1092results about "Devices for damping mechanical oscillations" patented technology

The invention provides an audible noise calculating method for a high-voltage direct current electric transmission line of 4 to 8 bundle conducting wires and can effectively solve the audible noise prediction problem of an extra-high-voltage direct current electric transmission line. The calculating method comprises three parts that (1) the surface electric field intensity of the conducting of the high-voltage direct current electric transmission line is calculated; (2) the audible noise level (in summer) of the high-voltage direct current electric transmission line is calculated; and (3) the audible noise level of other seasons is obtained through adding or reducing correction items. The calculating method is simple, the implementation is easy, the audible noise of the direct current line corona of the 4 to 8 bundle conducting wires obtained through the calculation can be preferably coincided with the measuring results of testing line in China through being compared with calculation results of other formulas. The direct current corona audible noise of multiple conducting wires, obtained through calculation by the calculating method provided by the invention can more adapt to the environment climate condition in China. The audible noise calculating method is particularly suitable for the extra-high-voltage direct current corona audible noise calculation when during the 4 to 8 bundle conducting wire adoption in north China.

A device for reducing a shock load having a longitudinal direction along a power line coupled through an insulator to a crossarm of a transmission tower, comprising: a rotary damper coupled between the insulator and the crossarm for rotating by the insulator in the longitudinal direction in response to the shock load, the damper having an axle to which the insulator is rotatably coupled; and, a torsion bar coupled at a first end to the axle and at a second end to the crossarm for resisting rotation of the insulator, whereby at least a portion of the shock load is absorbed.

The invention discloses a distribution line typhoon-preventing integrated device capable of achieving pole and wire protecting and achieving pole protecting, wire abandoning, energy absorbing and disengaging. The distribution line typhoon-preventing integrated device structurally comprises a notched elastic frame clamp (1). A clamping end of a clamping sliding block (6) is formed through a downward notch. The upper end of the clamp (1) is connected to a pole and tower cross arm end (3) of a distribution line through a spherical hinge (2), two chucks of the clamping end are respectively and fixedly provided with a long groove type plate (4), the upper ends of the two long groove type plates (4) incline towards the two sides while the lower ends of the two long groove type plates (4) incline towards the middle, a wide-end-up groove with a certain dip angle is formed by combining the two chucks, the middle of the top end in the frame clamp is provided with a tension spring (5), the tension spring (5) is connected with the clamping sliding block (6), connected with a rewinding spring (7) through a steel rope and downwards connected with an insulator / armor clamp (8) of the distribution line, and the insulator / armor clamp (8) is connected with a wire (9) of the distribution line. According to the integrated device, a pole and the wire can be protected when wind is weak, and when the line cannot resist the attack of violent typhoon, the pole can be protected, the wire can be abandoned, energy is saved for enabling the wire to disengage from the pole, the line and the line pole can be effectively prevented from broken, and the tower can be effectively prevented from falling down.

The invention relates to a computer simulation platform system for galloping of overhead transmission conductors, which comprises a transmission line system dynamic modeling subsystem, a fluid-solid coupling dynamic parameter simulation computing subsystem and a conductor galloping simulation subsystem. The dynamic modeling subsystem comprises a parameter input submodule, a general parameter database submodule, and a line system finite element submodule. The fluid-solid coupling dynamic parameter simulation computing subsystem comprises a terrain and meteorological parameter submodule, an aerodynamic parameter simulation submodule, a test parameter database submodule, and a working condition correction coefficient submodule. The conductor galloping simulation subsystem comprises a fluctuating wind load applying submodule, a real-time dynamic load applying submodule, a conductor galloping dynamic simulation computing submodule and a post-processing submodule. The computer simulation platform system for the galloping of the overhead transmission conductors is capable of implementing computer simulation of the galloping of the overhead transmission conductors of various line structures under optional terrain and meteorological conditions, obtaining vibration characteristics and system mechanical parameters of the line system under different working conditions, and providing technical guidance for the line system design.

The invention discloses an active anti-galloping method and an anti-galloping device for an overhead power transmission line. The active anti-galloping device comprises a fixture, a shell, an acceleration monitoring device, a control circuit and an anti-galloping actuating mechanism, wherein the acceleration monitoring device and the control circuit are arranged in the shell; the fixture fixes the anti-galloping device to the wire; the acceleration monitoring device can monitor the movement acceleration for the galloping of the wire and output the movement acceleration to the control circuit; and the control circuit outputs a control signal to control the action of the anti-galloping actuating mechanism according to the received acceleration value so as to suppress the galloping of the wire.

