JPH0587496A - Method for welding inner and outer metallic cylinders - Google Patents

Abstract

PURPOSE:To enable a contact length between an inner metallic cylinder and an outer metallic cylinder at a part of penetration under an irradiation of laser to be elongated and to improve an air-tightness by a method wherein one end of the inner metallic cylinder is formed with a flange directed outwardly and terminated at a middle part of thick wall part of an end surface at one end of the outer metallic cylinder. CONSTITUTION:One end 31 of an inner metallic cylinder 3 is formed with a flange (a) directed outwardly and terminated at the midway part of thick wall of an end surface 610 of an outer metallic cylinder 61 in advance. An ignition element A is inserted into an opening of one end 61 of the outer metallic cylinder and irradiated with a laser (b) at an interface between the flange (a) at one end 31 of the inner metallic cylinder and an end surface 610 of one end 61 of the outer metallic cylinder. With such an arrangement, if a height (h) of the flange (a) is set to cause metal penetration depth to reach the contact interface surface 63 between the inner surface of the metallic outer cylinder and the outer surface of the metallic inner cylinder, the inner and outer cylinders can be contacted at a right angled bending line within the metal penetration range, and the contacting length of the inner and outer cylinders can be correspondingly elongated. With such an arrangement, an air-tightness can be improved more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding of an inner and outer metal cylinder for hermetically sealing by welding between one end of a metal inner cylinder inserted into one end of a metal outer cylinder and one end of the metal outer cylinder. It is about the method.

[0002]

2. Description of the Related Art It is sometimes required to hermetically seal and fix one end of a metal inner cylinder inserted into one end of a metal outer cylinder and one end of the metal outer cylinder by welding. An example is shown.

FIG. 1 shows an example of an electric detonator, which includes a pair of leads.
The lead pins 2 and 2 are inserted into the ceramic plug body 1 having the dope pin insertion hole, the metal inner cylinder 3 is arranged in the rear portion of the ceramic plug body 1, and the glass is placed in the metal inner cylinder 3. 4 is sealed and an electric bridge wire 5 is bridged between the ends of the lead pins to create an ignition component A, and an additive 71 and a detonator 72 are placed in a metal outer cylinder 6 that is open at one end and closed at the other end. , The cup-loaded ignition charge 73 is sequentially loaded, and finally, the ignition component A is inserted into the one end opening 61 of the metal outer cylinder 6, and the end 61 of the metal outer cylinder 6 and the metal of the ignition component A are inserted. The one end 31 of the inner cylinder 3 is hermetically sealed and fixed.

The above-mentioned electric detonator is intended to stabilize the characteristics over a long period of time, and has a metal outer cylinder 6
It is required to use a welding method for sealing and fixing the one end 61 and the one end 31 of the metal inner cylinder 3.

Since the welding is carried out with the explosive and the ignition charge contained in the metal outer cylinder 6, it is necessary to use a welding method capable of performing welding in a short time, and the energy density is extremely high. Laser by irradiation of laser, which is a high and powerful concentrated heat source
The welding method is suitable.

[0006]

However, in fixing the one end of the metal outer cylinder and the one end of the metal inner cylinder in the above electric detonator, a strict airtightness is required to maintain the ignition characteristics of the ignition charge. However, it is difficult to achieve such a high degree of airtightness, which is required by the usual laser welding method.

An object of the present invention is to provide a welding method for an inner and outer metal cylinder in which one end of a metal outer cylinder and one end of a metal inner cylinder in an electric detonator can be sealed and fixed by laser welding with excellent airtightness. Especially.

[0008]

SUMMARY OF THE INVENTION A welding method for an inner / outer metal cylinder according to the present invention is a laser between one end of a metal inner cylinder inserted into one end of a metal outer cylinder and one end of the metal outer cylinder. In the method of hermetically sealing by welding, a flange is formed at one end of the metal inner cylinder, which is directed outward, and which terminates in the middle of the wall thickness of the end face of the metal outer cylinder, and the flange and the metal outer cylinder. The laser irradiation is applied to the boundary with one end face.

