WO2008010437A1

WO2008010437A1 - Lead line extracting type spd and spd manufacturing method

Info

Publication number: WO2008010437A1
Application number: PCT/JP2007/063737
Authority: WO
Inventors: Kenshichirou Mishima; Tsuyoshi Ikeda; Takeshi Maruyama; Kenji Kimoto
Original assignee: Otowa Electric Co., Ltd.
Priority date: 2006-07-20
Filing date: 2007-07-10
Publication date: 2008-01-24

Abstract

It is possible to simplify connection between an insulating coated type lead line extracted from a case containing zinc oxide varistor and an extracting conductor within the case and performing a stable connection with a high mechanical intensity. A lead line extracting first hole (31) is formed in the case (30) containing the zinc oxide varistor (1). An extracting conductor connecting second hole (32) is formed to orthogonally intersect the first hole (31). An insulating coated end (20') of the lead line (20) is inserted into the first hole (31) and the linear tip end of an extracting conductor (13) is inserted into the second hole (32). The tip is made to penetrate the insulating coated end (20') so as to make an electrical and mechanical connection to the lead line (20).

Description

Specification

Lead wire drawing type SPD and SPD manufacturing method

Technical field

[0001] The present invention relates to a structure of a lead wire lead-out type SPD (Surge Protective Device) from a case containing a zinc oxide type noristor and a manufacturing method thereof.

Background art

[0002] For the purpose of preventing lightning damage, a device that shunts a surge current by limiting a transient overvoltage caused by lightning between a single-phase or three-phase AC circuit or a DC circuit, and between the electrical equipment and the ground. SPD is installed. As this SPD element, a zinc oxide type varistor is generally used.

[0003] A zinc oxide type varistor (hereinafter simply referred to as a varistor) is a rectangular or circular plate-shaped lightning protection element mainly composed of ZnO, and electrodes are attached in a thin plate on both front and back surfaces. The NORISTR has a characteristic that the resistance changes according to the voltage applied between the electrodes on both the front and back surfaces, that is, it exhibits extremely high resistance and substantially insulation when a voltage lower than the threshold voltage is applied. Non-linear current-voltage characteristics indicating low resistance when a voltage exceeding the pressure is applied

[0004] In general, an SPD using a NORISTA is configured by combining the NORISTR with other SPD elements such as a discharge fuse, a thermal fuse for SPD protection, and a current fuse. When a lightning surge is repeatedly input, the NORISTOR may deteriorate over time depending on the input level, increase the leakage current, generate heat, and cause smoke and fire due to thermal runaway. Therefore, in SPD, as a protection measure to prevent smoke and fire due to thermal runaway of the varistor, a temperature fuse that is disconnected by heat generation due to the deterioration of the NORISTR is integrated into the NORISTOR (for example, see Patent Document 1). ).

[0005] In addition, SPDs that use NORISTA are designed to house multiple types of SPD elements including NORISTA in a resin insulating case, and to protect the SPD elements electrically and mechanically with the case. Yes. Pull the electrode of the SPD element including the varistor housed in the case out of the case. The lead-out is performed using a plurality of types of conductors such as a metal wire, a lead-out conductor of a metal plate, and an insulation-coated lead wire (for example, see Patent Document 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-229303

Patent Document 2: JP 2001-297904 A

Disclosure of the invention

Problems to be solved by the invention

[0006] An SPD with a lead wire from an insulated wire drawn from a case force and the SPD circuit is configured by connecting the electrode of the SPD element and the lead wire with a lead wire conductor of a metal wire or metal plate in the case. ing. The connection between such lead conductors and SPD elements and lead wires is equivalent to the connection process of SPD manufacturing and assembly because there are many forces and connection points that are applied by various simple methods such as soldering, force squeezing, and crimping. It requires a lot of man-hours and makes it difficult to reduce SPD manufacturing costs. In addition, when a lead wire is pulled out from the case, the lead wire is required to withstand a tensile load of several kg from the viewpoint of reliability. In order to satisfy this requirement, there is a problem that the lead wire is directly supported by the storage case by bending the tip of the lead wire within the case, resulting in a complicated configuration.

