57results about How to "Adjust the force" patented technology

The invention discloses a device and a method for preparing porous foam metal by a metal melt inflation process. The device comprises a metal melt groove, a foaming chamber, a fluid hole, a release valve and a metal crystallizer. The middle of the metal crystallizer is provided with a high-frequency ultrasonic oscillator; and the high-frequency ultrasonic oscillator is connected with a high-frequency ultrasonic power source used for adjusting the oscillation frequency, amplitude and power of the high-frequency ultrasonic oscillator. The high-frequency ultrasonic oscillator is started, when the bubble-containing metal melt passes through the metal crystallizer, bubbles are subjected to ultrasonic oscillation for fragmentation under the action of the high-frequency ultrasonic oscillation, and a bubble is fragmented into several smaller bubbles; and the oscillation frequency and the amplitude of the high-frequency ultrasonic oscillator are adjusted, so that the fragmentation degree and the size of the bubbles meet the requirements. The bubbles formed by high-frequency ultrasonic oscillation have uniform size and distribution; and the device and the method have the advantages of simple process and low cost, and are suitable for large-scale production, promotion and application.

The invention provides a cab side window for a rail transit locomotive. The cab side window comprises a bottom cross beam, a side window fixing frame, a glass supporting beam, a glass fixing frame, side window glass, a crank-connecting rod-sliding block mechanism and sliding rails. The length direction of the sliding rails is vertically arranged, the sliding rails are located in the center of the side window fixing frame in the width direction, the bottom ends of the sliding rails are fixedly connected to the bottom cross beam, and the top ends of the sliding rails are directly or indirectly connected to the side wall of a locomotive cab fixedly. A sliding block matched with the sliding rails is connected with the glass supporting beam. One end of a crank-connecting rod assembly is fixedly connected to the side window fixing frame, and the other end of the crank-connecting rod assembly and the sliding block are connected to form the crank-connecting rod-sliding block mechanism so as to support the sliding block to vertically move up and down in the sliding rails along with the side window glass. An existing crank-connecting rod mechanism which is eccentrically stressed is replaced with the crank-connecting rod-sliding block mechanism which is centrally stressed, the improved side window is balanced in stress, abrasion to an aluminum alloy window frame is reduced in the opening and closing processes of the side window, and the normal service life of the side window is prolonged.

The invention discloses a puncture simulation training device and a puncture simulation training method. The puncture simulation training device comprises at least one operation console, at least one touch operation screen and at least one host computer. An operation console is corresponding to a touch operation screen. A touch operation screen is corresponding to a host computer. Each touch operation screen is detachably connected with a corresponding operation console through a support structure. Each touch operation screen is connected with a corresponding host computer through a line. According to the invention, the puncture simulation training device can help students to carry out puncture simulation exercises through the operation console and the corresponding touch operation screen; and through a simulation technology, students carry out experiments in a virtual environment to realize a teaching function unavailable or difficult for real experiments to reach teaching purposes required by syllabus.

The invention discloses a method for hoisting a steel dome of a nuclear power plant in a balance-keeping manner. The method is realized by cooperation of a balance hosting device of the steel dome of the nuclear power plant and hoisting machinery and comprises the steps of assembling in place, trial hoisting, hoisting and the like. A plurality of adjustments are carried out in each step to stress related components in a balance-keeping manner, so that the stability of the hoisting process is ensured. The method can ensure the balance of multi-point hoisting stress and accuracy of levelness of a lower opening of the dome, is applicable to hoisting and mounting of the dome of a containment of the nuclear power plant, is used for ensuring the balance of hoisting stress and accuracy of levelness of the lower opening of the dome, and is also applicable to the hoisting process of other spherical segment and spherical coronary objects.

