Electric fireworks igniters

Abstract

To provide an electric ignition tool for firework which improves inflammation property to an explosive device for inflammation or blasting-off explosive by suppressing spreading of a flame to a rear side of the ignition tool when the electric ignition tool is ignited.SOLUTION: An electric ignition tool comprises: an igniter holding cylinder consisting of a resin material or a rubber material; a powder-state or granule-state igniter; and an embolization with bridge which closes the igniter holding cylinder and that a lead wire transferring ignition energy penetrates. The electric ignition tool is fixed to an explosive device for inflammation or a direct blasting-off explosive for firework, and ignited. In the electric igniter for firework, the igniter holding cylinder is fixed to the embolization with bridge in such a manner that a circuit is adhered with the igniter, the igniter holding cylinder is bottomed and has a structure that the vicinity of a bottom plate part and / or a peripheral edge sidewall part bursts by ignition power, and the igniter is a composition containing a metal oxide, a single body metal reductant and magnalium alloy.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric igniter for fireworks. [Background technology]

[0002] In the past, the most common methods for igniting fireworks and other pre-fired fireworks at firework consumption sites have been for a person to directly place a fire into a firing tube with a spark, or, in the case of quick firing, for a firework to be launched by dropping a firework with a firing charge into a metal in the tube. In recent years, for the purposes of ensuring safety during ignition and improving the aesthetic effect of firing in sync with music, there has been an increase in the use of remote ignition by electrical ignition, such as directly igniting a fire-transfer pyrotechnic device such as a quick-fire wire or fuse, or a firing charge such as small black powder pellets, using a matchhead-shaped igniter and an igniter or an ignition system linked to a computer.

[0003] In such electric ignition methods, the connection work and launch preparation are carried out by, for example, fixing an ignition ball to a fire-transfer pyrotechnic connected to the firework ball at the fireworks consumption location, or fixing an ignition ball to a launching powder measured in advance in a small bag, inserting it into a launching tube, and then putting the firework ball in. Furthermore, in order to prevent ignition errors due to the ignition ball slipping out, the ignition ball is generally fixed to the quick-ignition wire paper tube by making a notch in the end or middle of the tube, inserting it about 0.05 m to 0.1 m into the quick-ignition wire, and then fixing it in place with adhesive tape.

[0004] When fixing this ignition ball, the pyrotechnic device, particularly the rapid-ignition wire, has several cores made of cotton thread or similar material impregnated with black powder inserted into a single or double paper tube. When inserting the ignition ball, there is a risk that the black powder in the paper tube will come into direct contact with the ignition powder in the highly sensitive ignition ball, causing friction and resulting in ignition. Similarly, when inserting and fixing the ignition ball into the small bag containing the measured launching powder, the launching powder, such as small black powder pellets, will come into direct contact with the ignition powder. Furthermore, after the launching powder with the ignition ball attached is inserted into the launching tube, the weight load of the ball when the firework ball is inserted at the top, or the impact if it is accidentally dropped, will increase the friction between the black powder and the ignition powder, or increase the risk of ignition due to the load or impact.

[0005] The risk of frictional ignition when attaching an ignition ball to a fast-ignition wire has been pointed out, and ignition devices that use a cylindrical fixing device to seal the tip side have been known. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 6-30697 Summary of the Invention [Problem to be solved by the invention]

[0007] The inventors' research has revealed that with conventional electric ignition devices for fireworks, the flame force of the ignition charge when ignited is too strong, causing not only the tip (front) of the ignition charge holding cylinder but the entire ignition charge holding cylinder to burst, spreading the flame to the rear, and causing variations in the flame propagation properties of fire-transfer pyrotechnics and launching explosives. Therefore, an object of the present invention is to provide an electric igniter for fireworks that prevents the flame from spreading to the rear of the igniter when the electric igniter is ignited, and improves the ability to transmit fire to fire-transmitting pyrotechnics and launching explosives. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have completed the present invention as described below.

