304results about "Seismic energy generation" patented technology

The invention relates to the field of underground multi-physics field monitoring, in particular to an intelligent well completion underground multi-parameter fusion monitoring system, which comprises a functional casing acquisition module, an acoustic-electric-magnetic excitation module, an acoustic-electric-magnetic excitation module and a multi-parameter fusion monitoring module, wherein the functional casing acquisition module is integrated with a strain sensing element, a temperature sensing element, a stress sensing element and a resistivity sensing element; a double-domain inversion fusion module based on a multi-physics field equation and a graph time sequence causal network; the edge closed-loop regulation and control module adopts entropy modulation dual strategy reinforcement learning; and the communication interface has time slot encryption and version verification functions. According to the method, second-level data alignment, minute-level adaptive regulation and control and hour-level global optimization are realized, the crack conductivity is improved, the energy consumption is reduced, and yield increase and well completion integrity are considered.

The utility model relates to the technical field of electric spark sources, in particular to a portable electric spark source which comprises an input power supply, a central control box, an upper computer and an exciter, and a source system is arranged in the central control box; the seismic source system comprises a voltage detection module, a high-voltage power supply module, an energy storage module and a high-voltage switch module. The input power supply is electrically connected with the high-voltage power supply module, the voltage detection module and the high-voltage switch module respectively; the high-voltage power supply module is electrically connected with the voltage detection module, the upper computer, the energy storage module and the high-voltage switch module, and the high-voltage switch module is electrically connected with the energy storage module and the exciter. According to the portable electric spark source, the high-voltage power supply and the high-voltage switch are integrated, so that the size and the weight of equipment are remarkably reduced, and the portability is improved.

The invention discloses a dam disease three-dimensional nondestructive detection method, a storage medium and computer equipment, and relates to the technical field of geophysical detection.The dam disease three-dimensional nondestructive detection method mainly comprises the steps that a seismic source and a detector are used for detecting a target dam to obtain seismic data; obtaining first arrival travel time by using an improved self-correlation constraint energy ratio method, constructing an underground medium wave impedance initial model by using a back projection algorithm, performing forward modeling calculation to obtain theoretical travel time, and correcting an average slowness value in each grid by using a joint iteration method to obtain a corrected underground medium wave impedance model; and stopping iteration when the iteration is ended to obtain a dam disease three-dimensional nondestructive detection result. By implementing the dam disease three-dimensional nondestructive detection method, the storage medium and the computer equipment provided by the invention, the position of a dam hidden danger can be quickly, efficiently and accurately detected.

The invention belongs to the technical field of seismic exploration, and particularly relates to a coal mine underground hydraulic hammering type controllable seismic source vehicle device. The device comprises a crawler, a rotating platform and a hydraulic hammering system, the rotating platform, a four-column type lifting hydraulic support installed on the rotating platform and a hydraulic support in the hydraulic hammering system are hydraulically controlled, and the hydraulic hammering system can conduct 360-degree horizontal rotation, height stepless adjustment and horizontal stretching and retracting. And meanwhile, the crawler-type vehicle body and remote control operation are adopted, so that the crawler-type underground coal mine hammering vehicle is suitable for a complex walking environment in an underground coal mine, and the construction efficiency and the safety are improved.

The invention discloses a monitoring system and method for determining an abnormal geologic body based on distributed optical fiber sound wave vibration, and relates to the technical field of distributed optical fiber sound wave detection.The monitoring system comprises a distributed optical fiber sensing unit, a signal excitation unit, a photoelectric demodulation unit, a signal processing and analyzing unit, a result recording and outputting unit and the like; the distributed optical fiber is used for continuously collecting stratum vibration response; the signal excitation unit applies controllable disturbance to a known reference position to induce a potential abnormal geologic body to generate an inactive excitation response signal; the photoelectric demodulation unit performs phase demodulation on backscattered light transmitted back by the optical fiber to form distributed vibration measurement data; and the signal processing and analyzing unit is used for filtering and denoising the data, establishing a quantitative mathematical model of a signal incident angle and signal intensity, solving an epicentral distance and an incident angle and calculating the spatial position of an abnormal geologic body by combining propagation attenuation correction and least square inversion, and is suitable for dangerous section identification and avoidance decision before mining and construction.