The invention discloses a device and method for mechanical property evaluation and mechanical sealing evaluation of a cement ring when large fracturing is performed. The device comprises a to-be-measured cement ring, an inner cylinder sleeving an inner surface of the cement ring, an outer cylinder sleeving an outer surface of the cement ring, a pressure-adjustment mechanism connected with the inner cylinder to adjust a pressure acting on an inner wall of the cement ring, a temperature control mechanism connected with the cement ring and controlling temperature of the cement ring, and a detection assembly for detecting a stress state, a stress size and mechanical sealing performance of the cement ring. The device can test mechanical properties and mechanical sealing performance of the cement ring well, and a data support is provided for selection of a cement slurry system when large hydrofracture of, especially, an unconventional reservoir layer occurs.

The invention relates to a wall template bottom plugging device, a template supporting system and a formwork construction method, and relates to the technical field of building construction template structures, installation and protection. The wall template bottom plugging device comprises a locker, a grouting stop structure, and an adjusting structure respectively connected with the locker and the grouting stop structure, wherein the grouting stop structure comprises a flexible sealing body; the adjusting structure comprises an adjusting frame, a first adjusting screw rod and a second adjusting screw rod with one ends being respectively in threaded connection with the adjusting frame, and a first connecting body for tightly pressing the grouting stop structure; the rotation directions ofthe first adjusting screw rod and the second adjusting screw rod are opposite; and the central axes of the first adjusting screw rod and the second adjusting screw rod are collinear, and are inclinedtowards a part to be plugged. The template supporting system comprises the wall template bottom plugging device detachably connected with a steel pipe main keel on the bottommost part. The formwork construction method adopts the template supporting system. According to the wall template bottom plugging device, the template supporting system and the formwork construction method provided by the invention, the technical problem of a poor grouting stop effect of a plugging device in the prior art can be solved, and an effect on tightly plugging is achieved.

The invention discloses a hydraulic weighing unit and a ten-thousand-ton grade hydraulic electronic scale. The hydraulic weighing unit comprises a hydraulic cylinder, a control oil circuit, an oil pump and a pressure sensor; the oil pump controls the hydraulic cylinder through the control oil circuit; and the pressure sensor is arranged on the hydraulic cylinder, and is used for measuring the stress of the hydraulic cylinder. The hydraulic electronic scale comprises a displacement module and a stressed module, wherein the displacement module comprises at least three hydraulic weighing units, and each hydraulic weighing unit also is provided with a displacement sensor and a frequency converter; the frequency converter controls the oil pump of each hydraulic weighing units, and forms a position closed loop together with the displacement sensor; and the stressed module comprises at least one hydraulic weighing unit. Compared with the prior art, the electronic scale provided by the invention can conveniently weigh the weight of the ten-thousand-ton grade object, and can automatically collect and calculate the weight and gravity center data of the object.

The invention provides a side-mounted lens set and a mounting method thereof. The lens set comprises a frame, an optical lens and two hard supporting points which are symmetrically distributed at two sides of the vertical axis of the frame and are integrally formed with the frame, wherein each hard supporting point directly contacts with and is connected with the optical lens. The bottom of the optical lens is provided with an elastic supporting member in contact connection through an adjusting screw. The top of the frame is provided with a compression screw which is used for preventing axial displacement of the optical lens. The mounting method comprises the steps of placing the optical lens on the hard supporting member of the frame sideways; applying a force with a certain magnitude to the optical lens through the compression screw for making the optical lens abut against each hard supporting point; adjusting the supporting force of the elastic supporting member for supporting the optical lens, and locking the adjusting screw; mounting more than one pre-tightened reed, applying glue to glue applying holes for fixedly connecting the frame with the optical lens; and mounting an axial stopper. The side-mounted lens set and the mounting method have advantages of relatively high stability, relatively high face type precision and benefit for engineering realization.

