130 results about "Hypotenuse" patented technology

The embodiment of the invention provides a chip layout image processing method and device, electronic equipment and a storage medium, and the method comprises the steps: determining a basic structure type corresponding to a target graph according to the line segment position information in an obtained chip layout image; and determining a refined structure type corresponding to the target graph according to the line segment position information and the line segment angle information. And performing rule inspection on the target graph based on standard structure parameters preset for the refined structure type. The defect that only a graph parallel to the transverse axis direction or the longitudinal axis direction of a two-dimensional rectangular plane coordinate system or a graph with a specific bevel edge angle can be recognized at the present stage is effectively overcome and solved, and then the inspection precision and the inspection efficiency of design rule inspection or mask rule inspection are remarkably improved. The practicability and reliability of the rule checking process and the subsequent image adjusting process for the target graph are improved to a certain extent, so that the performance and the yield of the finally produced chip are powerfully guaranteed.

The utility model discloses a different-stroke type buried pipe loop hydraulic balance structure applied to single well control, which comprises at least one buried pipe group, and the buried pipe group comprises a water segregator, a water collector and a plurality of buried pipes; each buried pipe is correspondingly buried in a pipe well, the pipe wells are arranged in an isosceles right triangle shape, the water segregator and the water collector are arranged at the midpoint of the hypotenuse of the isosceles right triangle, the pipe wells are symmetrically arranged in the isosceles right triangle with the perpendicular bisector of the isosceles right triangle as the boundary, and the closer the buried pipes are to the water segregator and the water collector. And the buried depth is deeper. On the premise that the number of the buried pipes is not changed, hydraulic balance of a system meets requirements, energy consumption of a water pump is reduced, and operation cost of the system is reduced by changing the division mode of the buried pipe group, changing the pipeline arrangement mode of the horizontal connecting pipes and adjusting the buried depth of the vertical buried pipes; meanwhile, the number of sub-catchers is reduced, and initial investment is reduced.

The utility model discloses a gantry three-coordinate measuring machine, which comprises a cross beam, the cross section of the cross beam is an isosceles right triangle, and the cross beam comprises a hypotenuse part; a first right-angle notch part and a second right-angle notch part are respectively formed at two 45-degree corner parts of the cross beam; the sliding frame comprises a sliding frame connecting plate, and the sliding frame connecting plate is parallel to the bevel edge part; a first air floating sliding block and a second air floating sliding block are arranged at the bottom of the sliding frame connecting plate, the first air floating sliding block is in sliding contact with the first intersection part, and the second air floating sliding block is in sliding contact with the bevel edge part; a third air floating sliding block and a fourth air floating sliding block are installed on the top of the sliding frame connecting plate, the third air floating sliding block is in sliding contact with the second intersection part, and the fourth air floating sliding block is in sliding contact with the bevel edge part. Through the distribution of the six air floating sliding blocks, stable, effective and symmetrical sliding support can be realized for the cross beam, so that the sliding frame moves more stably, the abrasion of the sliding frame is reduced, the motion performance is obviously improved, the motion torsional pendulum is reduced, and the measurement precision of the measuring machine is improved.

A multi-purpose framer's speed square in the form of a right triangle comprising a top plate with a T-shaped edge and a series of etched top plate lines including framing top plate call outs, a notched front edge having a plurality of notches spaced along the length in ¼″ increments, ruler etching callouts, and lumber width callouts denoting lumber sizes, and a hypotenuse edge having etched top plate lines, common rafter window plumb cut outs and a hip / valley section disposed above the hypotenuse edge having etched degrees and hip / valley roof rafter plumb cuts.

