JP2006228634A - Surge absorber and power cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to be durable even against an insert mold, and enable to maintain stable performance over a long period of time. <P>SOLUTION: This surge absorber 1 has a cylindrical outer peripheral case part 4 made of metal, one end side case part 3 composed of an insulating member which blocks up one end side of the outer peripheral case part 4 in the axial direction, a first discharge terminal 6 which is supported by one end side case part 3, which is arranged apart from the outer peripheral case part 4, and which is arranged in a space 5 surrounded by the outer peripheral case part 4, and the other end side metallic case part 7 which is composed of a part of the outer peripheral case part 4 or of the other member, which closes the other end side of the outer peripheral case part 4 in the axial direction, which is the member arranged so as to be opposed to the first discharge terminal 6 at a spacing in the axial direction, and which serves as a second discharge terminal in combination. Furthermore, the second discharge terminal may be installed separately from the other end side case part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surge absorber that protects an electronic circuit, an electronic device, and the like from an overvoltage such as a lightning surge, and a power cord having the surge absorber.

  The surge absorber is connected between power supply lines or between the power supply line and the ground in order to protect electronic circuits, electronic devices, and the like from lightning surges caused by lightning strikes and overvoltage such as high voltage generated when the power is turned on and off. This type of surge absorber is usually incorporated as part of an electronic circuit or an electronic device. However, in the past, as an idea, an application in which a surge absorber is incorporated in a power plug has been filed (Patent Document 1).

  Known surge absorbers include silicon diodes, varistors, discharge-type gas tube arresters, microgap discharge elements, and the like. Furthermore, a surge absorber in which two discharge electrodes are arranged to face each other is also known as a kind of discharge-type gas tube arrester (Patent Document 2).

Japanese Utility Model Publication No. 6-24345 (abstract) JP 2000-21608 A (abstract)

  Patent Document 1 discloses an idea of incorporating a surge absorber in a power plug, but such a product has not appeared. First, since the power plug is formed by insert molding, if a surge absorber is to be assembled in the power plug, the surge absorber must also be integrally molded by insert molding. This is because it cannot withstand the shrinkage force. Second, the power plug must be in a completely open mode (leakage current is zero) under normal conditions, but it can maintain the open mode for a long period of time, and must absorb overvoltage when a surge occurs. This is because there is a strict demand for it.

  The discharge type gas tube arrester described above is preferable for the second problem described above, but the gas tube arrester is generally formed of a glass tube or a ceramic tube, and the case is discharged. Does not contribute, the discharge is concentrated on the terminal portion, and the change with time of the terminal portion becomes large, which is disadvantageous in terms of ensuring stable operation for a long time. Furthermore, the glass tube cannot withstand the shrinkage at the time of insert molding, and insert molding cannot be performed. In the case of the surge absorber of Patent Document 2, the case is made of glass or plastic, and has the same problem as a general gas tube arrester.

  The present invention solves the above-described problems all at once, and provides a surge absorber capable of withstanding an insert mold and maintaining stable performance for a long period of time, and a power cord incorporating the surge absorber. For the purpose.

  In order to solve the above-described problems, a surge absorber according to the present invention is a surge absorber in which at least two terminals for discharge are arranged to face each other, and a cylindrical outer case portion made of metal and an axial direction of the outer case portion One end side case portion made of an insulating member that closes one end side of the first end portion, and a first end portion that is supported by the one end side case portion and that is disposed away from the outer peripheral case portion and that is disposed in a space surrounded by the outer peripheral case portion. The discharge terminal is made up of a part of the outer case part or another member, and closes the other end side of the outer case part in the axial direction, and faces the first discharge terminal with an interval in the axial direction. It is a member to be arranged and has a metal other end side case portion that also serves as a second discharge terminal.

  Since the case surrounding the outer periphery of the surge absorber is made of metal, the surge absorber can sufficiently withstand strength even when incorporated by an insert mold. In addition, since the discharge is performed between the first discharge terminal and the outer case portion and the other end case portion, this surge absorber has a large discharge area and is resistant to changes with time. , Stable performance can be maintained over a long period of time.

  The surge absorber according to another invention is a surge absorber in which at least two terminals for discharge are arranged to face each other, insulating the cylindrical outer case portion made of metal and one end side in the axial direction of the outer case portion. One end side case portion made of a member, a first discharge terminal that is supported by the one end side case portion and arranged away from the outer peripheral case portion, and disposed in a space surrounded by the outer peripheral case portion; A second part which is made of a part of the outer case part or a separate member, closes the other end side of the outer case part in the axial direction, and is arranged so as to face the first discharge terminal at an interval in the axial direction. It has a discharge terminal and a second end side case portion that supports the second discharge terminal.

