SU1682157A1 - Method of effort control when tightening bolts - Google Patents

Description

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(21) 4708846/10

(22) 03.05.89

(46) 10/07/91. Bul №37

(71) Leningrad Institute of Mechanical Engineering (technical college) at the Production Association of Turbine Engineering Leningrad Metal Plant

(72) A.A.Levkovsky, V.E.Sherman and D.V.Ilyin

(53) 531.781 (088.8)

(56) Bolt showing tightening force. - Inventor and rationalizer, 1985, No. 11, p. 26

USSR Author's Certificate No. 1174221, cl. B 23 R 19/00. 1987

(54) METHOD OF CONTROL OF EFFORTS IN BOLTS AT TIGHTENING

(57) The method of controlling forces in bolts during tightening is in the field of mechanical engineering and can be used to control axial forces during tightening of bolts leading to deformation of their heads. The aim of the invention is to improve accuracy and speed. The way to control the bolt forces during tightening is that a through hole 3 is made in the head of the bolt, the axis of which does not coincide with the axis of the bolt, and beam 2 of laser 1 is directed to recorder 6 consisting of a collimator and a photodetector. In this case, the constant mutual arrangement of the axis of the laser beam, the axis of the aperture, and the photodetector during the process of tightening the bolt is maintained. The magnitude of the force in the bolt is judged by the magnitude of the decrease in the signal at the photodetector when the head is deformed. The signal from the photodetector enters the tracking system 7, which generates a control signal to the actuator 8. 2 Il.

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The invention relates to mechanical engineering and can be used to control axial forces in bolts that occur during tightening and cause deformation of the heads of the bolts.

The aim of the invention is to improve accuracy and speed.

FIG. 1 shows the course of the rays through the hole in the bolt head in the absence of deforming forces in it; in fig. 2 - the same, in the presence of normalized axial forces in the bolt and deformation of its head.

The method is implemented as follows.

From laser 1, beam 2 passes through hole 3 in head 4 of bolt 5 and reaches registrar 6 consisting of a collimator and a photodetector connected to tracking system 7, which is connected to actuator 8. beam 2 passes through hole 3 and reaches the receiver.

When normalized forces occur in the head 4 of the bolt 5, which leads to the corresponding deformations and curvature of the surface of the hole 3, the deformed surface of the hole 3 blocks the path of beam 2, and the photodetector registers a decrease in the level of illumination passing through the hole. Lower

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The magnitude of the signal at the output of the photodetector is recorded by the tracking system 7 and is compared with a predetermined level. When the target level is reached, a signal is generated to the actuator 8 and the bolt tightening stops.

Claims (1)

Claims The method of controlling forces in bolts during tightening, which means that the bolt is wrapped by applying a tool to its head, fixes, with a tracking system, the limiting strain of the bolt head, which is transmitted to the limit strain sensor, and stops tightening the bolt a mechanism for achieving permissible deformation, characterized in that, in order to increase control speed and accuracy, a through hole is made in the bolt head, the axis of which does not coincide with the axis of the bol This means that the laser and the limit deformation sensor in the form of a photodetector with a collimator are placed on the tool mandrel, while their position on one axis is kept constant during the bolt tightening, the laser beam is directed to the limit deformation sensor through the hole, and the signal from the photo receiver to the track system and the actuator.