RU2123657C1 - Detonating device operating on action of shock wave - Google Patents

Abstract

FIELD: safe initiating devices used in fast-action equipment to localize emergencies and prevent propagation of harmful substances outside point of emergency. SUBSTANCE: case of detonating device houses charges of high explosive of different density. Charge having least density borders on bottom of case or plate put on bottom. In this case thickness δ is chosen from condition A≤δ≤c/B(1/σ_вр-1/K),, where A is thickness calculated by bearing capability in absence of outside load; B=10^-2e,1/Pa s is sound velocity in material of bottom or plate, m/s; K=1,6 10⁹,Pa; σ_вр - is strength characteristic of material of bottom or plate, Pa. EFFECT: enhanced safety and efficiency in usage of this detonating device, decreased operating time and expanded application field. 3 cl, 4 dwg

Description

 The invention relates to initiating devices for explosive charges, specifically to detonators triggered by the action of a shock wave, and can be used in devices for localizing accidents and preventing the spread of flame, poisonous gases, dust, aggressive aerosols outside the accident site, as well as in mining.

 Known phenomenon of detonation through the influence, when the explosive charge can excite the detonation of another charge located at some distance from the first / E. Burloo. Knock through influence. Art Academy named after Dzerzhinsky, 1934 /.

 A known method of detonation detonation at a distance, consisting in the fact that from one active charge detonated by any of the main methods, one or more other passive charges are detonated at the same time, separated from the active charge by air and equipped with detonator capsules. In this case, without exception, all detonator caps inserted into the passive charges should face the open ends of the sleeve towards the active charge / A.I. Maureen et al. Subversive business. - M.: Military Publishing, 1957, p. 41 - 42, Fig. 18a /.

 A detonating device / A.C. is also known. Derzhavets, F.A. Baum, A.S. 163132 from 05.15.63, application 836138 / 22-3, F 42 B 3/10, Bull. N 12, 1964 /, in which the initial pulse is a powerful shock wave caused by a piston, which is placed in one housing with an initiated charge and is driven by a propelling charge, also placed in one housing with an initiated charge.

 The latter device is selected as a prototype. The disadvantages of the analogue are the presence of an initiating explosive in it, which entails high sensitivity and the need for special safety measures in the manufacture and official handling, as well as the time spent on preparation for work. The disadvantage of the prototype is that the initial pulse generator is placed in one housing with an initiated charge.

 The problem to which the invention is directed, is the creation of detonating devices that are triggered by a shock wave, containing only blasting explosive, having a response time in the microsecond range, not consuming external energy, operating in a standby mode, having an output signal power sufficient to trigger elements systems for localizing an accident or detonating an explosive charge.

 The technical result of the proposed solution is to increase the safety and efficiency of the application, simplifying the design, reducing the response time, expanding the scope.

где
A - постоянная конструкции;
B = 1 • 10^-2 • e, 1/Па•с;
c - скорость звука в материале дна, м/с;
K = 1,6 • 10⁹ Па;
σ_вр - прочностная характеристика материала дна, Па.The technical result is achieved by the fact that in a device that is triggered by the action of a shock wave, including a case with a closed bottom with charges of blasting explosive of different density enclosed in it, a charge of lower density is located on the side of the impact of the shock wave and is adjacent to the bottom of the case. A charge of higher density on one side is in contact with a charge of lower density, and on the other, through a cap covering the device’s cap, it is connected to a detonating cord. The device is mounted with a closed bottom in the direction of a potentially explosive object and can stand at a certain distance from it. The thickness of the bottom of the housing δ is selected from the following ratio:

Where
A - construction constant;
B = 1 • 10 ^-2 • e, 1 / Pa • s;
c is the speed of sound in the bottom material, m / s;
K = 1.6 • 10 ⁹ Pa;
σ _BP - strength characteristic of the bottom material, Pa.

 The restriction A on the bottom thickness from the bottom is due to its bearing capacity in the absence of an external load and is calculated by known methods. The upper limit corresponds to the condition that the bottom thickness is less than the thickness of the first spall plate under shock wave loading. If the device is made of durable material such as heat-treated steel, then they are guided by the left side of the ratio with an equal sign.

 In the manufacture of the device durable (in order to prevent the spread of fragments during operation), an artificial spall plate is placed inside the device right next to the bottom, the thickness of which is determined by the right side of the above ratio. In this case, under the influence of a shock wave that has passed through the bottom, the artificial spall plate acquires speed, during the movement it generates a shock wave in the charge of lower density, which initiates detonation.

