TW201541488A - Protection device - Google Patents

Abstract

The present invention provides a protection device comprising a resin base, a first terminal, a PTC element, a bimetal element, an arm, an upper plate, and a second terminal, the protection device being characterized in that: the first terminal, the PTC element, the bimetal element, and the arm are stacked in this order inside an internal space defined by the resin base inner walls, and the internal space containing these is sealed by the upper plate; the upper plate is held by the resin base inner walls; the first terminal, the arm, and the second terminal establish a series electric connection in this order; and when the bimetal element is operated, the first terminal and the arm become electrically cut off while the first terminal, the PTC element, the bimetal element, the arm, and the second terminal establish a series electric connection in this order. This protection device has a large internal space, can be reduced in size, and can be produced readily.

Description

protective device

The present invention relates to a protection device having a bimetal element and a PTC (positive temperature coefficient) element.

When an abnormality occurs when an excessive current flows to an electric device (for example, a motor) and the electric device is formed to an abnormally high temperature, or when the temperature of the electric device is abnormally high due to some reason other than the overcurrent, The current flowing through the electrical device is blocked, and then the cause of the abnormality as described above is solved as needed to ensure the safety of the electrical device. A bimetallic element is used as a means of interrupting the current as indicated above.

The bimetal element is formed of a sheet member having a bimetallic metal, and when it is formed at a high temperature exceeding a specific temperature, or when the ambient temperature around the bimetal element becomes high and the bimetal element exceeds a specific temperature to form a high temperature, Actuation (ie, deformation) is performed to interrupt the current flowing in the bimetal element.

When the bimetal element as described above is incorporated in an electric device, if the electric device is formed at an abnormally high temperature due to an overcurrent or other reasons, the electric current is interrupted. Although the temperature of the electric device is lowered by current interruption, the temperature of the bimetal element itself is also lowered, so that the bimetal element is restored to its original shape (ie, restored), and as a result, the cause of the abnormality is removed to secure the electrical device. The current can be allowed to flow again before safety.

In order to prevent the current from flowing again as shown above, it is necessary to ensure or maintain the bimetal element The state of action. Therefore, in the circuit of the electric device, the bimetal elements are arranged in series so as to interrupt the current of the circuit, and the PTC elements are arranged in parallel with respect to the bimetal element. With the configuration as described above, if the bimetal element is actuated, the current flowing therethrough is caused to be bypassed by the PTC element, and the PTC element is subjected to Joule heat due to the current, and the heat is transmitted to the bimetal element to maintain the double The operating state of the metal component.

As described above, in the circuit, a movable contact that operates to open the circuit by the action of the bimetal element is disposed, and a protection device configured by arranging the PTC element in parallel with the bimetal element has been disposed. Known. For example, Patent Document 1 discloses a spatial arrangement of a PTC element, a bimetal member, and an arm portion in a resin substrate, the resin cover member being disposed on a resin substrate, and in this state, the resin substrate and the resin cover member are borrowed A protective device that is integrally melted by ultrasonic waves. Further, Patent Document 2 discloses a space in which a first terminal, a PTC element, a bimetal element, an arm portion, and an upper plate member are disposed in a space in a resin substrate, and in this state, the resin cover member is overmolded ( For example, a protective device inserted into the shape).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-203277

[Patent Document 2] International Publication 2013/058362

The conventional protective device as described above is required to have a process of providing a resin cover member after spatially arranging the members in the resin substrate, for example, a process of setting by ultrasonic welding or secondary molding, which is complicated in the process. . In addition, due to the presence of a resin cover, increased protection The internal space of the device is not conducive to reducing the size of the protective device, and is particularly disadvantageous for reducing the thickness.

Therefore, an object of the present invention is to provide a protective device which is large in internal space, small in size, thin, and easy to manufacture.

As a result of intensive studies to solve the above problems, the present inventors have found that the upper plate member is held on the inner wall of the resin base, preferably at the upper edge portion thereof, thereby eliminating the necessity of the resin cover member and increasing the necessity. The internal space of the resin substrate or the size of the protective device is reduced.