The invention discloses a tension measuring and controlling device of a jig dyeing machine, which comprises a casing used for containing dye solution, a first cloth roller and a second cloth roller that is positioned above the first cloth roller; wherein, the first cloth roller and the second cloth roller are respectively connected with a variable-frequency motor that can control the rotating speed and the torque; the device also comprises a first lower track roller and a second lower track roller which are positioned inside the dye solution. The device is characterized by further comprising a force-measuring roller arranged between the first lower track roller and the second lower track roller, as well as a first hydraulic cylinder and a second hydraulic cylinder that are respectively arranged outside the casing; wherein, the two ends of a roll shaft of the force-measuring roller respectively act on the ends of hydraulic rods of the first hydraulic cylinder and the second hydraulic cylinder; the singles of a first pressure sensor used for measuring the pressure of the first hydraulic cylinder and a second pressure sensor used for measuring the pressure of the second hydraulic cylinder are transmitted into a control computer which can control the running of the variable-frequency motor that is respectively connected with the first cloth roller and the second cloth roller. The tension measuring and controlling device can realize the aim of immediately measuring and controlling the tension of cloth when the jig dyeing machine dyes.

The invention relates to a method and a device for testing tactile viscosity of an adhesive. The fixing device is beneficial to conveniently fixing various types of adhesive test pieces for quantitative test, and is beneficial to obtaining high-precision test data representing the tactile viscosity. The method, tactile viscosity of the adhesive in a non-room-temperature state can be measured. Themethod is advantaged in that the stress and the stress time of a bonding surface can be accurately and conveniently adjusted through the technical characteristics that a mass-adjustable assembly and an upper clamp fall off from the tension equipment in time and then are connected. By adopting the method, test pieces can be prepared and replaced easily, and the method can be suitable for mounting and testing various adhesive type test pieces.

The invention relates to the technical field of electromagnetic lock manufacturing, in particular to a cabin door electromagnetic lock for aviation. The cabin door electromagnetic lock comprises a main engine electronic loop device used for producing currents, a magnetizer communicated with the main engine electronic loop device, and armature fixed into a cabin door, wherein an electrifying switch used for controlling on-off of the currents produced by the main engine electronic loop device is arranged in the main engine electronic loop device, a copper coil used for generating magnetic force is arranged in the magnetizer, and the armature is used for being attracted by the magnetizer under the effect of the magnetic force. According to the cabin door electromagnetic lock, the copper coil is used for replacing an electromagnet, the electrifying switch adjusts magnitude of the currents and on-off of the currents to control the size and existence of a magnetic field of the magnetizer, and electromagnetic attracting lock force can be adjusted and controlled conveniently. Moreover, the structure design gap of a locking mechanism does not need to be reserved, the structural gap when the cabin door is in a closed state is reduced, and the problem that when the cabin door is closed, due to rigid impact of the locking mechanism, the structure is damaged is avoided.

The invention provides a printing head self-adaptive adjustment device which comprises a fixing rack, a connecting rack and a connecting component; the fixing rack is arranged on a printer base; a printing head is arranged on the connecting rack; the connecting rack is connected with the fixing rack by the connecting component; the connecting rack has a locking state and a rotation adjustment state relative to the fixing rack; the connecting component comprises a connecting piece and an elastic piece; the connecting rack is connected with the fixing rack through the connecting piece; and the elastic piece generates pressure on the matching end faces of the connecting piece and the fixing rack. In a rotation adjustment state, the printing head deflects relative to a rubber roller, by this time, the pressure on the contact line of the printing head and the rubber roller is not balanced, and then torque driving the connecting rack to deflect is generated till the contact line of the printing head and the rubber roller is stressed uniformly. Self-adaptive adjustment on the parallelism degree of the printing head and the rubber roller is realized, the contact line of the printing head and the rubber roller is stressed uniformly, and thus the printing quality is improved.