[0007] The present invention has been made in view of the above-described problems, and an object of the present invention is to simplify the connection between the lead wire protruding from the case housing the NORISTA and the lead conductor in the case. In addition, an object of the present invention is to provide a lead wire lead-out type SPD that can be connected with a stable and high mechanical strength.

Means for solving the problem

The present invention is an SPD in which an insulated linear lead wire and a lead conductor of an SPD element are connected in a case in which an SPD element including a noristor is housed. A lead hole that is inserted into the first hole, and has a first hole for connecting the lead wire and a second hole for connecting the lead conductor into which the leading end of the lead conductor is inserted. The lead wire and the lead conductor are electrically and mechanically connected by crossing and passing the end of the wire and the leading end of the lead conductor inserted into the second hole. The end of the lead wire may be the end of the insulation coating covered with the insulation coating, or the portion of the insulation covering stripping portion where the insulation coating has been partially removed. Here, a resin insulating case can be applied as the case. The SPD elements including the varistors housed in the case are the NORISTERS only and other types of SPD elements other than NORISTERS and varistors. Other SPD elements other than NORISTA are separate from the discharge gap (discharge gap parts that have been commercialized, discharge gaps formed in the middle of the lead conductor), thermal fuses that are formed integrally with the NORISTA, and the NORISTA. These include temperature fuses and current fuses that are wired to the NORISTR. When multiple SPD elements are housed in the case, the lead conductors of all the SPD elements are connected to the corresponding lead wires, or only a selected one of the multiple SPD elements is selected. The lead conductor is connected to the corresponding lead wire. In the present invention, the case is provided with a first hole and a second hole that are electrically and mechanically connected through the lead conductor corresponding to the lead wire.

[0010] An insulated electric linear lead wire is an insulated wire in which a conductor such as a stranded wire is insulation-coated with a resin such as vinyl chloride, and has an end portion without stripping insulation coating, and is a straight conductor (copper wire, The type that covers the entire outer periphery of an annealed copper wire, etc.) with an insulating coating material such as a resin material, or the type that has an insulating coating stripping part at the end where the insulation coating is partially removed to expose the conductor Is used.

[0011] The first hole of the case is a linear insertion hole in which an end portion of the insulated electric linear lead wire is detachable in the axial direction. The tip of the first hole is a closed end, and the end of the lead wire is inserted until it comes into contact with the closed end. The second hole opens at a predetermined location away from the tip of the first hole. The second hole is a straight insertion hole orthogonal to the first hole or intersecting at a predetermined intersection angle. From the end opposite to the first hole of the second hole, the straight end of the lead conductor is inserted into the second hole so as to be removable. Insert the end of the lead wire into the first hole, and insert the tip of the lead conductor into the second hole.

[0012] In the case of a lead wire whose end is covered with an insulation coating material, when the leading end of the lead conductor is a sharp end and this sharp end is inserted from the second hole into the first hole, the sharp end is It pierces part of the outer periphery of the end of the lead wire inserted into the first hole, and penetrates the insulation coating material and the conductor. Depending on the material of the insulation coating of the lead wire, a method of perforating so as to remove in advance the portion where the lead conductor of the insulation coating pierces may be used. The leading end of the lead conductor penetrates a part of the insulating coating end of the lead wire, so that both are electrically and mechanically connected. [0013] Further, in the case of a lead wire having an insulating coating stripping portion at the end, the insulating coating stripping portion and an insulating coating portion having a predetermined length continuous therewith are inserted into the first hole. A second hole is formed at one location facing the insulated wire peeling margin of the lead wire inserted into the first hole. The leading end of the lead conductor inserted into the second hole intersects the insulated wire stripping part of the lead wire. Alternatively, the lead conductor is inserted into the second hole and then the lead wire is inserted into the first hole, and the insulated wire stripping portion of the lead wire and the tip of the lead conductor are brought into contact with each other. The lead conductor penetrates through the conductor exposed at the stripped part of the insulated wire of the lead wire, and the lead wire and the lead conductor are electrically and mechanically connected.