According to one of the gist of the present invention, there is provided a protection device comprising: a resin substrate, a first terminal, a PTC element, a bimetal element, an arm portion, an upper plate member, and a second terminal; The first terminal, the PTC element, the bimetal element, and the arm are stacked in the internal space defined by the inner wall of the resin substrate in the following order, and the internal space including the members is surrounded by the upper plate. The upper plate is held by the inner wall of the resin substrate, and the first terminal, the arm portion, and the second terminal are electrically connected in series in this order, and when the bimetal member is actuated, the first terminal and the arm are In the state in which the portion is electrically blocked, the first terminal, the PTC element, the bimetal element, the arm portion, and the second terminal are electrically connected in series in this order.

According to another aspect of the present invention, an electric device comprising the above protective device is provided.

According to the present invention, there is a resin substrate, a first terminal, a PTC element, and a double gold In the protective device including the element, the arm, and the upper plate, the upper plate is held on the inner wall of the resin base, and the protective device can be constructed without using a resin cover. Since the protective device of the present invention does not require a resin cover member, the thickness of the protective device can be reduced. Further, by holding the upper plate member on the inner wall of the resin substrate, since the upper plate member does not require a portion for fixing itself to the resin substrate (for example, a leg portion, a hook, or the like), the resin substrate can be further widened. Internal space.

1, 1', 1" ‧ ‧ protective devices

2‧‧‧1st terminal

4‧‧‧2nd terminal

6‧‧‧ resin substrate

8‧‧‧PTC components

10‧‧‧ bimetallic components

12‧‧‧ Arms

14‧‧‧Upper plate

16‧‧‧ Space

18‧‧‧Exposed part

20‧‧‧Part of the first terminal

22‧‧‧Part of the 2nd terminal

24‧‧‧ inner wall

26‧‧‧Contact part of the first terminal

28‧‧‧Contacts of the arms

30‧‧‧Contacts

32‧‧‧Contacts

34‧‧‧Departure

36‧‧‧Contacts

38‧‧‧ shoulder

40‧‧‧ Press

42‧‧‧Fixed components

The first drawing schematically shows a plan view of a protective device 1 of one aspect of the present invention.

The second figure is a cross-sectional view schematically showing a vertical line x-x with respect to the upper surface of the protection device of the first figure.

The third diagram schematically shows an exploded perspective view of the protective device of the first figure, which is assumed to be decomposed into components constituting the same.

The fourth figure is a view for explaining a method of fixing the upper plate member on the resin substrate by heat riveting.

The fifth drawing schematically shows a plan view of a protective device 1' according to another aspect of the present invention.

The sixth figure is a cross-sectional view schematically showing a vertical line x-x with respect to the upper surface of the protection device of the fifth figure.

The seventh drawing schematically shows an exploded perspective view of the protective device of the fifth drawing, which is assumed to be decomposed into the members constituting the same.

The eighth drawing is a plan view schematically showing a protective device 1" of another aspect of the present invention.

The ninth drawing schematically shows a cross-sectional view perpendicular to the upper surface of the protective device of the eighth figure including a straight line x-x.

The tenth figure shows an outline of the protection device of the ninth figure, which is assumed to be decomposed into the components constituting the same. The resulting exploded oblique view.

The eleventh drawing schematically shows a cross-sectional view of a protective device 11 of another aspect of the present invention.

Fig. 12 is a cross-sectional view schematically showing a protective device 11' of another aspect of the present invention.

An embodiment of the present invention will be described in detail with reference to the drawings. In the third diagram, the protective device of the present invention shown in the first and second figures is schematically shown as being disassembled for each of the components constituting the same, and the third figure is schematically shown as being completed as a device. The protective device 1 of the present invention in the state is assumed to be decomposed into the exploded oblique view obtained when the members are constructed.

In summary, the protective device 1 of the present invention has the configuration shown in the first to third figures. Specifically, the protective device 1 includes a resin base 6 having a first terminal 2 and a second terminal 4, a PTC element 8, a bimetal element 10, an arm portion 12, and an upper plate member 14. The resin substrate 6 has a space 16 in which a part of the first terminal 2 is exposed, a PTC element 8 is disposed above the exposed portion 18, a bimetal element 10 is disposed above the arm member 10, and an arm portion 12 is disposed above the resin member 8 . The arm portion 12 is fixed to the second terminal 4 by caulking. The upper plate member 14 is held on the inner wall 24 of the resin substrate 6, thereby sealing the space 16 of the resin substrate 6.