The invention discloses a tension measuring and controlling device of a jig dyeing machine, which comprises a casing used for containing dye solution, a first cloth roller and a second cloth roller that is positioned above the first cloth roller; wherein, the first cloth roller and the second cloth roller are respectively connected with a variable-frequency motor that can control the rotating speed and the torque; the device also comprises a first lower track roller and a second lower track roller which are positioned inside the dye solution. The device is characterized by further comprising a force-measuring roller arranged between the first lower track roller and the second lower track roller; a first force-measuring bracket and a second force-measuring bracket are respectively arranged at the two sides of the force-measuring roller and outside the casing, and the two ends of a roll shaft of the force-measuring roller respectively act on the first force-measuring bracket and the second force-measuring bracket; the singles of a first electronic voltage-sensitive sensor used for measuring the pressure of the first force-measuring bracket and a second electronic voltage-sensitive sensor used for measuring the pressure of the second force-measuring bracket are transmitted into a control computer which can control the running of the variable-frequency motor that is respectively connected with the first cloth roller and the second cloth roller. The tension measuring and controlling device can realize the aim of immediately measuring and controlling the tension of cloth when the jig dyeing machine dyes.

The invention discloses an engine. The engine comprises a piston, a connecting rod and a piston pin used for connecting the piston with the connecting rod. The piston pin and the piston are tightly matched through a pin sleeve. The inner circle and the outer circle of the pin sleeve are provided with eccentric structures in order to adjust the relative positions of the piston pin and the piston through rotating of the pin sleeve. According to the engine, by arranging the pin sleeve to be of an eccentric structure, when the pin sleeve is at different angles, an inner hole of the pin sleeve is changed relative to the distance of the top surface of the piston, the total length of the piston and the connecting rod is changed, the movement position of the piston in a cylinder is changed, the combustion chamber volume is adjusted, because the engine displacement is unchanged, the compression ratio of the engine is adjusted along with rotation of the pin sleeve; and according to the engine, the fact that the compression ratio can be adjusted is achieved, meanwhile, the fact that eccentricity of the piston is adjustable is realized, according to different operating conditions, piston stress is adjusted, and the reliability of the piston is improved. The invention further discloses a vehicle comprising the engine.

The invention relates to medical equipment, in particular to exercise equipment for medical care after leg fracture rehabilitation. The to-be-solved technical problem is to provide exercise equipmentfor medical care after leg fracture rehabilitation, which does not need the limitation of a site and has low risk during exercise. According to the technical scheme, the equipment comprises a bottom plate, a first fixing block, a seat, a first sliding rail, a first sliding block, a supporting rod, a first nut, a connecting block, a first bearing seat and the like; the first fixing block is connected to the right upper side of the bottom plate, the seat is connected to the upper end of the first fixing block, the first sliding rail is connected to the left upper side of the bottom plate, and the first sliding block is slidably connected in the first sliding rail. The exercise equipment for the medical care after the leg fracture rehabilitation has the advantages that the limitation of the site is not needed, the risk during the exercise is low, by adopting a mode in which a user sits on the seat and then steps on a pushing plate to move leftward to exercise, the user can exercise without the limitation of the site and not fall during exercise.

A relief valve (1) capable of reducing the pressure of fuel in a discharge passage (214) is provided with: a valve housing (30) having a through-hole (310); a valve member (40) which is provided so asto be capable of reciprocating relative to the valve housing (30), prevents fuel from flowing between the discharge passage (214) and a fuel chamber (211) when in contact with an inner wall (311) formed around the through-hole (310), and permits fuel to flow between the discharge passage (214) and the fuel chamber (211) when moved away from the inner wall (311); a spring (45) for pressing the valve member (40) so that the valve member (40) and the inner wall (311) will be in contact with each other; an adjusting pipe (50) provided on the opposite side of the valve member (40) from the inner wall (311) and capable of adjusting the pressing force of the spring (45); and a stopper (60) provided as a separate element from the adjusting pipe (50) and coming in contact with the valve member (40) to prevent the valve member (40) from moving in the valve opening direction.

