A bellows densification shaping apparatus and method

Abstract

This invention designs a corrugated pipe dense corrugation shaping device and method, belonging to the field of corrugated pipe processing. It includes a tank support and a tank mounted on the support. A pressure gauge is installed on the tank and connected to a control console. A linear slide rail is installed inside the tank. One end of the linear slide rail is connected to an L-shaped fixed mounting plate, and the other end is connected to an L-shaped sliding mounting plate. The space between the fixed mounting plate and the sliding mounting plate is used to install the corrugated pipe. A distance sensor is also installed on the sliding mounting plate, and the sensing circuit of the distance sensor is connected to the control console via a wiring harness. It also includes an internal hydraulic pipeline, one end of which is connected to the corrugated pipe, and the other end passes through the tank and connects to the control console; and an external hydraulic pipeline, one end of which is connected to the inside of the tank, and the other end connects to the control console. This invention uses sensors to collect the corrugated pipe length value in real time and uses a PID algorithm for real-time feedback adjustment, which can accurately and efficiently achieve the ideal corrugation pitch shaping of the corrugated pipe.

Description

Technical Field

[0001] This invention designs a dense corrugation shaping device and method for corrugated pipes, belonging to the field of corrugated pipe processing. Background Technology

[0002] Metal hoses are widely used in aerospace, chemical, and nuclear power industries. With industry development, the requirements for pressure resistance and flexibility of metal hoses have gradually increased in recent years. Improving the pressure resistance and flexibility of hoses without changing their diameter has become paramount. Dense-wave corrugated pipes (i.e., reduced corrugation pitch) have become the best method for improving corrugated pipe performance. However, traditional dense-wave shaping methods, such as mechanical and external hydraulic methods, have limitations. Mechanical dense-wave shaping typically involves directly compressing all the corrugations, which can easily lead to adhesion between the waves. If the corrugations are not compressed, there will be a problem of small pitch at both ends and large pitch in the middle. While external hydraulic dense-wave shaping can achieve a specified pitch based on the external pressure, the initial external hydraulic shaping requires multiple rounds of experimentation and manual correction to achieve the ideal pitch. This method suffers from low efficiency and poor accuracy.

[0003] This invention designs a method for preparing dense corrugated pipes. The method uses a sensor to collect the length value of the corrugated pipe in real time and uses a PID algorithm to control the shaping pressure to adjust the length of the corrugated pipe, thereby accurately and efficiently shaping the theoretical wave pitch of the corrugated pipe.

[0004] Purpose of the invention

[0005] To address the aforementioned problems, this invention presents a device and method for shaping the dense wave pitch of a bellows. By utilizing the pressure difference between the inside and outside of the bellows and PID control, the theoretical wave pitch of the bellows can be precisely and efficiently shaped.

[0006] A corrugated pipe dense corrugation shaping device includes a tank support and a tank mounted on the tank support. A pressure gauge is installed on the tank and connected to a control console. A linear slide rail is installed inside the tank. One end of the linear slide rail is connected to an L-shaped fixed mounting plate, and the other end is connected to an L-shaped sliding mounting plate. A corrugated pipe is installed between the fixed mounting plate and the sliding mounting plate. A distance sensor is also installed on the sliding mounting plate. The sensing circuit of the distance sensor is connected to the control console through a wiring harness. The device also includes an internal hydraulic pipeline, one end of which is connected to the corrugated pipe and the other end of which passes through the tank and connects to the control console; and an external hydraulic pipeline, one end of which is connected to the inside of the tank and the other end of which connects to the control console.

[0007] The tank also has a pressure relief pipe.

[0008] The control console integrates a controller, which incorporates a PID algorithm and a formula for calculating the pressure required for the initial deformation of the bellows. It collects and monitors data in real time through sensors and converts the calculation results into pressure control signals for the internal and external hydraulic lines in the form of electrical signals.

[0009] The initial deformation pressure required for dense corrugating of a bellows is calculated using the following formula:

[0010]

[0011] Among them, except P 外 Apart from the parameter, all other parameters are known. By inputting the known parameters into the console, the initial deformation pressure value P can be calculated. 外 .

