Electric igniter for fireworks

Abstract

To provide an electric ignition tool for firework which inhibits flame from extending far behind the ignition tool upon ignition of the electric ignition tool, and has an improved inflammation character with respect to an explosive device for inflammation and a blasting-off explosive.SOLUTION: An electric ignition tool for firework is fixed on an inflammation explosive device for ignition or fixed directly on a blasting-off explosive, so as to be used for igniting the firework, and comprises: an igniter holding cylindrical body made from a resin material or a rubber material; igniter in a powder or particle state; and a plug with a bridge circuit, which plugs the igniter holding cylindrical body to transmit ignition energy, and through which a lead wire is disposed. Therein: the igniter holding cylindrical body is fixed on the plug with the electric circuit such that the electric circuit and the igniter contact closely, the igniter holding cylindrical body has a structure being bottomed with a vicinity of a bottom plate part and / or a peripheral side wall part being caused to explode by an ignition power; the igniter is a composition including metal oxide, a single metal reductant agent, and boron.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] In the places where fireworks are consumed, the ignition methods for percussion fireworks, set-piece fireworks, etc. are generally such that people directly hold a fire source and drop it into the percussion tube to ignite it, or in the case of quick firing, drop a firework with percussion gunpowder attached to the fuse in the tube and then launch it. In recent years, for the purpose of ensuring safety during ignition and improving the viewing effect by percussion synchronized with music, an ignition system linked with an ignition ball in the shape of a match head and an igniter or a computer is used, and remote ignition is increasingly carried out by electric ignition, such as directly igniting the transfer pyrotechnics such as a quick fuse or a fuse wire and the percussion gunpowder such as black fine gunpowder.

[0003] In such an electric ignition method, connection work and percussion preparation are carried out in procedures such as fixing the ignition ball to the transfer pyrotechnics connected to the firework ball at the place where fireworks are consumed, or fixing the ignition ball to the percussion gunpowder previously measured and bagged, inserting it into the percussion tube, and then inserting the firework ball. Also, the method of fixing the ignition ball to the quick fuse paper tube is generally to make a notch at the end or the middle part of the paper tube to prevent misfiring due to the ignition ball falling out, insert it about 0.05 m to 0.1 m deep into the quick fuse, and then fix it with an adhesive tape.

[0004] In the operation of fixing this ignition ball, especially for the quick fuse of the transfer pyrotechnics, several core charges impregnated with black gunpowder in cotton yarn or the like penetrate into a single or double paper tube. When inserting the ignition ball, there is a risk that the black gunpowder in the paper tube and the ignition powder of the highly sensitive ignition ball will directly contact and cause friction to ignite. Similarly, when inserting and fixing the ignition ball into a small bag in which the percussion gunpowder is measured, the percussion gunpowder such as black fine gunpowder and the ignition powder will directly contact. Furthermore, after inserting the percussion charge with the fixed ignition ball into the percussion tube and then inserting the firework ball at the top, the load of the ball or the impact when accidentally dropped may increase the frictional force between the black gunpowder and the ignition powder or lead to ignition due to the load or impact, increasing the risk.

[0005] Previously, the risk of friction ignition when attaching the ignition bulb to the quick-burning wire has been pointed out, and ignition devices that use a cylindrical fixing device and seal the tip are known. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 6-30697 [Overview of the project] [Problems that the invention aims to solve]

[0007] Our inventors' research has revealed that conventional electric igniters for fireworks produce too much flame from the igniter during ignition, causing not only the tip (front) of the igniter's holding cylinder but the entire cylinder to burst, resulting in flames spreading to the rear and causing inconsistencies in the ignition of the propulsion devices and launching powder. Therefore, the present invention aims to provide an electric igniter for fireworks that suppresses the spread of flames behind the igniter during ignition and improves the transfer of flame to the propulsion device and the launching powder. [Means for solving the problem]