The utility model discloses a sound barrier structure arranged back to a noise source, which comprises a T-shaped device body, the top end of the device body is provided with a sound absorber structure, the sound absorber structure comprises a plurality of tip sound absorbers which are arranged in sequence, each tip sound absorber is of an isosceles right triangle structure, and the tip sound absorbers are arranged at the top end of the T-shaped device body. The first right-angle side of each tip sound absorber serves as the bottom of the tip sound absorber and is connected with the top end of the T-shaped device body, the first right-angle sides and the inclined sides are arranged in the mode that the first right-angle sides and the inclined sides do not face a noise source, namely the second right-angle sides are opposite to the noise source, and the second right-angle side of each tip sound absorber serves as the height of the tip sound absorber and is right opposite to the noise source in a vertical mode. Compared with the prior art, the sound barrier structure has the highest insertion loss value within the center frequency range of 500 Hz to 1600 Hz, so that the sound wave absorption rate is highest, and the noise reduction effect is best.

Disclosed are a prism fixing structure of the optical machine and a projection optical machine. The prism fixing structure of an optical machine includes a body and a prism, the body is provided with a slot, a bearing surface and a baffle, and the prism includes a first side edge, a second side edge and a hypotenuse connected end to end; a glue point is provided between the first side edge and the bearing surface, the hypotenuse is fitted with the baffle, and an oblique angle end formed by the second side edge and the hypotenuse is clamped in the slot.

The utility model relates to the technical field of truss robots, and discloses a truss with an anti-collision structure, which comprises a mounting seat, the top end face of the mounting seat is fixedly connected with a truss body, the top end face of the truss body is fixedly connected with a truss robot, and the top end face of the mounting seat is provided with an anti-collision assembly. According to the truss with the anti-collision structure, the anti-collision plate is impacted to move, the sleeve rod shrinks into the anti-collision plate, so that the bevel edge of the triangle is shortened, the movable rod is pushed to move into the sleeve, the first spring absorbs impact force through elastic deformation and pushes the anti-collision plate to reset after being impacted, and the rubber strip improves damping between the movable rod and the sleeve; the impact force is relieved, the working precision and stability of the robot are protected, a part of impact force drives the mounting sleeve to longitudinally move through the supporting arm, the second spring is further elastically deformed, the impact force is absorbed and buffered, and the robot is protected against excessive impact.

The beam column reinforcing structure comprises a first reinforcing part installed between a beam body and a column body, the first reinforcing part is integrally formed and arranged in a right triangle frame shape, and the two right-angle sides of the first reinforcing part are attached and fixed to the side wall of the beam body and the side wall of the column body correspondingly; at least two reinforcing ribs are arranged on the bevel edge face of the first reinforcing piece, the two ends of each reinforcing rib are connected with the two right-angle edges of the first reinforcing piece respectively, and first supporting columns connected between the right-angle edges and the bevel edge are further arranged on the inner side of the first reinforcing piece. The method has the effect of improving the beam body reinforcing performance.

The utility model discloses a packing carton with a buffer structure, which relates to the technical field of packing cartons and comprises a carton body and a bottom layer, the bottom layer comprises a buffer layer, a support layer, a foam layer, a bearing layer and a group of damping strips, a group of protective corners for keeping stability are fixedly connected in the carton body, the foam layer is mainly used for buffering and damping, and the bearing layer is used for bearing the buffer layer. The shock-absorbing cushion has good elasticity and compressibility, can quickly deform and absorb a large amount of impact energy when an article is impacted, effectively protects the article in the cushion from being collided and damaged, the honeycomb structure can absorb energy through tiny deformation of the honeycomb structure and compression of air, the buffering and shock-absorbing effects are achieved, and triangles for protecting corners have stability; compared with the prior art, the structure can be kept relatively stable and not prone to deformation when being subjected to external force, meanwhile, the bevel edges of the triangle can guide impact force to be dispersed in the specific direction, energy is absorbed through extrusion and deformation of materials, and the corner of an object is well protected.

