90results about How to "Eliminate precision issues" patented technology

A press mounted cam has a slide guided on an adapter by structural features including as one or more T blocks fixed to the slide and received in a respective channel formed in the adapter. In an aerial cam embodiment, a vertical clearance space is provided between the T block and adapter channel such that positive driving engagement between cam surfaces on the slide and the adapter is momentarily delayed after the initial engagement of the slide and driver surfaces to let the momentum of the slide be absorbed prior to the beginning of positive driving by the press motion, reducing shock and noise. The slide is laterally located with respect to the driver by an upwardly projecting locator-guide key on the driver received in a central channel in the slide. A positive return is provided by engagement of a driver key having T features received in a T-shaped slide channel and captured therein when the slide is driven laterally. This engagement creates a positive return of the slide when the press upper platen is raised.

The invention discloses a digital out-of-pile nuclear measurement system based on a PC / 104 bus. The digital out-of-pile nuclear measurement system comprises a neutron detector, a front-end signal conditioning and amplifying unit and a signal digital processing unit, wherein the signal digital processing unit comprises a host processing unit, a data acquisition unit and a data output unit which are connected through the PC / 104 bus. Compared with the prior art, the digital out-of-pile nuclear measurement system based on the PC / 104 bus utilizes the PC / 104 bus as a safety software platform, facilitates adjusting of the control scheme and realization of various novel control strategies, reduces the number of components, and simplifies the hardware structure, thereby improving the reliability and meeting the requirement for nuclear safety digitization of ex-core nuclear instrumentation systems in large-scale nuclear power stations.

The invention provides an absolute propagation time measuring method for an ultrasonic flow meter. The method comprises the following steps of: setting an energy converter 3 at the center of an opposite side between an energy converter 1 and an energy converter 2, which are arranged in the shape of V; if the distance between the energy converter 1 and the energy converter 2 is set to be L, setting the transverse distance between the energy converter 3 and the energy converter 1 and the transverse distance between the energy converter 3 and the energy converter 2 are both to be L / 2; when the absolute propagation time in case of fair current is measured, leading the energy converter 1 to send out ultrasonic signals, and two receivers, i.e. the energy converter 2 and the energy converter 3, receive the signals; and obtaining the time difference of the signals received by the two receivers by a mode of getting the relative propagation time, wherein a metering result of the time difference is the time that the ultrasonic signals are propagated to the energy converter 2 from the energy converter 3, i.e. obtaining the fair current absolute propagation time in the case that the energy converter 2 and the energy converter 3 are distributed in the shape of Z, wherein the adverse current absolute propagation time measuring method is similar to the fair current absolute propagation time measuring method. The method is used without a timing module, i.e. absolute time measurement is converted into relative time measurement, so that the measurement precision is improved.

A microadvance system for accurate grinding machine is composed of a drive unit consisting of piezoelectric drive power supply, piezoelectric ceramics, man-machine interface type input device, and displacement-voltage table, an executing unit consisting of flexible hinge mechanism and microadvance bench, a detecting unit consisting of inductance-type position sensor or raster rule, detection signal acquiring module, displacement-voltage compensation data table, and signal processing-outputting module, and a control system consisting of microprocessor, D / A and A / D converters, data I / O display, signal amplifier, information integrating interface, and signal processing reference model and algorithm.

A press mounted cam has a slide guided on an adapter by structural features including as one or more T blocks fixed to the slide and received in a respective channel formed in the adapter. In an aerial cam embodiment, a vertical clearance space is provided between the T block and adapter channel such that positive driving engagement between cam surfaces on the slide and the adapter is momentarily delayed after the initial engagement of the slide and driver surfaces to let the momentum of the slide be absorbed prior to the beginning of positive driving by the press motion, reducing shock and noise. The slide is laterally located with respect to the driver by an upwardly projecting locator-guide key on the driver received in a central channel in the slide. A positive return is provided by engagement of a driver key having T features received in a T-shaped slide channel and captured therein when the slide is driven laterally. This engagement creates a positive return of the slide when the press upper platen is raised.

