1. The beam correction of the basic elements
28
The basic element
comprises a beam correction beam, and beam correction Lata station (FIG. 28 ). For effective corrective action, it must be three basic elements of a good combination, otherwise correction table drawing force will not be efficiently transmitted to the beam, or can not effectively correcting operation, there may be damage to the girders or other equipment and cause a serious accident. Accordingly, in order to change the strength and direction of the pulling force generated by Latta, it is necessary to change the number of fixed beams and a fixed point method.
2. Fixed beam
(1) using a chain and strong girder is fixed frame (FIG. 29)
29 [123 ]
this is the traditional method of fixing the girder. Although the method of the chain fixed beam of the easiest, but the chain can not be fixed beam in all directions, because the chain can not remain rigidity in all directions, while the chain can not resist the moment of inertia. Further, since the contact area between the chain and the small beam, beam area of contact with the chain there may be deformed, thus the method is difficult to make the chain fixed girder beam correction three basic elements to maintain good balance. But how girders for only a small distortion correction, and learning drawing force acting on a fixed point, fixed the chain is an effective method. By using a chain and strong frame, can be realized over substantially fixed. Next, the method of fixing the chain introduced point.
① each fixing point needs to 90deg two chains; fixed direction
When the beam pull-out force, the pulling force generated in the opposite direction of the chain fixed beam reaction force. If the chain and pulling the chain not fixed on a straight line, the beam will rotate until the formation of a straight chain, thus creating a moment of inertia. Therefore, when the other end is fixed girder other chain, if the direction of change of power drawn, then the beam will rotate until the chain up to a straight line (which would make the drawing direction deviates from the desired direction). To prevent rotation of the beam, each fixing point must be used as two chains 90 deg; fixed direction. By these two chainsThe pulling force balance bar, will produce the desired fixing force (resultant force). By using this method in the four position fixing beam, the beam can be prevented from unnecessary movement during the calibration process.
In the ② fixed longitudinal beam
30
Without using a rigid member for drawing operation, the drawing force does not It will be efficiently transmitted to the beam, because pulling force will be absorbed by the suspension spring. As (FIG. 30), if a frame is a chain diagonally fixed to the bracket, and the horizontal drawing frame, the beam will move downward inertia moment (this beam moves, the fixing chain and the chain form a line drawing), this is because the basic elements of imbalance correction. To curb the trend downward movement of the beam, it is necessary to use a rigid support or bottom support girder from the jack. By using a rigid support girder support at the bottom girder can curb the trend downward movement, the pulling force so that the loss can be prevented, also prevents withdrawal direction change.
(Continued)
(Qiu Lin)