A portable multipurpose subdivision graduation protractor comprises a main ruler, an auxiliary ruler and a precise hinge shaft unit. The main ruler is of a structure similar to a right triangle, two right-angle sides are main ruler arms, a bevel edge is replaced by a 135-degree fold line, and 45-degree, 135-degree and 90-degree external angles are provided and can be directly used as a fixed angle sample plate; the surface of the main ruler is provided with easily-identified fan-shaped distribution scales which are correspondingly arranged in two layers as difference reference lines; parallel step notches are formed in the upper edge of the vertical main ruler arm and are used for small-angle measurement; the auxiliary ruler is of a two-right-angle-side structure, the vertical side is an auxiliary ruler arm, and the auxiliary ruler can also be used as a fixed-angle sample plate. The horizontal side is a pointer arm, the end portion is of a fan-shaped structure, the radius is the same as that of the fan shape of the main ruler, and ruler reading visual errors can be reduced. Various interior angles can be widely measured and mapped, difference group scribed lines are effectively set, and an error conduction chain is shortened due to the fact that the whole ruler is not provided with redundant components. The precision machining problem is solved, and the measurement precision can be further improved.

The application relates to a multi-module bidirectional variable-configuration mechanism and belongs to the technical field of spaceflight. The mechanism comprises a first module, a second module, a first hinge group and a second hinge group, the first module and the second module are equilateral right-angled triangles, the number of the first module and the second module is four, the first module and the second module are alternately connected, the lower hypotenuse of the adjacent first module and the second module is connected through the second hinge group, and the upper right-angled side of the adjacent first module and the second module is connected through the first hinge group. Through ingenious structural design and driving layout, the mechanism solves the problems of a large number of driving quantity and a complex control system of a previous complex deformation structure, can realize configuration switching through one or two drives, is lightweight and small-sized, the adaptability is increased, and the control cost is reduced.

The utility model discloses a formwork wall installation perpendicularity measuring tool, relates to the technical field of building construction quality acceptance, and solves the problems that a perpendicularity measuring tool in the prior art is inconvenient to move and operate and low in use flexibility. A formwork wall installation perpendicularity measuring tool comprises a triangular support, the triangular support is of a right triangle structure, a graduated scale is arranged on one vertical edge of the triangular support, a supporting rod is arranged on the bevel edge of the triangular support, and a drop hammer is hung on the supporting rod. According to the tool, the structure of the supporting component is simplified, the triangular support which is simple and light in structure is arranged, taking and moving use are convenient, the calibrated scale is arranged and matched with the suspended drop hammer, whether the wall point position corresponding to the vertical edge where the calibrated scale is located deviates or not can be measured, and the inclination deviation degree can be determined. Moreover, the tool is light in structure, can achieve real-time measurement of the perpendicularity of the formwork wall in the installation process under various working conditions, and has the advantages of being accurate in measurement, easy and flexible to operate, rapid in paying off and the like.

The utility model discloses an outdoor measuring device for construction cost, which comprises a base horizontally arranged on the ground; the stand column is vertically arranged on the base; the dial is arranged in a fan shape and is horizontally fixed at the upper end of the stand column; the fixing rod is fixedly arranged on the lower end face of the dial and located at the position of the bevel edge of one side of the dial; the tail end of the movable rod is rotationally connected to the vertex angle position of the upper end face of the dial, and the movable rod is located above the fixed rod; and the laser range finder is arranged at the end parts of the fixed rod and the movable rod. The utility model has the following advantages and effects: the two laser range finders are adopted to measure the distance from the fixed point to the two ends of the position to be measured, and the length of the position to be measured can be calculated by utilizing the sine theorem according to the included angle on the dial, so that the whole measurement process does not need repeated turn-back of a worker, and measurement of multiple positions can be realized by standing at one position; the measuring process is more convenient, and meanwhile the measuring efficiency is improved.