[0009] [1] An electric ignition device for fireworks, comprising an ignition charge holding cylinder made of a resin material or a rubber material, an ignition charge in powder or granular form, and a plug with an electric bridge through which a conductor that blocks the ignition charge holding cylinder and transmits ignition energy passes, and which is intended to be fixed to a pyrotechnic for transmitting fire to a firework or a direct launching charge for ignition, wherein the ignition charge holding cylinder is fixed to the plug with an electric bridge so that the bridge and the ignition charge are in close contact, the ignition charge holding cylinder has a bottom and is structured so that the bottom plate and / or the peripheral side wall portion near the bottom plate and / or the peripheral side wall portion will rupture due to the ignition force, and the ignition charge is a composition containing a metal oxide, a simple metal reducing agent, and a magnalium alloy. [2] The electric igniter for fireworks described in [1], wherein the metal oxide is ferric oxide and the elemental metal reducing agent is aluminum. [3] The electric igniter for fireworks according to any one of [1] to [2], wherein the ignition charge contains 50 to 75 mass % of metal oxide, 13 to 39 mass % of simple metal reducing agent, and 8 to 12 mass % of magnalium alloy. [4] The electric igniter for fireworks according to any one of [1] to [3], wherein the mass ratio of aluminum to magnesium in the magnalium alloy is 35:65 to 65:35. [5] The electric igniter for fireworks according to any one of [1] to [4], wherein the reaction start temperature of the ignition charge is 500°C to 600°C. [6] The electric igniter for fireworks according to any one of [1] to [5], characterized in that the friction sensitivity of the ignition charge is sensitivity class 7. [7] The electric igniter for fireworks according to any one of [1] to [6], characterized in that the flame spreads radially forward when ignited. [Effects of the Invention]

[0010] According to the present invention, when the tip of the ignition charge holding cylinder is positioned forward, the flame is prevented from spreading to the rear, and an electric ignition device for fireworks is provided which has improved flame transmission to fire-transmitting pyrotechnics and launching explosives. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below.

[0012] The present invention will be specifically described below, focusing on preferred embodiments thereof. 1 is a partially cutaway schematic diagram showing an electric igniter for fireworks or an electric igniter such as an electric fuse according to the present invention. The electric igniter comprises an ignition charge holding cylinder 3, an ignition charge 4, and a plug 5 with a bridge 2 welded to the tip, through which a pair of parallel coated conductor wires 1 pass. Electric energy is supplied from an igniter or an ignition system linked to a computer, which heats the bridge through the conductor wires 1 and ignites the ignition charge 4 around the bridge 2. The ignition charge 4 emits a high-temperature flame and heat accompanied by thermal particles, igniting a fire-transfer pyrotechnic such as a fast-firing wire or a fuse, or a launching explosive such as small black powder, to launch fireworks or ignite a fireworks set-up.

[0013] The bridge plug 5 is made of a thermoplastic resin such as polyethylene, polypropylene, polyvinyl chloride, or nylon, and the parallel conductor 1 that transmits ignition energy through the bridge plug 5 is a wire material such as copper or copper-plated iron coated with a resin such as Teflon (registered trademark), polyethylene, or polyvinyl chloride, and for this application, the core diameter is preferably in the range of 0.0004 to 0.0007 m. An electric bridge 2 made of a wire material such as platinum or nichrome is formed at the tip of the parallel conductor 1 by resistance welding, friction welding such as ultrasonic welding, or embedded with a hook pinch, maintaining a resistance suitable for the energy supplied by the igniter or ignition system.