The invention discloses an electric spark source multi-wave micro-logging system and method, and relates to the technical field of seismic exploration, in particular to an electric spark source multi-wave micro-logging system which comprises a cable, a transverse wave converter, a seismic recorder, an electric spark source, a first three-component detector, a second three-component detector and a longitudinal and transverse wave data processing system. An electric spark electrode column is longitudinally arranged in an inner cavity of the transverse wave converter; after being started, the electric spark source discharges through an electric spark electrode column, water molecules at the position where the electric spark electrode column is located are electrolyzed to generate gas through discharging of the electric spark electrode column, the gas impacts a stratum to generate seismic waves, and a first three-component detector and a second three-component detector receive and record seismic wave signals and transmit the seismic wave signals to a longitudinal and transverse wave data processing system; the depth of the transverse wave converter and the depth of the electric spark electrode column are increased by pulling the mooring rope, so that the electric spark electrode column can excite a seismic source at a plurality of observation points, and the purpose of exciting the seismic source for multiple times is achieved.

The invention belongs to the technical field of excitation detection, and provides a movable seismic source system carried by a deep mine heading machine and a positioning excitation detection method, which are characterized in that the excitation time delay of each seismic source unit in an array is accurately controlled by utilizing a controllable seismic source, so that the seismic source units form synchronous superposition in a specific direction, and the detection of an active source is realized; in the aspect of passive source detection, vibration generated when the jumbolter cuts surrounding rock is used as a vibration source, a pilot sensor installed near an anchor rod drill is used for recording an original vibration signal, namely cutting vibration, when the jumbolter works, and signals collected when the jumbolter works and signals collected by the pilot sensor are subjected to cross-correlation processing, so that the original vibration signal is obtained. And reconstructing a virtual seismic source, and then carrying out data processing and passive source imaging. And the active source detection result and the passive source detection result are combined to interpret the unfavorable geologic body, so that the detection of the position is realized, and the geological interpretation of the whole space of the mine can be realized.

The invention relates to the technical field of coal seam inversion and imaging, in particular to a reflection channel wave imaging method and system considering the layering attenuation characteristic of a thick coal seam, and the method comprises the steps: constructing a coal seam layering geologic model, setting the initial wave velocity and initial quality factor of each layer, and forming an initial parameter field; setting an artificial seismic source and a plurality of detection points, exciting a seismic source signal at the artificial seismic source, recording seismic source information, and collecting a seismic wave response signal of each detection point; performing forward modeling by using a fractional order viscoelastic wave equation considering a spatial variable quality factor; carrying out full waveform inversion to obtain an inversion model; and on the basis of the inversion model, a level set function and a self-adaptive grid division strategy are adopted to express a barrier boundary in the coal seam to execute pre-stack wave field separation reverse time migration imaging, and a coal seam structure image is generated. The method can significantly improve the imaging resolution and calculation efficiency of the coal seam structure, and achieves the high-precision recognition of the boundary of the obstacle.

The invention discloses an ionic rare earth ore leaching liquid flow direction dynamic monitoring method based on cooperation of an active seismic source and a distributed optical fiber, and belongs to the technical field of ionic rare earth ore mining. The method comprises the following steps: determining a layout scheme of an active seismic source and a distributed optical fiber network; arranging a corresponding active seismic source and a distributed optical fiber network; exciting the active seismic source array to collect a rock-soil body background signal; injecting liquid through the liquid injection pipeline, and emitting elastic seismic waves with preset frequency and amplitude through the active seismic source; the distributed optical fiber network collects a strain fluctuation signal and an active seismic source response signal in real time; carrying out real-time signal data preprocessing and feature extraction; carrying out data processing to realize wave velocity-strain field joint inversion; and comprehensively analyzing to obtain the diffusion direction of the leaching solution. According to the method, reference is provided for scientific arrangement of liquid collecting systems such as horizontal drill holes and liquid collecting roadways, the recovery rate of the mother liquid in the ore leaching process is further increased, and pollution to the environment due to the fact that the ore leaching liquid permeates into underground water is reduced.

The invention belongs to the technical field of source vehicle corollary equipment, and particularly relates to a drop hammer source anti-secondary excitation device, which comprises an anti-secondary excitation body, the anti-secondary excitation body comprises a controller and a mounting plate, the mounting plate is provided with a mounting hole, the mounting plate is fixedly mounted on a source vehicle, and the controller is connected with the controller. A clamping assembly used for clamping a drop hammer is installed on the installation plate, a sound sensor used for detecting sound is installed on the installation plate, through the sound sensor and a controller, the clamping assembly is triggered to clamp the drop hammer, signal interference caused by secondary excitation of the drop hammer is blocked, and the accuracy and reliability of exploration data acquisition are ensured. Meanwhile, the workload and difficulty of subsequent seismic wave signal processing are greatly reduced, and the blank in the prior art is filled.