A charge of lower density is made on the basis of pentaerythritetranitrate with a density of 1.15 - 1.20 g / cm ³ , such a density corresponds to the greatest sensitivity upon initiation by a shock wave and is determined experimentally. In order for a detonation wave to form in a less dense charge, its length should be 4-6 critical diameters. With a shorter length, the initiating shock wave may not cause normal detonation, a longer length is unnecessary and leads to an increase in the dimensions of the device.

The bottom of the hull is flat flush with the end, either to prevent accidental impact on the bottom it is deepened relative to the end or made in the form of a cone with the apex facing inward and a solution angle of 60 - 90 ^o . In the latter case, detonation excitation is further facilitated by compressing the explosive in a more limited volume between the conical and cylindrical surfaces.

 In FIG. 1 shows the inventive device, FIG. 2, 3, 4 - embodiments of the bottom of the device, where 1 is the body, 2 is the blind bottom, 3 is an artificial spall plate, 4 is a poorly sealed primary explosive charge, 5 is a highly sealed charge, 6 is a cap, 7 is a detonating cord 8 - the direction of action of the shock wave.

An example of a specific implementation of the claimed device is a knock sensor, comprising a housing made of aluminum alloy with a cavity diameter of 6 mm At the bottom of the housing is a charge based on pentaerythritetranitrate with a density of 1.20 - 0.05 g / cm ³ . Charge length 6 mm. The bottom of the hull is 0.3 mm thick.

 The sensor operates as follows. Under the influence of shock wave 8 or a fragment, an explosion is excited in a more sensitive weakly packed charge 4. In order for a detonation wave to form in the primary charge, the charge length must be at least 4 critical diameters of the primary explosive. The detonation wave from the primary charge 4 passes into the main charge 5 and accelerates to a stationary speed. Next, the detonation pulse through the cap 6 passes into the detonating cord 7 docked to the sensor and reaches the actuators of the accident localization system via the cord.

 In order for the sensor to work with high reliability, the distance between it and the explosive object must be limited. The maximum removal is selected so that the detonation delay in the primary explosive charge does not exceed the duration of the compression phase of the initiating shock-wave pulse, and is determined by the mass (respectively, dimensions) of the explosive object.

 The thickness of the closed bottom is selected so that it does not exceed the thickness of the first spall plate, and in order to exclude unauthorized blows to the bottom, it is buried relative to the end of the body. If the device is made strong, respectively, the bottom is thick, then an artificial spall plate is placed inside the device close to the bottom.

 The response time of the sensor and the entire system is determined by the length of the detonating cord. Since the detonation speed is more than an order of magnitude greater than the speed of sound in air, the response time of a localization system equipped with the inventive sensor is also more than an order of magnitude less than a system with an acoustic sensor.

 Thus, the knock sensor, without consuming energy from the outside, operates in standby mode, does not require time to prepare for operation and converts its signal, generates a detonation pulse sufficient by means of a detonating cord to trigger mechanisms for localizing the accident or detonating an explosive charge.

Claims (4)

1. A detonating device that is triggered by the action of a shock wave, comprising a case with enclosed charges of a blasting explosive of different densities, the charge of a lower density being located on the side of the shock wave, characterized in that the charge of lower density adjoins the bottom of the case or plate installed on the bottom, while the thickness δ of the plate or the bottom of the body is selected from the following ratio:

where A is the thickness calculated by the bearing capacity in the absence of an external load;
B = 10 ^-2 • e, 1 / Pa • s;
C is the speed of sound in the material of the bottom or plate, m / s;
K = 1.6 • 10 ⁹ Pa;
σ _BP - strength characteristic of the material of the bottom or plate, Pa. 2. The device according to claim 1, characterized in that the charge adjacent to the bottom of the housing is made on the basis of pentaerythritetranitrate at a density of 1.15 - 1.2 g / cm ³ .  3. The device according to claim 1 or 2, characterized in that the ratio of the length of the housing adjacent to the bottom to its critical diameter is selected from 4 to 6. 4. The device according to any one of claims 1 to 3, characterized in that the bottom of the body is flat flush with the end face, either recessed relative to the end face, or made in the form of a cone with a vertex facing inward and a solution angle of 60 - 90 ^o .

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