Controllable angle transmission joint and design method thereof

Abstract

The application discloses a controllable angle transmission joint for polishing the inner wall of a bent pipe, which comprises a plurality of outer shafts and inner shafts connected in sequence through cylindrical pins, the inner shafts and the outer shafts can rotate by a certain angle around the cylindrical pins, the two ends of the inner shafts have a certain extension amount in the outer shafts, and there is a certain gap between the inner wall of the outer shaft and the outer wall of the inner shaft; the application further discloses a design method of the controllable angle transmission joint, and the controllable angle transmission joint can be designed according to the polishing requirements of bent pipes of different specifications.

Description

Technical Field

[0001] This invention relates to the field of pipe inner wall grinding technology, and in particular to a controllable angle transmission joint and its design method. Background Technology

[0002] Pipelines are widely used in nuclear power plants, petrochemicals, urban water supply and drainage, marine engineering, aerospace and other fields. Grinding and rust removal of the inner walls of pipelines can reduce contamination of fluid media and decrease pipeline resistance during transport, which is of great significance for energy conservation and environmental protection.

[0003] Currently, grinding the inner walls of pipes is typically done manually or with specialized machinery. The former requires a high level of worker skill, is inefficient, and involves high labor intensity, making it unsuitable for large-scale, batch operations. The latter mostly only works for grinding straight pipes and cannot grind bends. A few systems using flexible transmission can achieve this, but these systems are unstable, exhibiting large vibrations, resulting in unsatisfactory grinding results. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a controllable angle transmission joint and its design method. The transmission scheme of the controllable angle transmission joint of this invention solves the problems of difficult passage through bends and unstable transmission, and proposes a complete design method for this scheme, which can design a controllable angle transmission joint that is adapted to the grinding requirements of bends of different specifications.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a controllable angle transmission joint for grinding the inner wall of a bent pipe. The transmission joint includes multiple outer shafts and inner shafts connected in sequence by cylindrical pins. The inner shafts and outer shafts can rotate around the cylindrical pins at a certain angle. Both ends of the inner shaft extend into the outer shafts by a certain amount, and there is a certain gap between the inner wall of the outer shaft and the outer wall of the inner shaft.

[0006] As a further improvement of the present invention, a support frame is sleeved on the outer shaft to flexibly contact the inner wall of the pipe, and the support frame is used to guide and support the transmission section.

[0007] The present invention also provides a design method for a controllable angle transmission joint as described above, comprising the following steps:

[0008] Step 1: Determine the parameters for pipe bending and grinding;

[0009] Step 2: Select the structural parameters of the controllable angle transmission joint;

[0010] Step 3: Calculate the maximum relative rotation angle of the transmission joint;

[0011] Step 4: Determine the constraints;

[0012] Step 5: Optimize the structural parameters.

[0013] As a further improvement to the present invention, step 1 is specifically as follows:

[0014] According to the pipe diameter of the bend The grinding parameters are determined based on the center radius R, pipe material, and grinding precision; the grinding parameters include grinding power P and rotation speed n.

[0015] As a further improvement of the present invention, in step 2, the structural parameters include: the outer diameter D1 and inner diameter d1 of the outer shaft; the outer diameter D2 and inner diameter d2 of the inner shaft; the diameter D0 of the cylindrical pin; the extension amount S of the inner shaft; and the section length L of the inner and outer shafts.

[0016] As a further improvement of the present invention, in step 3, the controllability of the transmission joint angle is achieved through the cooperation of the inner and outer shafts, and the maximum relative angle is:

[0017]

[0018] As a further improvement of the present invention, in step 4, the constraints include geometric dimension requirements, angle controllability requirements, torsional strength requirements, and cylindrical pin shear strength requirements; specifically, the geometric dimension requirements are as follows: L=kS,k≥2,k is a design constant; Angle controllability requirements: Torsional strength requirements: In the formula, W t The torsional coefficient, Allowable shear stress of the material; shear strength of the cylindrical pin: Where D0 = (0.2 ~ 0.3)D2.

[0019] As a further improvement to the present invention, step 5 is specifically as follows:

[0020] Using minimum mass as the objective function, and taking geometric dimensional requirements, angle controllability requirements, torsional strength requirements, and cylindrical pin shear strength requirements as constraints, the following mathematical model is established to optimize the structural parameters:

[0021] x = [D1, d1, D2, d2, S] T

[0022]

[0023] In the formula, ρ represents the material density.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention solves the problem of difficult transmission inside a bent pipe, realizes stable power transmission under bent pipe conditions, increases the stability and controllability of the device, and can improve the quality of grinding the inner wall of the bent pipe.

[0026] 2. This invention is highly adaptable. It can not only operate in straight pipes, but also automatically adjust the rotation angle in curved pipes to achieve adaptive grinding from straight pipes to curved pipes.

[0027] 3. This invention solves the problem of difficult design parameters for controllable angle transmission joints, enabling the design of corresponding controllable angle transmission joints based on pipe geometry and grinding requirements. It provides a theoretical basis for the design of controllable angle transmission joints, improving design efficiency and success rate. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the transmission joint in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the required parameters for the bend in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the maximum rotation angle of the transmission joint in an embodiment of the present invention.