The invention discloses household kitchen garbage treatment equipment. The household kitchen garbage treatment equipment comprises a box body, a first frame body, a second frame body, a storage box, afirst stirring mechanism, and multiple second stirring mechanisms, wherein the first stirring mechanism comprises a first cylinder, a second cylinder, a first screw rod and multiple sets of stirringmodules. The household kitchen garbage treatment equipment can thoroughly crush household kitchen garbage in time and smoothly discharge the household kitchen garbage into a sewer, and is simple in structure, easy to operate and higher in economical practicability.

The invention belongs to the technical field of anti-rollover device, in particular to an anti-rollover device used in agricultural machinery based on hydraulic regulation. The anti-rollover device used in agricultural machinery based on hydraulic regulation comprises a force plate, a motor, a first belt pulley, a third belt pulley, a first fixed shaft, first supporting plates, a first fixed rod,a second fixed rod, an arc-shaped block and the like. One end of the motor is fixedly installed on the side face of an accommodation cavity, and the end face of one end of the first belt pulley is fixedly installed on the shaft end face of the motor. One end of the force plate is fixedly installed on the side face of a rear vehicle pocket, and the force plate is matched with the accommodation cavity. One ends of the two first supporting plates are fixed on the end face of the force plate. The anti-rollover device has good adjustment of the force condition of the front end of the agricultural machinery, and can quickly and conveniently adjust the force of the front end of the agricultural machinery, so that the rollover phenomenon of the agricultural machinery during the uphill process is prevented.

The invention belongs to the technical field of unmanned sailing boats, and provides a device capable of achieving wind power generation and power adjustment and control and an unmanned sailing boat.The device capable of achieving wind power generation and power adjustment and control comprises a wind sail, a mast, a supporting frame, two perpendicular shaft wind powered generators and two electric generator damping adjustment circuit modules. The wind sail is fixed to the supporting frame, the supporting frame comprises an upper supporting plate, a lower supporting plate and a plurality of supporting columns, and the two ends of each supporting column are fixedly connected with the upper supporting plate and the lower supporting plate correspondingly; the two perpendicular shaft wind powered generators are symmetrically distributed on the two sides of the wind sail, and comprise electric generators, wind wheels and rotating shafts, the electric generators are installed on the lower supporting plate, one ends of the rotating shafts are connected with the electric generators, the other ends of the rotating shafts are rotatably installed on the upper supporting plate, and the wind wheels are fixed to the rotating shafts; and the two electric generator damping adjustment circuit modules are connected with the two electric generators in a one-to-one corresponding mode, and used for adjusting the fan blade rotating speeds of the wind wheels. According to the unmanned sailing boat, automatic energy storage can be achieved by utilizing marine energy sources, and the problems of electric energy consumption and sailing boat unstability in the sailing process can further be solved.

The invention discloses a ceramic clay rubbing method, and relates to the technical field of ceramic processing. Ceramic clay processing equipment mainly comprises a rack, a workbench, a rotary disc,an upper pressure plate, a left pressure plate and a right pressure plate. The ceramic clay rubbing method comprises the following steps: (1) placing ceramic clay on the rotary disc; (2) enabling theupper pressure plate to move along with an oval, and utilizing the upper pressure plate to match with the rotary disc for performing pressure applying construction on the ceramic clay; (3) enabling the rotary disc to move up and down, enabling the rotary disc to match with the upper pressure plate to perform pressure applying construction on the ceramic clay; (4) enabling the left pressure plate to mutually open and close with the right pressure plate, and performing pressure applying processing on the ceramic clay; (5) enabling the rotary disc to rotate in single direction one grid by bone grid for rotating the ceramic clay, wherein steps (2) to (5) can be arranged and combined according to different sequences to realize difference processing actions. According to the ceramic clay rubbingmethod disclosed by the invention, the rotary disc, the upper pressure plate, the right pressure plate and the right pressure plate can be mutually matched in different ways to realize various processing actions, so that ceramic clay can be mixed more uniformly and finely.