In the protection device 1, when the overcurrent or abnormal heat generation does not occur, the first terminal 2, the arm portion 12, and the second terminal 4 are electrically connected in series. Further, the bimetal element 10 is bent in a convex upward direction (arm side) as shown in the drawing, and is separated from the arm portion 12. In this state, the current flows in the order of the first terminal 2, the contact portion 26 of the first terminal, the contact portion 28 of the arm portion, the arm portion 12, and the second terminal 4 (or vice versa), and the current does not flow. It flows to the PTC element 8 and the bimetal element 10. When an abnormality occurs, that is, when an overcurrent occurs or an abnormal heat occurs, the bimetal element 10 is actuated by the convex Upward (the paper surface in the second figure faces upward) becomes convex downward (the paper surface in the second figure faces downward), whereby the arm portion 12 is lifted up, the contact portion 28 of the arm portion and the first terminal The electrical connection of the contact portion 26 is blocked. Further, the deformed bimetal element 10 is formed in a state of being in contact with the PTC element 8 and the arm portion 12 and electrically connected thereto. In this state, the current flows in the order of the first terminal 2, the PTC element 8, the bimetal element 10, the arm portion 12, and the second terminal 4 (or vice versa), and the Joule heat generated by the current is caused by the Joule heat generated by the current. The PTC element 8 trips (action) and continues to generate Joule heat. By the Joule heat, the bimetal element 10 is held in a convex downward state, and the open state of the contact between the arm portion 12 and the first terminal 2 can be maintained. At this time, the current to be protected is substantially interrupted by the circuit (however, a small amount of current flowing as a leakage current may flow).

In one aspect of the present invention, the first terminal 2, the second terminal 4, and the resin substrate 6 are integrally formed by insert molding. As described above, by performing the insert molding, the adhesion between the first terminal 2 and the second terminal 4 and the resin substrate 6 can be improved. The resin substrate 6 has a space 16 and a portion 18 (hereinafter referred to as an exposed portion 18) of the first terminal 2 is exposed at the bottom thereof. The PTC element 8 is placed on the exposed portion 18 of the first terminal. The first terminal 2 is provided on the exposed portion 18 so as to be easily electrically connected to the PTC element 8, and has a plurality of, for example, three dome-shaped contacts 30 (see the third drawing). Further, in the second drawing, although the first terminal 2 is not exposed by the bottom surface of the resin substrate, the resin substrate may be thinned, and a part of the first terminal 2 (for example, the back side of the exposed portion 18) may be made of a resin substrate. The bottom surface is exposed. As described above, by exposing a part of the first terminal, in addition to reducing the thickness of the protective device, heat generated inside the protective device such as the contact between the first terminal and the arm can be efficiently dissipated to the outside. Keep the holding current even higher.

The material constituting the first terminal 2 and the second terminal 4 is not particularly limited as long as it is a conductive material, but a conductive metal is preferable. In the case of the materials shown above, the same as the conventional one can be used. By.

As described above, a part 20 of the first terminal and a part 22 of the second terminal extend outward through the side surface of the resin substrate 6. A part 20 of the first terminal and a part 22 of the second terminal are used to electrically connect the protective device 1 of the present invention to a predetermined electrical component, thereby realizing the original function of the terminal. As shown in the figure, the contact 32 may be provided in a part 20 of the first terminal and a part 22 of the second terminal.

The first terminal 2 has a contact portion 26 that is in contact with the contact portion 28 of the arm portion 12. The contact portion 26 can be formed by various methods, and can be formed by providing the contact material to the first terminal 2 by, for example, caulking, plating, or welding. Further, the contact portion 26 may be an inlay or a clad. Preferably, the contact portion 26 is formed by caulking a contact material through a hole penetrating at a position corresponding to the first terminal 2. For example, the contact portion is inserted through a hole provided in the first terminal, and has a contact material having a diameter equal to the diameter of the hole and having a thickness (or height) larger than the thickness of the hole, by The portion in which the hole protrudes upward and downward is formed by caulking and fixing the contact material to the first terminal. The contact material does not have to be cylindrical, and may be a prismatic shape or the like. By forming the contact portion as shown above in the first terminal 2, the contact portion can have a large heat capacity, thereby preventing even a relatively large current flowing to the protection device. The temperature of the contact portion rises sharply and the holding current of the protection device can be increased.