[0012] P 外 —Initial deformation pressure value, unit: MPa;

[0013] Dm—Mean diameter of the bellows, the average of the inner and outer diameters of the bellows, in mm;

[0014] m — number of layers in the corrugated pipe blank;

[0015] δp—Effective wall thickness of each layer of tube blank after corrugated pipe forming, unit: mm;

[0016] h—Corrugated pipe wave height, unit: mm;

[0017] q—Corrugated pipe pitch before shaping, unit: mm;

[0018] [σ]t——Allowable stress of the corrugated pipe material, unit: MPa.

[0019] The method for dense corrugating a bellows using the shaping equipment of the present invention is as follows:

[0020] The control console embeds a PID control algorithm and a formula for calculating the initial pressure required for bellows deformation. Parameters are input through the console's interactive interface, with the final bellows length as the algorithm's target value L_SET. The bellows is shaped by adjusting the pressure values ​​of the external and internal hydraulic lines. The pressure gauge for the internal hydraulic line is integrated inside the control console. Specifically, when the external hydraulic line pressure > the internal hydraulic line pressure, and the pressure difference reaches P... 外 At this time, the bellows length begins to shorten; when the external hydraulic line pressure is less than the internal hydraulic line pressure, and the pressure difference reaches P... 外 At that time, the length of the bellows begins to elongate.

[0021] This invention presents a shaping device based on a PID algorithm. Simply install the bellows on the device and set the parameters and the required bellows length, and the shaping process will begin automatically. The entire process eliminates the need for repeated adjustments to the shaping pressure and manual correction of the bellows length. This method is simple, convenient, efficient, and reliable, requiring minimal operator skill. Even if operators change, they can quickly master and implement the method proficiently, demonstrating good versatility and ease of use.

[0022] This invention presents a dense wave shaping method that uses sensors to collect the bellows length value in real time and employs a PID algorithm for real-time feedback adjustment. This method can accurately and efficiently achieve the desired wave pitch shaping of the bellows. Compared to traditional shaping methods that require manual measurement and calibration, this invention is more accurate and reliable. Attached Figure Description

[0023] Figure 1 Schematic diagram of dense wave shaping equipment.

[0024] Figure 2 , Sectional view of the tank.

[0025] Figure 3 The control logic block diagram of PID.

[0026] The markings are as follows: 1. Control console 2. Tank 3. Internal hydraulic pipeline 4. External hydraulic pipeline 5. Pressure relief pipeline 6. Wiring harness pipeline 7. Corrugated pipe 8. Sliding mounting plate 9. Fixed mounting plate 10. Linear slide rail 11. Distance sensor 12. Pressure gauge 13. Tank support. Detailed Implementation

[0027] A corrugated pipe dense corrugation shaping device includes a tank support 13 and a tank 2 mounted on the tank support 13. A pressure gauge 12 is installed on the tank 2 and connected to a control console 1. A linear slide rail 10 is installed inside the tank 2. One end of the linear slide rail 10 is connected to an L-shaped fixed mounting plate 9, and the other end is connected to an L-shaped sliding mounting plate 8. A corrugated pipe 7 is installed between the fixed mounting plate 9 and the sliding mounting plate 8. A distance sensor 11 is also installed on the sliding mounting plate 8. The sensing circuit of the distance sensor 11 is connected to the control console through a wiring harness pipe 6. The device also includes an internal hydraulic pipeline 3, one end of which is connected to the corrugated pipe 7, and the other end of which passes through the tank 2 and is connected to the control console. An external hydraulic pipeline 4 is connected at one end to the inside of the tank and at the other end to the control console.

[0028] The tank also has a pressure relief pipe 5.

[0029] The control console integrates a PID algorithm and a formula for calculating the pressure required for the initial deformation of the bellows. It collects and monitors data in real time through sensors and converts the calculation results into pressure control signals for the internal and external hydraulic lines in the form of electrical signals.