[0014] The electrical connection state between the two due to the piercing penetration is not stable as compared with other methods such as soldering and caulking, but the SPD corresponding to the lightning surge does not cause a problem for the reason described later. Because the lead wire of the first hole and the lead conductor of the second hole are crossed and penetrated, the mechanical connection between them is always made firmly and the lead wire is pulled out from the first hole. When a load is applied, the leading end of the lead conductor is locked in the second hole, and the tensile load of the lead wire is always increased to a few kilograms or more. The mechanical reliability of the lead wire lead-out SPD is increased. Get better.

In the present invention, the angle between the end of the lead wire inserted into the first hole of the case and the tip of the lead conductor inserted into the second hole is a right angle force or the first hole It is desirable to make an acute angle with respect to the lead wire drawing direction. The acute angle here is an angle between 45 ° and 90 °. With these crossing angle specifications, when a load is applied in the direction in which the lead wire is pulled out from the first hole, the leading end of the lead conductor bites into the lead wire side and pulls the lead wire. Make the load stronger and more stable.

In the present invention, a wire rod having a sharp tip can be applied to the lead conductor. A commercially available and inexpensive bare electric wire can be used as the lead conductor of the wire. In addition, a round hole with good workability can be applied to the second hole of the case corresponding to the lead-out conductor of the wire, and it becomes easy to insert the bow I lead conductor into this second hole.

In the present invention, the back of the first hole of the case can be a closed end where the tip of the lead wire inserted into the first hole abuts.

[0018] Here, the closed end at the back of the first hole can be formed by a side wall of the case. Lead wire The tip is inserted until the tip comes into contact with the closed end of the first hole and is positioned in the first hole. As a result, the amount of the lead wire inserted into the first hole is constant, and the electrical and mechanical connection with the lead conductor inserted from the second hole can be satisfactorily performed. In addition, the tip of the lead wire inserted into the first hole is exposed at the tip (cut surface) of the conductor, but this conductor tip surface is insulated and protected at the closed end of the first hole and protrudes to the outer surface of the case. This makes it easier to take insulation measures for SPD lead-out SPDs.

[0019] In the case of a lead wire having an insulating coating stripping portion at its end, the insulating coating portion of the lead wire inserted into the first hole can be fixed to the first hole of the case with an adhesive. By fixing the lead wire to the first hole with an adhesive in this way, the electrical and mechanical contact state between the insulated wire stripping margin of the lead wire and the lead conductor of the second hole is stabilized, and the lead wire The tensile load increases with the adhesive force of the adhesive.

[0020] Further, in the SPD manufacturing method of the present invention, the insulating coating stripping portion of the lead wire inserted into the first hole of the case and the leading end portion of the lead conductor inserted into the second hole are brought into contact with each other. The manufacturing method includes a cross contact step, a lead wire twisting step in which the lead wire is twisted and rotated in the first hole, and a lead wire bonding step in which the insulating coating portion of the lead wire is bonded to the first hole with an adhesive. This force S is possible.

[0021] After the above-described cross contact step, the lead wire is twisted and rotated in the first hole to increase the contact force between the insulated wire stripping portion of the lead wire crossing each other and the leading end of the lead conductor. And stabilize the mechanical connection. After this lead wire twisting process, the lead wire is fixed to the first hole with an adhesive to prevent the lead wire from rotating back and stabilize the electrical and mechanical connection between the lead wire and the lead conductor.

The invention's effect

[0022] According to the present invention, the lead wire and the lead wire can be pulled by a simple one-touch type operation in which the leading end of the lead conductor inserted into the second hole of the case is inserted into the lead wire inserted into the first hole of the case. Since the lead conductors can be electrically and mechanically connected, even if there are many connection points between the lead wires and the lead conductors, they can be connected with less man-hours and less work time. There is an excellent effect of facilitating the reduction of assembly cost. In addition, since the end of the lead wire is inserted into the first hole and the lead conductor is pierced and penetrated, it is further connected to the connection. By reducing the number, the workability of SPD manufacturing and assembly can be improved.