The invention discloses a special mechanism for automatically conveying a high-temperature saw bit. The mechanism comprises a base, an upright post and the like, wherein the upright post is fixed on the base, a rotating crossarm is connected with the upright post and can rotate around the upright post, and a slider fixed on a conveyer belt is driven to move on a sliding guide rail by a sliding driving motor which is fixed on the rotating corssarm through pulley transmission; actions of a movable paw of clamping and loosening a high-temperature sheet are realized through the rotation of a clamping driving motor fixed on the slider; and the rotating driving motor is fixed on the base, an output shaft is provided with a pinion which is meshed with a circular arc rack fixed on the rotating crossarm to drive the rotating crossarm to rotate around the upright post, and a positioning pin on the rotating corssarm slides on the rotating guide rail during rotating so as to realize the function of rotatably conveying the high-temperature saw bit. The mechanism can realize the high-speed high-efficiency conveying of the high-temperature saw bit, eliminates adverse influence such as the pressing precision reduction and quality reduction of the saw bit caused by overlarge temperature drop in the conveying process, and has the advantages of high efficiency, high speed, accuracy and reliability.

The invention discloses a control method for high-power reactive and harmonic dynamic hybrid compensation method. The hybrid compensation system comprises an SVG (static var generator), a TSF (thyristor switched filter) group and a controller, and the SVG and TSFs are parallelly connected to a grid. The three-phase current of the grid between the SVG and the TSFs is taken as a detection object, voltage and current values collected by sensors are processed through the controller, switching signals of the TSFs are acquired according to hybrid logic judgment, most of the reactive power of loads is compensated in a graded manner, and specific subharmonic is filtered out; control parameters of the SVG are acquired according to an instantaneous-power theory, and the surplus reactive power and harmonic of the loads are continuously compensated. A cost-effective scheme for rapid continuous compensation of the high-power reactive and harmonic is provided, impact of switching of passive equipment on the grid can be completely avoided, and harmonic current is avoided flowing to the grid, so that the control method is energy saving, emission reducing, green, environment friendly, good in social and economical effectiveness, wide in application range and especially applicable to the field of oil drilling.

The invention discloses a turbine blade air film hole precision forming method, and belongs to the field of rapid casting based on a photocuring forming technology. The turbine blade air film hole precision forming method comprises the following steps: 1) manufacturing a turbine blade resin mold by using the photocuring rapid forming technology; 2) pouring ceramic slurry into a resin mold prototype of a turbine blade through a gel casting method to obtain a casting mold blank body, so that forming of an air film hole ceramic core is realized; 3) further strengthening the air film hole ceramiccore through vacuum freeze drying and high-temperature sintering, so that forming of different ceramic-based air film hole ceramic cores is realized; and 4) for the air film hole ceramic cores with different types of ceramic bases, combining a directional solidification technology to realize air film hole casting forming of various high-temperature alloys, and finally removing the ceramic cores remained in a metal blade and an air film hole through a core removing process, so that high-quality forming of the cast air film hole is realized. The turbine blade air film hole precision forming method is reasonable in design and simple and convenient to operate, and can realize forming of the high-quality cast air film hole.

The invention relates to a fiber screen bag and a method for rapidly determining coarse fibers. After special fibers are used for making a screen with pore diameter being 25.0mum, a sample is put into a screen bag with certain size and is respectively boiled in acid and alkaline for 40min, then the sample is washed clean, dried and weighed and the content of the coarse fibers can be calculated by subtracting the weight of ash. The fiber screen bag and the method can be used by scientific research institutions, analysis and detection institutions, feed plants and the like to rapidly determine the content of the coarse fibers of feed, grains, oil and food on a large scale, and can also be used for rapidly determining neutral detergent fibers (NDF), acid detergent fibers (ADF), celluloses, hemicelluloses, dietary insoluble fibers, lignin and the like on a large scale. Compared with the traditional national standard method, the method has the advantages that the method is suitable for large-scale rapid determination, the efficiency is high, the time is short, the precision and the accuracy are high, the cost is low, and equipment such as any fiber determination instrument, filter and suction filtration devices and the like are not required. The fiber screen bag has the advantages that the bag is not floated, the weight is not lost, the moisture is not absorbed, the bag is not broken, the ash does not exist and the like when solvents such as acid, alkaline, acetone and the like are used for treatment.

A grinder for machining straight-line guide track is composed of a main body, a bench on the main body, a fixture on the bench, a gantry above the main body and consisting of two vertical columns and transverse beams, two servo motors at both sides of front transverse beam, feeding carriage driven by leading screw, electric mainshafts on said carriage, and lift adhesive discs arranged to lower end of each electric mainshafts. It has high machining precision.