[0009]

A flange is formed at one end of the metal inner cylinder toward the outside and terminates in the middle of the wall thickness of one end of the metal outer cylinder. Therefore, the inner and outer cylinders at the portion melted by laser irradiation. Since the contact length of the metal material can be increased and the long contact length portion can be welded, the airtightness can be increased.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electric detonator. In FIG. 1, reference numeral A denotes an ignition part, in which lead pins 2 and 2 are inserted into a ceramics plug body 1, a metal inner cylinder 3 is arranged at the rear portion of the ceramics plug body 1, and the metal inner cylinder is provided. The inside of 3 is sealed with glass 4, and an electric bridge line 5 is bridged between the ends of the lead pins 2 and 2. Reference numeral 6 denotes a metal outer cylinder, and the ignition component A is inserted into the one end opening 61 of the metal outer cylinder.

According to the present invention, one end 6 of the metallic outer cylinder 6 is
In order to seal and fix 1 and one end 31 of the metal inner cylinder 3, as shown in FIG. 2, the end face 610 of the metal outer cylinder one end 61 is directed toward the one end 31 of the metal inner cylinder 3 toward the outside. A collar a terminating in the middle of the wall thickness is formed in advance, and after the ignition component A is inserted into the opening of the metal outer cylinder one end 61, the collar a of the metal inner cylinder one end 31 and the metal outer cylinder one end are formed. The laser b is applied to the boundary between the end face 610 of the reference numeral 61 and the end face 610.

In FIG. 2, assuming that the inside of the dotted line frame is the melting range of metal due to laser irradiation, the contact interface between the inner cylinder metal material and the outer cylinder metal material within this melting range is welded,
The longer the welded length of the contact interface is, the more effective the airtightness is.

Thus, the laser to the boundary between the flange a of the one end 31 of the metal inner cylinder and the end face 610 of the one end 61 of the metal outer cylinder.
If the height h of the brim a is set so that the penetration depth of the metal due to irradiation reaches the contact interface 63 between the inner surface of the metal outer cylinder and the outer surface of the metal inner cylinder, the inner and outer cylinders are set within the melting range of the metal. Since the materials can be contacted with a right-angled bending line, and the contact length of the inner and outer cylinder materials within the metal penetration range can be lengthened by that much (this is the case when the collar is not provided at one end of the metal inner cylinder as shown in FIG. 2 above). It is also clear from the comparison with Fig. 3. In Fig. 2 and Fig. 3, the dotted line frame shows the melted range of equal size), and the airtightness can be strengthened accordingly.

The height h of the collar a is set according to the material of the inner and outer cylindrical members and the laser output. For example, if the material of the metal outer cylinder and the material of the metal inner cylinder are both stainless steel,
In case of AG laser and output of 40W, the height of tsuba is 0.1m
It is set to m to 1.0 mm.

[0016]

The welding method for the inner and outer metal cylinders of the present invention is configured as described above, and is between the one end of the metal inner cylinder inserted into one end of the metal outer cylinder and the one end of the metal outer cylinder. The
In the case of sealing and fixing by the welding, it is possible to enhance the airtightness of the welded portion only by forming a collar on one end of the metal inner cylinder in advance. Therefore, the present invention is useful for sealing and fixing one end of the metal inner cylinder and one end of the metal outer cylinder of the ignition member of the electric detonator shown in the figure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an electric detonator in which one end of a metal inner cylinder and one end of a metal outer cylinder are sealed and fixed according to the present invention.

FIG. 2 is an explanatory diagram showing the present invention.

FIG. 3 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 3 Metal Inner Cylinder 31 Metal Inner Cylinder One End a Tsuba 6 Metal Outer Cylinder 61 Metal Outer Cylinder One End 610 Metal Outer Cylinder One End Face

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Yoshida 3153-15, Gion, Tomicho, Himeji-shi, Hyogo Prefecture (72) Inventor Ayumu Kimura 690-1, Gion, Tomicho, Himeji-shi, Hyogo Prefecture

Claims (1)

[Claims] 1. A method for hermetically sealing the space between one end of a metal inner cylinder inserted into one end of the metal outer cylinder and one end of the metal outer cylinder by laser welding. A flange is formed at one end of the cylinder, which is directed outward and terminates in the middle of the thickness of the end surface of the one end of the metal outer cylinder, and a laser is irradiated to the boundary between this flange and the one end surface of the metal outer cylinder. A method for welding inner and outer metal cylinders characterized by the above.