[0023] Further, since the leading end of the lead conductor inserted into the second hole crosses and penetrates the lead wire inserted into the first hole of the case, a load is applied in a direction in which the lead wire is drawn out from the first hole. The leading end of the lead conductor is locked in the second hole when the wire is applied, and the tensile load of the lead wire can always be increased to several kilograms or more, and the highly reliable lead wire with stable mechanical strength. A drawer type SPD can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 and FIG. 2 show the main configuration of the lead wire lead-out type SPD showing the first embodiment, and FIG. 3 shows an equivalent circuit. The lead wire lead type SPD in the figure includes a varistor 1 mainly composed of ZnO and a discharge gap 2 connected to an electrode 12 on the back side of the varistor 1. Two types of SPD element force, NORISTA 1 and discharge gap 2, are housed in a common case 30. The Norristor 1 is a lightning protection element having a rectangular flat plate shape that is applied to a single-phase three-wire or three-phase three-wire AC circuit, and has a line-phase three electrode 11 on the surface side. The back surface side electrode 12 is a common electrode facing all of the front surface side three electrodes 11. The shape of the NORISTR 1 is not limited to a rectangular shape, and may be a disc shape. Case 30 is an insulating case made of resin. A total of four insulated linear lead wires 20 from case 30 are bowed in parallel to form a lead wire lead-out SPD.

One lead conductor 13 is connected by solder 5 to each of the three electrodes 11 on the surface side of the NORISTR 1. The three lead conductors 13 are bare wire wires, and their respective ends are electrically and mechanically connected to the corresponding lead wires 20. One lead conductor 14 is drawn out from the discharge gap 2 connected to the common electrode 12 of the NORISTR 1 and is electrically and mechanically connected to the corresponding one lead wire 20.

It should be noted that the discharge gap 2 shown in FIG. 3 is a product-made discharge gap component, to which an extraction conductor 14 is connected. Instead of such a discharge gap 2, a discharge gap (not shown) formed in the middle of the lead conductor 14 can also be applied. In the lead wire 20, a conductor 20a composed of a plurality of copper wire strands is covered with a resin insulation coating material 20b.

The case 30 is a rectangular box-shaped two-divided case, and includes a main body 30a and a lid 30b. The main body 30a has a rectangular box shape with a bottomed top opening, and has four first lead wire lead holes 31 parallel to the bottom. Each first hole 31 is straight, one for each insulation-coated end of the lead wire 20 Part 20 'is removably inserted. A varistor positioning and holding rib portion 30c and a second hole forming cylinder portion 30d are formed in the internal space of the main body portion 30a. The noristor 1 is positioned and placed on the rib portion 30c with the common electrode 12 on the back side facing down. The discharge gap 2 connected to the common electrode 12 of the NORISTR 1 by soldering or the like is disposed in the space between the bottom of the main body 30a and the varistor 1. A second hole forming cylinder portion 30d is formed corresponding to the three electrodes 11 on the surface of the noristor 1 positioned and mounted on the rib portion 30c. The second hole forming cylinder portions 30d are columnar cylinders protruding directly above the corresponding first holes 31, and each of the second hole forming cylinder portions 30d penetrates the second hole 32 in the axial direction. The second hole 32 is a straight through hole into which one of the lead conductors 13 of the wire rod is removably inserted and intersects the corresponding first hole 31.

[0028] As shown in FIGS. 5A and 5B, the tip of the first hole 31 is closed by the side wall of the case 30, and the insulating coating end portion 20 'of the lead wire 20 is inserted until it comes into contact with the closed end. Is done. The tip (lower end) of the second hole 32 opens at one location about 5 mm away from the closed end of the first hole 31. A small hole 33 as an extension hole of the second hole 32 is formed at the bottom of the first hole 31. The small hole 33 shown in FIGS. 5A and 5B may be a concave hole with a bottom that does not penetrate through the bottom plate of the storage case 30.

