JPH0424634Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a discharge tube, that is, a detonator used for circuit protection and the like.

(Background Art) Among this type of lightning arrester for circuit protection, etc., there is a type having a so-called external fail-safe mechanism.

FIGS. 5 and 6 show assembly diagrams of a conventional detonator with an external fail-safe mechanism.

In the figure, 10 and 10 are line electrodes, 12 is a ground electrode, 14 is a tubular insulator inserted between these electrodes, 16 is a line electrode lead wire, and 18 is a ground electrode lead wire.

Reference numeral 20 denotes a fail-safe conduction plate, which is fixed to the outer surface of the detonator main body 24 via a sheet-like insulator 22.

In this case, the fail-safe conduction plate 2 shown in FIG.
0 is formed in a shape in which three arc-shaped contact parts 28 extend from the connecting part 26, and are electrically connected and fixed by spot welding on the outer periphery of the earth electrode 12 at the center of the connecting part 26. The arc-shaped contact portion 28 is in elastic contact with the outer periphery of each corresponding electrode via the sheet-shaped insulator 22 described above.

Furthermore, the fail-safe conduction plate 20 shown in FIG.
is formed so that the overall shape is U-shaped with the contact portions 30 extending from both sides of the connecting portion 26,
The connecting portion 26 is electrically connected and fixed to the outer periphery of the earth electrode 12 by spot welding in the central depression, and both contact portions 30 are elastically connected to the end face of the line electrode 10 via the sheet-like insulator 22 mentioned above. are in contact with each other.

In both of the above conventional examples, the fail-safe conduction plate 20 is firmly fixed on the outer periphery of the detonator main body 24 by spot welding in order to prevent it from falling off from the detonator main body 24 and to ensure electrical continuity. It is being done.

Note that the above-mentioned fail-safe mechanism is such that when a high-voltage power source or the like is continuously applied to the detonator main body 24 for some reason, the detonator main body 24 overheats due to continuous discharge due to this high voltage, and the detonator main body 24 overheats. This is to prevent unexpected accidents such as fire from occurring due to overheating. That is, the sheet-shaped insulator 22 melts before overheating, thereby shorting the line electrode 10 and the ground electrode 12 via the fail-safe conduction plate 20, avoiding continuous discharge, and causing the detonator main body 24 to short-circuit. heating is prevented.

(Problems to be solved by the invention) However, both of the above conventional detonator caps have the following problems.

That is, as described above, the fail-safe conduction plate 20 cannot be held well on the detonator main body 24 by only the elastic contact force of the contact portion due to its structure, and reliable electrical continuity cannot be ensured. In order to securely fix it, it is essential to fix it by spot welding as described above.

However, in the assembly process of the detonator main body 24 and the pressing process for forming the fail-safe conduction plate 20,
Incorporating a spot welding process that is completely different from these processes not only results in an increase in the number of man-hours, but also causes problems in that the production line lacks consistency and production efficiency is reduced.

Also, for both of the above lightning arresters, the lead wires 16, 16,
Fail-safe conduction plate 2 to prevent interference with 18
0 is mounted on the main body of the detonator on the opposite side from these leads. However, since the lightning arrester is attached to the board with the lead wire facing the board, there is a problem that when it is attached to the board, the fail-safe conduction plate 20 is located in a space on the opposite side of the board, creating a spatial obstruction. .

Therefore, the present invention was devised to solve the various problems mentioned above.The purpose of this invention is to be able to firmly hold the fail-safe conductive plate on the detonator main body without spot welding, and to securely hold the fail-safe conductive plate on the detonator main body without spot welding. To provide a lightning arrester in which a fail-safe conducting plate does not become a spatial obstacle.

(Means for Solving the Problems) The present invention has the following configuration to solve the above problems.

In other words, in a detonator, a detonator body has a ground electrode and a line electrode connected to each other via an insulator, and a fail-safe conductive plate is in elastic contact with the line electrode and the earth electrode via a sheet-like insulator. , the fail-safe conduction plate is
A connecting piece that is approximately U-shaped and has a through hole in the center through which a ground electrode lead wire can be inserted; The fail-safe conductive plate is provided with a contact piece extending perpendicularly to the connecting piece, and the earth electrode lead wire is inserted through the through hole provided in the connecting piece, so that the connecting piece is grounded. The detonator is characterized in that it is attached to the detonator main body in a state in which the contact pieces contact the electrodes and are in elastic contact with each of the electrodes via a sheet-like insulator in a bridging manner.

(Function) The ground electrode lead wire is inserted through the connecting piece, and the elasticity of the connecting piece causes the contact piece to come into elastic contact with the electrode via a sheet-like insulator, so that the fail-safe conduction plate is completely connected to the detonator main body. It does not fall off and can be firmly held on the detonator body without the need for spot welding as in conventional methods.Furthermore, when attached to a circuit board, etc., the fail-safe conductive plate has a connecting piece that connects the circuit board, etc. and the detonator body. Since there is nothing located in between that protrudes above the detonator main body, there is no spatial obstruction.

(Embodiments) Hereinafter, preferred embodiments embodying the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is an assembly diagram of a detonator according to the present invention.
Since the detonator main body 24 is the same as the conventional one, each member is given the same number and the explanation thereof will be omitted.

The feature of this invention is the fail-safe conduction plate 3.
It is in the structure of 2.

