JPH09126697A - Block plug for detonator and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a block plug which can stably set the resistance value of a bridge wire between lead pins to a desired value in a wide range without influence of applied pressure by igniting explosive powder by excluding the directionality of a lead pin insertion hole without regulating the cross angle of the wire between the end faces of the pins. SOLUTION: The block plug for a detonator comprises a bridge wire connected between the end faces of a pair of lead pins 2 of an insulation plug 1 through which the pair of lead pins 2 are passed, and pircular collars 21 formed at the ends of the pins 2, wherein the ratio L1 /Lmin of the shortest interval Imin between the collars to the interval L0 between the centers of both the collars is set to 2.5 or more, and the wire 4 is connected to the surface of the collar 21 by including the collar edge positions (e).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detonator embolus and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a detonator used for blasting work, a detonator of a concrete crusher, a detonator of an air bag for an automobile, etc., a pair of lead pins are inserted between the lead pin tip end faces of an insulating plug body. It is known that an embolus formed by connecting electric bridge wires is inserted into a bottomed thin-walled metal cylinder containing an ignition powder. In the detonator embolus, the resistance value of the bridge wire connected between the lead pins, the stray current, to eliminate the explosive due to the monitor current, to ensure the ignition operation with the operating current for ignition, applications Is required to be set to a predetermined value.

Therefore, the applicant of the present invention made the tip portions of both lead pins non-circular, and the ratio L between the maximum distance L'and the minimum distance L between the facing outer edge portions of the lead pin tip end surfaces. '/ L is larger than the ratio when the cross section of the lead pin is circular with the same cross-sectional area, and by selecting the distance, the resistance value of the bridge wire between the lead pins is set to the maximum distance of the bridge. It has already been proposed to set a desired resistance value between the wire resistance value and the bridge wire resistance value of the minimum distance (Japanese Patent Laid-Open No. 5-133698).
No.). In addition, the applicant of the present invention has shown that as a welding method of the lead pin tip end surface and the bridge wire with the embolus, as shown in FIG.
As shown in Fig. 1, one electrode 51 'of the resistance welding machine is brought into contact with the bridge wire portion 40' on the tip end surface of the lead pin 2 ', and the other electrode 52' is attached to the tip end surface of the lead pin 2 '. Directly abutting on the lead pin 2 ′ and the bridge wire portion 4
It has already been proposed to perform resistance welding between 0'and 0 '(JP-A-5-172498). According to this welding method, since it is not necessary to heat the entire lead pin 2'or the entire bridge wire 4 ', the thermal interface of the seal interface between the lead pin 2'and the plug body 1'is not required. There is no fear of deterioration or damage to the bridge line 4 ',
It is advantageous.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the detonator embolus disclosed in Japanese Patent No. 698,
In order to set the resistance value of the bridge wire between the dopins to a predetermined value, it is premised on adjusting the cross angle of the bridge wire between the lead pin tip end faces, so positioning of the bridge wire is not easy. . In addition, since the cross section of the lead pin insertion hole of the embolus and the lead pin have directionality to the insertion, it is necessary to match the directions of both when inserting the lead pin. Compared with the case, the work of inserting the lead pin becomes more troublesome.

Further, in the above embolus, since the bridge wire is pressurized by the ignition powder (4 'in FIG. 8 and 71' in FIG. 8), the bridge wire and the lead pin tip end surface are As shown in FIG. 8 (a), when the welding is performed from the position e "separated from the edge e'of the lead pin tip end surface to the bridge wire end E ', the non-welded portion e'- The contact resistance of e ″ decreases due to the above-mentioned pressurization, and the design resistance value of the bridge wire 4 ′ having the original length L ′ as the design length fluctuates due to the current flowing through the path i ′. Yes, to eliminate such defects,
As shown in (b) of FIG. 8, it is effective to weld the bridge wire and the lead pin tip end face including the lead pin tip end face edge position e ′ to obtain the design length L. However, in this case, in order to use the above-mentioned welding method, the outer diameter of the welding electrode 51 'is made considerably larger than the welding length b'of the bridge wire, and a part of the welding electrode 51' is connected to the lead pin tip. It is advantageous to make it protrude from the end surface (it is difficult to recognize the boundary between the upper surface of the plug 1'and the tip end surface of the lead pin 2'because both are color-approximated). Yes, and therefore
(It is not easy to match the edge of the welding electrode end surface with the edge of the lead pin tip surface), and it is not possible to abut a pair of welding electrodes with such a large outer diameter on the tip end surface of the lead pin of the embolus shown in the figure. It is difficult (the embolism disclosed in Japanese Patent Laid-Open No. 5-133698 presupposes that the cross-sectional area of the lead pin is the same as that of the conventional circular lead pin even if the lead pin is non-circular). It is difficult to apply the welding method.