[0014] The ignition charge 4, which is ignited by the heat generated by the bridge, is a reaction composition containing a mixture of a metal oxide, a simple metal reductant, and a magnalium alloy. The use of this mixture improves the ignition charge's ignition characteristics and reaction duration. Because almost no gas is generated when the ignition charge is ignited, the ignition charge holding cylinder is less likely to explode in all directions when the ignition device is ignited, as shown in Figure 2, and the flame tends to concentrate forward. Since the ignition charge's flame force is not too strong when the ignition device is ignited, the flame is prevented from spreading backward or laterally when the tip of the ignition charge holding cylinder is positioned forward. This produces a wide-angle flame while still concentrating forward, improving the speed and stability of flame propagation to launching charges and fire-transfer pyrotechnics. In addition, by concentrating the flames at the front, the speed and stability of the flame propagation to the launching explosives and pyrotechnics for flame propagation can be improved, and variations in the altitude of the launch can be suppressed, such as the occurrence of low-altitude launch of smoke bombs (the phenomenon occurs when the explosives ignites immediately after launch and before the bomb reaches its intended height).In addition, since this mixture does not fall under the category of explosives under the Explosives Control Act, it is easy to handle, including consumption and storage.

[0015] The metal oxide component of the ignition charge is preferably one or more compounds selected from the group consisting of chromium trioxide (Cr2O3), manganese dioxide (MnO2), iron sesquioxide (Fe2O3), iron oxide trioxide (Fe3O4), copper (II) oxide (CuO), and red lead (Pb3O4). From the standpoints of reaction safety, cost, and handling, it is more preferable to use iron sesquioxide (Fe2O3), iron oxide trioxide (Fe3O4), and copper (II) oxide (CuO).

[0016] The content of the metal oxide, which is a component of the above ignition charge, is preferably 50 to 75 mass % of the total ignition charge, and more preferably 60 to 70 mass %, from the viewpoint that the fire force when ignited by the electric ignition device is appropriate and the probability of the fire being transmitted to the launching charge when ignited by the electric ignition device is increased.

[0017] The elemental metal reducing agent may be any elemental metal that acts as a reducing agent, and is not particularly limited thereto. However, aluminum powder is preferred from the viewpoints of ease of availability and wide range of applications. The particle size of such an elemental metal reducing agent is preferably an average particle size in the range of 1 to 20 μm, more preferably in the range of 5 to 10 μm. If the particle size is larger than 1 μm, the combustion of the ignition charge becomes gentle. Furthermore, if the particle size is smaller than 20 μm, the combustion of the ignition charge improves.

[0018] The content of the simple metal reducing agent, which is a component of the above-mentioned ignition charge, is preferably 13 to 39 mass % of the total ignition charge, and more preferably 18 to 29 mass %, from the viewpoint that the fire momentum when ignited by the electric ignition device is appropriate and the probability of the fire being transmitted to the launching charge when ignited by the electric ignition device is increased.

[0019] The magnalium alloy is preferably an aluminum-magnesium alloy powder having an aluminum:magnesium mass ratio in the range of 35:65 to 65:35. The magnalium alloy preferably has an average particle size in the range of 0.1 to 250 μm, preferably 0.1 to 100 μm, and more preferably 1 to 50 μm. A particle size of 250 μm or less makes it difficult for some of the components of the ignition charge to scatter during combustion, and improves the ignition ability of the ignition charge. Furthermore, a particle size of 0.1 μm or more reduces the reactivity of the ignition charge, resulting in gentler combustion of the ignition charge.

[0020] The reaction initiation temperature of the ignition charge is preferably 500 to 600°C, more preferably 510 to 590°C, still more preferably 520 to 580°C, and particularly preferably 530 to 570°C, from the viewpoint that the ignition charge is less susceptible to thermal changes and is highly safe.

[0021] The reaction initiation temperature was determined by simultaneous differential thermal analysis (TG-DTA) using a 2.0 mg sample at a heating rate of 10°C / min in the temperature range of 25°C to 1000°C in an air atmosphere. The temperature at which the exothermic peak rose was taken as the reaction initiation temperature. The TG-DTA equipment used was a Hitachi High-Tech Science STA7200.