The invention belongs to the nuclear power technical field and specially discloses a reactor coolant pump rotation speed measuring method based on an FPGA. The method is characterized by carrying out transient voltage suppression and electrostatic protection on a rotation speed sensor signal of a coolant pump; then, shaping the obtained rotation speed sensor signal into a single-polarity square wave signal; after carrying out lowpass filtering, carrying out optoelectronic isolation on the signal; determining a pulse count value of a high-speed clock pulse signal with high-speed clock pulse frequency in the FPGA being a reference; obtaining a reactor coolant pump rotation speed value; after carrying out value limitation processing, converting the rotation speed value into a digital signal; and outputting the digital signal to a current-type DAC device through a high-speed figure isolation chip. Preliminary calculation of the coolant pump rotation speed is carried out through high-speed clock pulses in the FPGA, so that, compared with that of the existing method, measurement accuracy is improved greatly; and meanwhile, pure hardware characteristics of the FPGA are utilized, and the method has higher reliability, compared with the conventional software processing.

The invention discloses a charge matching-based offset correction method of a full-symmetric four-terminal dynamic comparator. The charge matching-based offset correction method includes the following steps that: a comparator is controlled to come into an offset correction state according to clock signals, reset signals and correction signals; common-mode electric level signals are inputted into the input end of the comparator; and an adjustable capacitor connected with the output end of the comparator is controlled, so that the output positive and negative end charges of the comparator can be matched under the effect of the adjustable capacitor, wherein the adjustable capacitor can be formed through short circuiting of the source and the drain of an NMOS transistor. With the charge matching-based offset correction method of the full-symmetric four-terminal dynamic comparator of the invention adopted, influence of floating nodes on the speed and accuracy of the comparator can be eliminated, and offset caused by various factors in the dynamic comparator can be eliminated, and circuit accuracy can be improved. The invention also provides a charge matching-based offset correction system of the full-symmetric four-terminal dynamic comparator.

The invention belongs to the technical field of visual space positioning, and discloses a visual SLAM method based on optical flow and semantic segmentation, and the method comprises the steps: carrying out the segmentation of input image information through employing a semantic segmentation network to obtain a static region and a predictive dynamic region; performing feature tracking on the static region and the predictive dynamic region by adopting a sparse optical flow method; determining the types of the feature points in the input image information, and removing the dynamic feature points; and taking the set without the motion feature points as tracking data, inputting the tracking data into ORB-SLAM for processing, and outputting a pose result. According to the method, the problem ofpoor SLAM tracking and positioning effect in the dynamic environment is solved, and the trajectory information with high pose precision in the dynamic environment can be obtained.

The present invention relates to a reliability management-based uncertainty elimination scene perception system and a working method thereof. The system comprises a scene information collection module, a scene information processing module, a knowledge library module, a scene response module, a scene information application module, a scene information retrieval or subscription module, a scene information correction module, and a user feedback module. The scene processing module comprises a multi-algorithm incompleteness elimination unit, an algorithm result inconsistency elimination unit, a credibility management unit, a reliability management unit, an information source inconsistency elimination unit, a scene information fusion deduction unit, and an adaptive management unit. Through adoption of the system and method, more reliable scene information can be obtained, and the accuracy, reliability and self-adaptation of the scene perception system are improved remarkably.

The invention discloses an urban traffic volume acquisition method based on checkpoint and mobile phone flow bill data. The urban traffic volume acquisition method comprises the steps of: acquiring latitude and longitude coordinates of critical positions of a research road network, and filling road network coordinates with required precision by adopting a linear interpolation method; extracting road sections having checkpoints in a range of the research road network, and selecting mobile phone flow bill data with latitude and longitude falling into a precision range specified by the road sections; acquiring features of the mobile phone flow bill data in the road sections having the checkpoints after aggregation; performing traffic volume aggregation on checkpoint data in the range of the research road network at specified time interval; and acquiring traffic volume of road sections which are not provided with checkpoints in the research road network through selecting a prediction model. The urban traffic volume acquisition method is based on a multi-source data fusion concept, combines the mobile phone flow bill data and the checkpoint data, eliminates the defect of insufficient data volume caused by poor precision of mobile phone flow bill data and few arranged checkpoint point locations through complementation, and fills in a gap in the application of the mobile phone flow bill data in urban road network.

