Bolt ball net frame

Processing and production of bolt ball for grid

1. The depth of the process hole of the bolt ball must be greater than the sum of the radius of the bolt ball and the radius of the largest bolt hole of the ball. Otherwise, it is easy to produce vibration due to the unilateral cutting of the drill bit during the machining process.
No matter what methods and means are used, after processing the first bolt ball process hole, it must be inspected by a quality inspector.
(1) The roundness of the ball D≤120 is 1.2mm, and D>120 is the range of 2.5mm.
(2) Positioning hole.
(3) Thread tolerances must comply with the 6H level precision requirements in the national standard "Common Thread Tolerance and Fit" GB1997-81.
(4) The distance between the end face of the bolt hole and the center of the ball is ±0.2. The above metal must be guaranteed items.
2. Machining of other holes of the bolt ball: Process the balls of various specifications samples under the guidance of technicians to check the accuracy of the fixture, and the accuracy error cannot exceed the requirements of the tolerance of the ball. Exceeding must be adjusted; find out the cause of the error.
(1) Compulsory items: Must meet the 6H level accuracy regulations in GB197-81.
(2) Inspection items:
1) Use standard bolts to measure whether the screwing depth 1.2d (d is the bolt diameter) is sufficient.
2) The distance between the end face of the screw hole and the center of the sphere is ±0. 2mm, check with a vernier caliper, measuring mandrel, and height ruler.
3) The parallelism of the end faces of the two screw holes on the same axis D≤120 0.2 D>120 0.3.
4) The angle between the axes of two adjacent screw holes is ±30. Check with measuring mandrel and height gauge.
5) The verticality of the end face of the screw hole and the axis is 0.5%r, using a dial indicator.
3. In the process of bolt ball processing, the quality inspector must conduct random inspections every day, make a record of the random inspection, and put the inspector's stamp number on the end face of the positioning ball. In particular, each bolt hole must be screwed into 1.2d by hand. Otherwise, due to the residual chips in the hole, it will cause trouble to the installer.
4. The quality inspector must memorize the required items of the specification and the allowable deviation items, and also perform the inspection of the guarantee items. A. The finished ball must be tested for tensile strength of the largest screw hole. The load when the thread of the screw hole is cut is the ultimate bearing value of the bolt. The bolt is screwed into the depth ld during the test. The most unfavorable force in each project 600 balls of the same specification are only one batch, and more than 600 balls are still counted as one batch, and 3 balls are selected one by one for random inspection.

What is the maximum load of the bolted ball grid roof

The standard value du of bai for variable roof load is the dao specified in the GB50009-2012 "Building Structure Load Code", which is not a human roof (zhuan0.5KN/m²). The designer has no right to exceed the standard value specified by the shu specification. It's not as big as you can. Table 5.3.1 of the code Note 2. When the master roof is also used for other purposes, the variable load value of the corresponding floor should be taken according to the code. Special circumstances that exceed the specification should at least be demonstrated by the design expert group.

How to see the angle of the bolt ball of the grid

The spiral ball angle of the grid is bai degrees. Because of its novel du structure, reasonable stress, light weight and low steel consumption, the grid structure has emerged in large numbers from the late 1980s, and the annual rate is about 80~100. Million m2 increase. It is widely used in large stadiums, exhibition centers, theaters, shopping malls, terminal buildings, waiting halls, factory workshops, warehouses, TV towers, etc.
The domestic grid structure is mainly divided into two types: welded spherical joint grid and bolted spherical joint grid. The bolted spherical joint grid has a large amount of processing in the factory and is convenient for on-site installation. It is suitable for special-shaped structures with tight on-site construction periods, restricted construction conditions and power consumption, complex grid shapes and difficult positioning of rods.