[0022] The friction sensitivity of the ignition charge is preferably class 7, from the viewpoint of safety during the manufacture of electric firework igniters and during work using electric firework igniters.

[0023] The friction sensitivity of the ignition powder was measured based on the Explosives Society standard "Friction Sensitivity Test (ES-22)."

[0024] FIG. 1 is a cross-sectional view showing an embodiment of an ignition charge holding cylinder 3. As shown in FIG. By making the ignition charge holding cylinder 3 have a bottom, the ignition charge 4 does not come into direct contact with the core charge of the pyrotechnics for flame transmission such as a fast-fire wire or a fuse, or with the launching charge such as small black powder pellets, thereby improving safety such as friction ignition, and if it is completely sealed, it also has the effect of preventing moisture from entering, allowing long-term performance to be maintained. The bottomed portion 6 is preferably made of the same material as the ignition charge holding cylinder 3 and molded integrally with it, but it is also possible to use a different resin material, rubber material, or paper material that is adhesively attached in advance in a separate assembly process.

[0025] The ignition charge holding cylinder 3 has a bottom, which provides a desirable effect of protecting the ignition charge, but simply having a bottom will inhibit the spread of flame, thereby impairing the original purpose of ignition performance. Therefore, as described below, it is necessary to provide a structure such as using a soft material, making it shaped to easily concentrate stress in a local area, or providing a difference in thickness to actively and stably create a part that is likely to rupture in the same place.

[0026] The ignition charge holding cylinder 3 is preferably formed by injection molding, and its material is preferably a soft thermoplastic resin or rubber material, such as ethylene-vinyl acetate copolymer, ethylene-based ionomer, styrene-based, polyester-based, or polyolefin-based elastomer, with ethylene-vinyl acetate copolymer or styrene-based elastomer being more preferred because they are particularly soft. While the evaluation scale for physical properties may vary slightly depending on the resin or rubber material, and characteristics may change with temperature, for example, in the room temperature range, the tensile strength is preferably in the range of 1 to 30 MPa, and the durometer type A hardness is preferably in the range of 1 to 100. In particular, with ethylene-vinyl acetate copolymer, the material becomes softer and more easily ruptured as the vinyl acetate content increases, so a range of 1 to 50 wt % is preferred, and a range of 10 to 40 wt % is more preferred.

[0027] While some known igniters have slightly tapered ends, such as the end of a cylindrical fixture, to facilitate insertion of the igniter into a fast-firing paper tube, the present invention prefers a shape that favors localized stress concentration, thereby providing a consistent, consistent burst. The bottom plate 6 of the ignition charge holding tube 3 is preferably obliquely inclined or tapered. Alternatively, the bottom plate 6 can be provided at a tapered apex, with an obliquely inclined, flat, or rounded portion. This shape favors localized stress concentration near the apex. In other words, a diagonally inclined bottom plate 6 concentrates bending stress at the acute-angled apex, while a tapered bottom plate concentrates bending stress around the central apex, thereby favoring bursting due to the ignition force. When the bottom plate 6 is inclined, the acute-angled apex is preferably angled between 40 and 80 degrees, more preferably between 60 and 70 degrees. When tapering, the central apex is preferably angled at an angle between 20 and 80 degrees, more preferably between 30 and 60 degrees, so that the tapered portion does not become too long.

[0028] In one embodiment, by making the bottom plate 6 of the ignition charge holding cylinder 3 thinner and the peripheral side wall 7 thicker to create a difference in thickness, stress can be concentrated around the bottom plate 6, particularly at the top of the bottom plate on the acute angle side, as described above, resulting in an effect of making the ignition charge holding cylinder 3 more likely to rupture. When the peripheral side wall 7 has a thickness of, for example, 0.0005 to 0.0015 m, the thickness of the bottom plate 6 is preferably at least 0.0005 m or less, more preferably 0.0003 m or less, to ensure that the ignition charge holding cylinder 3 is easily ruptured and is injection moldable. When molding the bottom plate 6 to a thin wall, careful selection of the conditions and thickness is important because pinholes may occur due to welds caused by incomplete molding, peeling from welding to the mold, or poor gas release, depending on the properties of the selected material, molding conditions, mold structure, etc.