The invention discloses an energy-feed composite anti-galloping energy dissipation spacer comprising a body, wherein a cavity is formed inside the body; an excitation coil is mounted on the inner sideof the body; a metal clamp is arranged on the outer side of the body; a first insulating layer is arranged between the excitation coil and the body for insulation; a ring barrel filled with a magnetorheological fluid is arranged in the inner ring of the excitation coil; a metal ball which can roll in the ring barrel is arranged in the ring barrel; a plurality of piezoelectric generating units areinstalled at intervals on the inner ring of the ring barrel along the circumferential direction; pressure sensors is disposed at the two ends of each piezoelectric generating unit; the piezoelectricgenerating unit is connected in series with an electric energy extraction and storage unit, a controller and the excitation coil to form a closed loop; the inner ring of each piezoelectric generatingunit is provided with a second insulating layer; and an electromagnetic particle vibration absorption body is disposed on the inner side of the second insulating layer.

The invention relates to a damping device for inhibiting the windage yaw of transmission line insulators, which is characterized by comprising a cylinder, a two-way piston, a spring, hinge seats, a protective sleeve, and an insulating damping medium. The two parts of the two-way piston arranged at an interval are disposed in the cylinder and in sliding fit with the cylinder. The two parts of the two-way pistons are connected by the spring arranged in the interval. The piston rod ends of the two-way piston are equipped with the hinge seats. The cylinder is filled with the insulating damping medium. The two-way piston is provided with damping holes for the insulating damping medium to circulate. The damping device is connected with an insulator and a cross arm through the hinge seats at the piston rod ends. The damping device has the advantages of simple structure, convenience of installation and maintenance, high strength, high elastic modulus, good shock absorption performance, resistance to high and low temperature, corrosion resistance, good insulation property, and long service life. When in use, the damping device is installed between the insulator and the cross arm of a transmission line. The damping device can absorb the vibration impact of strong wind to the insulator, avoid flashover of the transmission line caused by windage yaw, and ensures safe and stable operation of the transmission line.

The invention discloses a quadrifid insulated damping conductor spacer matched with a hot-line de-icing scheme of a transmission line, which is realized by frameworks and a line clamp main body, wherein the frameworks are made of glass fiber reinforced plastics, consist of lug boss type positioning stop blocks and are symmetrically arranged close to the inner side outside each connecting hole on the inner side of a rectangular framework, and the line clamp main body consists of a line clamp with a connecting joint. The quadrifid insulated damping conductor spacer not only can reliably separate and support a quadrifid conducting line, but also has good insulating effect so as to ensure that four conducting lines are mutually insulated, thereby creating necessary conditions for the hot-line de-icing of the transmission line, avoiding the harm brought by ice and snow disasters and increasing the bearing strength of the conductor spacer. Because of the improvement on a positioning structure, the line clamp main body and a rubber block, the centripetal force of the conductor spacer can be increased at the same time of simplifying the structure so as to ensure that a damping joint moves along the conducting line all the time and guarantee that the conducting line has damping effect and good positioning when being moved within any possible ranges. The quadrifid insulated damping conductor spacer has simple structure, easy manufacture, reliable performance, low manufacturing cost, economy, practicality and convenient mounting and is suitable for popularization and ice coating areas.

The invention discloses a multistage composite type energy absorption and dissipation damping device, an application and a method. According to the multistage composite type energy absorption and dissipation damping device, the defect that in the prior art, in complex load action, energy dissipation in multiple directions cannot be conducted is overcome, and multistage and polydirectional damping can be effectively realized. According to the scheme, the device comprises an outer box, a mass block and a liquid container, wherein permanent magnets are arranged on the top and at the bottom of the outer box correspondingly, and magnet poles of the two permanent magnets are opposite; the mass block is arranged inside the outer box, and the side face of the mass block is connected with the inner wall of the outer box through a first elastic damping assembly to realize the energy dissipation and damping effects of the mass block in the horizontal direction; the liquid container is arranged below the mass block, liquid with a set volume is contained in the liquid container, the liquid container is internally provided with a second elastic damping assembly, the bottom end of the second elastic damping assembly is connected with the inner bottom of the liquid container, and the top end of the second elastic damping assembly is fixed to the mass block; and meanwhile in the moving process of the mass block, magnetic induction lines generated by the two permanent magnets are cut to conduct dissipating in the mode that mechanical energy is transformed into electric energy.

