Showing papers on "Frustum published in 2012"

Understanding the Edge Effect in Wetting: A Thermodynamic Approach

Abstract: Edge effect is known to hinder spreading of a sessile drop. However, the underlying thermodynamic mechanisms responsible for the edge effect still is not well-understood. In this study, a free energy model has been developed to investigate the energetic state of drops on a single pillar (from upright frustum to inverted frustum geometries). An analysis of drop free energy levels before and after crossing the edge allows us to understand the thermodynamic origin of the edge effect. In particular, four wetting cases for a drop on a single pillar with different edge angles have been determined by understanding the characteristics of FE plots. A wetting map describing the four wetting cases is given in terms of edge angle and intrinsic contact angle. The results show that the free energy barrier observed near the edge plays an important role in determining the drop states, i.e., (1) stable or metastable drop states at the pillar’s edge, and (2) drop collapse by liquid spilling over the edge completely or stay...

Pyramid as test geometry to evaluate formability in incremental forming: Recent results

Abstract: The present work has been undertaken with an objective to fill the gaps of previous studies and to explore guidelines to standardize the test specimen for evaluating formability with a single specimen in single point incremental forming (SPIF). Two candidate geometries for formability testing (i.e. varying wall angle pyramidal frustum and varying wall angle conical frustum) have been compared by varying geometrical parameters and materials. The critical size in horizontal plane (i.e. half-side length/curvature radius) and critical initial forming angle have been identified and compared for the two geometries. The critical size in horizontal plane has been found to be different for the two geometries. The critical initial forming angle has been found to be same for the two geometries. For various sheet materials, the difference in the formability of VWACF and VWAPF shows a dependence upon the percent reduction in area at tensile fracture.

On Heatshield Shapes for Mars Entry Capsules

Abstract: The 70deg sphere-cone - the standard geometry for all US Mars entry missions - is thoroughly examined via flow field simulations at a select few peak heating points along candidate flight trajectories. Emphasis is placed on turbulent heating based on the Baldwin- Lomax turbulence model. It is shown that increased leeward turbulent heating for a 70 sphere-cone flying at angle of attack is primarily due to the discontinuity in curvature between the spherical nose cap and the conical frustum - the attachment of the sonic line at this sphere-cone junction leads to a supersonic edge Mach number over the leeward acreage. In an attempt to mitigate this problem of elevated turbulent heating, alternate geometries, without any curvature discontinuities in the acreage, are developed. Two approaches, one based on nonlinear optimization with constraints, and one based on the use of non-uniform rational B-splines, are considered. All configurations examined remain axisymmetric. The aerothermal performance of alternate geometries is shown to be superior to that of the 70 sphere-cone.

Free convection from a truncated cone subject to constant wall heat flux in a micropolar fluid

Abstract: The paper studies the problem of free convection about a vertical frustum of a cone in a micropolar fluid It is assumed that the flow is laminar, steady and the wall is subjected to a constant heat flux and the angle of the frustum of the cone is large enough so that the transverse curvature effects are negligible Under these assumptions, the governing boundary layer equations subject to appropriate boundary conditions are transformed into a set of equations of parabolic type, that are solved using the local non-similarity method The space of parameters contains the Prandtl number Pr, the micropolar parameter Δ and the microrotation parameter n Numerical solutions are obtained by varying Pr from 67 to 100, Δ from 0 (Newtonian fluid) to 2 and considering two values of n with physical significance (0 and 05) Flow and heat transfer characteristics are determined and are shown in graphs The results are discussed and compared at some extent with those reported by the present author in a previous study (Postelnicu in Int J Eng Sci 44:672–682, 2006) on the isothermal case

Design and Optimization of a Millimetre Wave Compact Folded Magic-T

Abstract: A millimetre wave-folded magic-T junction compensated with metal cone is designed using a particle swarm optimization (PSO) algorithm. An off-centred metallic frustum was used to enhance the bandwidth and a metallic post is used to compensate the mismatched E-arm. The geometrical parameters of the frustum and the post are optimized by PSO. The optimized magic-T for W-band application is designed and tested. The design features are simple in structure and easy to fabricate. The 2% bandwidth with centre frequency of 94 GHz and return loss less than −20 dB is achieved.