[0029] In addition to the above, as one embodiment, by thinning not only the bottom plate portion 6 of the ignition charge holding cylinder 3 but also the peripheral side wall portion 8 that contacts the bottom plate as shown in Figure 1, it becomes possible to make the acute-angled bottom plate corners where stress is concentrated by the above-mentioned shape or the peripheral side wall portion 8 that contacts the bottom plate more prone to rupture. The difference in thickness between the thin-walled portion and the thick-walled portion is preferably within the above-mentioned range, but the thickness of the bottom plate portion 6 and the peripheral side wall portion 8 that contacts the bottom plate may or may not be the same.

[0030] Another method for making the injection-molded ignition charge-holding cylinder 3 more easily ruptured by ignition power by further thinning the wall is vacuum molding, a type of thermoplastic resin molding method in which a sheet-shaped material is heated and softened, and the air between the sheet and the mold is removed to create a vacuum. The thermoplastic resin used in this molding method is preferably amorphous or crystalline polyethylene terephthalate, polystyrene, polypropylene, or polyacrylonitrile, with polystyrene being more preferred because it can be molded into a thin wall. The original thickness of the sheet is preferably 0.001 m or less, more preferably 0.0007 m or less, and even more preferably 0.0004 m or less, so that the thickness after vacuum molding is even thinner than that of an injection-molded product, resulting in an effect of making the product more easily ruptured.

[0031] In order to make the area around the bottom plate 6 of the injection molded or vacuum molded ignition charge holding cylinder 3 or its surrounding areas more likely to rupture and improve ignition performance, it is desirable to make the cylinder 3 less likely to be scattered by the force of ignition, and it is preferable that the ignition charge holding cylinder 3 has a structure in which it is fixed to a plug 5 with an electric bridge.

[0032] As a method for fixing the ignition charge holding cylinder 3 to the plug with bridge 5, there are a method of bonding the fitting portion with an adhesive, or friction welding by ultrasonic waves or the like, a method of fixing with something that is easily plastically deformed like the tube mouth fastening of an electric detonator, a method of using a fastener to the fast-ignition wire like a known ignition device to prevent the ignition charge holding cylinder 3 from scattering, a method of increasing the fit strength between the fitting inner diameter of the peripheral side wall portion 7 of the ignition charge holding cylinder 3 and the fitting outer periphery of the plug with bridge 5, etc. However, there are also other methods that do not require additional components or joining equipment and do not increase the maximum outer diameter with the additional components. A more preferable and reliable method is to provide an unevenly molded portion called an undercut mold, in which at least one concave or convex portion is provided on the inside of the peripheral side wall portion 7 of the ignition charge holding cylinder 3 and one convex or concave portion is provided on the outer edge of the fitting portion of the bridge-equipped plug 5 so that each position corresponds to the other around the entire circumference, or to provide a structure in which an uneven pattern such as a roughened or embossed pattern is processed around the entire circumference on one or both of the two wall surfaces, thereby making assembly easier and more reliably preventing the ignition charge holding cylinder 3 from scattering, without the need for additional adhesive drying equipment, welding equipment, or other parts.

[0033] In addition, conventional ignition balls are produced by applying a wet or muddy ignition powder made with an organic solvent or the like in the form of a ball around the electric bridge formed at the tip of the parallel conductor that passes through the plug, and then drying it, which makes it difficult to adjust the amount of application and requires equipment such as drying equipment and exhaust devices.In contrast, with the electric igniter of the present invention, the ignition powder 4, which has already been produced in powder or granular form, is filled in a certain amount into the ignition powder holding cylinder 3 using a measuring machine and then combined with the plug with an electric bridge 5, so there are fewer steps and it is easy to produce.