The invention discloses a split conductor anti-galloping device. The split conductor anti-galloping device comprises a support, and a lead wire clamp is uniformly arranged towards outside on the support. The split conductor anti-galloping device is characterized in that a circular cylinder is also arranged on the support; a spring and an additional weight ball are arranged in the circular cylinder; one end of the spring is connected with the additional weight ball, and the other end of the spring is connected with the circular cylinder; the lead wire clamp is rotatablely connected with the support through a rotating shaft; the circular cylinder is in closed connection with the support; and antifreeze solution is filled into the circular cylinder. In the split conductor anti-galloping device, the energy dissipation is performed by adopting a spring quality system so as to retard galloping, and after being iced, each sub-lead of a split conductor can be adjusted automatically by adopting the lead wire clamp which is arranged rotatablely, so that each sub-lead is iced uniformly so as to remove the galloping, and the energy dissipation effect is enhanced further by adopting the mutual effect of the antifreeze solution and the spring quality system; and therefore, compared with other anti-galloping devices, the split conductor anti-galloping device has the advantages of excellent effects of galloping prevention and galloping elimination.

A device for limiting loads on towers that limits loads only in the longitudinal direction and does not affect the manner in which vertical and transverse loads are resisted by the structure. The device incorporates a shield to prevent ice buildup that could affect its operation. It also has optional antifriction bearings to provide a consistent release force independent of the amount of ice that may accumulate on the wires. The device is of simple construction. The device includes an optional energy absorber, such as that used in U.S. Pat. No. 3,211,260 that can provide a resisting force that is within the longitudinal strength of the tower. The device includes both a mechanical fuse and an energy absorbing mechanism that is used to arrest the wire movement. The energy absorber can extend as much as 50 ft to safely absorb the energy released by broken wires with heavy ice coatings.

The invention discloses an anti-vibration and anti-oscillation damping spring spacer which comprises a frame, and the frame is connected with a plurality of equant cable clamps. The anti-vibration and anti-oscillation damping spring spacer is characterized in that a body center of the frame is provided with a heavy ball, and the heavy ball is connected with the frame by at least two damping spring absorbers; and the damping spring absorber comprises a cylinder body, one end of the cylinder body is connected with a spring hook with a rotating dead axle, the inside of the cylinder body is provided with a piston spring hook protruded from the other end of the cylinder body, the upper end of a section of piston spring hook in the cylinder body is penetrably provided with a positioning plate and a counterweight plate, a spring and a damping rubber sleeve are arranged between the positioning plate and the counterweight plate, and the damping rubber sleeve is sleeved on the spring. The spacer disclosed by the invention can be split into four, six, right and twelve equal parts as required, so that the spacer can play a vibration energy decrement role in the aeolian vibration in the vertical direction of a split conductor, the subspan oscillation in the lateral horizontal direction, the fair-line vibration in the fair-line direction and the oscillation in the lateral torsion direction, thereby achieving the optimum anti-vibration and anti-oscillation effect.

A casing structure for a communication equipment in which panels mounted in the casing are electrically insulated from a messenger wire. When the casing of the communication equipment is mounted on the messenger wire, the insulation prohibits impediments otherwise caused by extraneous noise current flowing in the messenger wire. The mounting portion of the case has a handle structure which provides improved operability and convenience.

The invention discloses a semi-active vibration isolator of an overhead power transmission line and a semi-active vibration isolation method. The semi-active vibration isolator of the overhead power transmission line comprises a shell, a power supply, a control circuit, a motor, a transmission mechanism and an actuating mechanism, wherein the shell is provided with a fixture for fixing the vibration isolator to the wire; the control circuit, the motor and the transmission mechanism are arranged in the shell and powered by the power supply; the actuating mechanism is provided with an adjustable arm; the action of the motor is controlled by the control circuit; the adjustable arm of the actuating mechanism is driven to act by the motor through the transmission mechanism; and the damping characteristic of the actuating mechanism is varied through the mechanical action for varying the arm length of a damper so as to achieve the purpose of suppressing the aeolian vibration of the wire.