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

[0009] [1] An electric igniter for fireworks, comprising an igniter holding cylinder made of resin or rubber material, an igniter in the form of powder or granules, and a bridged plug through which a wire for transmitting ignition energy passes, which closes the igniter holding cylinder, and intended to be fixed to and ignited by a pyrotechnic device for propagating fireworks or a gunpowder for direct launching, wherein the igniter holding cylinder is fixed to the bridged plug so as to be in close contact with the bridge and the igniter, the igniter holding cylinder has a bottom and a structure in which the bottom plate portion and / or the peripheral side wall portion burst upon ignition force, and the igniter is a composition containing a metal oxide, an elemental metal reducing agent and boron. [2] The electric igniter for fireworks according to [1], wherein the metal oxide is copper(II) oxide and the elemental metal reducing agent is aluminum. [3] The electric igniter for fireworks described in [1]-[2], wherein the igniter contains 63-79% by mass of metal oxide, 15-20% by mass of elemental metal reducing agent, and 2-21% by mass of boron. [4] An electric igniter for fireworks according to any one of [1] to [3], characterized in that the friction sensitivity of the igniter is of sensitivity class 4 to 5. [5] An electric igniter for fireworks as described in any of [1] to [4], 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 igniter holding cylinder is positioned forward, the flame is prevented from spreading backward, and an electric igniter for fireworks is provided that improves the transfer of flame to the fire-transmitting pyrotechnics and the launching powder. [Modes for carrying out the invention]

[0011] The present invention will be described below.

[0012] The present invention will be described in detail below, with particular emphasis on its preferred embodiments. Figure 1 is a partially cutaway schematic diagram showing an electric igniter or electric fuse for fireworks according to the present invention. The electric igniter consists of an igniter holding cylinder 3, an igniter 4, and a bridged plug 5 through which a pair of parallel insulated conductors 1 pass and a bridge 2 is welded to the end. It receives electrical energy from an igniter or an ignition system linked to a computer, which heats up the bridge through the conductors 1 and ignites the igniter 4 around the bridge 2. The igniter 4 emits a high-temperature flame and heat accompanied by thermal particles, which ignites propagating pyrotechnics such as quick-burning wires and fuses, or launching powders such as black granules, to launch fireworks or ignite set fireworks.

[0013] The bridged embolizer 5 is made of a thermoplastic resin such as polyethylene, polypropylene, polyvinyl chloride, or nylon. The parallel conductor 1 that transmits ignition energy through the bridged embolizer 5 is made of a wire such as copper coated with a resin such as Teflon (registered trademark), polyethylene, or polyvinyl chloride, or iron with copper plating, and for this application, the core wire diameter is preferably in the range of 0.0004 to 0.0007 mm. A bridge 2 made of a wire such as platinum or nichrome embedded by friction welding such as resistance welding or ultrasonic bonding, or by hook pinching, is bridged at the tip of the parallel conductor 1, and a resistance value suitable for the energy supplied by the igniter or ignition system is maintained.

[0014] The igniter 4, which ignites due to the heat generated by the aforementioned electric bridge, uses a reaction composition in which boron is added to a mixture of a metal oxide and an elemental metal reducing agent. By using this mixture, the ignition properties and reaction duration of the igniter are improved, and since there is almost no gas generation when the igniter ignites, as shown in Figure 2, the igniter holding cylinder is less likely to burst in all directions when the igniter is ignited, and the flame tends to concentrate forward. As a result, the flame of the igniter is not too strong when the igniter is ignited, so when the tip of the igniter holding cylinder is facing forward, the flame is suppressed from spreading to the rear, sides, and flanks. Although the flame concentrates forward, a wide-angle flame is generated, improving the speed and stability of ignition to the launching charge and the pyrotechnic device used for propulsion. Furthermore, the concentration of flames forward improves the speed and stability of ignition to the launching charge and ignition-starting pyrotechnics, and suppresses variations in the height of the smoke bomb's development, such as the occurrence of low-altitude development (where the smoke bomb ignites immediately after launch and the phenomenon occurs before it reaches its intended height). In addition, since this mixture does not fall under the category of explosives under the Explosives Control Law, it is easier to handle, including consumption and storage.