The metal constituting the contact material is not particularly limited, but is preferably a large heat capacity, and is preferably silver-nickel, silver-copper, AgCdO, AgSnO ₂ , AgZnO, AgSnOInO, AgCu, or a copper-tungsten alloy. It is preferable to use a 90% silver 10% nickel alloy from the viewpoint that the hardness is low and the shape of the contact portion can be made, in particular, the thickness is finely designed and the heat capacity is large.

In a preferred aspect, at least one of the first terminal 2 and/or the second terminal 4 The portion to which the members are joined may also be plated by a metal that is not easily oxidized. For example, a portion (for example, a contact 32) that connects the first terminal 2 and/or the second terminal 4 to another electrical component, a contact between the first terminal 2 and the arm portion 12, and a first terminal 2 and a PTC element 8 are provided. The contact portion, the contact portion between the second terminal 4 and the arm portion 12 is preferably plated with a metal that is not easily oxidized. By plating with a metal as described above, it is possible to prevent, for example, a case where the protective device is subjected to heat treatment in a reflow furnace, and the contact is oxidized to increase the electric resistance.

The metal which is not easily oxidized is not limited thereto, and examples thereof include gold, platinum, silver, mercury, copper, and the like.

In a preferred embodiment, the resin substrate 6 is formed of a heat-resistant resin, preferably a resin which is stable in the temperature environment of the reflow furnace. By using the resin as described above, it is possible to prevent the protection device from being deformed even when it is delivered in a high-temperature environment such as a reflow furnace.

The heat resistant resin is, for example, an LCP (Liquid Crystal Polymer) resin, a polyamine resin, or a PPS (Poly Phenylene Sulfide) resin.

In the protection device of the present invention, the PTC element 8 is disposed above the exposed portion 18 of the first terminal. As a result, the first terminal 2 and the PTC element 8 are electrically connected to each other, for example, through the contact 30.

In the above PTC element, any of a ceramic PTC element or a polymer PTC element may be used, but a polymer PTC element is preferably used. The polymer PTC element has a lower resistance value than the ceramic PTC element, and is advantageous in that self-destruction is less likely to occur even if it is formed at a temperature higher than a certain level. In addition, the polymer PTC element has a lower voltage required to maintain the trip state than the ceramic PTC element, even in a state where the voltage of the circuit is low. It can also maintain the state of jumping. As a result, it is advantageous in that the contact can be maintained in an open state (latched state) and the chattering phenomenon of the open contact can be prevented from being opened and closed. In addition, if the current values are kept equal, the polymer PTC element is also preferable in terms of smaller size and lower resistance than the ceramic PTC element.

In general, the polymer PTC element has a layered PTC member obtained by extruding a conductive composition, and an electrode (for example, a metal foil) disposed on both sides thereof, and the conductive composition contains A polymer (for example, polyethylene, polyvinylidene fluoride, or the like) in which a conductive filler (for example, carbon black, a nickel alloy, or the like) is dispersed.

In the protective device of the present invention, when a polymer PTC element is used as the PTC element, the electric resistance value is preferably 0.8 to 15 Ω, and preferably 4.5 to 15 Ω. For example, by setting the resistance value of the polymer PTC element to 0.8 Ω or more, it is possible to maintain a state of jumping at 3 V. Further, by setting the resistance value of the polymer PTC element to 4.5 Ω or more, the leakage current at the time of the trip state at 3 V can be made 0.2 A or less. Further, by setting the resistance value of the polymer PTC element to 15 Ω or less, unevenness in resistance value can be easily reduced at the time of production.

Wherein, in the present specification, the resistance value of the polymer PTC element means The current value measured by applying a voltage of 6.5 mV (direct current) between the two electrodes of the polymer PTC element and the resistance value calculated by the applied voltage (measured by the 4-terminal method and the measurement of the resistance measuring device) In the range of applied current: 100 mA), the polymer PTC element is obtained by crimping an electrode (preferably a nickel foil) on both sides of a PTC member obtained by extruding a conductive composition containing a polymer. Here, when the resistance value of the electrode is compared with the resistance value of the PTC member, since the resistance is as small as almost negligible, the resistance value of the PTC element is substantially equal to the resistance value of the PTC member.