  Since the case surrounding the outer periphery is made of metal, this surge absorber can sufficiently withstand strength even if it is insert-molded. In addition, since the discharge is performed between the first discharge terminal and the outer case and the second discharge terminal, the surge absorber has a large discharge area and is resistant to changes over time. As a result, stable performance can be maintained over a long period of time.

  Moreover, it is preferable that the one end side case part protrudes toward the terminal for 1st discharge, and the terminal for 1st discharge is arrange | positioned at the protrusion front end side. With this configuration, since the edge distance from the first discharge terminal to the outer case is increased, the first discharge terminal melts at a high voltage, and a part of the first discharge terminal is formed on the surface of the one end side case. As a result, the risk that the first discharge terminal and the outer case portion are electrically short-circuited is reduced.

  The one end side case portion has a truncated cone shape, and a through-hole penetrating in the axial direction is provided at the center thereof, and a lead wire connected to the first discharge terminal is disposed in the through-hole. Is preferred. By adopting this configuration, it is possible to increase the strength of the case portion on one end side while increasing the edge distance. Moreover, it becomes easy to form a through-hole in the one end side case part and to easily center out.

  Furthermore, the outer peripheral case portion and the other end side case portion are formed of a bottomed cylindrical integral member, the outer peripheral case portion is the outer peripheral portion of the integral member, and the other end side case portion is the bottom portion of the integral member, It is preferable that a hole for injecting a gas sealed in the space is provided at the bottom. This surge absorber is more preferable in terms of strength and discharge performance because the outer case portion and the other end case portion have an integral structure.

  In addition, when the distance between the first discharge terminal and the outer case portion is X and the distance between the first discharge terminal and the second discharge terminal is Y, 0.5 ≦ Y / X ≦ 2 is preferable. With this configuration, the discharge is well balanced and easy to assemble.

  In addition, the first discharge terminal includes a conical or cylindrical terminal portion, a connecting portion having a smaller diameter than the terminal portion, which is connected to the terminal portion with a large diameter by crushing the tip of the lead wire. Preferably, the connecting portion is disposed at the protruding tip of the one end side case portion, and an axial gap is provided between the protruding tip and the terminal portion. When this configuration is adopted, the terminal portion and the connecting portion are joined by spot welding, so that the terminal portion can be easily and accurately positioned even if a bulge occurs around the bonded portion. .

  In the power cord of the present invention, the surge absorber described above is incorporated into a power plug by insert molding.

  The power cord can maintain a stable state for a long time because the surge absorber can sufficiently withstand insert molding.

  The power plug is preferably a two-terminal AC power plug, and a surge absorber is preferably connected between the two terminals. A power cord employing this configuration is very versatile.

  The surge absorber of the present invention can sufficiently withstand insert molding, and can maintain stable performance over a long period of time. The power cord of the present invention is a power cord with a surge absorber that can maintain stable performance over a long period of time.

  Hereinafter, a surge absorber according to an embodiment of the present invention will be described with reference to the drawings. Note that the power cord is appropriately determined in the explanation of the surge absorber.

[First Embodiment]
First, a surge absorber 1 according to a first embodiment of the present invention will be described with reference to FIGS. The surge absorber 1 is supported by a metal bottomed can case 2, an end case 3 made of an insulating member that closes one end of the can 2 in the axial direction, and the one end case 3. And a first discharge terminal 6 that is disposed apart from the outer peripheral case portion 4 that is the outer periphery of the can case 2 and that is disposed in a space 5 surrounded by the outer peripheral case portion 4. In this specification, one end side refers to the left side in FIG. 1, and the other end side refers to the right side in FIG.

  As shown in FIGS. 2 and 3, the can case 2 has an annular shape in which the other end side case portion 7 that becomes the bottom and the one end side case portion 3 abuts, in addition to the cylindrical outer case portion 4 that becomes the outer periphery portion. A stepped portion 11, a cylindrical one end holding portion 13 surrounding a space 12 in which an insulating resin material enters, and a circular hole 14 for injecting a gas such as an inert gas provided in the other end side case portion 7. And a cylindrical other end side holding portion 16 surrounding the circular dish-shaped space 15 into which the insulating resin material enters.