A kit for removing calcar bone from a resected face around a bone canal of a long bone prepared to receive an orthopaedic implant is provided. The kit includes a trial for insertion into the bone canal of the long bone and a fixture. The fixture has a connector for connecting the fixture to the trial and a guide for guiding the calcar reamer. The kit also includes a calcar reamer for removing calcar bone from the resected face around the bone canal of the long bone. The reamer includes a feature for cooperation with the guide of the fixture. The kit further includes an implant for insertion into the bone canal of the long bone.

The invention discloses a power converting and filtering device for a spaceborne wireless transceiver. The power converting and filtering device comprises a primary power protection module, a primarypower filtering module, a secondary power conversion module, a secondary power filtering module and a tertiary power conversion module which are connected in sequence, wherein a primary power supply sequentially passes through the primary power protection module and the primary power filtering module, generates s paths of secondary power voltage through the secondary power conversion module; the spaths of secondary power voltage enter the secondary power filtering module; the secondary power filtering module outputs n paths of low-noise secondary power voltage and m paths of common secondarypower voltage, wherein p paths of low-noise secondary power supplies and q paths of common secondary power supplies enter the tertiary power conversion module, and p paths of low-noise tertiary powersupplies and q paths of common tertiary power supplies are output; the low-noise secondary power supplies and the low-noise tertiary power supplies are used as the power supplies provided for a low-noise circuit or a linear circuit; and the common secondary power supplies and the common tertiary power supplies are used as the power supplies provided for the circuit which is insensitive to power supply noise.

The invention discloses a three-dimensional postweld weld stress processing system based on machine vision. The three-dimensional postweld weld stress processing system is constituted by a driving mechanism, a crosshead shoe, a rotating mechanism, and a double-camera acquisition device. A stepping motor is used to drive the crosshead shoe to carry out postweld weld precision positioning, and a servo direct current motor is used to control moving of a robot body. The rotating mechanism is cooperated with the crosshead shot to realize three-dimensional motion. The driving mechanism, the crosshead shot, the rotating mechanism, and the double-camera acquisition device are cooperated with each other to realize accurate tracking and stress processing of an ultrasonic impact gun in three-dimensional space. The three-dimensional postweld weld stress processing system is used to effectively solve problems of conventional postweld processing ways such as low precision, low efficiency, and inability of realizing multi-directional weld processing, and is used to improve the quality of the postweld weld.

The invention discloses an elevator speed governor action velocity calibration instrument, which comprises a control host, a driver, a master speed detector and a slave speed detector, wherein the driver, the master speed detector and the slave speed detector are connected to the control host. The control host is provided with an electrical action detection line for connecting an electrical safety switch of an elevator speed governor. The driver is a contact-type rotation driver and the rotation speed thereof is controlled by the control host. The master speed detector and the slave speed detector are respectively a contact-type speed detector. Linear velocity of a pitch circle of the speed governor can be measured accurately without measuring the diameter of the pitch circle of the speed governor or calculating the diameter of the pitch circle of the speed governor by measuring the diameter of a rope slot of the speed governor and the diameter of a steel wire rope of the speed governor during field calibration test; and the linear velocity of the pitch circle of the speed governor is measured accurately at the moment of electrical action and mechanical action of the speed governor without being influenced by the shape of the rope slot of the speed governor, wear of the steel wire rope of the speed governor and wear of the rope slot of the speed governor.

A protective circuit for a battery includes: (1) an MOS transistor having a first drain / source terminal coupled to one terminal of the battery; (2) a switch selectable to couple the bulk terminal of the MOS transistor to (a) the first drain / source terminal, (b) a second drain / source terminal, or (c) float; and (3) a control circuit which provides control signals for the gate terminal of the MOS transistor and the switch. By allowing the bulk terminal to float during normal operation (i.e., charging or discharging operation), a sensitive, low-power comparator used in the prior art is eliminated, thereby allowing the protective circuit to have a small foot-print. The protective circuit may further include a resistor. The switch connects the bulk terminal of the MOS transistor to the first drain / source terminal through this first resistor, thereby limiting any “rush” current which occurs when the battery circuit switches from discharging to charging, or vice versa, over a very short time period. Consequently, safe operation of the battery circuit is achieved.