The utility model discloses a PCB (printed circuit board) warpage measuring tool, which relates to the technical field of PCB detection, and comprises a measuring tool, the measuring tool is a right triangle plate, the included angle between the long straight edge and the bevel edge of the measuring tool is 10 degrees, the long straight edge of the measuring tool is provided with scale marks, and the bevel edge of the measuring tool is detachably provided with a support assembly. According to the utility model, the measuring tool is a right triangle with the angle of 10 degrees, the long straight edge of the measuring tool is provided with the scale marks, during measurement, the hypotenuse of the triangle is taken as the bottom, the measuring tool is inserted into the warping area, the scale of the long straight edge is read and recorded after insertion, and the warping value is obtained by multiplying the scale by sin 10 degrees, so that the measuring tool is simple and convenient to operate and does not need to be like a feeler gauge and a needle gauge; and different specifications need to be used for comparison one by one, so that the data measurement efficiency can be effectively improved.

The utility model discloses an anti-loosening unmanned aerial vehicle arm connecting piece which comprises a front arm and a rear arm. A boss extending outwards in the radial direction of the front arm is arranged at the end, facing the rear arm, of the front arm, and the locknut penetrates through the front arm to be in screwing fit with the rear arm. A step extending inwards in the radial direction is arranged at the end, away from the rear arm, of the lock nut, so that when the lock nut is screwed to the rear arm in a matched mode, the step abuts against the boss. A limiting groove penetrating in the thickness direction is formed in the end, facing the rear arm, of the locknut and penetrates through one side, in the length direction, of the locknut, the limiting groove is integrally arranged in a right triangle shape, and the limiting assembly comprises a groove obliquely formed in the bevel edge direction of the right triangle and a limiting rod arranged in the groove; a stop block formed along the protrusion is arranged on the limiting rod, and a spring is arranged between the stop block and the bottom of the groove in a sleeved mode, so that the limiting rod is clamped in the limiting groove when the spring does not generate elastic deformation. The utility model has the advantages of reasonable structural design, simplicity in operation, stronger stress and the like.

The invention discloses a cutting method, system and equipment for a sheet metal right-angle triangular component and a storage medium, belongs to the technical field of sheet metal cutting, and solves the technical problems of low productivity and material waste in an existing cutting mode. The method comprises the following steps: forming a first virtual rectangle by taking the bevel edges of the two right-angle triangular components as common edges; determining a cutting mode according to the height of the first virtual rectangle and the height of the raw material steel plate, wherein the cutting mode comprises a single-row cutting mode and a double-row cutting mode; setting a cutting path of a single-row cutting mode and a cutting path of a double-row cutting mode according to the principle of shortening the total cutting length; the cutting gun head of the cutting machine is in idle stroke from the original point to the point of the cutting path; arcing cutting is conducted, and the cutting gun head moves according to the cutting path to conduct cutting; and after cutting, the cutting gun head flames out and returns to the original point. According to the cutting process, the total cutting length can be effectively reduced, efficient and accurate material cutting is achieved, and material waste is reduced.

The present invention discloses a laying device for cable laying in a tunnel and a method of using the same, comprising a right-angled triangle frame structure, a cable pulley and a wire feeding angle adjustment structure, wherein the cable pulley is arranged on the hypotenuse of the right-angled triangle frame structure and is used for conveying cables, the wire feeding angle adjustment structure is arranged at the junction of the hypotenuse and the vertical side of the right-angled triangle frame structure and is used for adjusting the horizontal angle of the cable end and guiding the cable to a cable rack, the right-angled triangle frame structure comprises telescopic rods, which are respectively arranged on the hypotenuse and the vertical side of the right-angled triangle frame structure and are used for adjusting the height of the laying device, and the connection method of each component adopts a detachable connection method, which has low assembly difficulty and can effectively improve work efficiency, and at the same time, the scheme adopts an upper end movable connection of the wire feeding angle adjustment structure, which only bears the weight of a small section of cable during use, and bears a small load, thereby avoiding the risk of overturning of the cable laying vehicle.