Biological material vitrification freezing carrier

Abstract: The utility model discloses a biological material vitrification freezing carrier, which comprises a straw plug (1), a carrier tube (2) and an outer sleeve (3). The straw plug (1) consists of a cone frustum, a sealed cylinder and a handle, wherein the sealed cylinder and the handle are fixed to two ends of the cone frustum respectively. The carrier tube (2) is positioned in the outer sleeve (3); a bevel opening (2-1) is arranged at the left end of the carrier tube (2); the right end of the carrier tube (2) is in close fit with the sealed cylinder (1-1) of the straw plug (1); cotton fibers are arranged at the left end of the outer sleeve (3); and the right end opening of the outer sleeve (3) contacts with a conical surface of the cone frustum. The biological material vitrification freezing carrier has the advantages of low cost, high freezing rate, and simplicity and rapidness in operation. Damage to embryos during freezing is reduced, and freezing efficiency and the viability of the frozen embryos are improved.

Self-supported all-welded plate type heat exchanger

Abstract: The invention discloses a self-supported all-welded plate type heat exchanger, which is formed by welding adjacent heat-exchanging plate main bodies and is characterized in that protruding and sinking cone frustums are uniformly distributed on rectangular heat-exchanging plates at interval, opposite edgefolds are arranged at two parallel edge sides of each heat-exchanging plate only, and the height of each edgefold is the sum of the protruding height and the sinking depth of each cone frustum; and half of the edge-folded heat-exchanging plates and the other half of edge-folded heat-exchanging plates are arranged in a manner of equidirectionally arranging adjacent edgefolds by 90 degrees, the protruding cone frustums and the sinking cone frustums of every two plates are opposite, edge-folded end faces and the non-folded edges of the heat-exchanging plates are welded mutually by an angle of 90 degrees, thus, a 90-degree rectangular-block heat exchanger with mutually crossing channels are formed, the edges of four opposite faces of the heat exchanger are respectively welded in an edge extension manner on a same plane to form a border which is connected or welded with bolts of a fan cover, and an air leading-in port and an air leading-out hole of same media are spaced by 180 degrees. The self-supported all-welded plate type heat exchanger has the advantage that the problem on recovering waste heat under running micro-resistance during gas-gas heat exchanging of low-pressure or micro-pressure high-temperature tail gas, smoke and the like is solved.

Broadband beamfoming using Nested Planar Arrays and 3D FIR frustum filters

Abstract: A topology of planar array called Nested Planar Arrays (NPAs) is used for broadband beamforming. The NPAs consist of several Uniform Planar Arrays (UPAs), each one with the double element distance of the previous array. The signals from these arrays are fed into different subbands which process different octaves of temporal frequency bands. The combination of NPAs and multirate techniques leads to the same 3D frustum filter frequency specifications for all subbands. The passband of these 3D frustum filters does not include the low temporal frequencies where it is difficult to achieve high selectivity. Simulation results indicate that with the same number of sensors, NPA can achieve longer aperture size compared to a UPA and thus higher selectivity particularly for lower temporal frequencies. For the same aperture size, NPA can be implemented with much less sensors and much less computations than a UPA with small deterioration in the performance.

Rim locking chuck device

Abstract: The utility model relates to a rim locking chuck device, which comprises a frustum. A gear disc is arranged on the lower peripheral portion of the frustum. The rim locking chuck device is characterized in that positioning pins matched with small holes of a rim radial plate are arranged on the periphery of the frustum, a plurality of radial slots are uniformly distributed along the upper side of the frustum, a reciprocating slider driven by a central reciprocating driving mechanism is arranged on each radial slot, and positioning slots for centering and locking of the rim are arranged at outer edges of the reciprocating sliders respectively. The rim locking chuck device is simple in structure, convenient in use and firm in locking and positioning.

Disc steel bar straightening machine for building

Abstract: The utility model discloses a disc steel bar straightening machine for building, and belongs to auxiliary devices for building engineering. The disc steel bar straightening machine for building is characterized by mainly comprising a left clamp, a right clamp, a winding machine and a fixed pile, wherein the structures of the left clamp and the right clamp are the same, and the left clamp and the right clamp are opposite to each other at an interval; the left clamp mainly comprises a conical frustum, a sleeve ring and a rope ring; the diameter of the left end of the conical frustum is small, and the diameter of the right end of the conical frustum is large; the sleeve ring of which the inner diameter is smaller than the diameter of the right section of the conical frustum is sleeved on the middle section of the conical frustum; the rope ring is welded on the left end face of the conical frustum; a pull rope is tied on the rope ring and connected with the fixed pile on the left outer side; a steel wire rope connected to the rope ring of the right clamp is correspondingly connected with the winding machine on the right outer side; and the left end and the right end of a steel bar to be straightened are bent to form hooks which are correspondingly clamped between the conical frustums and the sleeve rings of the left clamp and the right clamp and straightened by tension. The disc steel bar straightening machine has a simple and rational structure and is convenient to manufacture and use; and the construction cost is reduced.

