type thermal fuse, the open end of the temperature sensitive device may be disposed on the second lead side.

In the heat sensitive pellet type thermal fuse, the heat sensitive device may have a lid on the open end side of the cylindrical case.

In the heat sensitive pellet type thermal fuse, the heat sensitive material may be made of a conductive metal material.

In the temperature sensitive pellet type thermal fuse, a pressing plate may be provided between the temperature sensitive material and the strong compression spring.

In the temperature-sensitive pellet type thermal fuse, the pressing plate may have a protrusion on the contact surface with the temperature-sensitive material.

In the temperature sensitive pellet type thermal fuse, the pressing plate may have a protrusion on the contact surface with the strong compression spring.

In the temperature sensitive pellet type thermal fuse, the lid may be provided so as to be sandwiched between the temperature sensitive material and the strong compression spring.

In the temperature sensitive pellet type thermal fuse, the lid may have a protrusion on the contact surface with the strong compression spring.

In the thermosensitive pellet type thermal fuse, at least a contact portion of the lid with the cylindrical case may be made of an elastic material.

In the temperature sensitive pellet type thermal fuse, the elastic material may be made of a polymer material or a metal material.

In the thermosensitive pellet type thermal fuse, the lid may be made of a composite material of an inorganic chemical material and a polymer material.

In the heat sensitive pellet type thermal fuse, the lid may be made of a composite material of a metal material and a polymer material.

In the temperature sensitive pellet type thermal fuse, at least a portion of the lid in contact with the cylindrical case may be insert-molded.

In the heat sensitive pellet type thermal fuse, at least a contact portion of the lid with the cylindrical case may be elastically coated.

In the temperature-sensitive pellet-type thermal fuse, the lid may be dish-like or cap-like.

In the temperature sensitive pellet type thermal fuse, the lid may close the open end of the cylindrical case at least after operation.

In the heat sensitive pellet type thermal fuse, the lid or the cylindrical case may be made of a material which the melted temperature sensitive material does not easily get wet.

In the thermosensitive pellet type thermal fuse, the lid or the cylindrical case may be made of a material which is nonreactive or hardly reactive with the thermosensitive material.

In the heat sensitive pellet type thermal fuse, the lid or the cylindrical case may be made of nonmagnetic or weak magnetic material.

In the heat sensitive pellet type thermal fuse, the lid or the cylindrical case may be made of polymer material, aluminum, aluminum alloy, alumite, stainless steel, Fe-Ni alloy, ceramic material, nickel or chromium Good.

In the heat sensitive pellet type thermal fuse, at least a portion of the lid or the cylindrical case in contact with the heat sensitive material is a polymer material, aluminum, aluminum alloy, alumite, stainless steel, Fe-Ni alloy, ceramic material , Nickel or chromium.

In the heat sensitive pellet type thermal fuse, the heat sensitive material is a 67In-32.4Sn-0.6Cu alloy, 56.5Bi-41.9Sn-1In-0.6Cu alloy, 57Bi-43Sn alloy, 52Bi-43Sn -5Sb alloy, 91.2Sn-8.8Zn alloy, 92.5Sn-4In-3Ag-0.5Bi alloy, 96.5Sn-3.5Ag alloy, 99.8Sn-0.2Cu alloy, 95Sn-5Sb alloy, 90Pb -10Sb alloy, 99.3Bi-0.5Ag-0.2Cu alloy, 97Bi-3Ag alloy, 88.6 Pb-9.5 In-1 Sn-0.9 Ag alloy, 98 Pb-1.8 Ag-0.2 Sn alloy, 93 Zn- It may be composed of an alloy material of 4Al-3Mg alloy, 95Zn-5Al alloy or pure tin material.

In the temperature-sensitive pellet-type thermal fuse, the temperature-sensitive material may have a conical or frusto-conical shape.

In the temperature sensitive pellet type thermal fuse, the temperature sensitive material may be such that the upper portion of a cone or a truncated cone is fitted in the hole of the strong compression spring.

In the temperature sensitive pellet type thermal fuse, the strong compression spring may have an outer diameter in the range of 0.90 to 0.97, where the inner diameter of the cylindrical case is 1.

In the heat sensitive pellet type thermal fuse, the pressing plate may control at least one of the flow direction, the jet amount and the jet position of the temperature sensitive material after melting.

In the temperature-sensitive pellet-type thermal fuse, the pressing plate may be provided with at least one flow hole.

In the temperature sensitive pellet type thermal fuse, the pressing plate may have any one of polygonal, star and flower shapes.

In the temperature-sensitive pellet type thermal fuse, the pressing plate may be provided with a notch at least at an outer peripheral portion.