[0015] The metal oxide component of the above-mentioned ignition agent is preferably one or more compounds selected from the group consisting of chromium trioxide (Cr2O3), manganese dioxide (MnO2), iron trioxide (Fe2O3), iron tetroxide (Fe3O4), copper(II) oxide (CuO), and red lead (Pb3O4). More preferably, iron trioxide (Fe2O3), iron tetroxide (Fe3O4), and copper(II) oxide (CuO) are used in terms of reaction safety, cost, and handling.

[0016] The metal oxide content of the above-mentioned igniter is preferably 63-79% by mass, more preferably 65-77% by mass, and even more preferably 67-75% by mass, relative to the total amount of the igniter, from the viewpoint of ensuring that the flame intensity when igniting the electric igniter is appropriate and that the accuracy of the ignition transfer to the launching charge when igniting the electric igniter is increased.

[0017] As a single-element metal reducing agent, any single-element metal that acts as a reducing agent is acceptable and is not particularly limited, but aluminum powder is preferred from the viewpoint of ease of availability and abundance of applications. The particle size of such a single-element metal reducing agent is preferably in the range of 1 to 20 μm, and more preferably in the range of 5 to 10 μm. If the particle size is larger than 1 μm, the combustion of the igniter becomes milder. If the particle size is smaller than 20 μm, the flammability of the igniter is improved.

[0018] The amount of elemental metal reducing agent, which is a component of the above-mentioned ignition agent, is preferably 15 to 20% by mass, and more preferably 16 to 20% by mass, relative to the total amount of the ignition agent, from the viewpoint of ensuring that the flame intensity when igniting the electric igniter is appropriate and that the accuracy of ignition of the launching charge is increased when igniting the electric igniter.

[0019] The boron content of the above-mentioned igniter is preferably 2 to 21% by mass, more preferably 4 to 18% by mass, and even more preferably 6 to 16% by mass, relative to the total amount of the igniter, from the viewpoint of ensuring that the flame intensity when igniting the electric igniter is appropriate and that the accuracy of the ignition transfer to the launching charge when igniting the electric igniter is increased.

[0020] From the perspective of safety during the manufacture of electric igniters for fireworks or during operations using electric igniters for fireworks, the friction sensitivity of the ignition charge is preferably at least Class 4.

[0021] The friction sensitivity of the ignition charge was measured based on the Pyrotechnics Society standard "Friction Sensitivity Test (ES-22)".

[0022] Figure 1 is a cross-sectional view showing an embodiment of the ignition charge holding cylinder 3. By making the ignition charge holding cylinder 3 have a bottom, the ignition charge 4 is prevented from directly contacting the core charge of a transfer pyrotechnic device such as a quick match or a fuse, or a percussion powder such as black fine powder, thereby enhancing safety such as preventing friction ignition. Furthermore, if it is completely sealed, the effect of preventing moisture intrusion can be obtained and long-term performance can be maintained. The bottom part 6 is more preferably made of the same material molded integrally with the ignition charge holding cylinder 3, but it is also possible to adhesively attach a different resin material, a rubber material, or a paper-like material in a separate assembly process in advance.

[0023] By making the ignition charge holding cylinder 3 have a bottom, a preferable effect of protecting the ignition charge can be obtained. However, simply having a bottom only suppresses the spread of flames, so the ignition performance, which is the original purpose, will be impaired. Therefore, as shown below, it is necessary to provide a structure such as using a soft material, having a shape that is prone to stress concentration in a local area, or providing a difference in wall thickness to provide a site that actively and stably ruptures easily at the same location.