Rapid pipe hole measurer

Abstract: The utility model discloses a rapid pipe hole measurer The top part of the measurer is provided with an operating handle; the lower part of the measurer is provided with a cone frustum part which is gradually transitional from big end to small end; scale marks are manufactured on the side face of the cone frustum part; and the numerical value marked by each scale mark is equal to the value of the diameter of the horizontal section of the corresponding cone frustum part The rapid measurer disclosed by the utility model is simple and practical in structure; reading can be accurate to one-thousandth; the measurement accuracy can be accurate to percentile; the operation is rapid and convenient; the maintenance is simple; people capable of reading a dividing rule can operate the measurer; the measurement efficiency is high, ie only a few seconds are needed from the operation to numerical value reading; and the pipe hole measurement requirements on components, such as pipe sheets and baffles in the field of chemical machinery manufacturing, boiler manufacturing and energy equipment manufacturing can be completely met

Shadow drafting method of large-scale outdoor scene

Abstract: The invention provides a shadow drafting method of a large-scale outdoor scene. The method comprises the following steps that: view frustum division is carried out according to a depth value, so that segmentation units of the view frustum are obtained; optic frustum division is carried out to obtain rectangular pyramid-shaped division units of the optic frustum; rendering is carried out on a shadow graph to obtain a rendering effect graph of the shadow graph; and rendering is carried out on a whole scene of a large-scale outdoor scene so as to obtain a rendering effect graph of the whole scene of the large-scale outdoor scene. According to the invention, a shadow drafting method of a large-scale outdoor scene is provided, wherein the method can be rapidly realized and has a small occupied memory space.

An LED light fixture

Abstract: The utility model provides an LED light fixture with an increased light-emitting angle and an expanded illumination range. The LED light fixture comprises a substrate used for fixing LED lighting chips and the LED lighting chips; the substrate is shaped as a quadrangular frustum pyramid, with the upper surface being a square or rectangular flat surface and the four sides being inclined surfaces shaped as an isosceles trapezoid; and the LED lighting chips are distributed on the upper surface and the four sides of the substrate and are connected with a power source electrically. By employing a quadrangular frustum pyramid structure, instead of a conventional plane structure, as a structure of the substrate for fixing the LED lighting chips, the LED light fixture solves the problem of a small light-emitting angle of a conventional LED light fixture and realizes wide-angle light-emitting and large illumination range, thereby having more extensive applications.

Rain cover for power switch mechanism box

Abstract: The invention discloses a rain cover for a power switch mechanism box. The rain cover comprises a cover body and is characterized in that the rain cover for the power switch mechanism box is in a shape of a cone frustum; the upper bottom surface of the cone frustum is matched with the cross section of a connecting rod on the power switch mechanism box; a rubber sealing ring is fixedly arranged on the circumference of the upper bottom surface of the cone frustum; and the rain cover comprises a pull-in device which is arranged on the cover body. By the rain cover for the power switch mechanism box, the rubber sealing ring is connected with the connecting rod in a sealing mode, the rainwater is effectively prevented from leaking along with an outer wall of the connecting rod, the rainproof effect is well achieved, and by arranging the pull-in device, the rain cover is simple in structure and convenient to mount and can be used for effectively preventing the rain.