In the temperature-sensitive pellet-type thermal fuse, the pressing plate may have rounded corners so that it is difficult to be caught on the cylindrical case.

According to an embodiment of the present disclosure, energization can be cut off more reliably during fuse operation.

The temperature-sensitive pellet type thermal fuse 10 which concerns on this indication is shown, (a) is sectional drawing before operation | movement, (b) is sectional drawing after operation | movement. In (b), the temperature sensitive material is omitted. The temperature-sensitive pellet type thermal fuse 20 which concerns on this indication is shown, (a) is sectional drawing before operation | movement, (b) is sectional drawing after operation | movement. In (b), the temperature sensitive material is omitted. The temperature-sensitive pellet type thermal fuse 30 which concerns on this indication is shown, (a) is sectional drawing before operation | movement, (b) is sectional drawing after operation | movement. FIG. 10 is a cross-sectional view of a modified example 1 of a temperature sensitive pellet type thermal fuse according to the present disclosure. It is a sectional view of modification 2 of the temperature sensitive pellet type thermal fuse concerning this indication. FIG. 10 is a cross-sectional view of Modification 3 of the temperature-sensitive pellet type thermal fuse according to the present disclosure. The modification 4 of the thermosensitive pellet type thermal fuse which concerns on this indication is shown, (a) is sectional drawing before operation | movement, (b) is sectional drawing after operation. However, the temperature sensitive material is omitted in (b). FIG. 10 shows a cross-sectional view of Modification 5 of the temperature-sensitive pellet type thermal fuse according to the present disclosure. The press board of the thermosensitive pellet type thermal fuse which concerns on this indication is shown, (a) is a top view, (b) is an IXb-IXb arrow directional cross-sectional view of (a). The press board of the thermosensitive pellet type thermal fuse which concerns on this indication is shown, (a) is a top view, (b) is a Xb-Xb arrow directional cross-sectional view of (a). The press board of the thermal pellet type thermal fuse which concerns on this indication is shown, (a) is a top view, (b) is a XIb-XIb arrow directional cross-sectional view of (a).

According to a first aspect of the present disclosure, the temperature-sensitive pellet-type thermal fuse includes a conductive cylindrical envelope having an opening at a first end, and a predetermined temperature accommodated in the envelope. A temperature sensing device thermally responsive to temperature, a first lead electrically insulated from the envelope at the opening of the envelope and having a fixed contact at its inner end, and a second end of the envelope A second lead connected to the part, a movable contact accommodated in the envelope and pressed by the temperature-sensitive device to abut the fixed contact, and accommodated in the envelope so that the movable contact is separated from the fixed contact And a weak compression spring for pressing in the direction of movement.

The temperature sensitive device includes at least a cylindrical case, a temperature sensitive material melted at a predetermined operating temperature accommodated in the cylindrical case, and a strong compression spring which presses the temperature sensitive material and brings the fixed contact and the movable contact into contact with each other. And a lid provided between the strong compression spring and the movable contact.

The strong compression spring can select one of a mode in which the temperature sensitive material is directly pressed, and a mode in which the temperature sensitive material is pressed with the pressing plate interposed therebetween. In one preferred configuration, at least the lid or the cylindrical case (which may further include a pressing plate) is easily fused with the melted temperature-sensitive material so that the melted temperature-sensitive material does not leak out of the cylindrical case. It is preferable to form at least a contact surface with the temperature sensitive material with a material which is difficult to wet (for example, aluminum, aluminum alloy, stainless steel, Fe-Ni alloy, ceramic material, nickel, chromium).

The lid or the cylindrical case (which may further include a pressing plate) may be connected to other components of the thermal fuse or peripheral members other than the thermal fuse by magnetic influence of the surroundings, such as magnetic restraint or electromagnetic induction heating. Nonmagnetic or weak magnetic ones are more preferred so that no interaction occurs.

When the lid and the cylindrical case are just brought together when the strong compression spring and the weak compression spring are extended, the lid which is in contact with the cylindrical case after operation is strongly pressed toward the cylindrical case It is possible to prevent defects such as tilting of the lid due to

According to a second aspect of the present disclosure, there is provided a conductive envelope having an opening at one end, a temperature-sensitive device thermally received at a predetermined temperature, housed inside the envelope, and an envelope A first lead having a fixed contact at its inner end, the second lead connected to the second end of the envelope, and an envelope A movable contact that is housed in the container and pressed by the temperature-sensitive device so as to abut on the fixed contact, and a weak compression spring that is housed in the envelope and presses the movable contact in a direction to separate from the fixed contact. There is.