  In the first embodiment, the can case 2 is made of iron, but may be stainless steel or other metal material. Further, the can case 2 has a bottomed cylindrical shape, but the other end side case portion 7 which is a bottom portion may be a separate member from the outer peripheral case portion 4 or may be a rectangular tube shape instead of a cylindrical shape. . Further, in the first embodiment, the other end side case portion 7 serves as a second discharge terminal.

  On the other end side of the other end side case portion 7 of the can case 2, a conductive columnar connecting portion 22 having a lead wire 21 is bonded to the other end side case portion 7 by spot welding or the like. The connecting portion 22 is installed concentrically with the can case 2. An insulating resin material is injected into the space 12 to form one end side insulating resin portion 23, while an insulating resin material is injected so as to cover the connection portion 22, and the other end side insulating resin portion 24 is formed. ing. The other end side insulating resin portion 24 may be a conductive material such as solder instead of the insulating resin material. Further, the other end side insulating resin portion 24 is formed after the inert gas is injected into the space 5 from the hole 14, thereby preventing leakage of the inert gas from the space 5. The one end side insulating resin portion 23 is formed before injecting the inert gas.

  The one end side insulating resin portion 23 has a function of fixing the lead wire 24 and a function of fixing the one end side case portion 3 in addition to the function of preventing the inert gas from leaking from the space 5. The other end side insulating resin portion 24 blocks the gas injection hole 14 and prevents the inert gas from leaking from the space 5, and also functions to protect the connecting portion 22 and the lead wire 21 and Plays the function of fixing.

  The surge absorber 1 is incorporated in a power plug of a normal electronic device such as a personal computer or a television, and is very small. For example, the axial length L1 of the can case 2 is 8 mm, and the outer diameter W1 is 4.5 mm. In addition, the axial length L2 of the space 5 is 5.2 mm, the inner diameter W2 is 3.8 mm, the axial thickness L3 of the other end side case portion 7 is 0.5 mm, and the other end side holding portion 16 The axial height L4 is 0.3 mm. The hole diameter W3 of the hole 14 is 0.4 mm.

  The one end side case part 3 is comprised with the insulating member which consists of ceramics for insulation, and has the circular base part 31 and the truncated cone-shaped cone part 32 by which the upper end was cut off by the cone shape. A circular concave portion 33 on which the first discharge terminal 6 is placed is provided on the other end side of the conical portion 32, and a through hole 34 having a circular cross section that extends in the axial direction from the bottom surface of the concave portion 33 is provided. ing. The concave portion 33 and the through hole 34 are provided so as to be concentric with respect to the outer diameter of the center of the one end side case portion 3 in the radial direction.

  The base portion 31 has an outer diameter of 4 mm, slightly smaller than the inner diameter of 4.1 mm of the one end side holding portion 13, and slightly smaller than the inner diameter W2 of the space 5 that is the inner diameter of the outer peripheral case portion 4. It has been enlarged. By adopting such dimensions, the one end side case portion 3 is smoothly inserted from one end side toward the other end side, and the other end side surface of the outer peripheral portion is a step portion of the can case 2. 11 and is prevented from moving in the direction of the other end. As a result, the space 5 has a predetermined capacity.

  The through hole 34 has an inner diameter slightly larger than the outer diameter of the lead wire 24 in order to facilitate insertion of the lead wire 24. When the insulating resin material is injected into the space 12, a part of the insulating resin material enters the through hole 34, and the lead wire 24 is strongly fixed to the one end side case portion 3.

  The inert gas injected into the space 5 is, for example, a rare gas such as helium, xenon, or argon, or an insulating gas. The space 5 is most preferably filled with an inert gas. However, for example, a mixture of an inert gas and a nitrogen gas or only clean dry air may be used. This point is the same in other forms described later.

  The first discharge terminal 6 is composed of a cylindrical terminal portion 41 and a connection portion 42 whose diameter is increased by crushing the tip of the lead wire 24. The terminal portion 41 is made of stainless steel, but may be iron. Further, other metal materials may be used. When iron is used, nickel plating is preferably performed on the outer periphery. The outer diameter M1 of the terminal portion 41 is 2 mm and the axial length M2 is 1 mm, but other sizes may be used. For example, both the outer diameter M1 and the axial length M2 may be 2 mm, both 1.7 mm, and 1.5 mm.