The application provides a double-side opening cabin type negative pressure air gun source and a firing method thereof, and belongs to the field of marine seismic exploration.The application comprises two upper and lower symmetrical firing units on the basis of the existing negative pressure air gun source and the single-side negative pressure air gun source, the firing cabin is surrounded by the firing cabin housings of the two firing units, each firing unit comprises a pushing cabin and a returning cabin, the pushing cabin is in a high pressure state, the returning cabin is in a vacuum state, the differential pressure makes the firing unit realize the effect of rapid opening of the cabin, and the implosion energy can be fully released.In addition, the two firing units of the application are synchronously fired, the opening speed can be further improved, the stress during the opening process is uniform, and the shaking of the cabin body is reduced.The double-side opening cabin mode can improve the consistency of the wavelet and improve the quality of the seismic data.

The invention discloses a method for determining a favorable seismic wave excitation part of seismic exploration by using electrical exploration, which belongs to the technical field of seismic exploration, and comprises the following steps of: 1, deploying an electrical exploration survey line; step 2, field data acquisition of electrical method data; 3, electrical method data processing and inversion imaging are carried out; 4, determining a resistivity threshold value of favorable-more favorable earthquake excitation; 5, circling a candidate favorable-more favorable seismic wave excitation section on a resistivity profile or plane distribution result; and step 6, optimizing shot point deployment in the candidate favorable-more favorable seismic excitation section. The method can solve the problem of selection of a favorable seismic wave excitation part in a complex surface lithology exposure area, and greatly improves the seismic exploration imaging quality and exploration precision. Meanwhile, due to the fact that shot point distribution is required to have certain uniformity, large notches on a seismic section are prevented.

The application belongs to the technical field of tunnel geological advanced prediction, and provides an electromagnetic controllable excitation device and method for longitudinal and transverse wave excitation of a deep-buried tunnel. The excitation device comprises a body, longitudinal and transverse wave excitation plates arranged on the body, and a rotating mechanism arranged on the body. The longitudinal and transverse wave excitation plates are perpendicular to each other, and the rotating mechanism is connected with a mechanical arm. The rotating mechanism is used to realize the operation switching of the longitudinal and transverse wave excitation plates at the same physical position, and longitudinal and transverse wave excitation is performed. The longitudinal and transverse wave excitation functions are integrated in a single excitation device, the structure is compact, and the device is suitable for operation requirements in a narrow space area in a tunnel. The rotating mechanism is used to realize 90-degree rapid switching, the detection efficiency is greatly improved, the physical positions of two times of excitation are completely consistent, and the data comparability is improved.

The utility model belongs to the technical field of exploration, and provides a high-power electric spark source transmitting probe, which comprises a first electrode, a second electrode, a first insulating part, a second insulating part, a discharge ring and a locking part, the first insulating part is arranged in the first electrode; the second electrode sleeves the inner side of the first insulating part, and the first end of the second electrode extends to the outer side of the first electrode opening; the discharge ring sleeves the outer side of the first end of the second electrode; the second insulating part is clamped between the discharge ring and the first electrode; the locking piece is used for locking the discharge ring and the second insulating piece to the outlet of the first electrode, and the first electrode is filled with high-voltage insulating glue. After the emission probe discharges, quick-wear parts such as the discharge ring and the second insulating part can be disassembled by disassembling the locking part, and the second insulating part and the discharge ring can be quickly replaced. Meanwhile, the first electrode is filled with the high-voltage insulation paste, so that the stability of the second electrode can be improved, and the phenomena of current leakage and the like in the first electrode can be prevented.