The temperature sensing device includes at least a cylindrical case disposed to close the opening end by pressing the opening end against the inner end of the envelope when the thermal fuse operates, and a predetermined operating temperature accommodated in the cylindrical case And a strong compression spring for pressing the temperature sensitive material to bring the fixed contact and the movable contact into contact with each other.

The strong compression spring can select one of a form in which the temperature sensitive material is directly pressed and a form in which the temperature sensitive material is pressed with the pressing plate interposed therebetween. In one preferable configuration, at least a cylindrical case or a pressing plate is a material (for example, a polymer) in which the molten temperature-sensitive material is not easily wettable so that the molten temperature-sensitive material does not leak out of the cylindrical case Material, aluminum, aluminum alloy, anodized aluminum, stainless steel, Fe-Ni alloy, ceramic material, nickel, chromium).

In addition, the cylindrical case or the pressing plate may not interact with other components of the thermal fuse or peripheral members other than the thermal fuse due to the magnetic influence of the surroundings, such as magnetic restraint or electromagnetic induction heating. And nonmagnetic or weak magnetic ones are more preferable.

According to a third aspect of the present disclosure, an electrically conductive envelope having an opening at one end, a temperature sensitive device that is thermally responsive to a predetermined temperature housed inside the envelope, and the envelope In the opening, there is provided a first lead having an electrical contact with the envelope and having a fixed contact at its inner end, a second lead connected to the second end of the envelope, and the envelope The movable contact which is accommodated and pressed by the temperature sensitive device so as to abut on the fixed contact, and the weak compression spring which is accommodated in the envelope and causes the movable contact to act in a pressing manner.

The temperature sensitive device includes at least a cylindrical case, a temperature sensitive material which melts at a predetermined operating temperature accommodated in the case, a strong compression spring which presses the temperature sensitive material and brings the fixed contact and the movable contact into contact with each other. It has a lid body provided by being sandwiched between the hot material and the strong compression spring.

In a more preferable embodiment, at least the lid or the cylindrical case is a material which is difficult for the melted temperature-sensitive material to easily get wet so that the temperature-sensitive material does not leak out of the container (e.g. Reactive or poorly reactive material).

Furthermore, the lid or cylindrical case is more preferably nonmagnetic or weakly magnetic so as not to interact with peripheral members during operation. Then, when the lid and the cylindrical case are just brought together when the two compression springs are extended, the lid which is in contact with the cylindrical case after operation is strongly pressed toward the cylindrical case. It is possible to prevent defects such as the inclination of the

The temperature sensitive material has its own surface tension when the temperature sensitive material is in a molten state, as the lid or cylindrical case for containing the temperature sensitive material is made of a material that is difficult for the melted temperature sensitive material to get wet easily. To minimize the surface area of the container. At this time, the temperature-sensitive material is surrounded by the cover and the hard-to-wet surface of the cylindrical case and is stored against the wall surface, so that the metal material flows out of the container by the wetting phenomenon such as extended wetting. There is no For example, since it can be held in the container by utilizing the repelling property and the property of being hard to get wet between the molten metal material and the wall surrounding the periphery thereof, the temperature-sensitive material melted even with a slight gap is the container It can be housed in a container without going outside.

Therefore, the lid or the cylindrical case is a material (polymer material, aluminum, aluminum alloy, alumite, stainless steel, Fe-Ni alloy) in which the melted temperature sensitive material is not easily wetted at least at a portion contacting the temperature sensitive material , Ceramic material, nickel, chromium, etc.). For example, the lid and the cylindrical case may be made of a composite of an inorganic chemical material such as a metal material coated on the surface with a thermal spray ceramic and a metal material.

The temperature-sensitive material of the present disclosure is not particularly limited as long as it can be melted and operated at a desired temperature and can be fused, for example, 67In-32.4Sn-0.6Cu alloy (melting temperature 124 ° C.), 56.5 Bi- 41.9Sn-1In-0.6Cu alloy (melting temperature 137 ° C), 57Bi-43Sn alloy (melting temperature 139 ° C), 52Bi-43Sn-5Sb alloy (melting temperature 146 ° C), 91.2Sn-8.8Zn alloy ( Melting temperature 198 ° C), 92.5 Sn-4In-3Ag-0.5Bi alloy (melting temperature 208 ° C), 96.5 Sn-3.5Ag alloy (melting temperature 222 ° C), 99.8 Sn-0.2Cu alloy (melting Temperature: 227 ° C.), 95 Sn-5 Sb alloy (melting temperature: 242 ° C.), 90 Pb-10 Sb alloy (melting temperature: 252 ° C.), 99.3 Bi-0.5 Ag-0. Cu alloy (melting temperature 262 ° C), 97Bi-3Ag alloy (melting temperature 268 ° C), 88.6 Pb-9.5 In-1 Sn-0.9 Ag alloy (melting temperature 289 ° C), 98 Pb-1.8 Ag-0.2 Sn Alloy (melting temperature 310 ° C), 93Zn-4Al-3Mg alloy (melting temperature 310 ° C), 95Zn-5Al alloy (melting temperature 385 ° C) [composition ratio is% by mass] alloy material or pure tin material ( A metal temperature sensitive material having a melting temperature of 232 ° C.) can be used. These metal materials are made of a material that exhibits conductivity.