The invention relates to the technical field of fixing components, in particular to a fixing component for cables, which includes two semicircular fixing parts, and a plurality of hemispherical grooves are respectively opened on the inner walls of the two semicircular fixing parts, and the semispherical grooves located outside the hemispherical grooves A shock-absorbing spring is fixedly connected to the circular fixing member, and the shock-absorbing ball is located in the shock-absorbing spring. The ends of the multiple shock-absorbing springs are respectively connected to a support plate, and a through hole is provided in the middle of the support plate, and a spring is arranged in the through hole. Two ends of the through hole are respectively inserted with connecting rods, and the ends of two adjacent connecting rods are respectively fixed at the two ends of the spring, and the connecting rods at both ends of the semicircular fixing part are connected with the inner wall of the semicircular fixing part. The fixing member used for the cable has the function of shock absorption for the cable when the cable is fixed. When the cable is shaken, it will not cause partial extrusion of the cable, prevent the cable from being deformed and damaged, and prolong the service life of the cable.

The invention relates to a multi-fission transmission lead torsional vibration swing-preventing device. More than two lead clamps for fixing transmission leads are evenly arranged on an annular spacer rod; a swing shaft can be rotatably arranged on the annular spacer rod through a bearing and the lead clamps are fixed on the swing shaft; and T-shaped swing rod is fixed at the bottom of the annular spacer rod and a balance weight ball and low-temperature anti-freezing fluid are held in an arc circular tube of the T-shaped swing rod. The torsion of overhead conductors can be prevented from rotating by self balance of round ball gravity; in addition, the multi-fission transmission lead torsional vibration swing-preventing device has the characteristics of simple structure, convenient installation and use and no need of frequent maintenance.

The invention discloses a combined structure of a suspension insulator string and a strain clamp and a construction method thereof. The combined structure of the suspension insulator string and the strain clamp is installed on a cross arm head of a linear tower, two suspension composite insulators are hung on the cross arm head of the linear tower, and the suspension composite insulators are connected with a first connecting plate by a hanging plate of a bowl head; the first connecting plate is connected with a second connecting plate by a first Z-shaped hanging plate; moreover, the first connecting plate and the second connecting plate are arranged in a mutually vertical way; the second connecting plate is also connected with a third connecting plate by a second Z-shaped hanging plate; and both sides of the third connecting plate are respectively connected with a wedge-shaped wire clamp, and conducting wires are installed in the wedge-shaped wire clamps. The combined structure of the suspension insulator string and the strain clamp and the construction method thereof disclosed by the invention are adopted on the linear tower, the stress of the conducting wires is favorably improved, and the vibratory injury of the conducting wires is greatly relieved, so that the running service life of the conducting wires of a power transmission line is prolonged.

The invention relates to a spacer for transmission line in the air, in particular to an adjustable sub-lead spacer, comprising a frame, wire clamp bodies and wire clamp cover boards; the frame is ring-shaped, binding plates are uniformly distributed on the outer circumference of the frame; the front part of the wire clamp body and the front part of the wire clamp cover plate are connected together through a connecting piece to form a hollow cavity for clamping the sub-lead; an adjusting plate is connected between two convex lugs at the rear end of the wire clamp body; the binding plate and the adjusting plate are provided with the racks on the sides opposite to each other; and the distance between the sub-leads is adjusted by changing the engaging position of the racks on the binding plate and the adjusting plate. The spacer has the advantages of compact structure, convenient installation, wide application range, and the like, thereby being capable of conveniently compensating the lead arc vertical installation error, and also being capable of adjusting the distance between the sub-leads in fine tuning mode or coarse tuning mode; and the distance is adjusted without blind region to realize stepless adjustment of the distance between the sub-leads.