The fail-safe conduction plate 32 has a shape in which the lower central portions of two contact pieces 34 facing each other in a U-shape are connected by an elastic connection piece 36 having a substantially U-shape.
The side surface shape formed by the two contact pieces 34 and the elastic connection piece 36 has a shape that can hold the detonator main body 24 from the outer periphery.

At the center of the connecting piece 36 is a ground electrode lead wire 1.
A through-hole 38 for insertion of 8 is provided.

Further, a sheet-like insulator 40 is adhered to the opposing surface of the contact piece 34.

If the fail-safe conduction plate 32 is applied to the outer periphery of the detonator main body 24 so that the ground electrode lead wire 18 is inserted through the through hole 38 of the connecting piece 36, and is pushed in against the elastic force of the elastic connecting piece 36,
The fail-safe conduction plate 32 can be fitted onto the outer periphery of the detonator main body 24.

In this case, the contact piece 34 comes into elastic contact with the outer periphery of the detonator main body 24 via the sheet-like insulator 40 due to the elastic force of the elastic connecting piece 35 . This elastic contact position is on the side opposite to the side where the earth electrode lead wire is located, of the two half-circle arc parts of the detonator main body 24 divided by a diameter B parallel to the tangent line A at the earth electrode lead wire position. (See Figure 2). As a result, the fail-safe conductive plate 32 is fitted onto the outer periphery of the detonator main body 24 without coming off. At the same time, the connecting piece 36 also comes into strong elastic contact with the outer periphery of the earth electrode 12, ensuring electrical continuity.

Further, since the ground electrode lead wire 18 is inserted through the through hole 38, the fail-safe conduction plate 32 is prevented from rotating on the outer periphery of the detonator main body 24.

FIG. 3 shows another embodiment.

In this embodiment, a plurality of tongue pieces 42 are provided on the inner wall of the through hole 38 provided in the connecting piece 36. The ground electrode lead wire 18 is configured to abut the tip of the tongue piece 42 and be press-fitted into the through hole 38.

This further ensures that the fail-safe conductive plate 32 is prevented from coming off and that the electrical continuity with the ground electrode 12 is further ensured.

FIG. 4 shows yet another embodiment.

In this embodiment, the center portion of the elastic connecting piece 36 is provided in a shallow arc shape.

As a result, the earth electrode 1 of the elastic connecting piece 36
The elastic contact force on the outer periphery of the electrode 2 becomes large, and electrical continuity with the ground electrode 12 becomes more reliable.

(Effects of the invention) As described above, according to the invention, the ground electrode lead wire is inserted through the connecting piece, and the elasticity of the connecting piece brings the contact piece into elastic contact with the electrode via the sheet-like insulator. As a result, the fail-safe conductive plate will never fall off the detonator body, and can be firmly held on the detonator body without spot welding as in conventional methods.Furthermore, when attached to a board, etc., the fail-safe conductive plate Since the connecting piece is located between the board, etc. and the lightning arrester main body, and there is nothing protruding above the lightning arrester main body, it is effective in that there is no spatial obstruction.

If a tongue piece is provided in the through hole of the elastic connecting piece, the tongue piece will come into strong contact with the ground electrode lead wire, making the electrical conduction more reliable and fixing the fail-safe conductive plate more securely.

Furthermore, by curving the central portion of the connecting piece, the connecting piece will come into strong elastic contact with the ground electrode, making electrical continuity even more reliable.

Although the present invention has been variously explained above using preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. be.

[Brief explanation of drawings]

Fig. 1 is an assembled diagram of a detonator according to the present invention, Fig. 2 is a side view thereof, Fig. 3 is an explanatory drawing showing a through hole provided with a tongue piece, and Fig. 4 is a side view showing another embodiment. be. FIGS. 5 and 6 are assembly diagrams each showing an example of a conventional detonator. 10...Line electrode, 12...Earth electrode, 1
4... Tubular insulator, 16... Line electrode lead wire, 18... Earth electrode lead wire, 20... Fail-safe conduction plate, 22... Insulator, 24... Lightning arrester body, 26... Connection portion, 28 , 30... Contact portion, 32... Fail-safe conduction plate, 34... Contact piece, 36... Elastic connection piece, 38... Through hole, 40
...Insulator, 42...Tongue piece.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A detonator main body in which a ground electrode with a lead wire and a line electrode are connected via an insulator, and a fail-safe conductive plate is connected to the line electrode and the ground electrode via a sheet-like insulator. In an elastically connected lightning arrester, the fail-safe conduction plate has a connecting piece that is approximately U-shaped and has a through hole in the center through which a ground electrode lead wire can be inserted, and a connection piece that extends from both ends of the connecting piece to the both ends. The contact piece is provided with a contact piece extending perpendicularly to the connecting piece so as to face the connecting piece so that the connecting base side thereof expands, and the fail-safe conductive plate is connected to a transparent plate provided on the connecting piece. The ground electrode lead wire is inserted through the hole, the connecting piece is in contact with the ground electrode, and both contact pieces are in elastic contact with each of the electrodes via a sheet-like insulator in a bridging manner, and then the detonator main body is opened. A lightning arrester installed in a 2. The lightning arrester according to claim 1, wherein the through hole provided in the connecting piece is provided with a plurality of tongue pieces that protrude inward and come into contact with the outer periphery of the earth electrode lead wire. 3. The detonation arrester according to claim 1 or 2, wherein the central portion of the connecting piece is provided in an arc shape that curves toward the opposite side of the detonation arrester main body.