As shown in FIG. 1, the temperature-sensitive pellet-type thermal fuse 10 according to the first embodiment of the present disclosure includes an envelope 11, a temperature-sensing device, an insulating tube 12, a first lead 14, a second lead 15, and a movable contact. 16 and a weak compression spring 17 are provided.

The envelope 11 is a cylindrical type made of a silver-plated copper alloy having an opening at a first end. The temperature sensitive device is housed inside the envelope 11 and thermally responds at 222 ° C.

The insulating tube 12 is made of ceramics that closes the opening of the envelope 11. The first lead 14 is made of a silver-plated copper alloy which penetrates the insulating tube 12 and whose inward end is a fixed contact 13. The second lead 15 is made of a silver-plated copper alloy disposed at the second end of the envelope 11.

The movable contact 16 is pressed by the temperature sensitive device so as to be accommodated in the envelope 11 and abut on the fixed contact 13, and is made of silver alloy. The weak compression spring 17 is accommodated in the envelope 11 and presses the movable contact 16 in the direction of separating it from the fixed contact 13.

The temperature sensitive device has a cylindrical case 100, a temperature sensitive material 101, a strong compression spring 102, a pressing plate 103 and a lid 104. The cylindrical case 100 is made of aluminum (with an anodized film) provided with an alumite coating having an opening at one end. The temperature sensitive material 101 is accommodated in the cylindrical case 100 and melted at an operating temperature of 222 ° C. The temperature sensitive material 101 is made of 96.5 Sn-3.5 Ag alloy. The strong compression spring 102 presses the temperature sensitive material 101 to bring the fixed contact 13 and the movable contact 16 into contact. The pressing plate 103 is disposed between the strong compression spring 102 and the temperature sensitive material 101, and is made of SUS304 stainless steel. The lid 104 is provided so as to be sandwiched between the strong compression spring 102 and the movable contact 16, and closes the opening of the cylindrical case 100 when the thermal fuse is operated. The lid 104 is made of SUS304 stainless steel.

In the temperature-sensitive pellet-type thermal fuse 10 of the first embodiment, the envelope 11 is sealed with a sealing material 1000 of an organic adhesive. A curable resin or an elastomer can be used for the organic adhesive. More preferably, an epoxy resin or silicone rubber can be used for the organic adhesive. In the first embodiment, the pressing plate 103 may be omitted. In the first embodiment, the open end of the cylindrical case 100 is provided toward the movable contact 16 side.

As shown in FIG. 1B, when the temperature-sensitive material 101 is melted, the biasing force for pressing the movable contact 16 toward the fixed contact 13 is weakened, and the weak compression spring 17 biases the movable contact 16 and the fixed contact. 13 and break apart. The lid 104 closes the opening of the cylindrical case 100 to prevent the molten temperature-sensitive material 101 from flowing out of the cylindrical case 100.

As shown in FIG. 2, the temperature-sensitive pellet-type thermal fuse 20 according to the second embodiment of the present disclosure is an envelope 21, a temperature-sensing device, an insulating tube 22, a first lead 24, a second lead 25, and a movable contact. And a weak compression spring 27.

The envelope 21 is a cylindrical type made of silver-plated copper alloy having an opening at a first end. The temperature sensitive device is provided inside the envelope 21 and thermally responds at 241.degree. The insulating tube 22 closes the open end of the envelope 21 and is made of ceramic.

The first lead 24 penetrates the insulating pipe 22 and has an inner end as a fixed contact 23 and is made of a silver-plated copper alloy. The second lead 25 is disposed at the second end of the envelope 21 and is made of silver-plated copper alloy. The movable contact 26 is pressed by the temperature sensitive device so as to be accommodated in the envelope 21 and to abut on the fixed contact 23, and is made of silver alloy. The weak compression spring 27 is accommodated in the envelope 21 and presses the movable contact 26 in the direction in which the movable contact 26 is separated from the fixed contact 23.

The temperature sensing means includes a cylindrical case 200, a temperature sensing material 201, a strong compression spring 202, and a pressing plate 203.