[0029] The lead wire lead-out type SPD of the above embodiment can be manufactured and assembled as follows. As shown in FIG. 4, the lid 30b is opened from the main body 30a of the case 30, and the lead wire 20 of the insulated wire corresponding to the first hole 31 at the bottom of the main body 30a is inserted. The lead wire 20 is a conductor 20a whose outer periphery is covered with an insulation coating material 20b. The insulation coating material 20b is peeled off! /, And the insulation coating end 20 'is lightly placed in the corresponding first hole 31. It is inserted like a press fit. As shown in FIG. 5A, the lead wire 20 is inserted until the end of the insulating coating end portion 20 ′ comes into contact with the closed end of the first hole 31.

[0030] Such lead wire insertion can be performed on each of the four lead wires 20 in order or at the same time using four jigs (not shown). After inserting the lead wire, the varistor 1 with a lead conductor is assembled to the body 30a of the case 30 as shown in FIG. 4, and the lead conductor 13 extending from the varistor 1 is inserted into the corresponding second hole 32 at this time. .

As shown in FIG. 5B, the leading end of the wire lead conductor 13 is sharpened, the leading end is inserted into the second hole 32, and the lead wire 20 in the first hole 31 extends from the second hole 32. Insulation end 20 ' Penetrate in the direction of insertion. The leading end of the lead conductor 13 reaches the first hole 31 without being deformed by being guided by the second hole 32, and the sharp end thereof pierces the insulating covering material 20b of the insulating covering end portion 20 'as it is, and the insulating covering material 20b And reaches the small hole 33 through the conductor 20a. The leading end of the lead conductor 13 passes through the conductor 20a of the lead wire 20, so that both are electrically and mechanically connected, and the connection work is completed.

[0032] Such a connection operation can be performed sequentially or simultaneously on the three lead conductors 13 using a jig (not shown). Further, the lead wires corresponding to the lead terminals 14 of the discharge gap 2 can be connected in the same manner as described above. Such connection work is the first? In addition, it is possible to perform a simple operation simply by inserting a lead wire and inserting a lead-out terminal into the second hole. This greatly reduces the number of SPD manufacturing and assembly steps and facilitates shortening the assembly time. become.

[0033] The first embodiment described above is also applicable to the force S described in the case of applying the lead wire 20 with the end portion covered with insulation and the lead wire 20 with the end portion covered with the insulating cover. FIG. 6 and FIG. 7 show a second embodiment of the lead wire lead-out type SPD using the lead wire 20. The same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted.

[0034] As shown in FIGS. 9A and 9B, the tip of the first hole 31 is closed by the side wall of the storage case 30, and the one end portion 20 ′ of the lead wire 20 extends so far as to contact the closed end 30e. Entered. As shown in FIG. 8, one end portion 20 ′ of the lead wire 20 has an insulating coating stripping portion 20p from which the insulating coating material 20b has been removed at a length of about 1 cm from the tip, and a predetermined length continuous therewith. It consists of an insulation coating 20q. When the lead wire 20 is inserted into the first hole 31 until the tip of the lead wire 20 comes into contact with the closed end 30e, the second hole 32 and the small hole 33 are positioned substantially above and below the center of the insulating coating stripping portion 20p. The dimensions are set. Further, the opening end portion of the first hole 31 and the outer periphery of the insulating covering portion 20q of the lead wire 20 are fixed by the adhesive 50.

[0035] The lead wire lead-out type SPD of the above embodiment can be manufactured and assembled as follows. As shown in FIG. 8, the lid 30b is opened from the main body 30a of the case 30, and the one end 20 ′ of the insulated linear lead wire 20 corresponding to the first hole 31 at the bottom of the main body 30a is inserted. Lead wire One end part 20 'is inserted into the first hole 31 first from the insulation coating stripping part 20p on the tip side, then Thus, the insulating coating portion 20q is inserted so as to be lightly press-fitted into the first hole 31. As shown in FIG. 9A, the lead wire 20 is inserted until the end of the insulating coating stripping portion 20p comes into contact with the closed end 30e of the first hole 31.

Such lead wire insertion can be performed on each of the four lead wires 20 in order, or can be performed simultaneously using four jigs (not shown). After inserting the lead wire, as shown in FIG. 8, the varistor 1 with a lead conductor is assembled to the main body 30a of the storage case 30, and at this time, the lead conductor 13 extending from the varistor 1 is inserted into the corresponding second hole 32. .