  In this Embodiment 1, the distance N1 from the terminal part 41 to the outer periphery case part 4 is 0.9 mm, and the distance N2 to the other end side case part 7 is 0.98 mm. X = Y is most preferable when the distance N1 is X and the distance N2 is Y. This is because the terminal portion 41 and the can case 2 are equidistant from each other, so there is no bias in the discharge generated between them, and it is easy to discharge, and the terminal portion 41 and part of the can case 2 are melted. This is because the risk is reduced. As for the relationship between X and Y, from the applicant's experimental results, if 0.5 ≦ Y / X ≦ 2, good results are obtained compared to other ranges, and 0.8 ≦ Y / X It has been found that even better results can be obtained if ≦ 1.2.

  The distances N1 and N2 are preferably 0.5 mm or more and 1.5 mm or less. This is because welding between terminals is less likely to occur when the thickness is 0.5 mm or more, and discharge is likely to occur when the thickness is 1.5 mm or less.

  The terminal part 41 and the connection part 42 are bonded by spot welding. Spot welding is performed over the entire circumference of the outer peripheral surface on the other end side of the connecting portion 42. After spot welding, the welded portion is swelled, but since the gap G is formed between the terminal portion 41 and the one end side case portion 3, the gap G serves as a relief of the spot welded portion, and the first The discharge terminal 6 can be assembled with high accuracy. Further, the presence of the recess 33 enables the connection portion 32 to be installed at the tip of the one end side case portion 3 with high accuracy and efficiency.

  As shown in FIG. 5, the surge absorber 1 having this structure is incorporated into a power plug 50 located at the tip of the power cord by insert molding. The power plug 50 is for a single-phase AC power source having two terminals 51 and 52, and the surge absorber 1 is connected between the two terminals 51 and 52. However, the surge absorber 1 may be incorporated into a power plug for a three-terminal single-phase AC power source, or can be incorporated into a power plug for a three-phase AC power source.

  In the case of a two-terminal power plug, the surge absorber 1 is connected between the two terminals. In the case of a three-terminal power plug, one is connected between the AC power output terminals and one is connected between each AC power output terminal and the ground terminal. It is preferable to incorporate a total of three surge absorbers 1 each. When assembling the surge absorber 1 into the power plug 40, the assembled surge absorber 1 is insert-molded once to form a mold body 53, and then the mold body 53 is connected to the terminals 51 and 52, and then insert-molded again. The power plug 40 is formed.

  The power cord having the power plug 50 can change the discharge start voltage by changing the size of the terminal portion 41 and the type of inert gas to be injected.

[Embodiment 2]
Next, a surge absorber 1A according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same member as the surge absorber 1 concerning Embodiment 1, and the description is abbreviate | omitted or simplified. In addition, members having the same reference numerals and similar reference numerals are formed of the same materials as those in the first embodiment.

  The main points of the surge absorber 1A different from the surge absorber 1 are a first discharge terminal portion and a second discharge terminal portion. The first discharge terminal 6A of the surge absorber 1A has a conical terminal portion 41A with a pointed tip, and a lead wire 24 made of iron is bonded to one end side of the terminal portion 41A by spot welding. Yes. Note that the tip of the lead wire 24 on the other end side has a slightly larger diameter than the other portions, and serves as a connection portion 42A.

  Spot welding is performed between the terminal portion 41A and the connection portion 42A, and both are temporarily bonded. Thereafter, the insulating resin material enters the through hole 34 to cover the spot welded portion, and the resin material adheres to the terminal portion 41A, whereby the terminal portion 41A and the connecting portion 42A are completely bonded. This bonding method can also be applied to the surge absorber 1 of the first embodiment and the example described later. In addition, the resin material which flowed into each clearance gap is shown by painting black in FIG.

  The bonding surface of the connection portion 22A connected to the other end side case portion 7 serving as the second discharge terminal has a diameter equal to or larger than the maximum diameter M1 of the terminal portion 41A. Thus, efficient discharge is performed by setting the bonding surface of the connecting portion 22A to be equal to or larger than the outer diameter of the terminal portion 41A. This structure can be applied to other examples. The other end side insulating resin portion 24 does not cover the other end side surface of the connecting portion 22A.

  Similarly to the surge absorber 1, the surge absorber 1A is also incorporated into the power plug of the power cord by an insert mold, and has the same functions and operations. In the surge absorber 1A, since the terminal portion 41A has a conical shape, the discharge between the outer peripheral case portion 4 and the other end side case portion 7 is performed at the pointed portion of each tip. It will be suitable.