The cylindrical case 200 is disposed so as to close the opening end thereof by pressing it against the inner end of the envelope 21 when the thermal fuse operates. The cylindrical case 200 is made of SUS304 stainless steel. The temperature sensitive material 201 is made of 95Sn-5Sb alloy which is accommodated in the cylindrical case 200 and melts at an operating temperature of 241.degree. The strong compression spring 202 presses the temperature sensitive material 201 and brings the fixed contact 23 and the movable contact 26 into contact. The pressing plate 203 is disposed between the strong compression spring 202 and the temperature sensitive material 201, and is made of SUS304 stainless steel.

In the temperature sensitive pellet type thermal fuse 20 according to the second embodiment, the envelope 21 is sealed with a sealing material 1000 of an organic adhesive. In the second embodiment, the pressing plate 203 may be omitted. In the second embodiment, the open end of the cylindrical case 200 is disposed on the second lead 25 side.

As shown in FIG. 3, the temperature-sensitive pellet-type thermal fuse 30 according to the third embodiment of the present disclosure is an envelope 31, a temperature-sensing device, an insulating tube 32, a first lead 34, a second lead 35, and a movable contact. 36 and a weak compression spring 37.

The envelope 31 has an opening at a first end, and is made of silver-plated copper alloy and is tubular. The temperature sensitive device is provided inside the envelope 31 and thermally responds at 292 ° C. The insulating pipe 32 is made of ceramics that closes the open end of the envelope 31.

The first lead 34 is made of a silver-plated copper alloy which penetrates the insulating pipe 32 and whose inward end is a fixed contact 33. The second lead 35 is made of silver-plated copper alloy disposed at the second end of the envelope 31. The movable contact 36 is accommodated in the envelope 31 and pressed by the temperature sensitive device to abut on the fixed contact 33 and is made of silver alloy. The weak compression spring 37 is accommodated in the envelope 31 and presses the movable contact 36 in the direction of separating it from the fixed contact 33.

The temperature sensitive device has a cylindrical case 300, a temperature sensitive material 301, a lid 304, and a strong compression spring 302. The cylindrical case 300 is made of ceramic. The temperature sensitive material 301 is made of 95 Sn-5 Sb alloy which is accommodated in the cylindrical case 300 and melts at 242 ° C.

The lid 304 is provided so as to be sandwiched between the temperature sensitive material 301 and the strong compression spring 302. The strong compression spring 302 is accommodated in the envelope 31 to press the temperature sensitive material, and brings the fixed contact 33 and the movable contact 26 into contact.

In the temperature-sensitive pellet-type thermal fuse 30 according to the third embodiment, the envelope 31 is sealed with an organic adhesive sealant 1000, and is sandwiched between the movable contact 36 and the strong compression spring 302. It has a discoid body 2000 provided. Furthermore, a step 305 may be provided on the bottom surface inside the case so that the temperature sensitive material 301 can be disposed with a gap between it and the inner wall of the cylindrical case 300.

The pressing plate 103 of the temperature sensitive pellet type thermal fuse 10 has a columnar protrusion 406 on the contact surface with the temperature sensitive material 401 like the pressing plate 403 of the temperature sensitive pellet type thermal fuse 40 of the first modification shown in FIG. To make the pressing plate 403 convex. The protrusion 406 of the pressing plate 403 of the first modification abuts on the temperature sensitive material 401 at the tip end portion, and is installed so as to provide a gap between the outer periphery and the inner wall of the cylindrical case 400. After operation, the protrusion 406 is buried in the melted temperature sensitive material. At this time, the temperature-sensitive material 401 melted moves so as to fill the gap between the protrusion 406 and the inner wall of the cylindrical case 400, so that the temperature-sensitive material 401 is prevented from spouting out of the cylindrical case 400. .

The lid 104 of the temperature sensitive pellet type thermal fuse 10 may be shaped like a lid 504 a of the temperature sensitive pellet type thermal fuse of the second modification shown in FIG. 5A. Further, as in a lid 504 b of FIG. 5 (b), a cap may be used. In that case, the plate-like or cap-like lids 504 a and 504 b are disposed so as to close the open end of the cylindrical case 500 after operation.

The lid 304 of the temperature sensitive pellet type thermal fuse 30 according to the present invention may be dished like the lid 604 a of the temperature sensitive pellet type thermal fuse 60 of the third modification shown in FIG. Alternatively, it may be formed in a cap shape as in a lid 604 b shown in FIG. 6 (b). The

lid

604e or 604f of the third modification is disposed to close the opening of the cylindrical case 600 at least after operation.