The invention discloses a balanced hoisting device for a nuclear power plant steel dome. The balanced hoisting device is used in cooperation with hoisting machines and comprises a hoisting unit and a fixing unit. The hoisting unit comprises main hoisting steel wire ropes, at least one layer of balance pulley and at least one layer of auxiliary hoisting steel wire rope. The fixing unit comprises at least two fixing ropes and second adjusting devices fixed to the lower ends of the fixing ropes. When the number of the main hoisting steel wire ropes is larger than or equal to two, a first adjusting device used for adjusting the balance stress of the corresponding auxiliary hoisting steel wire rope is fixed to the tail end of any one of auxiliary hoisting steel wire ropes of the corresponding last layer of each main hoisting steel wire rope. The fixing unit comprises at least two fixing ropes and the second adjusting devices fixed to the lower ends of the fixing ropes. According to the balanced hoisting device, multi-point hoisting stress balance and levelness accuracy of a lower opening of the dome can be guaranteed. The balanced hoisting device is suitable for hoisting and installing the nuclear power plant safety shell dome and used for guaranteeing the hoisting stress balance and the levelness accuracy of the lower opening of the dome and can also be used for hoisting other spherical-segment-shaped objects and spherical-crown-shaped objects.

The invention discloses a double-ball joint combined motion type bird-imitating flapping wing device and belongs to the field of bird-imitating flapping wings. The device comprises a connecting wing rod, an upper edge rib, a lower edge rib and multiple intermediate ribs. The upper edge rib, the intermediate ribs and the lower edge rib are aligned and stacked in one row, a pin shaft penetrates through one end of the upper edge rib, one end of each intermediate rib and one end of the lower edge rib to fix the ends, the other ends are movably expanded in a bundle shape, a foldable wing film covers the upper edge rib, the intermediate ribs and the lower edge rib to form a wing face, the fixed ends of the lower edge rib and the upper edge rib extend, the extending ends are each provided with aball joint, the two ball joints are connected through a spring, any ball joint is coaxially and fixedly connected with a motor, and the motor is coaxially fixed to the connecting wing rod. The force moment is applied to the first ball joint through the motor, and the second ball joint and the lower edge rib are driven by the spring to rotate. The device is simple in structure, convenient to use and control, good in stability and particularly suitable for upper-air flight of a bird-imitating flapping wing robot.

The invention discloses a polyurethane microcellular foam material for a railway under-rail backing plate and a preparation method thereof, the polyurethane microcellular foam material is composed of 100 parts by mass of a material A and 93-105 parts by mass of a material B. The material A is composed of 100 parts by mass of polyester polyol, 6-9 parts by mass of a micromolecule chain extender, 0.06-0.10 part by mass of a foaming agent, 0.4-0.6 part by mass of a foam stabilizer and 1.3-1.5 parts by mass of a catalyst; the material B is prepared from the following components in parts by mass: 47 to 50 parts of isocyanate and 50 to 53 parts of polyester polyol; the polyurethane microcellular foaming material disclosed by the invention has the characteristics of light weight, easiness in deformation, good folding resistance, impact resistance, easiness in molding and good buffering performance, can bear higher load, and avoids the problem of stress concentration of the under-rail backing plate; and under the stress deformation condition, the deformation is uniform, and the stress at each part is uniform, so that the service life is longer under the severe track state and huge transportation volume condition of the heavy-load existing line.

The invention discloses a kitchen waste treatment system. The kitchen waste treatment system comprises a box body, a material charge hopper, a material charge mechanism, a suction filtration mechanism, a crushing mechanism and a material discharge mechanism, wherein the material charge mechanism comprises a first cylinder body, a second cylinder body, a first screw rod and a plurality of groups ofmaterial discharge assemblies; the suction filtration mechanism comprises a material storage box, a liquid storage box and a first pipe body; the crushing mechanism comprises a first rotary body anda second rotary body; the material discharge mechanism comprises a material discharge box and a plurality of stirring assemblies. The kitchen waste treatment system has the advantages that the kitchenwaste can be timely and thoroughly crushed, and be smoothly discharged via a sewer, and the blockage accident of the sewer is prohibited; the structure is simple, the manufacturing cost is lower, theconsumption level of more users can be met, and the economy and practicality are higher.