In the protection device of the present invention, a bimetal is disposed above the PTC element 8. Element 10. The bimetal element 10 is supported by a step portion 34 provided in the space 16 or a shoulder portion of the PTC element 8. It is preferably supported by the shoulder of the PTC element and separated by the step portion 34. By configuring as described above, if the temperature of the protection device is lower than the usual use temperature, for example, when the temperature is -40 ° C from room temperature, the curvature of the bimetal element becomes large, and the height thereof (bimetal element) The height from the edge to the apex portion becomes high, but until the edge of the bimetal element reaches the step portion 34, the apex of the bimetal element can be suppressed from approaching the arm portion. Further, it is preferable that the step portion 34 has a convex portion along the edge of the step portion as shown in the drawing.

The bimetal element 10 is not particularly limited as long as it is formed at a temperature that is determined to be in an abnormal state, or is a current that is determined to be in an abnormal state, and a person known per se can be used. Normally, the bimetal element 10 may or may not be electrically connected to the PTC element 8, but is electrically connected when abnormal.

The bimetal element 10 is preferably as large as possible, that is, the surface area of the main surface is large as long as the space 16 of the resin substrate can be tolerated. By increasing the surface area, the unevenness of the operating temperature can be reduced, and when the deformation is abnormal, the force for lifting the arm portion 12 upward can be increased.

In the illustrated embodiment, the bimetal element 10 is one, but two or more of them may be used. By using a plurality of bimetallic elements, the force for lifting the arm portion 12 upward becomes large when the deformation is abnormal. When two or more bimetal elements are used, these may be the same bimetal elements or different bimetal elements. Specifically, those having different operating temperatures may be used. For example, the operating temperature of the upper bimetal element is higher than the operating temperature of the lower bimetal element; the thickness and/or the size are different; and the contact of the bimetal elements with each other is used. The curvature of the face is used; or in addition to the lowermost bimetallic element, a person without a central protrusion can also be used. As shown above, by combining various bimetal elements, the bimetal element can be adjusted to be convex downward. The lifting force of the arm at the time.

It is preferable that the bimetal element 10 has a protrusion, for example, a dome-shaped convex portion, in the vicinity of the central portion of the lower surface (the PTC element side). This projection is formed in a state of being in contact with the PTC element 8 when the bimetal element 10 is actuated and is formed to be convex downward in a convex upward state. The arm portion 12 is pushed upward more at a portion corresponding to the height of the protrusion, so that even when the degree of bending of the bimetal member 10 itself is smaller, the arm portion 12 can be pushed up sufficiently to move the arm The electrical connection between the portion and the contact of the first terminal is more reliably interrupted.

In the protection device of the present invention, the arm portion 12 is disposed above the bimetal member 10, and is electrically connected to the second terminal 4 and the contact portion 28 at opposite ends. The method of connecting the arm portion 12 and the second terminal 4 is not particularly limited, and examples thereof include caulking, welding, welding, and the like, and are preferably connected by caulking. By connecting the arm portion 12 and the second terminal 4 by caulking, the arm portion can be more firmly fixed, the fixing unevenness of the arm portion 12 and the second terminal can be suppressed, and the resistance value of the protection device itself can be suppressed. Uneven.

The material constituting the arm portion 12 is not particularly limited as long as it is a conductive material, but a conductive metal is preferred. In the case of the materials shown above, the same ones as those known in the art can be used.

Further, the arm portion 12 has the contact portion 28, and as shown in the drawing, it is preferable that the contact portion 28 is formed in a curved state so as to be slightly below the horizontal direction (the extending direction of the bottom surface of the resin substrate). The contact portion 28 is in contact with the contact portion 26 of the first terminal in a normal state. When the bimetal 10 is deformed, the arm portion 12 is lifted upward, and the contact state is released.

The contact portion 28 is formed by various methods similarly to the contact portion 26 of the first terminal, but is preferably formed by caulking a contact material at a hole provided at a position corresponding to the arm portion 12. . By forming the contact portion as shown above in the arm portion 12, the contact portion can be made larger. With the heat capacity, even when the current flowing through the protection device is relatively large, the temperature of the contact portion can be prevented from rising sharply, and the holding current of the protection device can be increased. In addition, any of the contact portion 26 of the first terminal and the contact portion 28 of the arm portion 12 may be formed by caulking a contact material, but it is more preferable that both contact portions are riveted to a contact material. form. The contact portions of both sides are formed by riveting the contact material, whereby the holding current can be further increased.

The metal constituting the contact material may be the same as the contact material constituting the contact portion 28 forming the first terminal.