In this case, by providing a suitable gap between the lid 604b and the outer peripheral wall of the cylindrical case 600 as shown in FIG. 6B, the inner wall of the lid 604b and the outer peripheral wall of the cylindrical case 600 Can prevent interference with As in the case of the lid 604f of FIG. 6 (b), the tubular case 600 and the lid 604b may be combined to form a capsule shape before operation.

As shown in FIG. 6A, the step 605 may be tapered so that the temperature sensitive material can be easily attached to the center of the bottom surface of the cylindrical case. In the arrangement direction of the plate-like lid 604a, there are two cases: the case where the upper surface of the plate shown in FIG. 6A contacts the strong compression spring 602, and the case where the back surface of the plate contacts the strong compression spring 602. is there.

The temperature sensitive material 101 of the temperature sensitive pellet type thermal fuse 10 may be changed to a truncated cone like the temperature sensitive material 701 of the temperature sensitive pellet type thermal fuse 70 of the fourth modification shown in FIG. 7A. The temperature sensitive material 701 may be conical. As shown, the conical or frusto-conical temperature sensitive material 701 is advantageous for miniaturization as the conical top can be fitted into the hole of the strong compression spring 702. In addition, since the positioning of the strong compression spring 702 is facilitated, the structure is easier to assemble.

In the conventional temperature sensitive material made of organic chemical material, the spring load is concentrated on the contact portion when attached to the hole, so there is a possibility that the temperature sensitive material may be deformed or broken, and the shape as in the modification 4 is It could not be used. It is preferable to use an inorganic material such as a metal material which is less likely to be deformed than the organic chemical material.

The pressing plate 103 and the lid 104 of the temperature sensitive pellet type thermal fuse 10 have an inner diameter of the strong compression spring 802 like the pressing plate 803 and the lid 804 of the temperature sensitive pellet type thermal fuse 80 of the fifth modification shown in FIG. A columnar projection 806 may be provided to mate with the (spring hole). The pressing plate 803 and the lid 804 are deformed in a convex shape by providing the projections 806.

By providing the projections 806, it is possible to prevent the displacement of the pressing plate 803, the lid 804 and the strong compression spring 802. The connectivity and interlocking between the pressing plate 803, the lid 804 and the strong compression spring 802 can be improved. In addition, although the protrusion 806 was provided in both the pressing plate 803 and the cover body 804 in FIG. 8, it is good also as only any one.

The strong compression spring of the above embodiment is configured such that the outer diameter of the strong compression spring is in the range of 0.90 to 0.97, where the internal diameter of the cylindrical case into which the strong compression spring is inserted is 1. It is preferable then. When the outer diameter ratio of the strong compression spring is less than 0.90, the strong compression spring is easily inclined in the cylindrical case, and it becomes difficult to press the temperature sensitive material appropriately. When the outer diameter ratio of the strong compression spring exceeds 0.97, the contact with the inner wall of the cylindrical case is intensified and the normal extension of the spring is impeded.

In the lid of the above embodiment, at least the contact portion with the cylindrical case may be made of an elastic material having elasticity. The elastic material which comprises a lid is not restricted to a metal material. For example, in order to easily seal the open end of the cylindrical case, the entire lid or at least the outer periphery of the lid or a portion contacting the cylindrical case may be made of liquid crystal plastic (LCP), heat-resistant resin such as fluorine resin, or fluorine It can also be composed of a polymer material such as rubber.

The lid may be made of a composite material. For example, it may be composed of a composite of an inorganic chemical material such as glass reinforced plastic (FRP) and a polymer material. Furthermore, for example, the contact portion of at least the outer peripheral side of the metal lid with the cylindrical case may be covered with resin by insert molding. An elastic coating of rubber or resin may be applied to at least a contact portion of the metal lid with the cylindrical case. Thus, the lid may be made of a composite of a polymer material and a metal.

In these lids, when the lid contacts the cylindrical case, at least the outer peripheral portion of the lid is elastically pressed by the pressure of the weak compression spring, thereby reliably sealing the opening of the cylindrical case. It can stop.

In the cylindrical case according to the present embodiment, the whole of the cylindrical case or at least the outer periphery of the open end of the cylindrical case or a portion in contact with the lid is made of heat resistant resin such as liquid crystal plastic (LCP) or fluororesin, It can also be composed of a polymer material such as, or an inorganic material such as ceramic.

The pressing plate used for the temperature-sensitive pellet type thermal fuse of the present embodiment can be configured to control the flow direction, the amount of ejection, and the ejection position of the temperature-sensitive material after melting. For example, as shown in FIG. 9, it is possible to provide the pressing plate 93 with a through hole 98 through which the melted temperature-sensitive material passes. By adjusting the flow direction and the ejection amount of the temperature-sensitive material after melting by the flow holes 98, it is controlled so that the melted temperature-sensitive material does not easily flow out of the cylindrical case after operation.