Cylinder device applied for belt conveyor

Abstract: The utility model discloses a cylinder device applied for a belt conveyor, which overcomes the defects that when the existing belt conveyor conveys wet materials, wet materials easily adhere to conveying belts and tail wheels so that the conveying volume and the working efficiency are reduced In the cylinder device, bottoms of two frustum type cylinders are symmetrically welded on two sides of a central supporting board and are sleeved outside a main shaft vertically penetrating through the central supporting board, and each of tops of the two frustum type cylinders is welded with each of two end face supporting boards which are perpendicular to the main shaft, the end face supporting boards are provided with opening holes; a supporting partition is arranged on the outer surface of each of frustum type cylinders and is connected with the central supporting board and the end face supporting boards; outer edges of the central supporting board and the two end face supporting boards are fixedly connected with a plurality of round steels which are parallel to the main shaft, a gap is arranged between two adjacent round steels, and the round steels form a cage-type cylindrical structure The cylinder device applied for the belt conveyor can effectively discharge the wet materials adhering to the back of the conveying belts

Carbon fiber layer thin shell reinforced supporting cabin

Abstract: The invention relates to a carbon fiber layer shell reinforced supporting cabin, comprising a carbon fiber layer frustum cabin body, a carbon fiber layer middle frame connected with an inner wall of the carbon fiber layer frustum cabin body, and a carbon fiber layer cap type reinforcing rib connected with an outer wall of the carbon fiber layer frustum cabin body; wherein the carbon fiber layer frustum cabin body comprises an upper end frame arranged on a top end thereof, a lower end frame arranged on a bottom end thereof, and a skin which is used for pressing and fixing the upper end frame and the lower end frame and is laid on the outer wall of the carbon fiber layer frustum cabin body. The carbon fiber layer shell reinforced supporting cabin provided by the invention can effectively increase carrying capacity of rockets, actively improve satellite-rocket vibration environment, solve the satellite-rocket vibration response coupling problem, ensure high precision of cabin body connection face, and enable outer surfaces of the cabin body to be smooth and beautiful.

Variable cross-section cross box-shaped conversion steel column

Abstract: The utility model discloses a variable cross-section cross box-shaped conversion steel column, which comprises a box-shaped column, a cross frustum column and steel corbels, wherein the box-shaped column is welded on the on the upper portion of the cross frustum column, the steel corbels are welded on the outer surface of the box-shaped column. Reinforced concrete is replaced with variable cross-section cross box-shaped conversion steel columns, so that the cross section of the cross column at the bottom is reduced through the variable cross section, and the bearing capacity is guaranteed, at the same time, cost and space are saved.

Special-shaped thermal insulation and decoration integrated external wall cladding panel, manufacture method thereof and mould for processing same

Abstract: The invention relates to a special-shaped thermal insulation and decoration integrated external wall cladding panel, a manufacture method thereof and a mould for processing the same. The integrated cladding panel comprises an intermediate thermal insulation layer and a structural layer, wherein the structural layer wraps the periphery of the intermediate thermal insulation layer and is matched with the intermediate thermal insulation layer in shape. The inner side face of the intermediate thermal insulation layer is in the shape of a quadrangular frustum pyramid, the outer side face of the intermediate thermal insulation layer and the inner side face thereof are in parallel and are separated by a certain gap, the upper bottom of the intermediate thermal insulation layer and an upper bottom hole of the quadrangular frustum pyramid are positioned in the same plane, and the lower bottom of the intermediate thermal insulation layer is perpendicular to the plane of a lower bottom hole of the quadrangular frustum pyramid. The structural layer comprises a border, a reinforcing steel frame and a concreting layer, wherein the border is formed by a fiberglass mesh fabric, the reinforcing steel frame is positioned at the lower bottom and is arranged in the fiberglass mesh fabric border, and the concreting layer is formed by inlaying fiberglass chopped strands filled inside and outside the fiberglass mesh fabric border and the reinforcing steel frame into cement paste and comprises an inner surface layer, an outer surface layer, an upper bottom layer and a lower bottom layer. The special-shaped thermal insulation and decoration integrated external wall cladding panel perfectly combines thermal insulation with decoration, so that remarkable technical progress and good economic benefit are obtained.

Hopper of plastic extruding machine used for sensor forming process

Abstract: The utility model discloses a hopper of a plastic extruding machine used for a sensor forming process. The hopper comprises a hopper body consisting of a cylindrical storage cylinder, a frustum body connected with the lower part of the storage cylinder, and a discharge cylinder connected with the lower part of the frustum body; the whole hopper body has a cavity structure; the frustum body at least provided with two air nozzles which are connected with a high-pressure air source through a pipeline; and the top of the storage cylinder is provided with a sealing cover which is provided with a filtering device. According to the hopper, the top of the storage cylinder is provided with the sealing cover, so that powder can be prevented from being blown out by high-pressure air; the sealing cover is provided with the filtering device, the powder is baffled in the hopper body by the filtering device, and the high-pressure air is discharged out simultaneously, so that pressure in the hopper body is reduced; and the hopper is simple in structure and convenient and practical.