In addition, when the arm portion 12 is deformed when the abnormality occurs, the bimetal member is deformed, and the electrical connection between the arm portion and the bimetal member is more sure, and the contact portion may be contacted when the bimetal member is deformed into a convex downward direction. 36.

Preferably, the arm portion 12 has a concave shape on the upper plate side in the space 10 as shown in the drawing. That is, as shown in the second figure, the portion of the arm portion 12 located above the bimetal member has a shape curved toward the upper plate member side. By forming the shape as described above, a large distance from the bimetal element 10 can be obtained at ordinary times, and the insulation state can be surely ensured.

The material constituting the arm portion 12 is not particularly limited as long as it is a conductive material, and preferably includes a copper alloy such as phosphor bronze or beryllium copper, Ni, or surface treatment of the metals (gold, silver, and Ni). )By.

The arm portion 12 is preferably as wide as possible. By widening the width of the arm portion, the contact pressure between the contact portion 26 of the first terminal and the contact portion 28 of the arm portion can be further increased, and a brief interruption due to collision, vibration, or the like can be suppressed. At this time, it is preferable to increase the size of the bimetal element so that the contact between the contact portion 26 of the first terminal and the contact portion 28 of the arm portion can be surely opened during an abnormality.

In the protection device of the present invention, the arm portion 12 in the space 16 is disposed above the arm portion 12. Upper plate 14. The upper plate member 14 is held by the inner wall 24 of the resin substrate 6, preferably the upper edge portion of the inner wall 24.

The material constituting the upper plate member is not particularly limited, and for example, metal, resin, or the like can be used. When abnormal heat is generated from the outside, heat can be efficiently transmitted to the inside of the protective device, so that it is preferable to use a metal material. As the metal material, nickel, stainless steel, iron, copper, aluminum, tin, titanium, or an alloy of the metals, or the like is preferably used.

The upper plate member is preferably substantially planar. Wherein, substantially planar means that there are no claws, hooks, feet, etc. for fixing to other members, and does not mean that the plate is completely flat. For example, as shown in the figure, a portion which is held by the inner wall, for example, a peripheral end portion of the upper plate member may have a step.

The method of holding the upper plate member 14 on the inner wall 24 of the resin substrate is not particularly limited, and examples thereof include caulking, welding, and the like. In other methods, an adhesive may also be used to secure the inner panel and retain the upper panel. Preferably, the holding is achieved by riveting the upper plate member 14 to the inner wall 24. The method of riveting is not particularly limited, but it is preferred to use hot riveting. The heat staking system, for example, as shown in the fourth figure, forms a shoulder 38 on the inner wall 24, where the upper plate member 14 is disposed, and the heated press 40 is pressed in the direction of the arrow, and the inner wall can be made by one side. The front end portion is softened and bent while being bent inward.

The upper plate member may be held by at least the inner wall of the resin substrate, preferably by the inner wall of the resin substrate.

The upper plate member 14 is held by the inner wall 24 of the resin substrate 6, whereby it can be further miniaturized as compared with other holding methods. For example, if it is compared with the method of holding with a resin cover member, the protective device can be reduced, or the internal space can be increased, and thus the thickness of the resin cover member can be increased. The difference in degrees. Further, if the holding member is provided with a fixing claw, a hook, a leg, or the like for holding the upper plate member, the protection device can be reduced or the internal space can be increased, so that the claw, the hook, and the like are as described above. The difference between the foot and the component parts corresponding to the components. Larger bimetallic components can be used by ensuring a wide internal space. By using a larger bimetal element, the characteristic unevenness of the bimetal element can be reduced. Further, the force applied to the arm portion can be increased, and the arm portion whose arm portion is pressed at the contact point of the first terminal can be used, so that a short interruption due to vibration or the like can be suppressed.

The upper plate member 14 held by the inner wall of the resin substrate can be exposed by the upper portion of the protective device. When the upper panel 14 is exposed to the outside, when abnormal heat is generated outside, heat can be efficiently transmitted to the inside of the protection device. Therefore, the protection device of the present invention can quickly sense abnormal heat generation and operate the bimetal element 10, and can interrupt the current. In addition, normally, the heat generated inside the protection device, especially at the junction, can be efficiently dissipated outside the device, thereby increasing the holding current.

Preferably, the exposed surface of the upper plate member 14 is plated by a metal that is not easily oxidized. By performing plating on the metal as described above, it is possible to prevent oxidation of the exposed surface when the protective device is heat-treated in the reflow furnace.