The invention provides a two-parameter expansion method and a device confirming an underground velocity structure, and belongs to the technical field of seismic explosion. First, velocity of longitudinal wave scanning calculation is conducted to original seismic data to obtain a velocity spectrum and the number and the approximate position of a master stratum. An initial velocity field is obtained through speed analysis. An initial velocity ratio gamma field is set by using the initial velocity field, initial two-parameter velocity analysis and calculation are conducted to obtain an energy curved surface which changes along with two-parameter, namely, a two-parameter velocity spectrum. Then, two-parameter velocity analysis and calculation are further conducted to the selected two-parameter value on the two-parameter velocity spectrum to obtain a novel stack energy profile and a novel two-parameter spectrum. A point with high stack energy is selected on each velocity analysis position and each two-parameter velocity spectrum, the two-parameter field of the point is further confirmed, and an imaging formula is expanded by the two-parameter for imaging. At last, the two-parameter filed is used for acquiring the layer velocity of each layer, and the underground velocity structure is obtained.

The invention discloses a high-stability dielectric loss factor standard device and relates to the technical field of dielectric loss measuring equipment in electrical equipment. The high-stability dielectric loss factor standard device adopts a capacitor shunt type RC dielectric loss model; and through parallel connection between a bridging capacitor and a dielectric loss simulation resistor, resistance and heating power of the dielectric loss simulation resistor are reduced, thereby reducing resistance and power of a resistor in each gear subunit, facilitating model selection of the resistorwithout customization, and meanwhile, eliminating influence of heating of the resistor on the resistance and precision, and preventing influencing stability and precision of the test data. The standard device realizes simulation of dielectric loss value gears larger than the number of gear subunits by controlling the gear subunits to carry out gear combination, thereby greatly reducing size and weight of the dielectric loss factor standard device; and the dielectric loss factor standard device is allowed to be more compact in structure, more reliable and intelligent in performance, and more suitable for on-site calibration of a first production line.

The invention provides a quick analysis method for nonlinear dynamic response of a thermal protection connection structure. The method comprises the steps: constructing a finite element model of the thermal protection connection structure, and extracting an overall mass matrix and an overall rigidity matrix; reducing the total mass matrix and the total rigidity matrix, and defining a structure damping matrix; establishing a contact nonlinear model of the thermal protection connection structure and establishing a nonlinear kinetic differential equation set; converting the nonlinear kinetic differential equation set in the time domain into a nonlinear algebraic equation set in the frequency domain by adopting a high-order harmonic balance method; solving the nonlinear algebraic equation seton the frequency domain of the single frequency by adopting an iterative algorithm, and obtaining a convergence solution of the frequency point along the frequency domain by adopting an arc length continuation technology; judging the stability of the convergence solution; and continuously iterating, converting and solving in the time domain and the frequency domain until the frequency domain response of the whole contact nonlinear system is obtained. The method can achieve the quick solving of the nonlinear frequency domain dynamic response of the thermal protection connection structure.

The invention relates to a gluing machine. The gluing machine includes a base provided with a gluing workstation; a gluing table used for fixing an optical film to be glued and disposed at the gluingworkstation on the base; a movement driving device disposed on the base and outputting matching linear power according to a preset gluing path; and a gluing device in drive connection with the movement driving device and capable of completing gluing operation on the optical film along the preset gluing path under drive by the liner power. Compared with traditional manual gluing manners, the gluingmachine can eliminate a precision problem caused by manual operation errors, can ensure that the optical film has high gluing precision and good gluing operation uniformity, and can effectively protect the optical film from deformation, warping, and the like.

The invention relates to a topping head. The topping head comprises a mounting plate, a first driving piece arranged on the mounting plate, and a topping executing mechanism in drive connection with the first driving piece, wherein topping executing mechanism can be close to or far from an optical diaphragm to accomplish topping operation. Compared with the traditional manual topping mode, the topping head has the advantages that the topping head can eliminate accuracy problem caused by manual error, ensures that the optical diaphragm has high topping accuracy, the consistency of topping operation is good, and the problems of deformation and warping of the optical diaphragm can be effectively prevented.