[0024] The igniter holding cylinder 3 is preferably molded by injection molding, and its material is preferably a soft thermoplastic resin or rubber material, specifically ethylene vinyl acetate copolymer, ethylene ionomer, styrene-based, polyester-based, or polyolefin-based elastomer, with ethylene vinyl acetate copolymer or styrene-based elastomer being particularly preferred due to their softness. The evaluation scale for physical properties may differ slightly depending on the resin or rubber material, and the properties may change with temperature, but 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, as the vinyl acetate content increases, the material becomes softer and ruptures well, with 1 to 50% by weight being preferred, and more preferably in the range of 10 to 40% by weight.

[0025] Furthermore, while some known igniters have a slightly tapered tip on the fixing device of the cylindrical body to facilitate insertion into the quick-burning paper tube, in the present invention, it is preferable to have a shape that easily concentrates stress locally, thereby providing a part that is prone to actively and stably rupturing at the same location. It is preferable that the bottom plate portion 6 of the igniter holding cylinder 3 has an oblique incline or a tapered shape, or the bottom plate portion 6 is provided at the tapered top and can have an oblique incline, a flat surface, or a rounded portion. By creating a shape that easily concentrates stress locally near the top, that is, if the shape of the bottom plate portion 6 is oblique incline, bending stress concentrates at the top of the bottom plate on the acute angle side, and if it is tapered, bending stress concentrates around the top in the center, thus providing the effect of actively making it easier to rupture with ignition force. When the bottom plate portion 6 is oblique incline, it is preferable that the angle of the top of the bottom plate on the acute angle side is in the range of 40 to 80 degrees, and more preferably in the range of 60 to 70 degrees. Furthermore, when tapering, it is preferable to angle the central apex between 20 and 80 degrees, but more preferably between 30 and 60 degrees, as this does not result in the tapered portion being too long.

[0026] Furthermore, as one embodiment, by making the bottom plate portion 6 of the igniter holding cylinder 3 thinner and the peripheral side wall portion 7 thicker, a difference in wall thickness can be created, similar to the above, to concentrate stress around the bottom plate portion 6, especially on the acute-angled side of the bottom plate top, thereby making it more prone to rupture. When the peripheral side wall portion 7 has a wall thickness of, for example, 0.0005 to 0.0015 mm, the wall thickness of the bottom plate portion 6 should preferably be at least 0.0005 mm or less, and more preferably 0.0003 mm or less, as a wall thickness that is prone to rupture and can be injection molded. When molding the bottom plate portion 6 to a thin wall, depending on the characteristics of the selected material, molding conditions, mold structure, etc., pinholes may be formed due to welding and peeling from the mold or poor gas release, so careful selection of conditions and wall thickness is important.

[0027] Furthermore, in one embodiment, in addition to the above, by making the thickness of the peripheral side wall portion 8 in contact with the bottom plate in addition to the bottom plate portion 6 of the igniter holding cylinder 3 thinner, as shown in Figure 1, it becomes possible to make the acute angle bottom plate corner or the peripheral side wall portion 8 in contact with the bottom plate, where stress is concentrated in the above shape, more likely to rupture. The thickness difference between the thin-walled portion and the thick-walled portion is preferably within the above range, but the thickness of the bottom plate portion 6 and the peripheral side wall portion 8 in contact with the bottom plate may or may not be the same.

[0028] Another method to further thin the ignition charge holding cylinder 3 molded by the injection molding method described above, thereby making it more likely to burst due to ignition force, is a type of thermoplastic resin molding method called vacuum molding, in which a sheet-like material is heated and softened, and the air between the sheet and the mold is removed to create a vacuum for molding. The thermoplastic resin used in this molding method is preferably amorphous or crystalline polyethylene terephthalate, polystyrene, polypropylene, or polyacrylonitrile, and more preferably polystyrene because it can be molded in 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 wall thickness after stretching by vacuum molding is even thinner than that of the injection-molded product, thereby providing the effect of making it more likely to burst.