The metal which is not easily oxidized is not limited, and examples thereof include gold, platinum, silver, copper, and the like, and gold is particularly preferable.

The protective device of the present invention does not need to cover the resin cover member of the upper plate member, and therefore can be miniaturized, and in particular, the thickness can be formed, for example, to be 1.5 mm or less, preferably 1.0 mm or less, more preferably 0.9 mm or less, and further preferably It is a size of 0.7 mm or less. Further, it is preferable that the protection device of the present invention has a width of 2.0 to 4.5 mm and a length of 4.5 to 15.0 mm.

Since the protective device of the present invention does not require a resin cover member, when it is delivered to the reflow process, the resin cover member is deformed by heat, and the possibility of adversely affecting each member existing in the internal space can be reduced. Furthermore, the size of the protective device can be reduced, in particular the thickness can be reduced. Further, in the production of the protective device, the step of molding the resin cover member which is required to flow the resin to the minute portion can be omitted, which is advantageous in terms of technology and cost.

In one aspect, the protection device of the present invention may be covered and protected by an insulating resin or the like in addition to a part of the first terminal and the second terminal which are connected to other electrical components.

One embodiment of the present invention has been described above, but the protection device of the present invention can be variously modified.

For example, in other aspects of the invention, the protection device 1' of the configuration shown in Figures 5 to 7 is provided.

The protective device 1' is characterized in that a part of the first terminal 2 and the second terminal 4 are present on the same plane below the resin substrate 6, and the other configuration is the same as that of the above-described protective device 1. In other words, it corresponds to bending a part 20 of the first terminal of the protective device 1 and a part 22 of the second terminal toward the lower side of the resin substrate.

By forming the configuration as shown above, the protective device of the present invention can be easily surface-mounted.

Further, in other aspects of the invention, the protection device 1" of the configuration shown in the eighth to tenth drawings is provided.

The protective device 1" functions as a second terminal, that is, as shown in the eighth to tenth embodiments, the protective device 1" of the present invention has a first terminal 2 and a solid The resin substrate 6, the PTC element 8, the bimetal element 10, the arm portion 12, and the upper plate member 14 of the member 42 are fixed. The resin substrate 6 has a space 16, and a part of the first terminal 2 is exposed at the bottom thereof, and the PTC element 8 is placed above the exposed portion 18, and the bimetal element 10 is placed above the arm portion 12, and the arm portion 12 is placed above the resin element 8. The arm portion 12 is fixed to the upper plate member 14 by riveting. The upper plate member 14 is held on the inner wall 24 of the resin substrate 6, thereby sealing the space 16 of the resin substrate 6.

The protective device 1" having the above-described structure is electrically connected in series to the first terminal 2, the arm portion 12, and the upper plate member 14 functioning as the second terminal, and the arm portion 12 and the fixing member are integrally connected. 42 is isolated or electrically insulated. In this state, the current flows in the order of the first terminal 2, the arm portion 12, and the upper plate member 14 (or vice versa), and the PTC element 8 and the bimetal element 10 are not When the abnormality occurs, the bimetal element 10 is actuated, the arm portion 12 is lifted up, and the electrical connection between the arm portion 12 and the first terminal is blocked. Further, the deformed bimetal element 10 is connected to the PTC element. 8 and the arm portion 12 are in contact with each other to be electrically connected to the battery. In this state, the current is based on the first terminal 2, the PTC element 8, the bimetal element 10, the arm portion 12, and the upper plate member 14. The sequence (or vice versa) flows, and the Joule element 8 performs tripping (action) by the Joule heat generated by the current, and the current corresponding to the protected circuit is substantially blocked.

In this aspect, the upper plate member is formed of a conductive material, preferably directly welded to the upper plate member, and thus is preferably made of a conductive metal material, specifically nickel, stainless steel, iron, copper, Aluminum, tin, titanium, or an alloy of these metals.

Since the plane including the exposed surface of the upper plate member 14 functioning as the second terminal does not exist as an obstacle, the connection direction of the wire or other electrical member is not limited. Further, since the area of the exposed surface can be increased, the connection process becomes easier, and in particular, the connection of a plurality of wires or other electrical components becomes easier.