Cell-covering small caliber sleeve plus cone loading antenna

Abstract: The utility model relates to an antenna, in particular to a small caliber loading antenna. The cell-covering small caliber sleeve plus cone loading antenna comprises an oscillator (2), a sleeve (4) and a cable, and is characterized in that the oscillator (2) is sleeved by the sleeve (4) and extends out of the sleeve (4), the cable is connected with the oscillator (2) through the false connector (5), outside the sleeve (4) there is provided a frustum (3), and the upper end of the frustum (3) is connected with the upper end of the sleeve. In order to achieving better matching, the upper end of the oscillator (2) is also provided with a loading sheet (1). The oscillator (2) is a brass tube with an inner diameter of 3 mm and an outer diameter of 5 mm, the sleeve (4) is a brass sheet with a diameter of 40 mm and a thickness of 0.3 mm, the frustum (3) is a brass sheet with a small caliber of 40 mm, a lower caliber of 58 mm an a thickness of 0.3 mm, and the loading sheet (1) is a brass sheet with a diameter of 40 mm and a thickness of 0.5 mm. Although the antenna with such a structure is small in size, the antenna has a low frequency range from 806 to 960 MHz and a high frequency range from 1710 to 2690 MHz, thereby completely satisfying the demands of 4G and a gain of 2-3 dB, and having an excellent coverage effect.

Superfine water mist nozzle

Abstract: The utility model relates to fire fighting and fire extinguishing equipment, and discloses a superfine water mist nozzle. The superfine water mist nozzle comprises a nozzle body and at least one nozzle seat, wherein the nozzle body is provided with a water inlet and a water outlet, and at least one nozzle seat is arranged at the water outlet of the nozzle body. The superfine water mist nozzle is characterized in that a support, a flow guiding body arranged on the support and a nozzle sleeve for accommodating the flow guiding body are sequentially arranged in the nozzle seat; the nozzle sleeve is provided with a spout; and the flow guiding body is composed of a mounting column, a transition cone frustum and a whirling column which are in butt joint, wherein the mounting column is inserted in the support in a sliding manner, and the outer wall of the whirling column is provided with spiral grooves. The superfine water mist nozzle is simple in structure, and the diameter of mist is less than 100 microns.

Testing device and measuring method for measuring early-age anti-cracking performance of concrete with different thicknesses

Abstract: The invention discloses a testing device and measuring method for measuring early-age anti-cracking performance of concrete with different thicknesses.. The testing device comprises an anti-cracking device, working strain gauges, a temperature compensation gauge, a strain acquisition system and a computer, wherein the working strain gauges and the temperature compensation gauge are installed on the anti-cracking device, a signal input terminal of the strain acquisition system is connected with the working strain gauges and the temperature compensation gauge, and a signal output terminal of the strain acquisition system is connected with the computer. The testing device is characterized in that the anti-cracking device is in the shape of a cone frustum and comprises a bottom plate, an inner steel ring and an outer template, wherein both the inner steel ring and the outer template are installed on the bottom plate, the outer template is the shape of a cone frustum, and the inner side of the inner steel ring is provided with at least five layers of working strain gauges in the height direction. The testing device provided by the invention is simple in structure, convenient to disassemble, and applicable to the measurement of the early-age anti-cracking performance of concrete with different thicknesses in one anti-cracking device.

Pin back-riveting device

Abstract: The utility model discloses a pin back-riveting device. An annular groove for insertion of a part is formed between a frustum of a part reference base and an external mandril sleeve arranged outside the frustum; opposite radial through holes are formed in the frustum and the external mandril sleeve; an internal mandril and an external mandril which are opposite to each other are arranged in the radial through holes; grooves opposite to the external mandrils are formed in an inner hole of a rotating ring outside the external mandril sleeve, and the radiuses of the grooves are gradually reduced; a power rod of which the top is provided with a slop is inserted into an axial hole of the frustum and is driven by one end of a raising rod with a lever structure to move up and down; the rotating ring rotates, and each groove in the inner hole can be prevented from pressing the external mandrils; the raising rod swings, so that the end of the raising rod can push the power rod to move up; and the internal mandril can outwards move along the slope, so that the inner end of a pin is expanded to be open, and a back-riveting effect is achieved. The pin can be back-riveted only by driving the raising rod to quickly swing; the whole operation process is simple, convenient and high in efficiency; furthermore, the back-riveting operation of the pin is automatically and mechanically finished; the quality is easy to guarantee; and the reject rate is low.

