A manual straightening method for small-diameter pipes

Abstract

The present invention relates to a manual straightening method for small-diameter pipes, comprising the following steps: Step 1: inserting a straightening tool onto the pipe to be straightened, adjusting the height of an upper straightening roller so that the bottom of the upper straightening groove of the upper straightening roller and the bottom of the lower straightening groove of the lower straightening roller both contact the surface of the pipe to be straightened; Step 2: observing the bending of the pipe to be straightened, rotating the straightening screw of the straightening tool so that the orientation of the upper straightening roller is consistent with the orientation of the curved arch surface of the pipe to be straightened; Step 3: pulling the straightening tool, observing the straightness of the pipe after straightening, and fine-tuning the height of the upper straightening roller according to the straightness of the pipe after straightening; Step 4: repeatedly pulling the straightening tool and adjusting the height of the upper straightening roller according to the straightness after straightening until the required straightness is achieved. This method can achieve the straightening operation of a partial pipe section of a small-diameter pipe after bending, and is low-cost, simple to operate, highly applicable, and easy to carry.

Description

Technical Field

[0001] The invention relates to a pipe straightening method, in particular to a manual straightening method for small-caliber pipes. Background Art

[0002] Currently, small-diameter, thick-walled pipes are widely used in people's daily lives, especially in steam generators for small reactors. These pipes are usually installed in the evaporator in the form of bends as the main heat exchange component. Evaporator bends mainly come in two types: U-bends and spiral bends. Before the bends are formed, the pipes must be straightened along their entire length using a straightening machine. Straightening equipment available on the market mainly includes pressure straighteners, balanced roller straighteners, inclined roller straighteners, and rotary reverse bend straighteners. These devices are generally installed on the ground, occupying a large amount of space. They achieve full-length straightening by biting into the pipe. However, if the straight section after the bend is deformed or bent, these straightening devices cannot meet the straightening requirements. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a manual straightening method for small-diameter pipes, which can be used for straightening and correcting the straight pipe section after small-diameter elbow forming, so as to avoid the straightness of the straight pipe section after forming not meeting the requirements. The specific technical solution is as follows:

[0004] A manual straightening method for small-diameter pipes comprises the following steps:

[0005] Step 1: Insert the straightening tool onto the pipe to be straightened, and adjust the height of the upper straightening roller so that the bottom of the upper straightening groove of the upper straightening roller and the bottom of the lower straightening groove of the lower straightening roller are in contact with the surface of the pipe to be straightened;

[0006] Step 2: Observe the bending condition of the pipe to be straightened, and rotate the straightening screw of the straightening tool to make the position of the upper straightening roller consistent with the position of the curved arch surface of the pipe to be straightened;

[0007] Step 3: Pull the straightening tool, observe the straightness of the pipe after straightening, and fine-tune the height of the upper straightening roller according to the straightness of the pipe after straightening;

[0008] Step 4: Pull the straightening tool repeatedly and adjust the height of the upper straightening roller according to the straightness after straightening until the required straightness is achieved;

[0009] Wherein, the straightening tool includes: a straightening frame, a lower straightening roller and a straightening screw installed on the straightening frame, a lifting frame rotatably installed on the straightening screw, and an upper straightening roller installed on the lifting frame; the lower straightening roller is located on both sides of the upper straightening roller, and the lower straightening roller has at least one more lower straightening roller than the upper straightening roller, the upper straightening roller is provided with an upper straightening groove, and the lower straightening roller is provided with a lower straightening groove arranged opposite to the upper straightening groove; the straightening screw is used to drive the upper straightening roller to rise and fall.

[0010] Preferably, the upper straightening groove and the lower straightening groove are both semicircular, and the diameter is not less than the diameter of the pipe to be straightened.

[0011] Preferably, the center distance between the two lower straightening rollers is not less than the diameter of the upper straightening roller, and the height of the bottom of the upper straightening groove of the upper straightening roller is not lower than the bottom of the groove of the lower straightening roller.

[0012] Preferably, the straightening frame and the lifting frame are both U-shaped frames made of aluminum alloy, and the lifting frame and the lower straightening roller are both located inside the straightening frame.

[0013] Preferably, the straightening frame is provided with a plurality of weight-reducing holes.

[0014] Preferably, the upper straightening roller and the lower straightening roller are both made of engineering plastics.

[0015] Preferably, the upper straightening roller is mounted on an upper connecting shaft via a bearing, and the upper connecting shaft is fixed on the lifting frame.

[0016] Preferably, the lower straightening roller is installed under the lower connecting shaft through a bearing, and the lower connecting shaft is fixed on the lifting frame.