[0034] As mentioned above, the rapid-fire wire, a pyrotechnic device for flame transmission, is a paper tube made of single or double layers of thin paraffin paper or the like, into which several wicks made of cotton thread or the like impregnated with black powder penetrate. The paper tube has an inner width of approximately 0.01 m and a circumference of approximately 0.02 m, which translates to a diameter of 0.0065 m when converted to a cylinder. Because several wicks penetrate the paper tube as described above, if the electric igniter is cylindrical, the maximum outer diameter, including the ignition charge holding cylinder 3 and the bridge plug 5, is preferably 0.005 m or less, more preferably 0.0045 m or less, and even more preferably 0.004 m, which allows for smooth insertion of the rapid-fire wire, reduces friction with the wick, and ensures safety. Furthermore, a cylindrical shape is preferred for the electric igniter, as this reduces directional constraints in mass production, but an elliptical cylindrical or prismatic shape is also acceptable. In this case, when the bridge plug 5 and the ignition charge holding cylinder 3 are fitted together, it is necessary to restrict both in all three axial directions.

[0035] The ratio (L / D) of the length L to the maximum outer diameter D of the ignition charge holding cylinder 3 shown in Figure 1 is preferably in the range of 0.7 to 6.0 within the aforementioned outer diameter range, so that the cylinder has a vertically elongated cylindrical shape. When the cylinder is tapered, the length L refers to the length from the top to the end, and similarly when the cylinder is inclined as shown in Figure 1, it refers to the length from the top to the end. For example, an example of a minimum of 0.7 can be considered as the case of the maximum diameter and the minimum charge amount, and when the maximum outer diameter D is 0.005 m, the length L is 0.0035 m. As mentioned above, in order to make the area around the bottom plate 6 of the ignition charge holding cylinder 3 or its surrounding areas more prone to rupture and to improve ignition performance, it is desirable to make the cylinder 3 less likely to fly apart due to the force of ignition.In order to increase the fit strength between the inner diameter of the fitting portion of the peripheral side wall 7 of the cylinder 3 and the outer peripheral edge of the fitting portion of the bridge plug 5, or to fix it by providing an undercut molding portion, a fitting length is required, and it is preferable that it be 0.003 m or more.

[0036] The length of 0.0035 m, which is an example of an L / D ratio of 0.7, takes into account the length of the fitting margin. The remaining 0.0005 m of length is where the ignition charge 4 is enclosed, making the vertically elongated cylindrical shape preferable. On the other hand, an example of a maximum L / D ratio of 6.0 is considered to be the case with the minimum diameter and maximum charge amount. When the outer diameter D is 0.004 m, the length L is 0.024 m. In this case, the length of the fitting margin is also taken into account, and the length of the fitting margin is preferably 0.5 to 1.5 times the length of the chamber in which the ignition charge 4 is enclosed. Therefore, the length L of the ignition charge holding cylinder 3 is preferably 1.5 to 2.5 times the length of the chamber, which is the sum of the chamber length and the fitting margin. In this example, when the length is 1.5 times the chamber length, the chamber length is 0.016 m and the fitting margin is 0.008 m. In other words, the length of the fitting margin, which is formed by applying an undercut molding portion or the like to make the ignition charge holding cylinder 3 less likely to scatter, is preferably at least 0.003 m, and the ratio (L / D) of the length L of the ignition charge holding cylinder 3 to the maximum outer diameter D, taking into consideration 0.5 to 1.5 times the length of the chamber, is preferably in the range of 0.7 to 6.0, and the ignition charge holding cylinder is preferably a vertically elongated cylinder. [Example]

[0037] The present invention will be described based on examples.