In the protective device 1", the upper plate member 14, particularly at the exposed portion thereof, preferably has a thickness of more than 0.1 mm, more preferably 0.2 mm or more. By forming the thickness as shown above, it can be raised above. The exposed portion of the plate directly saturates the resistance of the welding load when the wire or other electrical component is welded. That is, the wire or other electrical component may be directly welded to the exposed portion of the upper plate. Further, the thickness of the upper plate member 14 is not particularly limited. For example, it is 1.0 mm or less, preferably 0.5 mm or less. By forming the thickness of the upper plate member to 1.0 mm or less, the protection device can be further miniaturized.

The protective device 1" has a fixing member 42, but the present invention is not limited to this aspect, and the fixing member may not exist. Further, the position of the fixing member is not limited to the illustrated example, and may be provided in a configurable manner. In addition, there may be a plurality of fixing members, for example, two, three, or four or more. The fixing members may be provided for various purposes, for example, when the protection device is disposed on the substrate, in order to support the protection device. Or in order to make the protection device more secure and more stable on the substrate.

In the protective device 1", since a part of the first terminal 2 and a part of the fixing member 42 exist on the same plane below the resin substrate, the surface structure can be performed. However, the present invention is not limited to the above, as described above. Like the protective device 1, the first terminal 2 and the fixing member 42 may be straightly extended from the side surface of the protective device.

Further, in other aspects of the invention, the protection device 11 of the configuration shown in Fig. 11 is provided.

The protective device 11 has substantially the same configuration as the above-described protective device 1′′ except that a part of the first terminal and the fixing member are not wound under the resin substrate. That is, the protective device 11 has the first terminal 2 And a resin substrate 6, a PTC element 8, a bimetal element 10, an arm portion 12, and an upper plate member 14 of the fixing member 42. The resin substrate 6 has a space 16, an upper plate member 14 functions as the second terminal 4.

Further, in another aspect of the invention, the protection device 11' of the configuration shown in Fig. 12 is provided.

The protective device 11' has the same configuration as the above-described protective device 11 except that a part of the first terminal is exposed from the bottom of the resin substrate. That is, the protection device 11 includes the resin base 6 having the first terminal 2 and the fixing member 42, the PTC element 8, the bimetal element 10, the arm portion 12, and the upper plate member 14. The resin substrate 6 has a space 16, and the upper plate member 14 functions as the second terminal 4, and a part of the first terminal 2 is exposed at the bottom of the resin substrate 6.

[Industrial Availability]

The protection device of the present invention can suitably utilize a protection device for a battery unit of a lithium ion battery such as a mobile phone or a tablet device.

1‧‧‧protection device

2‧‧‧1st terminal

4‧‧‧2nd terminal

6‧‧‧ resin substrate

14‧‧‧Upper plate

Claims (12)

A protection device comprising: a resin substrate, a first terminal, a PTC element, a bimetal element, an arm portion, an upper plate member, and a second terminal, wherein the protective device is configured to be formed of a resin substrate The inner space defined by the inner wall overlaps the first terminal, the PTC element, the bimetal element, and the arm portion in the following order, and the inner space including the members is closed by the upper plate member, and the upper plate member is made of resin The inner wall of the base is held, and the first terminal, the arm portion, and the second terminal are electrically connected in series in this order. When the bimetal element is actuated, the first terminal and the arm are electrically blocked. In other cases, the first terminal, the PTC element, the bimetal element, the arm portion, and the second terminal are electrically connected in series in this order. The protective device of claim 1, wherein the arm portion is riveted to the second terminal. The protective device of claim 1 or 2, wherein the upper plate has a substantially planar configuration. The protective device according to any one of claims 1 to 3, wherein the upper plate member is exposed by an upper portion of the protective device. The protective device according to any one of claims 1 to 4, wherein the upper plate member is fixed to the resin substrate by heat riveting. The protective device according to any one of claims 1 to 5, wherein the resin substrate is formed of a heat resistant resin. A protection device according to any one of claims 1 to 6, wherein the first end A part of the sub-terminal and the second terminal are present on the same plane below the resin substrate. The protective device according to any one of claims 1 to 7, wherein the upper plate functions as a second terminal. The protective device of claim 8, wherein the upper plate has a thickness of 0.1 mm or more. The protective device of claim 8 or 9, wherein the protective device has a fixing member. A protective device according to claim 10, wherein a part of the first terminal and a part of the fixing member are present on the same plane below the resin substrate. An electric device characterized by having the protection device according to any one of claims 1 to 11.