The invention provides a ground-conductor spacer bar. The ground-conductor spacer bar comprises a ground wire clip, a spacer bar insulator, an energy release bar, a connection fitting and a conductor spacer bar, which are connected in sequence, wherein the ground wire clip is movably connected with the spacer bar insulator, the connection fitting and the conductor spacer bar. The energy release bar includes a ground wire end fitting, a conductor end fitting, and an energy release mechanism, wherein the energy release mechanism includes a sleeve, a bushing, a guide rod and a spring; the ground wire end fitting is inserted into one end of the sleeve; a buffer cushion is placed in the sleeve at a position to which the ground wire end fitting is adhered; the other end of the sleeve is connected with the bushing having a contraction section and a guide rod moving port; an inner seal ring and an inner retainer ring are arranged between the contraction section and the sleeve; the guide rod with a guide block and a guide head is arranged in the bushing in a sliding manner, extends outside from the guide rod moving port, and is connected with the conductor fitting; and a spring is sheathed on the guide rod between the guide block and the inner retainer ring. The ground-conductor spacer bar provided by the invention can solve problem of tripping due to reduction of inter-wire safe distance and wave of the ground wire and the conductor caused by icing and deicing, thereby improving the operation security of the power transmission line.

The invention relates to an active anti-galloping device of an overhead power transmission line, and belongs to the technical field of power transmission line safety protection. According to the active anti-galloping device of the overhead power transmission line, a rack is adopted for transmitting rotation motions of a driving gear, and the design idea that one rotation motion is finally converted into two symmetrical rotation motions is realized. When galloping of the overhead power transmission line is restrained, the swing amplitude of pendulum bobs can be adjusted by combining the conductor galloping amplitude which is monitored in real time. After galloping acceleration signals caused by different wind speeds are monitored, conductor galloping acceleration signals are transmitted to a signal processing system through a conductor, the signals are processed by the signal processing system, and the processed signals are output to an anti-galloping control device through a conductor. The anti-galloping control device conducts recognition on the signals and outputs control instructions, the control instructions are transmitted into a stepping motor through a conductor and the stepping motor rotates by corresponding angles according to the control instructions so as to adjust the amplitude of the motions of the pendulum bobs.

The invention relates to a double-pendulum anti-galloping device of overhead transmission lines and an application method of the double-pendulum anti-galloping device. The double-pendulum anti-galloping device comprises wire clamps, small bolts, an annular isolation ring, short connecting rods, a resonance-pendulum absorber and a parametric-resonance-pendulum absorber, wherein one ends of the wire clamps are fixedly connected to transmission wires, the other ends of the wire clamps are fixedly connected to the annular isolation ring in an even distribution manner through the small bolts, and the number of the wire clamps is matched with the number of the transmission wires; a plurality of through holes are evenly formed in the annular isolation ring, the two short connecting rods are arranged at the bottom of the annular isolation ring, the included angle of the two short connecting rods is alpha, the symmetry axis of the short connecting rods passes the circle center of the annular isolation ring, and the bottom ends of the short connecting rods are connected with the resonance-pendulum absorber which swings in a reciprocating manner around the center of a bundle conductor to absorb the vibration energy of the transmission wires so as to reduce the vibration of the transmission wires. The double-pendulum anti-galloping device has the advantages that the resonance-pendulum absorber and the parametric-resonance-pendulum absorber are combined to form the integral double-pendulum anti-galloping device, and horizontal vibration, vertical vibration and inclined vibration can be reduced at the same time.

A clamp for a spacer-damper includes a first jaw and a second jaw connected to the first jaw. The first jaw has a first clamping surface and a first aperture. The first aperture retains the fastener in an initial position and in a second position spaced latterly from said initial position. The second jaw has a second clamping surface and an open-ended second aperture. The second aperture receives the fastener in the second position. The first jaw may also include a keeper surface for receiving the fastener in an initial position, a keeper pocket for receiving the fastener in a second position and a keeper protrusion is positioned between the keeper surface and the keeper pocket.

The invention provides a semi-solid single-point waving prevention device which comprises a cover, a piston and a base, wherein the cover, the piston and the base are sequentially arranged on the same axis in parallel. The semi-solid single-point waving prevention device is characterized in that an outer barrel is arranged on the base, the piston located in the outer barrel is connected with the cover through a piston rod, a spring is arranged between the cover and the base and located on the outer side of the outer barrel, and silicon oil is arranged in the outer barrel. Compared with the prior art, the semi-solid single-point waving prevention device is good in waving prevention performance, can effectively restrain waving of an electric transmission line under ice wind shock excitation, is simple in structure and easy to mount, can be matched with a sub conductor spacer, and is good in economic performance and suitable for large-scale popularization and use.