The utility model provides a reinforcing structure of a special-shaped column template, which belongs to the technical field of concrete temperature measurement and comprises a square and round buckle which is used for being sleeved on the periphery of the special-shaped column template and is of a rectangular structure. The first side edge, the second side edge and the third side edge of the square and round buckle are parallel to the first pouring formwork, the second pouring formwork and the third pouring formwork respectively, and the fourth side edge of the square and round buckle is opposite to the fourth pouring formwork and the fifth pouring formwork at the same time. The right-angle-shaped triangular framework is arranged in the square and round buckle, the right angle of the right-angle-shaped triangular framework is opposite to the right-angle included angle between the third side edge and the fourth side edge, and the bevel edge of the right-angle-shaped triangular framework is used for being attached to the outer side of a fourth pouring formwork; the square wood is used for being arranged in a gap between the fifth pouring formwork and the square and round buckle so that force transmission between the square and round buckle and the fifth pouring formwork can be achieved. When the pouring formwork is fixed, the fixing device has the advantages of being easy to operate and high in practicability.

The invention provides a folding unmanned aerial vehicle parking apron and a use method of the unmanned aerial vehicle parking apron, and relates to unmanned aerial vehicles. The folding type unmanned aerial vehicle parking apron comprises a basket body, a box body and a telescopic supporting piece. The box body is placed on the basket body and comprises four folding assemblies, each folding assembly comprises a side plate, a first connecting plate and a second connecting plate, the side plates are square, the first connecting plates are isosceles right triangles, the right-angle sides of the first connecting plates are hinged to the third edges, and the right-angle sides of the first connecting plates are equal to the third edges in length. The second connecting plate is an isosceles right triangle, the hypotenuse of the second connecting plate is hinged to the second edge, and the hypotenuse of the second connecting plate is equal to the second edge in length; the number of the telescopic supporting pieces is multiple, one side plate is at least provided with one telescopic supporting piece, and one second connecting plate is at least provided with one telescopic supporting piece. Stable supporting and convenient storage of the unmanned aerial vehicle parking apron are achieved.

The utility model discloses a formwork supporting construction structure for a well protection wall. The formwork supporting construction structure comprises the well protection wall and a formwork supporting device, the steel formwork is tightly attached to the side edge of the well protection wall; a triangular supporting assembly is installed on the side edge, away from the well protection wall, of the steel formwork, and the inclined edge of the triangular supporting assembly can be adjusted to stably support the steel formwork. The bottom of the inclined batten is clamped into a notch formed between the abutting wood block and the horizontal batten, and a corresponding wood wedge block is installed in the notch to carry out heightening adjustment on the bottom of the inclined batten, so that the steel formwork is stably supported by the adjustable bevel edge of the triangular supporting assembly. The problem that an inclined supporting rod, an adjusting supporting rod and a fixed support rod are connected through welding or bolts and are not convenient to adjust to adaptively support a formwork is solved.

This invention belongs to the field of bridge construction surveying technology, specifically a method for measuring the verticality of bridge tower piers at close range and with large inclination angles in mountainous areas. The method includes: S1, calculating the angle between the intersection hypotenuse and the vertical line of the tower pier based on the known elevation and measured slope distance of the measuring point at the top of the tower pier, then calculating the horizontal distance and solving for the first corrected coordinates of each measuring point, thus avoiding vertical angle observation errors under large inclination angles; S2, accurately measuring the actual distance between the measuring points of the two tower piers, and using this as a constraint to adjust the first corrected coordinates to obtain a high-precision second corrected coordinate for the center of the tower top; S3, calculating the verticality based on the second corrected coordinates of the tower top and the known coordinates of the tower bottom. This invention effectively overcomes the problem of low measurement accuracy caused by close-range, large-inclination angle observations in narrow mountainous terrain, eliminates the need for multi-layered control networks, improves measurement efficiency and accuracy, and reduces operational risks and costs.