[0017] Preferably, a straightening handwheel is provided on the top of the straightening screw.

[0018] Preferably, the upper straightening roller and the lower straightening roller have the same structure.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The manual straightening method for small-diameter pipes provided by this invention can straighten the partial sections of small-diameter pipes after bending, achieving a straightness of less than 1 mm / m. This method is low-cost, simple to operate, highly adaptable, and portable, solving the problem of straightening and correcting the partial sections of small-diameter pipes after bending, and has considerable industrial value. Theoretically, the diameter of small-diameter pipes should not exceed 18 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a cross-sectional view of the straightening tool;

[0022] Figure 2 is a front view of the straightening tool. DETAILED DESCRIPTION

[0023] The present invention will be further described with reference to the accompanying drawings.

[0024] like Figure 1 and Figure 2As shown, a manual straightening method for small-diameter pipes includes the following steps:

[0025] Step 1: Insert the straightening tool onto the pipe 6 to be straightened, and adjust the height of the upper straightening roller 4 so that the bottom of the upper straightening groove 41 of the upper straightening roller 4 and the bottom of the lower straightening groove 51 of the lower straightening roller 5 are in contact with the surface of the pipe 6 to be straightened;

[0026] Step 2: Observe the bending condition of the pipe 6 to be straightened, and rotate the straightening screw 3 of the straightening tool so that the orientation of the upper straightening roller 4 is consistent with the orientation of the curved arch surface of the pipe 6 to be straightened;

[0027] Step 3: Pull the straightening tool to observe the straightness of the pipe after straightening, and fine-tune the height of the upper straightening roller 4 according to the straightness of the pipe after straightening;

[0028] Step 4: Pull the straightening tool repeatedly and adjust the height of the upper straightening roller 4 according to the straightness after straightening until the required straightness is achieved;

[0029] The straightening tool includes a straightening frame 1, a lifting frame 2, a straightening screw 3, an upper straightening roller 4 and a lower straightening roller 5.

[0030] Both the straightening frame 1 and the lifting frame 2 are made of aluminum alloy and have a U-shaped structure. The straightening frame 1 is provided with several weight-reducing holes 11 for reducing weight. The straightening screw 3 is mounted on the top of the straightening frame 1, and a straightening handwheel is installed on the top of the straightening screw 3 to facilitate rotation of the straightening screw 3. The top of the lifting frame 2 is rotatably mounted on the bottom of the straightening screw 3, and the bottom of the straightening screw 3 is provided with an upper limit ring 31 and a lower limit ring 32. The upper limit ring 31 and the lower limit ring 32 are located on either side of the lifting frame 2, respectively, allowing the straightening screw 3 to be rotatably connected to the lifting frame 2 and limiting its axial position. The lifting frame 2 is located inside the straightening frame 1, and the lower straightening roller 5 is also located inside the straightening frame 1. The lower straightening roller 5 is mounted below the lower connecting shaft 52 via a bearing, which is fixed to the lifting frame 2. The upper straightening roller 4 is mounted on the upper connecting shaft 42 via a bearing, which is fixed to the lifting frame 2. The bearings reduce friction, making pushing the straightening tool more labor-efficient. The upper and lower straightening rollers 4, 5, have identical structures and are interchangeable. One upper straightening roller 4 is positioned opposite and between two lower straightening rollers 5, with one lower straightening roller 5 always outnumbering the upper straightening roller 4 by one. The center-to-center distance between the two lower straightening rollers 5 should be between the roller diameter and 200 mm. In this embodiment, the lower straightening rollers 5 are symmetrically positioned on either side of the upper straightening roller 4, with the center-to-center distance between the two lower straightening rollers 5 being no less than the diameter of the upper straightening roller 4. Furthermore, the bottom of the upper straightening groove 41 of the upper straightening roller 4 is lowered no lower than the bottom of the groove of the lower straightening roller 5. The upper straightening roller 4 is equipped with an upper straightening groove 41, and the lower straightening roller 5 is equipped with a lower straightening groove 51, which is located opposite the upper straightening groove 41. Both the upper straightening groove 41 and the lower straightening groove 51 are semicircular in shape, with a diameter no smaller than that of the pipe 6 to be straightened, and typically the same as or slightly larger than the diameter of the pipe 6 to be straightened. Both the upper straightening roller 4 and the lower straightening roller 5 are made of engineering plastic to reduce weight. The straightening screw 3 is used to drive the upper straightening roller 4 up and down.