The invention relates to the technical field of blasting, and discloses a rock mass longitudinal wave velocity inversion method based on blast hole detonation velocity measurement, which comprises the following steps: drilling a blast hole; explosive and a monitoring probe of monitoring equipment are arranged in the blast hole; detonating the explosive, monitoring and outputting a curve chart that the propagation distance of the detonation wave changes along with the propagation time through monitoring equipment, the longitudinal coordinate of the curve chart being the propagation distance of the detonation wave, and the horizontal coordinate of the curve chart being the propagation time of the detonation wave; according to the distribution condition of each rock stratum in the blast hole, the curve graph is divided into a plurality of curve segments, and each curve segment corresponds to the propagation process of detonation waves in the corresponding rock stratum; the slope of each curve section is calculated, and actually measured explosive detonation velocities of different rock stratums are obtained; and substituting the actually measured explosive detonation velocity into the theoretical formula of the explosive detonation velocity and the longitudinal wave velocity of the rock, and inverting the longitudinal wave velocity of the corresponding rock stratum. Through the inversion method provided by the invention, detonation wave monitoring and longitudinal wave velocity inversion of different rock stratums through which the blast hole passes can be completed through one-time blasting.

The invention belongs to the field of earth exploration, and provides an urban underground collapse hidden danger area rapid detection system and method.The urban underground collapse hidden danger area rapid detection system comprises a miniature intelligent sensor array and a central processing unit, the miniature intelligent sensor array comprises a plurality of detection lines arranged side by side, and each detection line comprises a plurality of miniature intelligent sensors arranged at intervals; the adjacent micro intelligent sensors on the same detection line are connected through a towing cable; the distance between the adjacent micro intelligent sensors is adjustable; and the central processing unit is used for receiving the vibration data acquired by each miniature intelligent sensor, performing inversion on the vibration data by using a background noise surface wave imaging algorithm to obtain an underground transverse wave velocity structure model, and identifying a low-speed abnormal region as a collapse hidden danger region. According to the invention, efficient, accurate, wide-coverage and non-sensitive detection of urban underground collapse hidden dangers can be realized.

This invention relates to the field of earthquake loss assessment technology and discloses a method for assessing the functional loss of urban medical buildings that incorporates site characteristics of seismic zones. The method obtains seismic parameters for the target area, constructs an earthquake occurrence model based on the truncated G-R formula, and generates several simulated earthquake events using stochastic simulation. Based on the seismic design code response spectrum of the site where the medical building is located, natural seismic waves with similar spectral characteristics are selected from the earthquake database. The theoretical peak ground acceleration (PGA) at the medical building is calculated based on the simulated earthquake events, and the PGA is used to modulate the amplitude of the natural seismic waves to obtain the acceleration time history of the input seismic wave corresponding to each simulated earthquake event. The medical building is systematically divided, and a probabilistic seismic demand model and a probabilistic seismic vulnerability model are constructed. Combining repair costs and component importance coefficients, the overall functional loss assessment result of the medical building system is obtained. This invention improves the accuracy of the assessment results.

The invention belongs to the technical field of deep mineral resource development, and provides a rock mass catastrophe sound wave detection sensing method and system for deep solid resource mining, an observation system is arranged, a controllable seismic source is arranged in the middle of the observation system and used for exciting seismic waves, a sensor is arranged on a mining equipment tool bit and used for detecting a passive source, and a rock mass catastrophe sound wave detection sensing system is arranged in the middle of the observation system. The positions of the vibroseis and the sensor are adjustable, and a certain depth adjusting range is achieved; active detection is carried out on the underground medium by using the vibroseis; then carrying out passive source detection; the signals are processed by adopting a mutual drying method, the mutual influence among the sensors of the observation system is removed, and the data are enhanced by adopting a wave field superposition technology according to the signals processed by adopting the mutual drying method; and performing inversion processing on the enhanced signal data by adopting a reverse time migration imaging technology, and reconstructing an underground rock mass structure. The problem that rock catastrophe information cannot be obtained in time in a traditional method is solved.

The invention discloses an electromagnetic ejection seismic source for seismic exploration in a well and an excitation method, which can continuously excite seismic waves, realize flexible output of seismic wave frequency and energy level, meet the requirement of shallow exploration for high-frequency signals in the well and adapt to the requirement of middle and deep layers for low-frequency signals. The seismic source comprises a control system, a shell and an electromagnetic ejection system, the control system is arranged at the top of the shell, the electromagnetic ejection system is arranged in the shell, the electromagnetic ejection system is connected with the control system, and the control system is used for controlling the electromagnetic ejection system, so that the electromagnetic ejection system hammers the well wall from the two sides of the shell at the same time, and the same seismic waves are generated on the well walls on the two sides of the shell at the same time; the excitation method comprises the steps of setting parameters, charging the high-voltage capacitor bank, charging the coil to enable the catapult to move in an accelerated mode, powering off the coil after the catapult reaches a balance position, enabling the hammer body to hammer a well wall when the catapult moves to a limit position, powering on the coil to enable the catapult to move reversely to enable the hammer body to return to an initial position after hammering delay time is reached, and the like.