An object of the present invention is to provide a plug with a pair of lead pins, a bottomed metal cylinder containing an ignition plug, which is an embolus formed by welding a bridge wire between the tip end faces of the lead pins. When manufacturing the detonator by inserting it inside, the direction of the lead pin insertion hole should be eliminated without adjusting the cross angle of the bridge line between the lead pin tip end faces, An object of the present invention is to provide an embolus capable of stably setting the resistance value of a bridge wire to a desired value within a wide range without being affected by the pressure applied by an ignition agent and a manufacturing method thereof.

[0007]

The detonator embolus according to the present invention is for a detonator in which an electric bridge wire is joined between the tip end faces of the lead pins of an insulating plug body having a pair of lead pins penetrating therethrough. In the embolus, a circular collar portion is formed at the tip of each lead pin, and the ratio of the shortest distance Lmin between the collar portions to the distance L ₀ between the centers of both collar portions is L ₀ /
Lmin is set to 2.5 or more, and the bridge wire and the surface of the collar portion are joined together including the edge portion of the collar portion. A method of manufacturing a detonator embolus according to the present invention comprises a pair of leads.
Weld the tip end face of each lead pin of the insulation plug body that penetrates the lead pin and each end part of the bridge wire to connect the bridge line between the tip end faces of both lead pins to form the detonator plug. In the manufacturing method, a circular collar portion is formed at the tip of each lead pin,
The ratio L ₀ / Lmin of the shortest distance Lmin between the collars and the distance L ₀ between the centers of both collars is set to 2.5 or more, and one welding electrode of the resistance welding machine is brought into contact with the end of the bridge wire, And, it is arranged so as to partially protrude from the edge of the collar portion, and the other welding electrode is brought into direct contact with the collar surface to perform resistance welding between each bridge wire end portion and each collar surface. The configuration is characterized by.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1A is a sectional view showing the detonator embolus according to the present invention, and FIG. 1B is a plan view of the same. In FIG. 1A and FIG. 1B,
Reference numeral 1 is an insulating plug, for example, a ceramic plug. 2,
Reference numeral 2 denotes a pair of lead pins, each having a circular flange portion 21 formed at the upper end, and the thickness of the flange portion 21 is thicker toward the center of the flange portion. Reference numeral 3 is a lead pin through hole provided in the insulating plug body, and a hole on one end face of the plug body is a taper hole 31, and the lead pin 2 is inserted into each through hole 3 to form a taper hole 31. A sealant 32 such as glass or epoxy resin is sealed between the back surface of the collar portion 21 and the back surface. The outer diameter d of the collar 21 is L ₀ > d ≧ with respect to the distance L ₀ between the centers of both flanges (the distance between the lead pin centers) L _0.
0.6L ₀ , the shortest distance Lmin between the collars and the distance L
The ratio L ₀ / Lmin of ₀ is set to 2.5 or more. 4 is Lee
It is a bridge line welded between the flange portions 21 and 21 of the dopins 2 and 2. It is welded from the edge position e of the flange portion to the vicinity of the center of the flange portion 21 and is extremely small at the end of the bridge line 4. The length is as non-welded. It is appropriate that the welding length b is 5 to 10 times the outer diameter of the bridge wire in order to guarantee the welding strength.
In the above description, the collar portion 21 at the tip of the lead pin may have the same thickness as shown in FIG.

For the bridge wire 4, simple metals such as iron, nickel, molybdenum, platinum, tungsten and tantalum, and alloys such as nickel-chromium and iron-chromium-aluminum can be used. The lead pin 2 is made of a material that can be easily connected to a bridge wire and easily sealed with the plug 1 such as glass or epoxy resin.
A single metal such as iron, nickel, or copper, or an alloy such as nickel-iron system can be used.