[0029] To make the area near the bottom plate 6 of the injection-molded or vacuum-formed igniter-holding cylinder 3, or the surrounding area, more prone to rupture and to improve ignition performance, it is desirable that the cylinder 3 be less likely to scatter due to the force of ignition, and therefore, it is preferable that the igniter-holding cylinder 3 has a structure in which it is fixed to the bridged embolization plug 5.

[0030] Methods for fixing the igniter holding cylinder 3 to the bridged bolster 5 include bonding the fitting portion with an adhesive, friction welding using ultrasonic waves, fixing it with something that is easily plastically deformable like the tube opening clamp of an electric detonator, preventing the igniter holding cylinder 3 from scattering by using a fixing device to a fast-burning wire, as in known ignition devices, and increasing the fitting strength between the inner diameter of the fitting portion of the peripheral side wall portion 7 of the igniter holding cylinder 3 and the outer peripheral edge of the fitting portion of the bridged bolster 5. However, the method should not require additional components or joining equipment, and should not increase the maximum outer diameter with such additional components. A more preferable and reliable method is to provide an undercut molding process, which involves creating a recessed or convex shape on the inside of the peripheral side wall portion 7 of the igniter holding cylinder 3, and at least one convex or concave shape on the outer periphery of the fitting portion of the bridged embolizer 5, with their respective positions corresponding around the entire circumference. Alternatively, by providing a structure that involves processing one or both sides of the two wall surfaces with a rough or embossed pattern around the entire circumference and then fixing them together, assembly can be made easier without the need for adhesive drying equipment, welding equipment, or other additional parts, and the scattering of the igniter holding cylinder 3 can be prevented more reliably.

[0031] Furthermore, conventional ignition bulbs are produced by coating a pellet-shaped igniter, moistened with an organic solvent or the like, around a bridge that cross-links the ends of parallel conductors that penetrate an embolize, and then drying it. This makes it difficult to adjust the amount of coating, and requires equipment such as drying facilities and exhaust systems. In contrast, the electric igniter of the present invention is produced by quantitatively filling a pre-produced powder or granular igniter 4 into the igniter holding cylinder 3 using a meter and then combining it with the bridged embolize 5. This process is simpler and easier to produce.

[0032] As described above, the quick-burning wick, which is a pyrotechnic device for ignition, is made of a thin single or double layer of paraffin paper, with several wicks made of cotton thread or similar material impregnated with black powder inserted into the paper tube. The inner width of the paper tube is approximately 0.01 m and the circumference is about 0.02 m, so when converted to a cylinder, its diameter is 0.0065 m. As described above, since several wicks are inserted, if the electric igniter is cylindrical, the maximum outer diameter including the igniter holding cylinder 3 and the bridged 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 into the quick-burning wick, reduces friction with the wick, and improves safety. Furthermore, the outer shape of the electric igniter is preferably cylindrical as it relatively reduces directional constraints for mass production, but it may also be elliptical or prismatic. In this case, when the electric bridge embolization plug 5 and the igniter holding cylinder 3 are fitted together, both need to be restricted in all three axial directions.

[0033] The ratio (L / D) of the length L to the maximum outer diameter D of the igniter holding cylinder 3 shown in Figure 1 is preferably between 0.7 and 6.0 within the outer diameter range, and is preferably a vertically elongated cylinder. When the cylinder is tapered, the length L refers to the length from the top to the end, and similarly when it is inclined at an angle as shown in Figure 1, it refers to the length from the top to the end. For example, one example for the minimum value of 0.7 is the case where the maximum diameter corresponds to the minimum amount of propellant, and when the maximum outer diameter D is 0.005 m, the length L is 0.0035 m. As mentioned above, the area near the bottom plate 6 of the igniter holding cylinder 3, or the surrounding area, is prone to rupture. In order to ensure good ignition, it is desirable that the cylinder 3 is less likely to scatter due to the force of ignition. Therefore, a fitting length is necessary to increase the fit strength between the inner diameter of the fitting portion of the peripheral side wall portion 7 of the cylinder 3 and the outer edge of the fitting portion of the bridged plug 5, or to fix it by applying an undercut molded portion, and it is preferable that this length be 0.003 m or more.