The invention relates to an automatic container cutting device in which the cutting procedure can automatically run. The cutting device comprises a three jaw chuck, a cutting unit, a controller, a first installing base and a second installing base. The three jaw chuck comprises jaws and a chuck body. The chuck body is driven by a first drive motor to achieve rotating and speed changing. The jaws are driven through a second drive motor to achieve inward or outward movement. The first installing base is provided with a linear guide rail. The cutting unit can be driven by a third drive motor to move along the linear guide rail. The second installing base is provided with an ejecting mechanism corresponding to the cutting unit. The ejecting mechanism is provided with a contact element used for making contact with a tank container. The second installing base is provided with a linear guide rail. The ejecting mechanism can be driven by a fourth drive motor to move along the linear guide rail. The first drive motor, the second drive motor, the third drive motor and the fourth drive motor are all connected with the controller.

An electropneumatic transducer is disclosed having a pneumatic pressure-regulating valve for regulating a control pressure in a pressure chamber by a regulator diaphragm, which rests on (e.g., against a counter-bearing). The counter-bearing can include at least one pressure disk, a regulator spring and an adjusting screw, the regulator diaphragm being held in force equilibrium by the regulator spring and the control pressure. The regulator diaphragm can be coupled to a control valve such that the control valve opens or closes as a function of actual control pressure. The counter-bearing can include an electrically drivable actuator.

The invention discloses a high-pressure direct-injection natural gas engine gas inlet pressure stabilizing device based on the variable coherent wavelength. The device comprises a natural gas pressureadjusting unit, a temperature sensor, a buffer tank, a buffer tank stop valve, a 1 / 4 wavelength pipe assembly, a pressure sensor, a second high-pressure natural gas pipeline and a 1 / 4 wavelength pipeeffective length adjusting device. The first high-pressure natural gas pipeline is sequentially provided with the natural gas pressure adjusting unit, the temperature sensor, the second high-pressurenatural gas pipeline, the 1 / 4 wavelength pipe assembly and the pressure sensor. One end of the second high-pressure natural gas pipeline is connected with a side opening of the first high-pressure natural gas pipeline, and the other end of the second high-pressure natural gas pipeline is connected with the buffer tank. The buffer tank stop valve is arranged on the second high-pressure natural gaspipeline. Multiple 1 / 4 wavelength pipes are arranged in the 1 / 4 wavelength pipe assembly, and each 1 / 4 wavelength pipe is connected with the side opening of the first high-pressure natural gas pipeline. The length of each 1 / 4 wavelength pipe connected into the first high-pressure natural gas pipeline is controlled through the 1 / 4 wavelength pipe effective length adjusting device.

The invention provides an LED mounting base, an adjusting mechanism containing the LED mounting base and an inner red dot sighting telescope containing the adjusting mechanism. The LED mounting base comprises a sliding block base and a base with an LED chip on the center of the front end face, a sliding groove parallel to the length direction of the base is formed in the front end face of the sliding block base, a blind end is arranged at one end of the sliding groove, the other end of the sliding groove is opened, the base is arranged behind the sliding groove, the front end face of the baseand the front end face of the sliding block base are flush, due to modular design of the LED mounting base, compactness is achieved, and gap effects are reduced. Closing force generated during adjusting in the up and down and left and right two-dimensional direction is decomposed into the single direction. The phenomena that the closing force formed by spring elastic force in the different directions increases friction force, due to tolerance transmission between parts, a part gap is caused, the precision of the adjusting mechanism is poor, and interference is caused are avoided. Deflection and clamping caused by adjusting in two directions do not exist, machining difficulty of parts can be reduced, and the production efficiency is improved.

The invention discloses a production line for rolling hollow steel and a rolling forming production method for hollow steel. The production line comprises a heating furnace, a roughing rolling unit, an intermediate rolling unit, a precision rolling unit and a cold bed which are arranged in sequence in the rolling direction, wherein the roughing rolling unit, the intermediate rolling unit, and the precision rolling unit are respectively formed by a plurality of four-roller rolling machines arranged in a staggered manner; the four-roller rolling machines can form circular or hexagonal rolling holes; the included angle between every two adjacent rolling machines is 45 to 90 degrees; the forming method comprises the steps of heating, continuous rolling, cutting for scaling-off and cooling. According to the invention, the conventional composite rolling production line and production process for hollow steel are improved in the light of the deformation rule of metal, so that a set of multi-roll rolling (circular and hexagonal) hollow steel production line and production method is formed, the problem of easy occurrence of out-of-tolerance fracture surface dimensional precision, especially the problem of high out-of-roundness of core holes in the conventional method is eliminated from the pass-by-pass evolution theory of a rolled piece.