FIG. 3 is an explanatory view showing a method of manufacturing a detonator embolus according to the present invention. The structure of the embolus is the same as that shown in FIGS. 1 (a) and 1 (b). -After sealing with a solid sealant 32 such as glass between the hole 31 and the back surface of the collar portion 21, one welding electrode 51 of the resistance welding machine is brought into contact with the bridge wire end portion 40. And is arranged in a state of partially protruding from the edge e of the collar portion 21, and the other welding electrode 52 is brought into direct contact with the surface of the collar portion 21 so that each bridge wire end portion 40 and each collar portion. 21 Resistance welding is performed between the surface and the surface.

FIG. 4 shows an outline of the current distribution state of the welding current in this case. The welding electrode 51 in contact with the bridge wire end 40 is a positive electrode, and from the flange edge e of this electrode 51. Since the sum of the currents flowing into the bridge line 4 from the protruding portion 510 becomes the bridge line welding current at the brim edge position e,
In order to guarantee the welding strength of the bridge wire 4 at the flange edge position e, the length of the protruding portion 510 from the flange edge e of the positive welding electrode 51 is made considerably large so that the welding current is sufficient. It is necessary to make it large (overhang length is appropriate to be at least 5 times the outside diameter of the bridge wire). On the other hand, it is appropriate that the welding length b of the bridge wire 4 is at least 5 times or more the outer diameter of the bridge wire in order to guarantee the welding strength, as described above. Therefore, the outer diameter of the welding electrode 51 is
It is appropriate that the outer diameter is at least 10 times or more.
However, the outer diameter d of the collar 21 is L ₀ > d ≧ 0.6L _{0 with} respect to the distance L ₀ between the centers of both flanges (the distance between the lead pin centers) L _0.
Since it is sufficiently large, even with a pair of welding electrodes having such a large outer diameter, the minus side welding electrode 52 can be satisfactorily welded by contacting the minus side welding electrode 52 with a sufficient area on the upper surface of the collar portion (for example, reel When the outer diameter of the dopin is 1.0 mm, L ₀ is usually 3.0 mm, so the minimum diameter of the collar is 1.8.
mm. The diameter of the bridge wire is usually 0.03 mm, so that the minimum outer diameter of the welding electrode is 1.0 mm. Even if a pair of welding electrodes having such a diameter are brought into contact with the upper surface of the brim having an outer diameter of 1.8 mm in the arrangement as shown in FIG. 4, the contact area between the negative welding electrode 52 and the upper surface of the brim portion 21 can be sufficiently secured.

In the detonator embolus according to the present invention, the ratio L ₀ of the shortest distance Lmin between the collar portions and the distance L ₀ between the centers of both the collar portions.
/ Lmin is 2.5 or more, and as shown in (b) of FIG. 1, even if the bridge line 4 is parallel to the center line OO passing through the centers of both lead pins, the minimum effective bridge Line length (both leads
The ratio between the minimum distance between the flange edges of the doping pin and the maximum effective bridge wire length can be set to 2.5 or more. Therefore, with the resistance value of the minimum effective bridge wire length as the reference value, this reference resistance value And that 2.5
A desired resistance value can be set within the range of a resistance value that is twice or more.

FIG. 5 shows a detonator using an embolus according to the present invention. A metal end plate 61 is fixed to the end of the plug 1 with a sealing agent 62 such as glass or epoxy resin, and one lead pin is used. 2a and the metal end plate 61 are hermetically sealed by welding 63 and electrically connected, and the other lead pin 2b and the metal end plate 61 are insulated by a gap 64. ,
The metal wire is inserted into the bottomed thin-walled metal cylinder 72 containing the ignition powder 71 at the bottom to bring the electric wire 4 into close contact with the ignition powder 71, and the metal end plate 61.
The peripheral skirt portion 610 and the mouth of the bottomed thin metal tube 72 are hermetically sealed by welding 73 and electrically connected.

FIG. 6 shows another example of the detonator using the embolus according to the present invention. A metal end plate 61 is brought into contact with the end portion of the plug body 1, and one lead pin 2a and the metal end plate 61 are connected to each other. Is welded 63 to be airtight and electrically conductive, and the other lead pin 2b, the metal end plate 61 and the plug 1 are sealed with an insulating seal material (glass, epoxy resin, etc.) 62. At the same time, the other lead pin 2b and the metal end plate 61 are insulated from each other, and this embolus A has a bottomed thin-walled metal cylinder 7 in which the ignition agent 71 is stored at the bottom.
2 and the electric bridge wire 4 is brought into close contact with the ignition powder 71, and the peripheral skirt portion 610 of the metal end plate 61 and the bottomed thin-walled metal cylinder 72.
The opening is hermetically sealed by welding 73 and electrically connected. As shown in the figure, the metal end plate 5 is
In addition to having a lead pin insertion hole with a boss that has an inner diameter approximately equal to the outer diameter of the lead pin and a lead pin insertion opening that has an inner diameter that is larger than the outer diameter of the lead pin, an inner diameter that is larger than the outer diameter of the lead pin. It is also possible to use one having two lead pin insertion openings with the same boss. In this case, before or during welding, the tip of one of the bosses may be squeezed to be approximately equal to the outer diameter of the lead pin and then welded.