To provide a highly convenient self-assembly fan that can be used for multiple purposes. [Solution] A thin, transparent film sheet material is punched using a Thomson die to form a rectangle 3 continuing from the bottom of the oval fan portion, two right-angled triangles continuing from the rectangle 3 with fold lines K4, K5 of the same length as both sides of the rectangle, two right-angled triangles continuing from the adjacent sides with fold lines K4, K5 of the same length as both sides of the rectangle, a trapezoid continuing from the hypotenuse K3 of each right-angled triangle, two right-angled triangles continuing from one side of each of the trapezoids with fold lines K2, K8, and tabs T1, T2 for insertion purposes continuing from these.

The present invention discloses a mixed flow fan module and an air handling unit using the same, comprising a motor and a mixed flow fan wheel. The motor drives the mixed flow fan wheel to rotate. The mixed flow fan wheel comprises a cover plate, a bottom plate and a plurality of blades. The blades are surrounded by a blade inlet edge, a blade outlet edge, a blade top and a blade root. The projection of the spatial modeling curve of the blade inlet edge on the axial plane is composed of two arcs, namely, arc AB and arc BC. The chord AB of arc AB is the hypotenuse of the right triangle ADB; the chord BC of arc BC is the hypotenuse of the right triangle BEC, and a rectangle ODBE is formed. The radii of arc AB and arc BC are R respectively. AB 、R BC ; The proportion relationship meets the following requirements: 0.33≤AO:CO≤3; 0.25≤DO:EO≤4; 1≤R AB :AO≤4;1≤R BC :DO≤4; It greatly optimizes the state of the blade air inlet flow field, thereby reducing the airflow impact loss at the blade inlet, thereby achieving the effect of improving the wind wheel efficiency.

The utility model discloses a guide space ring device for a post-shearing roller way of a bar, which comprises the post-shearing roller way and a plurality of guide space rings, the plurality of guide space rings are sleeved and fixedly arranged on the post-shearing roller way, the cross section of each guide space ring is a right triangle, and two sides of the hypotenuse of each right triangle are chamfered. Guide space rings at the two ends of the roller bed are designed on the roller surface of the flat roller of the post-shearing roller bed, are made of materials with higher wear resistance and are welded at the two ends of the flat roller of the post-shearing roller bed; the novel guide space ring device has the advantages of being simple in structure, low in manufacturing cost, convenient and fast to maintain and the like, and the field use requirement can be well met.

The utility model discloses a self-powered comprehensive platform capable of being butted on the sea, which comprises a truss, a floating body and a deck, a first butting part is arranged at the edge of at least one side of the deck, and a second butting part is arranged at the edge of at least one side of the deck; the first butt joint parts are a plurality of trapezoidal bulges horizontally extending outwards, the top edges of the trapezoids are close to the inner side, and the bottom edges are close to the outer side; the second butt joint part is a plurality of rectangular grooves which are horizontally recessed inwards, wedge-shaped movable plates capable of horizontally stretching out and drawing back are installed on the two sides of each groove respectively, and the slope of the bevel edge of each movable plate is equal to that of the bevel edge of the first butt joint part. Through the arrangement of the first butt joint part and the second butt joint part, the butt joint difficulty of the offshore comprehensive platform is reduced, the modular design of the offshore comprehensive platform is facilitated, and the design and manufacturing difficulty and cost are reduced while the comprehensive requirements are met.

The present invention provides a flow control method based on a curved fish-scale bionic structure, comprising the following steps: S1. constructing the main structure of an impeller blade, including a suction surface e and a pressure surface f, each of which is provided with a fish-scale region g having a plurality of regularly arranged fish-scale bionic structure coupling elements; S2. constructing and designing a single fish-scale bionic structure coupling element, including a bottom surface conforming to the blade surface and a top surface in a fish-scale structure, the top surface including a sector-shaped surface whose vertex coincides with the midpoint of one side of the bottom surface, and two triangular oblique surfaces with the hypotenuse of the sector surface as the hypotenuse, establishing a spatial rectangular coordinate system with the vertex of the sector as the origin, and constructing the fish-scale bionic structure coupling element in the spatial rectangular coordinate system; S3. establishing a regular arrangement of the plurality of fish-scale bionic structures. Based on the control of flow by the bionic structure, the present invention can improve the flow characteristics of fluid on the blade surface and reduce noise during the operation of a vane pump.