[0031] Taking a pipe with a diameter of 12 mm as an example, the following steps are included:

[0032] Step 1: Insert the straightening tool onto the pipe 6 to be straightened. The diameter of the upper straightening groove 41 and the lower straightening groove 51 are 12 mm. Rotate the straightening screw 3 and adjust the height of the upper straightening roller 4 so that the bottom of the upper straightening groove 41 of the upper straightening roller 4 and the bottom of the lower straightening groove 51 of the lower straightening roller 5 are in contact with the surface of the pipe 6 to be straightened.

[0033] Step 2: Observe the bending condition of the pipe 6 to be straightened, and rotate the straightening screw 3 of the straightening tool so that the orientation of the upper straightening roller 4 is consistent with the orientation of the curved arch surface of the pipe 6 to be straightened;

[0034] Step 3: Pull the straightening tool and observe the straightness of the pipe after straightening. Turn the straightening screw 3 according to the straightness of the pipe after straightening and fine-tune the height of the upper straightening roller 4.

[0035] Step 4: Pull the straightening tool repeatedly and rotate the straightening screw 3 to adjust the height of the upper straightening roller 4 according to the straightness after correction until the required straightness is achieved.

[0036] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily devise other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the claims of the present invention.

Claims

1. A manual straightening method for small diameter pipes, characterized in that: The following steps are involved: Step 1: insert the straightening tool onto the pipe (6) to be straightened, and adjust the height of the upper straightening roller (4) so ​​that the bottom of the upper straightening groove (41) of the upper straightening roller (4) and the bottom of the lower straightening groove (51) of the lower straightening roller (5) are in contact with the surface of the pipe (6) to be straightened; Step 2: Observe the bending condition of the pipe (6) to be straightened, and rotate the straightening screw (3) of the straightening tool so that the orientation of the upper straightening roller (4) is consistent with the orientation of the curved arch surface of the pipe (6) to be straightened; Step 3: Pull the straightening tool, observe the straightness of the pipe after straightening, and fine-tune the height of the upper straightening roller (4) according to the straightness of the pipe after straightening; Step 4: repeatedly pull the straightening tool and adjust the height of the upper straightening roller (4) according to the straightness after straightening until the required straightness is achieved; The straightening tool comprises: a straightening frame (1), a lower straightening roller (5) and a straightening screw (3) mounted on the straightening frame (1), a lifting frame (2) rotatably mounted on the straightening screw (3), and an upper straightening roller (4) mounted on the lifting frame (2); the lower straightening roller (5) is located on both sides of the upper straightening roller (4), and the number of the lower straightening roller (5) is at least one more than the number of the upper straightening roller (4); the upper straightening roller (4) is provided with an upper straightening groove (41), and the lower straightening roller (5) is provided with a lower straightening groove (51) arranged opposite to the upper straightening groove (41); the straightening screw (3) is used to drive the upper straightening roller (4) to move up and down; The upper straightening roller (4) and the lower straightening roller (5) are both made of engineering plastics; Among them, the diameter of small-diameter pipes does not exceed 18mm; The upper straightening groove (41) and the lower straightening groove (51) are both semicircular, and the diameter is not less than the diameter of the pipe (6) to be straightened; The center distance between the two lower straightening rollers (5) is not less than the diameter of the upper straightening roller (4), and the height of the groove bottom of the upper straightening groove (41) of the upper straightening roller (4) is not lower than the groove bottom of the lower straightening roller (5).

2. A manual straightening method for small-diameter pipes according to claim 1, characterized in that: The straightening frame (1) and the lifting frame (2) are both U-shaped frames made of aluminum alloy, and the lifting frame (2) and the lower straightening roller (5) are both located inside the straightening frame (1).

3. A manual straightening method for small-diameter pipes according to claim 1 or 2, characterized in that: The straightening frame (1) is provided with a plurality of weight-reducing holes (11).

4. A manual straightening method for small-diameter pipes according to claim 1, characterized in that: The upper straightening roller (4) is mounted on an upper connecting shaft (42) via a bearing, and the upper connecting shaft (42) is fixed on the lifting frame (2).

5. A manual straightening method for small-diameter pipes according to claim 1, characterized in that: The lower straightening roller (5) is mounted under a lower connecting shaft (52) via a bearing, and the lower connecting shaft (52) is fixed on the lifting frame (2).

6. A manual straightening method for small-diameter pipes according to claim 1, characterized in that: A straightening hand wheel is mounted on the top of the straightening screw rod (3).

7. A manual straightening method for small-diameter pipes according to claim 1, characterized in that: The upper straightening roller (4) and the lower straightening roller (5) have the same structure.

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