In any of these detonators, generation of a potential difference due to electrostatic induction between the thin metal cylinder and the lead pin is prevented, and the risk of explosion due to the discharge of the potential difference can be reliably eliminated. In any of the above detonators, the bridge wire is pressurized with the ignition powder, but since the bridge wire and the lead pin flange surface are welded including the flange edge position,
The electric conductance between the bridge wire and the surface of the lead pin collar is kept constant without being affected by the pressing force,
The set resistance value of the bridge line can be reliably maintained.

[0016]

In the detonator embolus according to the present invention, the resistance value of the bridge wire can be set in a wide range by joining the bridge wire between the tip end faces of the lead pins without adjusting the cross angle. Since the bridge wire can be easily joined and the lead pin is circular over the entire length, the lead pin can be easily inserted into the plug body without any restriction on the directionality. Further, since the lead pin can be thinned except for the upper end, the wall thickness can be made sufficiently thick without increasing the outer diameter of the plug body, and the plug body can be downsized and mechanically high strength can be well ensured.

Further, according to the method of manufacturing the detonator embolus according to the present invention, the bridging wire and the surface of the lead pin collar portion are joined to each other by the method described in JP-A-5-172498. The detonator embolism that can be easily performed including the position and that can stably maintain the set resistance value of the bridge wire regardless of the pressurization of the bridge wire by the ignition powder, is installed between the lead pin and the plug body. −
It can be easily manufactured without fear of thermal deterioration of the interface or damage to the bridge wire.

[Brief description of the drawings]

1 (a) is a sectional view showing a detonator embolus according to the present invention, and FIG. 1 (b) is a plan view of the same.

FIG. 2 is an explanatory view showing another example of the circular collar portion of the lead pin of the detonator embolus according to the present invention.

FIG. 3 is an explanatory diagram showing a method of manufacturing an embolus for a detonator according to the present invention.

FIG. 4 is an explanatory view showing a distribution state of welding current in the method for manufacturing the detonator embolus according to the present invention.

FIG. 5 is an explanatory view showing an example of a detonator using the embolus according to the present invention.

FIG. 6 is an explanatory view showing another example of the detonator using the embolus according to the present invention.

FIG. 7 is an explanatory view showing a conventional method for manufacturing a detonator embolus.

FIG. 8 is an explanatory diagram showing instability of the resistance value of a bridge wire of a conventional detonator embolus.

[Explanation of symbols]

 1 Plug 2 Lead pin 21 Circular brim e Edge of brim 4 Edge bridge line

Claims (2)

[Claims] 1. A detonator embolus in which an electric bridge wire is joined between the tip end faces of the lead pins of an insulating plug body having a pair of lead pins penetrating therethrough, wherein a circular collar portion is provided at the tip of each lead pin. And the ratio L ₀ / Lmin of the shortest distance Lmin between the collars to the distance L ₀ between the centers of both collars is 2.5 or more, and the bridge wire and the surface of the collar are joined together at the edge of the collar. Embolus for detonator characterized by being performed including the position. 2. An electric bridge is provided between the tip end faces of both lead pins by welding the tip end faces of the lead pins of the insulation plug body having a pair of lead pins penetrating the respective end portions of the bridge wires. In the method of manufacturing a detonator embolus by connecting wires, a circular collar portion is formed at the tip of each lead pin, and the ratio L ₀ between the shortest distance Lmin between the collar portions and the distance L ₀ between the centers of both collar portions is L _0. / Lmin is 2.5 or more, and one of the welding electrodes of the resistance welding machine is placed in contact with the end portion of the bridge wire and partially protruded from the edge of the collar portion, and the other welding electrode is placed. A method for manufacturing an embolus for a detonator, comprising directly contacting a flange surface with each other to perform resistance welding between each bridge wire end and each flange surface.