[0037] As shown in FIG. 9B, the leading end of the wire lead conductor 13 is sharpened, the leading end is inserted into the second hole 32, and the lead wire 20 in the first hole 31 is inserted into the second hole 32. The insulating conductor stripping portion 20p is pierced and penetrated in a direction intersecting almost the center of the stripped conductor 20a. Such piercing and penetration can be easily and reliably performed because the exposed conductor 20a of the insulating coating stripping portion 20p is stranded. The leading end of the lead conductor 13 reaches the first hole 31 without being deformed by being guided by the second hole 32, and the sharp end directly penetrates the insulating coating stripping portion 20 p and reaches the small hole 33. The leading end of the lead conductor 13 passes through the conductor 20a of the lead wire 20, so that both are electrically and mechanically connected.

[0038] Such connection work can be performed sequentially or simultaneously on the three lead conductors 13 using a jig (not shown). Further, the lead wires corresponding to the lead terminals 14 of the discharge gap 2 can be connected in the same manner as described above. Such connection work is the first? In addition, it is possible to perform a simple operation simply by inserting a lead wire and inserting a lead-out terminal into the second hole. This greatly reduces the number of SPD manufacturing and assembly steps and facilitates shortening the assembly time. become.

[0039] After the lead conductor 13 is passed through the corresponding lead wire 20 and the two conductors are electrically and mechanically connected, an adhesive 50 is applied to the insulating coating portion 20q of the lead wire 20 and the opening end portion of the first hole 31. Apply lead wire and fix the lead wire 20 in the first hole 31. With this fixing, the lead wire 20 is not twisted and rotated with respect to the first hole 31, and the electrical and mechanical connection between the two conductors is stabilized.

[0040] The lead wire lead-out type SPD can be manufactured and assembled in the following order.

Insert the tip of the bow I lead conductor 13 corresponding to the second hole 32! /, And insert the one end 20 ′ of the lead wire 20 corresponding to the first hole 31. Insulate the tip at the stage of inserting the lead wire. The conductor 20a, which is a stranded wire of the coating stripping portion 20p, is digged into the lead conductor 13 from the side, and the two conductors are crossed and contacted. Thereafter, the lead wire 20 is fixed to the first hole 31 with the adhesive 50.

It is also effective to twist and rotate the lead wire 20 that is in contact with the lead conductor 13 before the lead wire 20 is fixed to the first hole 31 with the adhesive 50. That is, after the cross-contact process in which the insulating coating stripping portion 20p of the lead wire 20 inserted into the first hole 31 and the leading end portion of the lead conductor 13 inserted into the second hole 32 are crossed and brought into contact with each other, A lead wire twisting process is provided in which the lead wire 20 inserted into the hole 31 is twisted and rotated in either the left or right direction. In this lead wire twisting process, the insulation coating stripping portion 20p of the lead wire 20 that intersects the lead conductor 13 rotates to increase the contact force with the lead conductor 13, and the electrical and mechanical connection between the two conductors. The state becomes stronger and stable. Such a lead wire twisting process can be performed easily and reliably with the fingertip of the operator. After the lead wire twisting step, the lead wire 20 corresponding to the first hole 31 is fixed with the adhesive 50 (lead wire adhering step).

In the connecting step shown in FIG. 5B or FIG. 9B, if the leading end of the lead conductor 13 is passed through the lead wire 20, the sharp end of the lead conductor 13 may protrude from the small hole 33 at the bottom of the case 30. The sharp end protruding in this way is cut with a blade or the like, and an insulating seal 35 such as a nameplate is attached to the back of the case 30 as shown in FIG. 1 or FIG. Alternatively, the small holes 33 may be filled with an insulating material and the small holes 33 may be insulated and sealed. As described above, if the small hole 33 is formed into a concave hole with a bottom so that the sharp end of the lead conductor 13 does not protrude out of the case, the special insulation measures as described above are unnecessary.