[0030] The controller inside console 1 (usually a PLC or a conventional microcontroller) integrates the calculation formula for the initial pressure value required for bellows deformation. Known parameters are input into the console via an interactive interface, and the console converts the calculation results into electrical signals (usually voltage signals) and sends them to the actuators (such as water pump motors) in the external or internal hydraulic lines. At this point, initial pressure is present in the piping system, the bellows begins to deform, and subsequently, the PID controller is triggered to begin its actual operation.

[0031] The principle of PID control is as follows:

[0032] After the bellows deforms, the distance sensor ⑪ converts the actual length value it collects into a standard electrical signal (such as a current signal, voltage signal, etc.) and sends it to the controller inside the control console ① (usually a PLC or a conventional microcontroller). Upon receiving this signal, the control console 1 compares it with a pre-set target length value and then converts the comparison result into a new electrical signal (usually a voltage signal) and sends it to the actuator (such as a water pump motor). The actuator adjusts the motor frequency according to the received electrical signal, thereby controlling the pipeline pressure. The PID control logic block diagram is shown below. Figure 3 .

[0033] The internal hydraulic line 3 is connected to the bellows 7. When the line is pressurized, pressure is injected into the bellows 7, theoretically causing it to lengthen. The external hydraulic line 4 is connected to the tank 2. When the line is pressurized, pressure is injected into the outside of the bellows 7, theoretically causing it to shorten. When the bellows 7 deforms due to the internal and external pressure difference, one end can move freely along the linear slide rail 10. A distance sensor 11 is installed on the sliding mounting plate 8, which can monitor the length of the bellows in real time and transmit the collected data to the control console 1 in the form of an electrical signal through the wiring harness 6.

[0034] The method for dense corrugating a bellows using the shaping equipment of the present invention is as follows:

[0035] The control console incorporates a PID control algorithm and a formula for calculating the initial pressure required for bellows deformation. Using the final bellows length as the algorithm's target value L_SET, the bellows is shaped by adjusting the pressure values ​​of the external and internal hydraulic lines. The pressure gauge for the internal hydraulic line is integrated within the control console. Specifically, when the external hydraulic line pressure > the internal hydraulic line pressure, and the pressure difference reaches P... 外 At this time, the bellows length begins to shorten; when the external hydraulic line pressure is less than the internal hydraulic line pressure, and the pressure difference reaches P... 外At this time, the bellows begins to elongate; the formula for calculating the initial pressure required for the bellows deformation is as follows:

[0036]

[0037] This formula is for internal use by the applicant. Except for P... 外 Apart from the known parameters, all other parameters can be input into the control panel to calculate the initial deformation pressure value P. 外 .

[0038] P 外 —Initial deformation pressure value, unit: MPa;

[0039] D m —Mean value of bellows mean diameter, bellows inner diameter, and bellows outer diameter, unit: mm;

[0040] m — number of layers in the corrugated pipe blank;

[0041] δp—Effective wall thickness of each layer of tube blank after corrugated pipe forming, unit: mm;

[0042] h—Corrugated pipe wave height, unit: mm;

[0043] q—Corrugated pipe pitch before shaping, unit: mm;

[0044] [σ] t — Allowable stress of corrugated pipe material, unit: MPa.

[0045] The control console embeds a PID control algorithm, using the final length of the bellows as the target value L_SET. By adjusting the pressure values ​​of the external and internal hydraulic lines, it overcomes problems such as pressurization lag and length overshoot. The control console then calculates the initial deformation pressure value P. 外 The initial pressure threshold is set as the initial threshold for PID control to avoid meaningless low-pressure adjustments. Because the bellows has limited pressure-bearing capacity and should not be stretched or excessively compressed, the PID algorithm sets an upper limit for the bellows pressure difference and a length limit. When the pressure is too high, it will be relieved through the pressure relief pipe.