[Embodiment 3]
Next, a surge absorber 1B according to a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same member as the surge absorber 1 concerning Embodiment 1, and the description is abbreviate | omitted or simplified. In addition, members having the same reference numerals and similar reference numerals are formed of the same materials as those in the first embodiment.

  The main points that this surge absorber 1B is different from the surge absorber 1 are the structure of the can case, the one end side case portion, and the second discharge terminal portion. The surge absorber 1B as a whole is symmetrical in the left-right and up-down directions, and the can case 2B is also a left-right symmetric cylindrical shape in FIG. The can case 2 </ b> B has the outer peripheral case portion 4 and the one end side holding portion 13, but does not have the other end side case portion 7, but instead has the other end side holding that extends to the other end side having the same shape as the one end side holding portion 13. It has a portion 16B.

  The one end side case portion 3B is made of an insulating ceramic and has substantially the same shape as the pedestal portion 31, but the pedestal portion 31B whose surface on the other end side extends to the vicinity of the center portion, a cylindrical columnar portion 32B, and a recess 33 Although these are different from the one end side case portion 3 in these points, they are the same in other points. The first discharge terminal 6 </ b> B has a terminal part 41 </ b> B that is flatter than the first discharge terminal 6 and a connection part 42 </ b> B similar to the connection part 42.

  The second discharge terminal 61 has the same shape and the same material as the first discharge terminal 6B, and is supported by the other end side case portion 62 having the same shape and the same material as the one end side case portion 3B. Yes. The other end side case portion 62 includes a base portion 31 </ b> B, a cylindrical portion 32 </ b> B, and a concave portion 33. The other end side case portion 62 may not be an insulating ceramic, but may be other materials such as a metal material, or a member formed as a pair with the outer peripheral case portion 4.

  When injecting the inert gas into the surge absorber 1B, the through hole 34 for inserting the lead wire 21 provided in the other end side case portion 62 is used. Although the hole for inert gas injection is not specially provided, a hole for gas injection may be provided in a portion facing the space 5 in the base portion 31B of the other end side case portion 62. . Further, as shown by a one-dot chain line in FIG. 7, a connecting portion 64 with a lead wire 63 may be bonded to the outer peripheral case portion 4 so that the outer peripheral case portion 4 functions as a third discharge terminal.

  Since the surge absorber 1B has a symmetrical shape on both the left and right sides, the component manufacturing cost is reduced and the assembling efficiency is increased.

[Effect of each embodiment]
The surge absorbers 1, 1 </ b> A, 1 </ b> B shown in each embodiment have a cylindrical outer case made of metal, so that they can sufficiently withstand strength even if they are incorporated into a power plug by an insert mold. Become. Further, the discharge is performed between the first discharge terminals 6, 6 </ b> A, and 6 </ b> B and the outer case 4 and the other end side case 7 that also serves as the second discharge terminal and the second discharge terminal 61. Therefore, the area of the discharge portion becomes large, and it is resistant to changes over time, so that stable performance can be maintained over a long period of time.

  Since the conical portion 32 and the cylindrical portion 32B of the one end side case portions 3 and 3B and the cylindrical portion 32B of the other end side case portion 62 increase the edge surface distance between the terminal portions 41 and 41B and the outer case portion 4, the terminal portion 41,41B and the outer periphery case part 4 reduce the danger that it will electrically short-circuit.

[Other forms]
As mentioned above, although each embodiment of this invention was described, this invention can be variously implemented unless it deviates from the summary. For example, the can case 2 and the outer peripheral case portion 4 are formed in a cylindrical shape, but may have a square cross section or the bottom portion of the can case 2 may be a separate member. When the bottom part is a separate member, the material is preferably the same as that of the outer case part 4.

  Moreover, the shape of the one end side case parts 3 and 3B and the other end side case part 62 may be a shape without the conical part 32 and the cylindrical part 32B, and the edge surface distance may not be so long. Conversely, in order to increase the edge distance, irregularities may be provided on the outer peripheral surfaces of the conical portion 32 and the cylindrical portion 32B. Furthermore, although the through hole 34 is provided at the center in the radial direction of the surge absorbers 1, 1A, 1B, it may be provided at a position shifted from the center. Further, the recess 33 may not be provided.