The invention discloses an efficient energy-saving garbage crusher. The efficient energy-saving garbage crusher comprises a box, a feed hopper, a suction-filtration mechanism, a discharging box and acrushing mechanism, wherein the suction-filtration mechanism comprises a material storage box and a liquid storage box; the crushing mechanism comprises a first frame body, a second frame body and a plurality of stirring mechanisms. By adopting the efficient energy-saving garbage crusher, household garbage can be disposed rapidly in situ. The efficient energy-saving garbage crusher has the advantages of high efficiency, saving in energy, environmental friendliness, higher economical practicability and the like.

The invention relates to ceramic clay rubbing equipment, and relates to the technical field of ceramic processing. A workbench is horizontally arranged on a rack; a rotary table can be horizontally and rotatably embedded in the workbench and is provided with a ratchet wheel driving mechanism enabling the rotary table to unidirectionally rotate; a left pressing plate and a right pressing plate canbe arranged on the rack in a left and right moving manner through a lead screw sliding table driving mechanism and are oppositely distributed on the left and right sides of the rotary table; and an upper pressing plate is movably arranged on the rack through a multi-connecting rod driving mechanism in a manner of substantially elliptical motion, and is located above the rotary table. According tothe ceramic clay rubbing equipment, the rotary table, the upper pressing plate, the left pressing plate and the right pressing plate can cooperate with each other in different ways, thus, a variety ofprocessing actions are realized, and the ceramic clay can be mixed more uniformly and delicately.

The invention relates to a magnetic field adjusting device on a high-openness superconduction magnetic resonance magnet. The design difficulty of the high-openness superconduction magnetic resonance magnet is large than that of the common superconduction magnetic resonance magnet, an imaging region has more non-uniform magnetic field and larger leakage magnetic field range due to the limit of the openness of the high-openness superconduction magnetic resonance magnet to sizes of all parts of the magnet, and a superconduction coil and other ferro magnetic materials bear sizable magnetic force. The invention discloses a magnetic field regulating device on the high-openness superconduction magnetic resonance magnet, which comprises a low-temperature dewar fixed on an iron yoke superconduction coil and a superconduction coil arranged in the low-temperature dewar, wherein a magnetic field regulating device corresponding to the superconduction coil is arranged on the iron yoke, and comprises one or more high-permeability components. By using the change of the ferro magnetic material to the magnetic field, the uniformity of the magnetic field of the imaging region is improved, and the size and the range of a leakage magnetic field are reduced.

The invention discloses a grinding-area-adjustable stone grinding machine for bridge construction. The grinding-area-adjustable stone grinding machine comprises a rack and a grinding unit, the grinding unit includes a grinding assembly and a lifting mechanism for driving the grinding assembly to ascend and descend, the grinding assembly includes a grinding rotation shaft, a first motor used for driving the grinding rotation shaft to rotate, and a grinding body fixedly mounted at the bottom end of the grinding rotation shaft, the grinding body comprises a millstone, an adjusting block, a connecting rod, a worm gear ring, and a worm, the lifting mechanism comprises an electric push rod, a first mounting plate, a second mounting plate, and a compression spring, and further includes a dust reduction unit and a cleaning unit. According to the grinding-area-adjustable stone grinding machine for bridge construction, the grinding assembly is arranged, the grinding diameter during grinding canbe adjusted to achieve the effect of adjusting the grinding area according to demand; the lifting mechanism is arranged and can protect the grinding body, and meanwhile the compression amount of the compression spring can be adjusted to achieve the purpose of adjusting the grinding amount; the dust reduction unit and the cleaning unit are arranged to avoid affecting the environment and the healthof workers, and debris is avoided from affecting the grinding quality and even damaging the grinding body.