The invention provides a universal vibration absorption ball. The universal vibration absorption ball is composed of an inner ball body, an outer shell, and elastic pieces arranged between the inner ball body and the outer shell, wherein the elastic pieces are springs or silica gel bodies. The universal vibration absorption ball is simple in structure and low in construction cost; when a power transmission line moves horizontally, the two springs are used for damping the resistance and elastic force in each direction, and the power line can swing leftwards and rightwards, and play upwards and downwards, so that the vibration in each direction is effectively reduced. The resistance and tensile force can reduce the swinging of a circuit, and the vibration absorption effect can be effectively realized.

The invention discloses a vibration damper capable of preventing slippage or ponding in the technical field of vibration dampers. The vibration damper comprises a steel strand and a damper head, wherein the steel strand is connected with the damper head; the bottom of the damper head is fixedly connected with a balance weight screw; a row of balance weights are arranged on the balance weight screw; the end of the balance weight screw is in screw joint with two groups of anti-falling nuts; the end of the steel strand is connected with a sleeve; a fine tuning screw is connected into the sleeve in an inserted manner; a clamping piece is locked on the fine tuning screw through bolts; and a check ring, a spring and a limiting ring are arranged at each of two ends of the clamping piece. The balance weights are additionally arranged on the balance weight screw, the adjustment for the weight of the vibration damper is realized so as to adapt different circuit conditions, the vibration damper is convenient for antiskid clamping fixation through the arrangement of a fixed plate, a mounting clamping plate and an antiskid clamping piece, and ponding is convenient to drain through the arrangement of anti-ponding inclined grooves formed in the mounting clamping plate and the fixed plate.

A clamp (40) for attaching a vibration damper to an energized suspended conductor (98) includes a base (42) having a first clamp member (46) with first and second extension sections (50, 52). The clamp (40) further includes a second clamp member (56) positioned between the extension sections (50, 52), and an eyebolt (58) for securing the second clamp member (56), to the first clamp member (46). The extension sections (50, 52) continuously abut the second clamp member (56) to prevent its rotation about the eyebolt (58). During installation, the eyebolt (58) is captured by a hook member (92) of shotgun stick (94) and a single lineman secures the vibration damper to the conductor (98).

The invention discloses an annular multi-split vibration-damping galloping preventer which comprises a closed annular tube. The external surface of the annular tube is provided with a plurality of lead clamps. The annular tube is internally provided with a vibration damping system. Furthermore antifreezing and anti-corrosion liquid is filled in the annular tube. According to the annular multi-split vibration-damping galloping preventer, integrated design of a spacer rod a multi-split galloping preventer is realized. The vibration damping system which is arranged in the closed annular tube can restrain the vertical vibration amplitude of the lead to a certain extent by means of self weight for preventing an overlarge tension load of the lead because of excessive deformation of the lead on one hand; and on the other hand, the vibration damping system can generate resonance before a power transmission lead for consuming system energy, thereby reducing torsion and vibration degrees, and prolonging service life of a lead system. Through reducing torsion amplitude of the multi-split lead in galloping, the annular multi-split vibration-damping galloping preventer has functions of effectively restraining vibration amplitude, improving a lead operation environment, and prolonging service life of the lead.

The invention relates to a long-span two-body damper, in particular to a long-span special two-body damper which belongs to a protection tool for absorbing the vibration energy of an overhead cable and is especially suitable for complex transmission lines with long span and frequent line vibration. The long-span two-body damper comprises a cable clamp I, a cable clamp II, a pre-twisted wire, a steel strand, a middle hammer, a big hammer I and a big hammer II; a hook-shaped sleeve is respectively arranged at the upper part of the cable clamp I and the cable clamp II, a neck is respectively arranged at the head part of the cable clamp I and the cable clamp II, a through hole is respectively arranged at the lower part of the cable clamp I and the cable clamp II, the hook-shaped sleeves arranged at the upper parts of the cable clamp I and the cable clamp II are sleeved on a cable, the pre-twisted wire passes through the necks at the upper parts of the cable clamp I and the cable clamp II and are fixedly connected with the cable, and the steel strand are arranged in the through holes at the lower parts of the cable clamp I and the cable clamp II in a penetrating way and pressed and fixed; the steel stand passes through the through holes arranged at the lower parts of the cable clamp I and the cable clamp II, the middle part of the steel strand passes through the middle hammer, two ends of the steel strand respectively extend into the bag hammer I and the big hammer II, and the three hammers are connected in series by the adhesion of adhesive.