At least one or more through holes 98 are provided in the pressing plate 93. For example, as shown in FIG. 9, one may be provided at the center, or a plurality of holes may be provided on the plate surface of the pressing plate. The flow holes 98 can be changed in position, size, shape and the like of the holes according to the heat flow characteristics of the temperature sensitive material to be applied.

As shown in FIGS. 10 and 11, the flow direction and the amount of the temperature-sensitive material after melting may be controlled by deforming the shapes of the

pressing plates

103 and 113 into polygons, stars, flowers and the like. . By providing the

notches

109 and 119 in the outer peripheral portion of the

pressing plates

103 and 113, the opening between the

pressing plates

103 and 113 and the inner wall of the cylindrical case 100 can be adjusted, and the same effect as the above-described flow holes can be obtained. . At that time, it is preferable that the corner of the pressing plate is rounded so that it is difficult to be caught on the cylindrical case. As shown in FIG. 10, the flow holes 108 and the notches 109 can be used in combination.

In the temperature sensitive pellet type thermal fuse of the present embodiment, a conductive temperature sensitive material can be used without inhibiting the opening operation of the movable contact. In particular, the material and the shape can be stably maintained even when exposed to a high temperature environment around 200 ° C. for a long time. For example, it is possible to provide a highly reliable temperature sensitive pellet type thermal fuse in terms of insulation after operation.

It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of claims.

The present disclosure is applicable to a contact-opened thermal fuse having a movable contact and sensing an abnormal temperature to open the contact, and in particular, to a pellet-type thermal fuse suitably used.

10, 20, 30, 40, 60, 70, 80 Temperature-sensitive pellet type thermal fuse, 11, 21, 31 envelope, 12, 22, 32, insulating tube, 13, 23, 33 fixed contact, 14, 24, 34

1st lead

15, 25, 35

2nd lead

16, 16, 36

movable contact point

17, 27, 37

weak compression spring

93, 103, 203, 403, 803 Plate, 98, 108 flow hole, 100, 200, 300, 400, 500, 600 cylindrical case, 101, 201, 301, 401, 701 temperature sensitive material, 102, 202, 302, 602, 702, 802 strong compression spring, 104, 304, 504a, 504b, 604a , 604 b, 604 e, 604 f, 804 lid, 109 notches, 305, 605 steps, 406, 806 protrusions, 1000 seals Wood, 2000 board-like body