Hanging mechanism of exhaust pipe

Abstract: The invention belongs to the field of auto parts and particularly relates to a hanging mechanism of an exhaust pipe. The hanging mechanism of the exhaust pipe is characterized by comprising a connecting cone frustum and a cylindrical connecting block, wherein a connecting lug is connected on the upper surface of the connecting cone frustum; a connecting through hole connected with an automobile chassis is arranged on the connecting lug; a plurality of spring shock-absorbing devices are arranged between the cylindrical connecting block and the cone frustum; a second connecting lug is arranged at the lower surface of the cylindrical connecting block; and a connecting hole connected with the exhaust pipe is arranged on the second connecting lug. Aiming at defects of a conventional lifting lug technology of the exhaust pipe, the invention provides the hanging mechanism of the exhaust pipe, which adopts a soft material as a connecting matrix and has the effects of shock absorption and noise reduction.

Die for lock hole of car door inner plate

Abstract: The utility model relates to the technical field of punching dies, particularly to a die for the lock hole of a car door inner plate. The die comprises a male die and a female die, wherein a frustum is arranged at the lower end of the male die, a cylindrical table is arranged in the center of the lower end surface of the frustum, a semi-sphere is arranged in the center of the lower end surface of the cylindrical table, the diameter of the bottom end surface of the frustum is larger than that of the cylindrical table, the female die is provided with a groove matched with the frustum of the male die, and a cavity matched with the cylindrical table, the height of the frustum is larger than the depth of the groove, and the cavity is higher than the cylindrical table. The die has the advantages of convenience in maintenance, simplicity in assembling, low difficulty in design, and high quality of products, and low cost.

Gas atomization nozzle for preparing superfine metal powder

Abstract: The invention discloses a gas atomization nozzle for preparing superfine metal powder. The nozzle is characterized in that the working portion of an upper nozzle (1) is a cone frustum and a metal outflow channel (3) is axially arranged in the center of the upper nozzle; a lower nozzle (2) is formed by connecting an inner cone frustum below a cylindrical inner cavity; an arc-shaped transition section (7) of the lower nozzle is arranged at the joint; an air inlet cavity (4) is formed between the upper nozzle (1) and the cylindrical inner cavity of the lower nozzle (2); and throats (5) and airflow expansion sections (6) are formed by combination of the cone frustum of the upper nozzle (1) and the inner cone frustum of the lower nozzle (2), thus forming a channel with Laval nozzle structure characteristics. The nozzle is suitable for atomization of all the metals and alloy melts with melting points below 1500 DEG C and especially provides a new solution to preparation of the superfine powder of such metals with low melting points as aluminium, zinc, magnesium, tin and the like and alloys.

Rolling method of right cone frustum shell bodies

Abstract: The invention relates to a rolling method of right cone frustum shell bodies. The rolling method comprises the following steps of: 1) before rolling, cutting a shell body into an unfolded-fan-shaped workpiece according to a design drawing, dividing the workpiece into 4-12 equal parts according to the length of each fan-shaped steel plate, and causing the length of each equal part to be subject tothe standard that the workpiece rolls in parallel and does not to warp; 2) making roll arc sample plates R1 and R2, the radian of R1 is equal to the diameter of an upper opening of the fan-shaped workpiece, and the radian of R2 is equal to the diameter of a lower opening of the fan-shaped workpiece; during rolling the shell body, using the sample plates to check up the degree of circular curve ofthe upper opening and the lower opening; 3) during rolling the shell body, the lift angle Beta of one end of a three-roll plate bending machine is equal to 90 degrees minus Alpha, and Alpha is the degree of an angle of inclination of the shell body of a cone furnace; and 4) sequentially processing all shell bodies piecewise, keeping the rolling of each equal part and the upper roll shaft of the three-roll plate bending machine be a ray state, and rolling processing in parallel. The rolling method has strong operability, simple steps, convenience for checking up and high degree of accuracy, the damage of a crank shaft and the shell bodies is decreased, and the quality and efficiency are increased.