[0043] In the SPD manufacturing and assembly described above, the electrical connection state due to the contact between the lead wire 20 and the lead conductor 13 is not stable compared to the connection state such as soldering or caulking, and the contact between the two conductors is poor. Defects can occur. However, when it is used as an element for SPD (lightning surge protection device), there is no problem because the defective electrical connection operates as a discharge gap. In other words, a large surge voltage is applied to the poorly connected part during SPD operation, and a large current flows for a very short time of several tens of s. Therefore, even if the contact resistance is increased due to an oxide film, it is oxidized with a large surge voltage. Do not destroy the coating and reduce the reliability. [0044] Further, the lead conductor 13 is passed through the corresponding lead wire 20 to mechanically connect the two conductors, whereby the mechanical strength is increased and stabilized. As shown in FIG. 5B or FIG. 9B, when the crossing angle of the first hole 31 and the second hole 32 is Θ, this crossing angle Θ is in the drawing direction X of the lead wire 20 inserted into the first hole 31. Set a right angle force and an acute angle. When a tensile load is applied to the lead wire 20 in the pulling direction X, the leading end of the lead conductor 13 that penetrates the lead wire 20 is locked in the second hole 32, and the required tensile load for the lead wire 20 is set large. can do. Such a tensile load is effectively increased by a force S when the crossing angle Θ is a right angle or an acute angle close to a right angle.

Next, a third embodiment of the present invention will be described with reference to FIGS. 10 and 11 show the configuration of the main part of the lead wire lead-out type SPD of the third embodiment, and FIG. 12 shows an equivalent circuit. The lead wire lead type SPD in the figure has a thermal fuse function for each of the lead conductors 13 corresponding to the three electrodes 11 of the NORISTAR 1, and the heat fuse operation due to the deterioration of the varistor 1 makes the temperature fuse operation visible. Is provided. This third embodiment is applicable to both the first embodiment and the second embodiment described above.

The lead conductor 13 is a wire, and the tip portion is inserted into the corresponding second hole 32 and penetrates the lead wire 20. A partial force at the rear end of the lead conductor 13 is joined to the corresponding electrode 11 of the varistor 1 with a low melting metal alloy 41. The low-melting metal alloy 41 is a low-melting-point alloy that melts due to the heat generated by excessive surge deterioration of the NORISTOR 1. The rear end portion of the lead conductor 13 protrudes rearward from the low melting metal alloy 41, and the display plate 42 is fixed to the front end. A display window 43 is formed in a portion of the case 30 facing the display plate 42. The display panel 42 and the display window 43 constitute one display 40. One such display device 40 is installed on each of the lead conductors 13 corresponding to the three electrodes 11 of the NORISTR 1.

[0047] The lead conductor 13 shown in FIG. 10 has a spring force that causes the rear end portion to be separated from the electrode 11 of the varistor 1 by melting the low-melting metal alloy 41 due to abnormal heat generation due to aging of the noristor 1. Have. Strictly speaking, at the time of softening before the low-melting metal alloy 41 is completely melted, the lead conductor 13 is displaced by its spring restoring force, and the thermal fuse is blown, and the state shown in FIG. 11 is obtained. FIG. 11 shows a state in which the lead conductor 13 is displaced from the front end portion inserted into the second hole 31 as a base, and the display plate 42 at the rear end portion moves. Display 42 The surface is set to be at least twice as large as the display window 43, and the display plate 42 is displaced so that half of the color of the display surface faces the display window 43. Then, by distinguishing the color of the display panel 42 from the display window 43, the normal state of FIG. 10 or the abnormal state of FIG. 11 can be recognized at a glance.

[0048] The varistor in the lead wire lead-out type SPD described above is a three-phase multi-terminal noristor in which three electrodes are formed on the front side and a common electrode is formed on the back side. The present invention is not limited to this. A two-terminal noristor with a pair of electrodes formed on the front and back surfaces of the noristor is also applicable.

Brief Description of Drawings

FIG. 1 is a side view including a partial cross-section showing a configuration of a main part of a lead wire lead-out SPD according to a first embodiment of the present invention.

FIG. 2 is a front view including a partial cross section of the SPD of FIG.

[Fig. 3] Equivalent circuit of SPD in Fig. 1.

FIG. 4 is an exploded side view of the SPD of FIG. 1 during manufacturing and assembly.