[0046] The PID algorithm employs a closed-loop logic of "setup value – acquisition – calculation – execution – feedback" to shape the bellows. The required bellows length value L_SET is used as the target value for algorithm control, and the bellows length is acquired in real-time via a distance sensor. If the acquired value is far from the target value L_SET, P (proportional control) is activated to increase the pressure increase rate, causing the bellows length to quickly approach the target value L_SET. When the length approaches the target value L_SET, the effect of P (proportional control) weakens to prevent excessive pressure increase leading to length overshoot. At this point, I (integral control) eliminates the error, further bringing the bellows length closer to the target value L_SET. D (derivative control) increases or decreases the pressure change rate in advance based on the rate of change of the bellows length (e.g., the length rapidly approaches the target value L_SET), thus addressing the hysteresis of the pressure difference between the inside and outside of the bellows. The algorithm also sets a length tolerance ΔL (e.g., ±2mm) for the target value L_SET to avoid frequent PID adjustments caused by small deviations.

[0047] Traditional forming equipment requires changing tooling such as forming mandrels due to differences in bellows diameter. This invention integrates theoretical formulas and PID algorithms into the forming equipment, eliminating the need to change mandrels and other tooling. It achieves automated forming of bellows of all diameters and materials using a hydraulic method.

Claims

1. A corrugated pipe dense corrugation shaping device, characterized in that, The system includes a tank support (13) and a tank (2) mounted on the tank support (13). A pressure gauge (12) is mounted on the tank (2) and connected to a control console (1). A linear slide rail (10) is installed inside the tank (2). One end of the linear slide rail (10) is connected to an L-shaped fixed mounting plate (9), and the other end is connected to an L-shaped sliding mounting plate (8). A bellows pipe (7) is installed between the fixed mounting plate (9) and the sliding mounting plate (8). A distance sensor (11) is also installed on the sliding mounting plate (8). The sensing circuit of the distance sensor (11) is connected to the control console (1) through a wire harness pipe (6). The system also includes an internal hydraulic pipeline (3), one end of which is connected to the bellows pipe (7), and the other end passes through the tank (2) and is connected to the control console (1). An external hydraulic pipeline (4) is connected to the inside of the tank (2) at one end and to the control console (1) at the other end.

2. The corrugated pipe dense corrugation shaping equipment according to claim 1, characterized in that, The tank also has a pressure relief pipe (5).

3. A method for dense corrugating a corrugated pipe using the shaping equipment described in claim 1 or 2, characterized in that: The control console embeds a PID control algorithm and a formula for calculating the initial pressure required for bellows deformation. Parameters are input through the console's interactive interface, with the final bellows length as the algorithm's target value L_SET. The bellows is shaped by adjusting the pressure values ​​of the external and internal hydraulic lines. The pressure gauge for the internal hydraulic line is integrated inside the control console. Specifically, when the external hydraulic line pressure > the internal hydraulic line pressure, and the pressure difference reaches P... 外 At this time, the bellows length begins to shorten; when the external hydraulic line pressure is less than the internal hydraulic line pressure, and the pressure difference reaches P... 外 At that time, the length of the bellows begins to elongate; The formula for calculating the initial pressure required for the bellows deformation is as follows: ； P 外 —Initial deformation pressure value, unit: MPa; Dm—Mean diameter of the bellows, the average of the inner and outer diameters of the bellows, in mm; m — number of layers in the corrugated pipe blank; δp—Effective wall thickness of each layer of tube blank after corrugated pipe forming, unit: mm; h—Corrugated pipe wave height, unit: mm; q—Corrugated pipe pitch before shaping, unit: mm; [σ]t——Allowable stress of the corrugated pipe material, unit: MPa.

4. The method according to claim 3, characterized in that, The PID control algorithm also sets the upper limit of the bellows pressure difference and the length limit. When the pressure is too high, the pressure is relieved through the pressure relief pipe.

5. The method according to claim 3, characterized in that, If the collected value is far from the target value L_SET, P is activated to increase the pressure increase rate, so that the bellows length quickly approaches the target value L_SET. When the length approaches the target value L_SET, the effect of P is weakened to avoid excessive pressure increase leading to length overshoot. At this time, I is used to eliminate the error, so that the bellows length further approaches the target value L_SET. D increases or decreases the pressure change rate in advance according to the rate of change of the bellows length, thereby solving the hysteresis of the pressure difference inside and outside the bellows.

6. The method according to claim 3, characterized in that, The PID control algorithm also sets a length tolerance ΔL for the target value L_SET to avoid frequent PID adjustments caused by small deviations.

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