[0034] In the case of an L / D ratio of 0.7, the example of 0.0035m takes into account the length of the fitting allowance, and since the igniter 4 is enclosed in the remaining 0.0005m portion, the elongated cylindrical shape is preferable. On the other hand, in the case of a maximum of 6.0, one example is the case of the smallest diameter and largest amount of propellant, where the length L is 0.024m when the outer diameter D is 0.004m. In this case as well, the length of the fitting allowance is taken into consideration, and the length of the fitting allowance is preferably 0.5 to 1.5 times the length of the chamber in which the igniter 4 is enclosed. Therefore, the length L of the igniter holding cylinder 3 is preferably 1.5 to 2.5 times the length of the chamber, which is the sum of the length of the chamber and the length of the fitting allowance. In this example, when the length is 1.5 times the length of the chamber, the length of the chamber becomes 0.016m, and the length of the fitting allowance becomes 0.008m. In other words, the length of the fitting area, which is formed by an undercut molding section or the like to prevent the ignition charge holding cylinder 3 from scattering, 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 is elongated vertically. [Examples]

[0035] The present invention will be described based on examples.

[0036] [Example 1] The igniter holding cylinder 3, which is injection molded from ethylene vinyl acetate copolymer resin and has the shape shown in Figure 1, is cylindrical with an outer diameter of 0.004 mmφ, with the top of the bottom plate portion 6 having a 70-degree oblique incline, and the peripheral side wall portion 7 having a wall thickness of 0.0005 mm, the peripheral side wall portion 8 in contact with the bottom plate having a wall thickness of 0.0003 mm, and the bottom plate portion 6 having a wall thickness of 0.0002 mm, thus creating a difference in wall thickness. The igniter holding cylinder 3 contains 74% by mass of copper(II) oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average particle size 0.1-1 μm) as a metal oxide, and aluminum as a pure metal. An electric ignition device was assembled by measuring out 20 mg of an ignition agent 4, which was formulated with 19% by mass of (VA-2000, manufactured by Yamaishi Metal Co., Ltd., average particle size 5-10 μm) and 7% by mass of boron (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average particle size 0.1-1 μm), and fitting together a bridged embolite 5, which had a platinum wire bridge 2 crosslinked by ultrasonic bonding, at the tip of a cylindrical embolite with an outer diameter of 0.004 mφ made of polyethylene resin through which parallel conductors 1 coated with polyvinyl chloride resin passed, at the portions that had been pre-molded with undercuts.

[0037] [Example 2] An electric igniter was assembled in the same manner as in Example 1, except that 73% by mass of copper(II) oxide was used as the metal oxide, and 18% by mass of aluminum and 9% by mass of boron were used as the elemental metals.

[0038] [Example 3] An electric ignition device was assembled in the same manner as in Example 1, except that 71% by mass of copper(II) oxide was used as the metal oxide, and 18% by mass of aluminum and 11% by mass of boron were used as the elemental metals.

[0039] [Example 4] An electric ignition device was assembled in the same manner as in Example 1, except that 70% by mass of copper(II) oxide was used as the metal oxide, and 17% by mass of aluminum and 13% by mass of boron were used as the elemental metals.

[0040] [Example 5] An electric igniter was assembled in the same manner as in Example 1, except that 68% by mass of copper(II) oxide was used as the metal oxide, and 17% by mass of aluminum and 15% by mass of boron were used as the elemental metals.

[0041] [ reference example 1 ] An electric igniter was assembled in the same manner as in Example 1, except that 76% by mass of copper(II) oxide was used as the metal oxide, and 19% by mass of aluminum and 5% by mass of boron were used as the elemental metals.

[0042] [ reference example 2 ] An electric ignition device was assembled in the same manner as in Example 1, except that 66% by mass of copper(II) oxide was used as the metal oxide, and 17% by mass of aluminum and 17% by mass of boron were used as the elemental metals.