Claims

A conductive envelope having an opening at a first end,
A temperature sensitive device thermally accommodated at a predetermined temperature, which is accommodated inside the envelope;
A first lead having a fixed contact and mounted in the opening of the envelope in electrical insulation with the envelope;
A second lead connected to the second end of the envelope;
A movable contact housed in the envelope and pressed by the temperature sensitive device to abut the fixed contact;
A weak compression spring which is accommodated in the envelope and presses the movable contact in a direction in which the movable contact is separated from the fixed contact;
The temperature sensitive device comprises a cylindrical case having an open end at least on the first lead side;
A temperature sensitive material which melts at a predetermined operating temperature housed in the cylindrical case;
A temperature sensitive pellet type thermal fuse, comprising: a strong compression spring which presses the temperature sensitive material and brings the fixed contact and the movable contact into contact with each other.
The temperature sensitive pellet type thermal fuse according to claim 1, wherein the open end of the temperature sensitive device is disposed on the second lead side.
The temperature sensitive pellet type thermal fuse according to claim 1, wherein the temperature sensitive device has a lid on the open end side of the cylindrical case.
The temperature sensitive pellet type thermal fuse according to any one of claims 1 to 3, wherein the temperature sensitive material is made of a conductive metal material.
The temperature sensitive pellet type thermal fuse according to any one of claims 1 to 4, wherein a pressing plate is provided between the temperature sensitive material and the strong compression spring.
The temperature sensitive pellet type thermal fuse according to claim 5, wherein the pressing plate has a protrusion on the contact surface with the temperature sensitive material.
The temperature sensitive pellet type thermal fuse according to claim 5, wherein the pressing plate has a protrusion on the contact surface with the strong compression spring.
The temperature sensitive pellet type thermal fuse according to claim 3, wherein the lid is provided so as to be sandwiched between the temperature sensitive material and the strong compression spring.
The temperature sensitive pellet type thermal fuse according to claim 8, wherein the lid body has a protrusion on the contact surface with the strong compression spring.
The temperature sensitive pellet type thermal fuse according to any one of claims 2, 8, and 9, wherein at least a contact portion of the lid with the cylindrical case is made of an elastic material.
The thermosensitive pellet-type thermal fuse according to claim 10, wherein the elastic material is made of a polymer material or a metal material.
The temperature sensitive pellet-type thermal fuse according to claim 10, wherein the lid is made of a composite material of an inorganic chemical material and a polymer material.
The thermosensitive pellet-type thermal fuse according to claim 10, wherein the lid is made of a composite material of a metal material and a polymer material.
The temperature sensitive pellet type thermal fuse according to any one of claims 8 to 10, wherein at least a contact portion of the lid with the cylindrical case is insert-molded.
The temperature sensitive pellet type thermal fuse according to any one of claims 8 to 10, wherein at least a contact portion of the lid with the cylindrical case is elastically coated.
The temperature sensitive pellet type thermal fuse according to claim 8 or 9, wherein the lid is in the shape of a dish or a cap.
The temperature sensitive pellet type thermal fuse according to any one of claims 3 and 8 to 16, wherein the lid closes the open end of the cylindrical case at least after operation.
The temperature sensitive pellet-type temperature according to any one of claims 3 and 8 to 17, wherein the lid or the cylindrical case is made of a material which the melted temperature sensitive material does not easily get wet. fuse.
The temperature sensitive pellet according to any one of claims 3 and 8 to 18, wherein the lid or the cylindrical case is made of a material which is nonreactive or hardly reactive with the temperature sensitive material. Mold temperature fuse.
The temperature sensitive pellet type thermal fuse according to any one of claims 3 and 8 to 19, wherein the lid or the cylindrical case is made of a nonmagnetic or weak magnetic material.
The said lid or the said cylindrical case was comprised from the polymeric material, aluminum, aluminum alloy, alumite, stainless steel, Fe-Ni alloy, a ceramic material, nickel, or chromium. The temperature-sensitive pellet-type thermal fuse according to any one of the above.
The lid or the cylindrical case is configured such that at least a portion in contact with the temperature sensitive material is made of a polymer material, aluminum, aluminum alloy, alumite, stainless steel, Fe-Ni alloy, ceramic material, nickel or chromium. A temperature sensitive pellet type thermal fuse according to any one of claims 3 and 8 to 20.
The temperature sensitive material includes 67In-32.4Sn-0.6Cu alloy, 56.5Bi-41.9Sn-1In-0.6Cu alloy, 57Bi-43Sn alloy, 52Bi-43Sn-5Sb alloy, 91.2 Sn-8. 8 Zn alloy, 92.5 Sn-4 In-3 Ag-0.5 Bi alloy, 96.5 Sn-3.5 Ag alloy, 99.8 Sn-0.2 Cu alloy, 95 Sn-5 Sb alloy, 90 Pb-10 Sb alloy, 99.3 Bi-0. 5Ag-0.2Cu alloy, 97Bi-3Ag alloy, 88.6 Pb-9.5 In-1 Sn-0.9 Ag alloy, 98 Pb-1.8 Ag-0.2 Sn alloy, 93 Zn-4 Al-3 Mg alloy, 95 Zn-5 Al alloy The temperature-sensitive pellet-type thermal fuse according to claim 4, wherein the temperature-sensitive pellet-type fuse is made of any one alloy material or pure tin material.
The temperature sensitive pellet-type thermal fuse according to any one of claims 1 to 23, wherein the temperature sensitive material has a conical or frusto-conical shape.
The temperature sensitive pellet type thermal fuse according to claim 24, wherein the temperature sensitive material has a conical or truncated cone upper portion fitted in a hole of the strong compression spring.
26. The strong compression spring according to any one of claims 1 to 25, wherein when the inside diameter of the cylindrical case is 1, the outside diameter is in the range of 0.90 to 0.97. Temperature-sensitive pellet-type thermal fuse.
The temperature-sensitive pellet type temperature according to any one of claims 5 to 7, wherein the pressing plate controls at least one of a flow direction, an ejection amount and an ejection position of the temperature-sensitive material after melting. fuse.
The temperature sensitive pellet type thermal fuse according to any one of claims 5 to 7, wherein the pressing plate is provided with at least one flow hole.
The temperature-sensitive pellet-type thermal fuse according to any one of claims 5 to 7, wherein the pressing plate has a polygonal, star-like or flower-like shape.
The temperature sensitive pellet type thermal fuse according to any one of claims 5 to 7, wherein the pressing plate is provided with a notch at least at an outer peripheral portion thereof.
The temperature sensitive pellet type thermal fuse according to claim 29 or 30, wherein the pressing plate has rounded corners so that it is difficult to be caught in the cylindrical case.