The present invention relates to the field of safety detection of escalators, and discloses a measuring instrument for the gap between the escalator step and the skirt board, which includes a first strain sensor, a second strain sensor, a signal processing device, a display device and a sheet-shaped body of the ruler; the cross-section of the body of the ruler is a right triangle, a cantilever beam is arranged on the hypotenuse of the body of the ruler, the first strain sensor is installed at one end of the cantilever beam, a fixed beam is arranged on the short right-angle side of the body of the ruler, the second strain sensor is installed at one end of the fixed beam, the signal processing device and the display device are both installed on the body of the ruler, and the first strain sensor, the second strain sensor and the display device are all connected to the signal processing device. The present invention also discloses a method for measuring the gap between the escalator step and the skirt board. The beneficial effects are as follows: small in size and convenient to carry, the measurement result can be directly displayed numerically, the error caused by manual observation is eliminated, and the measurement accuracy and measurement efficiency are improved.

The utility model relates to the technical field of measuring tools, in particular to a metal set square ruler structure, which comprises an integrally formed triangular metal substrate, and is characterized in that the triangular metal substrate is integrally of an isosceles triangle structure and is provided with a first right-angle side, a second right-angle side and an inclined side, the first right-angle side, the second right-angle side and the bevel edge are all provided with continuous length scales, according to the metal set square ruler structure, the integrally-formed 6061 aluminum alloy base plate is combined with hard anodic oxidation treatment, the abrasion resistance and the structural strength are remarkably improved, and it is ensured that deformation is avoided after long-term use; metric / English dual-system scales are arranged on the three edges, different measurement requirements are met, oblique dimensions can be directly measured through the bevel edge scales, and the drawing flexibility is improved; a center hollow light-weight groove reduces the weight, meanwhile, three measurement channels extend, two of the three measurement channels are parallel to the right-angle side so that parallel lines can be drawn conveniently or positioning can be assisted, and the third channel provides oblique measurement support.

The caliber-adjustable electromagnetic flowmeter comprises a shell, four moving modules and a pushing part, the shell is used for containing the moving modules and the pushing part, the section of each moving module is an isosceles right triangle, the number of the moving modules is four, the four moving modules are arranged in an annular array, and the pushing part is arranged on the shell. A closed square hole channel is defined by the four moving modules, the right-angle sides of the four moving modules are opposite in pairs in the vertical direction and the horizontal direction respectively, and the adjacent side faces of the right-angle sides of the cross sections of the four moving modules are attached to the other adjacent side faces of the right-angle sides of the cross sections of the adjacent moving modules. The four moving modules are connected with the shell in a sliding mode in the length direction of the bevel edges of the cross sections of the moving modules, and the two ends of the four moving modules are attached to the inner walls of the two ends of the shell. Due to the adoption of the technical scheme, when the electromagnetic flowmeter with the adjustable caliber is used for monitoring a rainwater pipe, the electromagnetic flowmeter can measure more accurately to a certain extent.

To provide a bird prevention device capable of being easily produced and easily installed.SOLUTION: A bird prevention device 1 includes a bird prevention part 2 formed by a metal wire 21 spirally wound in a triangular shape when viewed in an axial direction and extending in the axial direction, and attachment parts 3 for attaching the bird prevention part 2 to a structure T. The bird prevention part 2 includes a plurality of bottom side parts 211 extending in a width direction when viewed in the axial direction, and a plurality of one-pairs of oblique side parts 212, 213 extending in a height direction. Each attachment part 3 includes a support part 32 configured to support at least a portion of one bottom side part 211 among the plurality of bottom side parts 211, and a fixing part 31 for fixing the support part 32 to the structure T.SELECTED DRAWING: Figure 1