[0043] [ reference example 3 ] An electric ignition device was assembled in the same manner as in Example 1, except that 78% by mass of copper(II) oxide was used as the metal oxide, and 19% by mass of aluminum and 3% by mass of boron were used as the elemental metals.

[0044] [ reference example 4 ] An electric ignition device was assembled in the same manner as in Example 1, except that 64% by mass of copper(II) oxide was used as the metal oxide, and 16% by mass of aluminum and 20% by mass of boron were used as the elemental metals.

[0045] [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 agent.

[0046] [Ignition test] A 6V voltage was applied to an electric igniter to ignite the material, and the spread of the flame and the intensity of the fire after ignition were filmed and observed with a video camera.

[0047] [Black small particle gunpowder ignition test] Furthermore, 1g of black granular gunpowder was measured out and placed in a paper bag. The electric bridged igniter 5 was then pushed into the bag until it was completely hidden, and the end of the bag was secured with paper adhesive tape. 100 ignition tests were then conducted.

[0048] [Fast-fire ignition test] An electric igniter was inserted 0.05m into the end of a 0.3m long paper tube of quick-burning wire, secured with paper adhesive tape, and 100 ignition tests were conducted.

[0049] The results of the above tests are shown in Table 1.

[0050] [Table 1]

[0051] As described above, in the embodiment, the friction sensitivity of the igniter is low, resulting in high safety during operation, almost no gas generation during ignition, and as shown in Figure 2, when the tip of the igniter holding cylinder is facing forward, the flame diffuses radially and at a wide angle, suppressing the flame from spreading backward, to the sides, or laterally, thus providing an electric igniter for fireworks that ensures stable ignition of the launching charge and quick-burning wire. On the other hand, in Comparative Example 1, the high friction sensitivity of the igniter resulted in low safety during operation, and a large amount of gas was generated during ignition. As shown in Figure 3, when the tip of the igniter holding cylinder was facing forward, the flame extended backward, to the sides, and laterally, and it was confirmed that the propagation to the launching charge and quick-burning wire was unstable. [Brief explanation of the drawing]

[0052] [Figure 1] A schematic diagram showing a portion of the electric ignition device of the present invention cut away. [Figure 2] This figure shows a photograph taken when the electric igniter of the present invention is fixed with its front facing upward and ignited, and the flame is suppressed from spreading to the rear, sides, or lateral directions of the igniter. [Figure 3] This diagram shows a photograph illustrating how the flame extends slightly to the rear and side of a conventional electric igniter when it is fixed with its front facing upwards and ignited. [Explanation of Symbols]

[0053] 1 conductor 2 electric bridge 3Ignition powder holding cylinder 4-point explosive 5 Embolization with electrical bridge Bottom plate of the 6-point gunpowder holding cylinder Peripheral side wall of the 7-point explosive holder cylinder Peripheral side wall portion in contact with the bottom plate of the 8-point explosive holder cylinder

Claims

1. An electric igniter for fireworks, comprising an igniter holding cylinder made of resin or rubber material, an igniter in powder or granular form, and a bridged plug through which a conductor for transmitting ignition energy passes, which closes the igniter holding cylinder, and intended to be fixed to and ignited by a pyrotechnic device for propagating fireworks or a gunpowder for direct launching, wherein the igniter holding cylinder is fixed to the bridged plug so that the bridge and the igniter are in close contact, the igniter holding cylinder has a bottom and a structure in which the bottom plate and / or peripheral side wall area bursts upon ignition force, and the igniter is a composition containing 67-75% by mass of copper(II) oxide, 16-20% by mass of aluminum, and 6-16% by mass of boron.

2. The electric igniter for fireworks according to claim 1, characterized in that the friction sensitivity of the igniter is of sensitivity class 4 to 5.

3. An electric igniter for fireworks according to claim 1 or 2, characterized in that the flame spreads radially forward when ignited.

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