Positioning device for pull rod positioning sleeve of sizing rack
By using six cylindrical pins on the sizing mill stand to position the positioning sleeve and the long shaft, the problem of cylindrical pin shearing caused by relative movement of the sizing mill stand during rolling is solved, the long shaft is stably positioned, the blue line defect is reduced, and the surface quality of the steel pipe is improved.
Patent Information
- Application Number
- CN202422986155.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-04
AI Technical Summary
During the rolling process, the tie rod and the tail end positioning sleeve of the sizing mill stand are prone to relative movement, which can cause the cylindrical pin to break, resulting in the tie rod to unwind and the sizing mill stand rolls to misalign, producing blue line defects and affecting the surface quality of the steel pipe.
Six cylindrical pins are used to position the positioning sleeve and the long shaft. The included angle between the cylindrical pins is evenly distributed, and the fit clearance is controlled between 0.01 and 0.06 mm. The fit clearance between the cylindrical pin hole and the cylindrical pin is between 0.3 and 0.5 mm. 42CrMo material is used for heat treatment to increase strength and ensure that the cylindrical pins do not shear off.
It effectively prevents the long shaft from loosening, reduces the phenomenon of tie rod unwinding, reduces blue line defects, and improves the surface quality of steel pipes.
Smart Images
Figure CN223571655U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of rolling equipment, and is a device for positioning the positioning sleeve of the frame pull rod by using multiple cylindrical pins. BACKGROUND
[0002] In the production of steel pipes, the sizing frame used in the sizing process often causes the pull rod to back off, resulting in blue lines on the surface of the steel pipe. In particular, when rolling products with a relatively thick wall thickness and a high alloy content, the long shaft is subjected to a relatively large instantaneous impact force during biting and throwing, which easily causes relative movement between the tail end positioning sleeve and the long shaft, resulting in the shearing of the tail end cylindrical pin under the shearing force, causing the pull rod and the locking nut to back off, and thus causing the sizing frame roll to be misaligned and resulting in blue lines and other defects.
[0003] The steel pipe with blue lines on the surface has the following disadvantages: it is not aesthetically pleasing, it is easy to break the buckle when machining the sleeve thread, the skin turning amount increases, and relatively deep blue lines can cause the steel pipe to be scrapped. SUMMARY
[0004] The utility model aims to provide a sizing frame pull rod positioning sleeve positioning device that can stably fix the long shaft and the tail end positioning sleeve without causing relative movement for a long time, and prevent the pull rod from being directly subjected to stress during rolling, thereby causing blue lines.
[0005] Technical scheme of the utility model:
[0006] The sizing frame pull rod positioning sleeve positioning device comprises a positioning sleeve, a pull rod, a roll, a locking nut, a cylindrical pin, and a long shaft. The roll is pre-assembled in the frame, and the long shaft is inserted into the roll and assembled in the positioning sleeve. The positioning sleeve and the long shaft are positioned by six cylindrical pins, and the included angle between the six cylindrical pins is uniformly distributed at 60°. The fitting gap between the long shaft and the positioning sleeve is between 0.01 and 0.06 mm, and the fitting gap between the cylindrical pin hole and the cylindrical pin is between 0.3 and 0.5 mm, so that the six cylindrical pins can be smoothly installed during installation.
[0007] Further, the cylindrical pin hole and the cylindrical pin are chamfered by 5-7 mm to smoothly align the cylindrical pin during installation and improve the assembly efficiency.
[0008] Further, the cylindrical pin is made of 42CrMo material and is quenched and tempered to increase the strength of the cylindrical pin and prevent the cylindrical pin from being sheared under stress.
[0009] The utility model has the following beneficial effects: when rolling a product with a relatively large deformation resistance, the long shaft is subjected to a relatively large instantaneous impact force during biting and throwing. The positioning sleeve and the long shaft are positioned by six cylindrical pins, which can ensure that the instantaneous shearing force acting on each cylindrical pin is uniformly distributed and only one sixth of the single cylindrical pin, thereby ensuring that the long shaft does not loosen and significantly reducing the loosening and back-off phenomenon, thereby reducing the blue lines and other defects on the surface of the steel pipe caused by the back-off of the pull rod. BRIEF DESCRIPTION OF DRAWINGS
[0010] Fig. 1 Figure 1 is a main sectional view of the positioning device for the positioning sleeve of the sizing stand tie rod.
[0011] Fig. 2 Figure 2 is a side view of the positioning sleeve part.
[0012] Fig. 3 Figure 3 is an enlarged main view of the positioning sleeve part.
[0013] In the figure: 1 - locking nut; 2 - tie rod; 3 - long shaft; 4 - roll; 5 - cylindrical pin; 6 - positioning sleeve; 7 - cylindrical pin hole. DETAILED DESCRIPTION
[0014] The embodiments are described below with reference to the accompanying drawings.
[0015] Figs. 1-3 As shown: the positioning device for the positioning sleeve of the sizing stand tie rod, comprising locking nut 1, tie rod 2, long shaft 3, roll 4, cylindrical pin 5, positioning sleeve 6. The long shaft 3 is installed in the positioning sleeve 6, and the roll 4 is pulled tight by using the locking nut 1 through the tie rod 2, so that the roll 4 does not move during the rolling process of the stand. The positioning sleeve 6 and the long shaft 3 are positioned by six cylindrical pins 5, and the six cylindrical pins 5 are evenly distributed with an angle a = 60° between them. When the stand is in the instant of biting the steel pipe or under a large rolling force, the cylindrical pins 5 do not shear due to the relative force when the positioning sleeve 6 and the long shaft 3 are under the relative force, which ensures the pre-tightening force of the tie rod 2 and thus the roll 4 does not produce axial movement. The fitting gap between the long shaft 3 and the positioning sleeve 6 is between 0.01-0.06mm, and the fitting gap between the cylindrical pin hole 7 in the positioning sleeve 6 and the cylindrical pin 5 is between 0.3-0.5mm. The cylindrical pin 5 and the cylindrical pin hole 7 are chamfered by 5-7mm for easy assembly. The cylindrical pin 5 is made of 42CrMo material for quenching and tempering treatment to increase the strength.
Claims
1. A sizing stand tie rod positioning sleeve positioning device characterized by: It comprises a positioning sleeve, a pull rod, a roller, a locking nut, a cylindrical pin and a long shaft; the roller is assembled in the frame in advance, and then the long shaft is inserted into the roller and assembled in the positioning sleeve; the positioning sleeve and the long shaft are positioned by six cylindrical pins, which are evenly distributed at an interval of 60°; the fitting gap between the long shaft and the positioning sleeve is between 0.01-0.06mm, and the fitting gap between the cylindrical pin hole and the cylindrical pin is between 0.3-0.5mm.
2. The sizing press frame tie rod positioning sleeve positioning device of claim 1 wherein: The cylindrical pin and the cylindrical pin hole are chamfered by 5-7mm.
3. The sizing press frame pull rod positioning sleeve positioning device of claim 1, wherein: The cylindrical pin is made of 42CrMo material and is quenched and tempered.