A method can include receiving seismic data of a subsurface region; performing an iterative full waveform inversion using at least a portion of the seismic data to generate a model of the subsurface region, where the performing includes, after one or more iterations of the full waveform inversion, automatically selecting one or more parts of the seismic data for inclusion in the at least a portion of the seismic data based on data classification using one or more quality attributes; and outputting the model of the subsurface region.

The invention relates to the technical field of oil-gas well exploration, in particular to an oil-gas well drill bit advanced detection method for unfavorable geology. According to the technical scheme, the method comprises the following steps of S1, installing a probe device, S2, exciting a detection signal while drilling, S3, receiving a reflection and scattering signal, S4, preprocessing an underground signal and extracting features, S5, compressing data and uploading the data in real time, S6, processing and imaging ground data, S7, interpreting geology and identifying risks, and S8, generating early warning and decision support. The advanced detection device has the beneficial effects that the advanced detection device is directly integrated on the drill bit, the drill bit is used as a part of a detection source or a sensor, drilling and detection are carried out at the same time, and early warning is sent to the drill bit before the drill bit encounters an unfavorable geologic body; therefore, precious time is won for adjusting drilling parameters, optimizing a well body track or starting a safety program, and the safety, efficiency and economic benefits of drilling are fundamentally improved.

The invention relates to the technical field of seismic exploration equipment, and provides a controllable seismic source device driven by a linear motor, which comprises a touch foundation plate and a guide rail supporting column vertically mounted on the touch foundation plate, an elastic piece connected to the top in the guide rail supporting column, and a connecting rod in the middle of the connecting piece extending into a top plate of the guide rail supporting column to be connected with the elastic piece. The two ends of the connecting piece are connected with the counter weights arranged on the two sides of the guide rail supporting column, rails of the linear motor are installed on the two sides, corresponding to the counter weights, of the guide rail supporting column, permanent magnet sets evenly arranged in the length direction are embedded in the rails, and driving coils of the linear motor are connected to the counter weights relative to the rails. The counter weight is driven by the driving coil to reciprocate up and down along the track, and generated excitation counter force is transmitted to the ground touching base plate through the connecting piece, the elastic piece and the guide rail supporting column to drive the ground touching base plate to move up and down on the ground to generate seismic waves. According to the invention, 2Hz low-frequency output of the vibroseis is ensured, and the problems of huge size and poor portability of a traditional vibroseis are solved.

A method is provided for statics correction of seismic data comprising a plurality of traces representing signals recorded by each of a plurality of seismic receivers disposed proximate to an area of Earth's subsurface to be evaluated. The signals are in response to one or more actuations of one or more seismic energy sources. The method includes identifying arrival times of refraction events in each of the plurality of traces. Long wavelength statics components and short wavelength statics components are separated from the arrival times. The separated long wavelength statics components are used as input to a refraction analysis to generate a velocity model of Earth's subsurface.

This invention belongs to the field of analog integrated circuit technology, specifically relating to a frequency adaptive circuit for downhole detection. This invention utilizes a closed-loop adaptive feedback mechanism, employing multiple excitation frequencies generated by a frequency generator to continuously match and adapt to the transducer's resonant frequency. When a set of excitation frequencies achieves the highest matching degree with the resonant frequency, the echo energy reaches its peak. The frequency generator is adaptively adjusted based on the excitation frequency corresponding to the maximum peak signal obtained during the detection phase, and this optimal excitation frequency is used to generate the excitation signal in subsequent operations, thus completing the adaptation between the excitation frequency and the resonant frequency. This invention effectively avoids the influence of downhole temperature and pressure changes on the transducer's resonant frequency, and combines high automation, good real-time performance, and high imaging quality.