FIG. 5A is a partially enlarged cross-sectional view of the SPD of FIG. 1 during manufacturing and assembly.

FIG. 5B is a partially enlarged sectional view when two conductors are connected.

FIG. 6 is a side view including a partial cross-section showing the configuration of the main part of the lead wire lead-out SPD of the second embodiment of the present invention.

FIG. 7 is a front view including a partial cross section of the SPD of FIG.

FIG. 8 is an exploded side view of the SPD of FIG. 6 during production and assembly.

FIG. 9A is a partially enlarged cross-sectional view of the SPD of FIG. 6 during manufacturing and assembly.

FIG. 9B is a partially enlarged cross-sectional view when two conductors are connected.

FIG. 10 is a side view including a partial cross section showing a configuration of a main part of a lead wire lead-out SPD according to a third embodiment of the present invention.

FIG. 11 is a side view including a partial cross section during thermal fuse operation of the SPD of FIG.

FIG. 12 is an equivalent circuit of the SPD in FIG.

Explanation of symbols

[0050] 1 Zinc oxide varistor, element for SPD 2 Discharge gap, SPD element

1 1, 12 electrodes

13, 14 Lead conductor

20 Lead wire

20, Insulation end

20a conductor

20b Insulation coating

20p Insulation stripping margin

20q insulation coating

30 storage case

30a Main unit

30b Lid

30e closed end

31 1st hole

32 Second hole

33 Small hole

~ -Lolo

40 ^ ヽ ^

41 Low melting metal alloy

42 plate

43 丰衣小； ^ έ ：、 =

50 Adhesive

Θ Crossing angle

X Lead wire drawing direction

Claims

The scope of the claims

[1] An SPD in which an insulated electric wire lead wire and a lead conductor of the SPD element are connected in a case containing an SPD element including a zinc oxide type noristor, and the case is connected to an end of the lead wire. A first lead hole for inserting a lead wire and a second hole for connecting a lead conductor that is partially opened in the first hole and into which a leading end of the lead conductor is inserted. The lead wire and the lead conductor are electrically and mechanically connected by crossing and passing the end of the lead wire inserted into the lead hole and the leading end of the lead conductor inserted into the second hole. Lead wire drawer type SPD.

[2] The angle between the end of the lead wire inserted into the first hole and the leading end of the lead conductor inserted into the second hole is perpendicular or relative to the lead wire drawing direction in the first hole. The lead wire lead-out type SPD according to claim 1, wherein the lead wire has an acute angle.

[3] The lead wire lead-out SPD according to claim 1 or 2, wherein the lead conductor is a wire rod having a sharp tip.

[4] The lead wire lead-out according to any one of claims 1 to 3, wherein the back of the first hole is a closed end against which a tip of a lead wire inserted into the first hole abuts. SPD

Yes

[5] The lead wire lead-out type SPD according to any one of claims 1 to 4, wherein an end portion of the lead wire is covered with an insulating coating.

[6] The lead wire lead-out SPD according to any one of [1] to [4], wherein an end portion of the lead wire is an insulating coating stripping portion obtained by partially removing the insulating coating.

7. The lead wire lead-out SPD according to claim 6, wherein an insulating coating portion of the lead wire inserted into the first hole is fixed to the first hole with an adhesive.

[8] An SPD manufacturing method for connecting an insulated electric wire lead wire and a lead conductor of the SPD element in a case housing an SPD element including a zinc oxide type noristor, wherein the case includes the lead wire A first hole for lead wire drawing into which one end portion of the insulating coating stripping portion from which the insulating coating has been partially removed and a continuous insulating coating portion is inserted, and the first hole is partially opened. A lead conductor connecting second hole into which the leading end portion of the lead conductor is inserted, and the insulation coating stripping portion of the lead wire inserted into the first hole and the second hole. A cross contact step of crossing and contacting the inserted lead conductor tip, a lead wire twisting step of twisting and rotating the lead wire in the first hole, and the lead in the first hole A lead wire drawing type SPD manufacturing method comprising a lead wire adhering step of adhering an insulating coating portion of the wire with an adhesive.