[0038] [Example 1] The ignition charge holding cylinder 3 is injection molded from ethylene vinyl acetate copolymer resin and has the shape shown in FIG. 1 , in which the cylinder has an outer diameter of 0.004 mm, the top angle of the bottom plate 6 is inclined at 70 degrees, the thickness of the peripheral side wall 7 is 0.0005 mm, the thickness of the peripheral side wall 8 in contact with the bottom plate is 0.0003 m, and the thickness of the bottom plate 6 is 0.0002 m, giving a difference in thickness. The ignition charge holding cylinder 3 is filled with 65 mass % of iron sesquioxide (Toda Pigment Co., Ltd., Todacolor 100ED, average particle size 0.1 μm) as a metal oxide and aluminum (Yamaishi Metal Co., Ltd., 20 mg of ignition powder 4, which was a mixture of 25 mass% of VA-2000 (manufactured by Co., Ltd., average particle size 5-10 μm) and 12 mass% of magnalium alloy (manufactured by Marunaka Metals Co., Ltd., Al:Mg=50:50 (mass%), average particle size 45 μm), was weighed out and placed in the chamber. An electric igniter was assembled by fitting and joining a plug 5 with a bridge, which had a platinum wire bridge 2 cross-linked by ultrasonic welding, to the tip of a cylindrical plug made of polyethylene resin with an outer diameter of 0.004 mm and through which a parallel conductor 1 coated with vinyl chloride resin had passed, at the portion where they had been previously undercut.

[0039] [Example 2] An electric igniter was assembled in the same manner as in Example 1, except that 61 mass % of ferric oxide was used as the metal oxide, 27 mass % of aluminum as the elemental metal, and 12 mass % of magnalium alloy were used.

[0040] [Example 3] An electric igniter was assembled in the same manner as in Example 1, except that 69 mass % of ferric oxide was used as the metal oxide, 19 mass % of aluminum as the elemental metal, and 12 mass % of magnalium alloy were used.

[0041] [Example 4] An electric igniter was assembled in the same manner as in Example 1, except that 63 mass % of ferric oxide was used as the metal oxide, 27 mass % of aluminum as the elemental metal, and 10 mass % of magnalium alloy were used.

[0042] [Example 5] An electric igniter was assembled in the same manner as in Example 1, except that 69 mass % of ferric oxide was used as the metal oxide, 21 mass % of aluminum as the elemental metal, and 10 mass % of magnalium alloy were used.

[0043] [Example 6] An electric igniter was assembled in the same manner as in Example 1, except that a magnalium alloy (Al:Mg=35:65 (mass %)) was used.

[0044] [Example 7] An electric igniter was assembled in the same manner as in Example 1, except that a magnalium alloy (Al:Mg=65:35 (mass %)) was used.

[0045] [ reference example 1 ] An electric igniter was assembled in the same manner as in Example 1, except that a magnalium alloy (Al:Mg=70:30 (mass %)) was used.

[0046] [ reference example 2 ] An electric igniter was assembled in the same manner as in Example 1, except that a magnalium alloy (Al:Mg=30:70 (mass %)) was used.

[0047] [ reference example 3 ] An electric igniter was assembled in the same manner as in Example 1, except that 51 mass % of ferric oxide was used as the metal oxide, 37 mass % of aluminum as the elemental metal, and 12 mass % of magnalium alloy were used.

[0048] [ reference example 4 ] An electric igniter was assembled in the same manner as in Example 1, except that 74 mass % of ferric oxide was used as the metal oxide, and 14 mass % of aluminum and 12 mass % of magnalium alloy were used as the elemental metals.

[0049] [ reference example 5 ] An electric igniter was assembled in the same manner as in Example 1, except that 48 mass % of ferric oxide was used as the metal oxide, and 40 mass % of aluminum and 12 mass % of magnalium alloy were used as the elemental metals.

[0050] [ reference example 6 ] An electric igniter was assembled in the same manner as in Example 1, except that 77 mass % of ferric oxide was used as the metal oxide, 11 mass % of aluminum as the elemental metal, and 12 mass % of magnalium alloy were used.