  The values L1, L2, L3, L4, W1, W2, and W3 described in the first embodiment are examples, and other numerical values, for example, values within ± 20% of each value or other values are adopted. It is possible to do. Further, the relationship between the value M1 and the value M2 can be appropriately changed according to the required performance. Furthermore, the relationship between the value N1 and the value N2 described in the first embodiment is preferably applied to the second and third embodiments.

  The surge absorbers 1, 1 </ b> A, 1 </ b> B are suitable for incorporation into various types of power plugs such as the power plug 50 shown in FIG. 5, but instead of being incorporated into the power plug, You may make it incorporate in the apparatus etc.

It is sectional drawing of the surge absorber concerning Embodiment 1 of this invention. It is sectional drawing of the can case in the surge absorber of FIG. It is the figure which looked at the can case of FIG. 2 from the left side of FIG. It is a side view of the one end side case part in the surge absorber of FIG. It is a figure explaining the state in which the surge absorber of FIG. 1 was integrated in the power plug of the power cord. It is sectional drawing of the surge absorber concerning Embodiment 2 of this invention. It is sectional drawing of the surge absorber concerning Embodiment 3 of this invention.

Explanation of symbols

1, 1A, 1B Surge absorber 2 Can case 3 One end side case part 4 Outer peripheral case part 5 Space (space where inert gas is injected)
6, 6 </ b> A, 6 </ b> B First discharge terminal 7 Other end side case portion (also serves as second discharge terminal)
14 holes (for gas injection)
21 and 24 Lead wire 31 Base part 32 Conical part 33 Concave part 34 Through hole 41 Terminal part 42 Connection part 50 Power plug 61 Second discharge terminal 62 Other end side case part G Gap

Claims (9)

In a surge absorber in which at least two terminals for discharge are arranged to face each other,
A cylindrical outer case made of metal;
One end side case portion made of an insulating member that closes one axial end side of the outer peripheral case portion;
A first terminal for discharge disposed in a space supported by the one end side case portion and spaced apart from the outer peripheral case portion and surrounded by the outer peripheral case portion;
The outer peripheral case part is made of a part or another member, and closes the other end side in the axial direction of the outer peripheral case part, and is arranged so as to face the first discharge terminal with an interval in the axial direction. A second end case made of metal that also serves as a second discharge terminal;
A surge absorber characterized by comprising: In a surge absorber in which at least two terminals for discharge are arranged to face each other,
A cylindrical outer case made of metal;
One end side case portion made of an insulating member that closes one axial end side of the outer peripheral case portion;
A first terminal for discharge disposed in a space supported by the one end side case portion and spaced apart from the outer peripheral case portion and surrounded by the outer peripheral case portion;
The outer peripheral case part is made of a part or another member, and closes the other end side in the axial direction of the outer peripheral case part, and is arranged so as to face the first discharge terminal with an interval in the axial direction. A second discharge terminal;
The other end side case portion supporting the second discharge terminal;
A surge absorber characterized by comprising:   The said one end side case part protrudes toward the said 1st terminal for discharge, The said 1st terminal for discharge is arrange | positioned at the protrusion front end side. surge absorber.   The one end side case portion has a truncated cone shape, and a through-hole penetrating in the axial direction is provided at the center thereof, and a lead wire connected to the first discharge terminal is disposed in the through-hole. The surge absorber according to claim 3.   The outer peripheral case portion and the other end side case portion are formed of a bottomed cylindrical integral member, the outer peripheral case portion is an outer peripheral portion of the integral member, and the other end side case portion is a bottom portion of the integral member. The surge absorber according to claim 1, wherein a hole for injecting a gas sealed in the space is provided at a bottom portion of the surge absorber.   When the distance between the first discharge terminal and the outer case portion is X and the distance between the first discharge terminal and the second discharge terminal is Y, 0.5 ≦ The surge absorber according to claim 1 or 2, wherein Y / X≤2.   The first discharge terminal includes a conical or cylindrical terminal portion and a connecting portion having a smaller diameter than the terminal portion, which is connected to the terminal portion with a large diameter by crushing the tip of the lead wire. 4. The connecting portion is disposed at a protruding tip of the one end side case portion, and an axial gap is provided between the protruding tip and the terminal portion. Surge absorber.   A power cord, wherein the surge absorber according to any one of claims 1 to 7 is incorporated into a power plug by insert molding. The power cord according to claim 8, wherein the power plug is an AC power plug for two terminals, and the surge absorber is connected between the two terminals.

Images