The invention belongs to the technical field of tunnel geology advanced prediction, and provides an electromagnetic controllable excitation device and method for longitudinal and transverse wave excitation of a deep tunnel, a vibration exciter comprises a body, a longitudinal wave excitation plate and a transverse wave excitation plate which are arranged on the body, and a rotating mechanism arranged on the body; the longitudinal wave excitation plate and the transverse wave excitation plate are perpendicular to each other, and the rotating mechanism is connected with the mechanical arm. Operation switching of the longitudinal wave excitation plate and the transverse wave excitation plate at the same physical position is realized through the rotating mechanism, and excitation of longitudinal waves and transverse waves is carried out; the longitudinal wave excitation function and the transverse wave excitation function are integrated into a single vibration exciter, the structure is compact, the device meets the operation requirement of a narrow space area in a tunnel, 90-degree rapid switching is achieved through the rotating mechanism, the detection efficiency is greatly improved, it is ensured that physical positions of two times of excitation are completely consistent, and the data comparability is improved.

The application discloses a non-explosive seismic source device and a shock method for seismic exploration, relates to the technical fields of seismic exploration and blasting, and comprises a blasting cylinder, a top cover and a pipe plug, the pipe plug is arranged in the blasting cylinder, one end of the blasting cylinder is sealed, the other end is connected with the top cover through threads, and a gas-stopping pad, a sponge column and a gas generator are sequentially arranged in the blasting cylinder. The non-explosive seismic source device and the shock method for seismic exploration have the advantages of simple structure, easy material acquisition, no influence of the use environment, no harmful gas generation, no need of approval procedures, no need of a blasting operation certificate for an operator, easy operation after simple training, good coupling between the device and a stratum, use in complex terrain areas, use in water areas such as lakes and oceans, and high safety and good operability compared with a gas explosion seismic source.

The utility model discloses a semi-explosion type transverse wave source based on high-pressure gas explosion near-field waveform regulation and control, which comprises a cylindrical detonation tube, a gas chamber is arranged in the detonation tube, one side of the gas chamber is an arc-shaped surface, the central axis of the arc-shaped surface is consistent with that of the detonation tube, the other side of the gas chamber is an isolation surface, and the isolation surface is arranged on the detonation tube. A groove consistent with the detonation tube in the extending direction is formed in the side, close to the isolation face, of the tube wall of the detonation tube to form a waveform regulation and control chamber, an annular notch groove is formed in the side, close to the arc-shaped face, of the tube wall of the detonation tube, and sealing heads are arranged at the two ends of the detonation tube. The semi-explosive shear wave source realizes near-field waveform regulation and control on a high-pressure gas detonation pressure field through structural design, performs near-field waveform regulation and control on the pressure field generated by detonation through structural design of the detonation tube, enables the energy proportion of a generated shear wave signal to be amplified, is a brand-new shear wave source generation way, and can be applied to the field of high-pressure gas detonation. The system has the advantages of being strong in transverse wave signal, environmentally friendly, good in economical efficiency, good in field adaptability and the like.

The application discloses an automatic planning method and device for a walking route of a land controllable seismic source, and belongs to the field of physical exploration. The application introduces a TSP idea, and finally obtains a seismic source vehicle driving route which is short in path, less in barrier crossing, less in driving restriction, and in line with the driving operation habit of a driver through steps of constructing a map, setting relevant parameters and weight ratios, and solving the walking route of the land controllable seismic source by using a TNH combination algorithm. The application combines the advantages of a two-approximation algorithm, a Heuristic algorithm and an NSGA_II algorithm to propose the TNH combination algorithm for solving the walking route of the land controllable seismic source, so that the automatic planning of the walking route of the controllable seismic source is realized, the operation efficiency is accelerated, the accuracy of operation results is improved, the calculated route is more in line with the demand of field construction, and the exploration operation is further developed intelligently. The application is applied to the field of physical exploration to plan the walking route of the controllable seismic source.

Generator (1) of acoustic waves for submarine environments, wherein a hollow body (10) is developed along an axis (AX) and delimited by a first closed end (100) and by a second end (102) provided with an acoustic diffuser member (1020); the hollow body (10) presenting a first cylindrical portion (104) delimited by the first end (100) and housing a first piston (20) and a second cylindrical portion (106) delimited by the second end (102) and housing a second piston (22) in a freely axially sliding manner; the second piston (22) being mechanically free from the first piston (20) and presenting a face (220) facing the said diffuser member (1020); an impulsive actuating means (30) being associated with the first piston (20) to move it towards the second piston (22); adjusting means (40) of a longitudinal motion of the second piston (22) being arranged between the first piston (20) and second piston (22).