[0051] [Comparative Example 1] An electric igniter was assembled in the same manner as in Example 1, except that 55% by mass of lead thioxanate, 43% by mass of potassium chlorate, and 2% by mass of zirconium were used as the ignition charge.

[0052] [Ignition test] An ignition test of the electric igniter was carried out, and the flame diffusion and intensity of the electric igniter flame were photographed and observed with a video camera.

[0053] [Black powder ignition test] In addition, 1 g of small black powder pellets was weighed out and placed in a paper bag, and the electric ignition device was pushed into the bag to the extent that the plug 5 with an electric bridge was hidden, and the end of the bag was fixed with paper adhesive tape, and 200 ignition tests were carried out.

[0054] [Fast-fire wire ignition test] An electric igniter was inserted 0.05 m into the end of a 0.3 m long paper tube of rapid-ignition wire and fixed with paper adhesive tape, and 200 ignition tests were conducted.

[0055] The test results are shown in Table 1.

[0056] [Table 1]

[0057] As described above, in the embodiments, the friction sensitivity of the ignition charge is low and the reaction initiation temperature is high, making it safe to use, generating almost no gas when ignited, and as shown in Figure 2, when the tip of the ignition charge holding cylinder is positioned forward, the flame spreads radially forward and at a wide angle, preventing the flame from spreading rearward or to the sides or lateral directions, providing an electric igniter for fireworks that provides stable flame propagation to the launching charge and rapid-fire line. On the other hand, in Comparative Example 1, the frictional sensitivity of the ignition charge was high and the reaction initiation temperature was low, resulting in low safety during operation, and a large amount of gas was generated upon ignition. As shown in Figure 3, when the tip of the ignition charge holding cylinder was positioned forward, the flame spread to the rear and side / lateral directions, and it was confirmed that the flame did not spread stably to the launching charge or the rapid-fire line. [Brief explanation of the drawings]

[0058] [Figure 1] 1 is a partially cutaway schematic diagram of an electric igniter according to the present invention. [Figure 2] This is a photograph showing how, when the electric igniter of the present invention is fixed with the front facing upward and ignited, the flame is prevented from spreading to the rear, sides, and lateral directions of the igniter. [Figure 3] This is a photograph showing the flame extending slightly to the side and rear of a conventional electric igniter when the front of the igniter is fixed facing upward and ignited. [Explanation of symbols]

[0059] 1 conductor 2 electric bridge 3Ignition powder holding cylinder 4-point gunpowder 5 Embolization with electric bridge 6 Bottom plate of the gunpowder holding cylinder 7. Peripheral side wall of the ignition charge holding cylinder 8. Peripheral side wall portion in contact with the bottom plate of the ignition charge holding cylinder

Claims

1. 1. An electric igniter for fireworks, comprising an ignition charge holding cylinder made of a resin material or a rubber material, an ignition charge in a powder or granular state, and a plug with an electric bridge that closes the ignition charge holding cylinder and has a conductor that transmits ignition energy passing through it, the electric ignition device being intended to be fixed to a pyrotechnic device for transmitting fire to a firework or a direct-launching explosive for ignition; the ignition charge holding cylinder is fixed to the plug with an electric bridge so that the bridge and the ignition charge are in close contact with each other; the ignition charge holding cylinder has a bottom and is structured so that the bottom plate and / or the vicinity of the peripheral side wall are ruptured by the force of ignition; the ignition charge is a composition containing 60 to 70 mass % of ferric oxide, 18 to 29 mass % of aluminum, and 8 to 12 mass % of magnalium alloy, and the magnalium alloy has an aluminum:magnesium mass ratio of 35:65 to 65:

35.

2. 2. The electric igniter for fireworks according to claim 1, wherein the reaction start temperature of the ignition charge is 500°C to 600°C.

3. 3. The electric igniter for fireworks according to claim 1, wherein the friction sensitivity of the ignition charge is class 7.

4. 4. The electric igniter for fireworks according to claim 1, wherein the flame spreads radially forward when ignited.

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