[0031] Figure label:

[0032] 1. Bend, 2. Outer shaft, 3. Inner shaft, 4. Cylindrical pin, 5. Support frame. Detailed Implementation

[0033] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] Example

[0035] like Figure 1 As shown, a controllable-angle transmission joint is used to grind the inner wall of a bend 1. The transmission joint includes multiple outer shafts 2 and inner shafts 3 connected in sequence by cylindrical pins 4. The inner shafts 3 and outer shafts 2 can rotate around the cylindrical pins 4 at a certain angle. Both ends of the inner shaft 3 have a certain amount of insertion into the outer shaft 2, thereby determining the maximum relative rotation angle between the inner shaft 3 and the outer shaft 2. There is a certain gap between the inner wall of the outer shaft 2 and the outer wall of the inner shaft 3. A support frame 5 is sleeved on the outer shaft 2 and flexibly contacts the inner wall of the pipe 1. The support frame 5 is used to guide and support the transmission joint.

[0036] This embodiment also provides a design method for a transmission joint with a controllable angle, which is carried out according to the following steps:

[0037] Step 1: Determine the parameters for pipe bending and grinding;

[0038] According to such Figure 2 The pipe diameter of the bend shown The grinding parameters, including grinding power P and rotation speed n, are determined based on the center radius R, pipe material, and grinding precision.

[0039] Step 2: Select the structural parameters of the controllable angle transmission joint;

[0040] like Figure 3 The controllable angle transmission joint shown includes an outer shaft, an inner shaft, and a cylindrical pin. Therefore, the outer diameter D1 and inner diameter d1 of the outer shaft, the outer diameter D2 and inner diameter d2 of the inner shaft, the diameter D0 of the cylindrical pin, the extension amount S of the inner shaft, and the joint length L of the inner and outer shafts are selected as structural parameters.

[0041] Step 3: Calculate the maximum relative rotation angle of the transmission joint;

[0042] The controllability of the transmission joint angle is achieved through the cooperation of the inner and outer shafts. Figure 3 The position shown is the position of maximum relative angle. At this point, the maximum relative angle is:

[0043]

[0044] Step 4: Determine the constraints;

[0045] The design of a controllable angle transmission joint must meet certain constraints, including: geometric dimension requirements, angle controllability requirements, torsional strength requirements, and shear strength requirements.

[0046] Geometric dimensional requirements:

[0047] L = kS, k ≥ 2

[0048] Where k is a design constant, which can be selected according to the design, and must be greater than 2 to meet the geometric requirements;

[0049] Angle controllability requirements:

[0050]

[0051] Torsional strength requirements:

[0052]

[0053] In the formula, W t The torsional coefficient, The allowable shear stress of the material;

[0054] Shear strength of cylindrical pin:

[0055]

[0056] Where D0 = (0.2 ~ 0.3)D2

[0057] Step 5: Parameter optimization.

[0058] Based on the structural dimensions of the bent pipe, the clearance between the inner and outer shafts, the length of the inner and outer shafts, and the extension of the inner shaft are dynamically adjusted. Under the premise of adapting to the structural shape of the bent pipe, the maximum relative angle between the inner and outer shafts is limited, thereby reducing the vibration of the transmission joint and avoiding jamming of the transmission joint.

[0059] From the perspective of compact structure and smooth transmission, taking the minimum mass as the objective function, and using geometric dimension requirements, angle controllability requirements, torsional strength requirements, and shear strength requirements as constraints, the following mathematical model is established for parameter optimization.

[0060] x = [D1, d1, D2, d2, S] T

[0061]

[0062] In the formula, ρ represents the material density.

[0063] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A design method for a controllable angle transmission joint, characterized in that, A controllable-angle transmission joint is used for grinding the inner wall of a bent pipe. The transmission joint includes multiple outer and inner shafts connected sequentially by cylindrical pins. The inner and outer shafts can rotate around the cylindrical pins at a certain angle. Both ends of the inner shaft extend into the outer shafts by a certain amount, and there is a certain gap between the inner wall of the outer shaft and the outer wall of the inner shaft. A support frame is fitted onto the outer shaft, flexibly contacting the inner wall of the pipe. The support frame guides and supports the transmission joint. The design method includes the following steps: Step 1: Determine the parameters for pipe bending and grinding; Step 2: Select the structural parameters of the controllable angle transmission joint; Step 3: Calculate the maximum relative rotation angle of the transmission joint; Step 4: Determine the constraints; Step 5: Optimize the structural parameters; Step 1 is described in detail as follows: According to the pipe diameter of the bend and center radius The grinding parameters are determined based on the pipe material and grinding precision; the grinding parameters include grinding power. and rotational speed ; In step 2, the structural parameters include: the outer diameter of the outer shaft. , inner diameter The outer diameter of the inner shaft , inner diameter ; Diameter of the cylindrical pin and the amount of inner shaft extension and the pitch length of the inner and outer shafts ; In step 3, the controllability of the transmission joint angle is achieved through the cooperation of the inner and outer shafts, and its maximum relative rotation angle is: ； In step 4, the constraints include geometric dimensional requirements, angle controllability requirements, torsional strength requirements, and cylindrical pin shear strength requirements; specifically, the geometric dimensional requirements are as follows: , , Design constant; Angle controllability requirements: Torsional strength requirements: In the formula, The torsional coefficient, Allowable shear stress of the material; shear strength of the cylindrical pin: ,in ; Step 5 is described in detail below: Using minimum mass as the objective function, and taking geometric dimensional requirements, angle controllability requirements, torsional strength requirements, and cylindrical pin shear strength requirements as constraints, the following mathematical model is established to optimize the structural parameters: ； In the formula, Represents the density of the material.

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