Large oil cylinder V group seal external leakage automatic detection system and adjustment method

Abstract

The invention discloses a large oil cylinder V-group seal external leakage automatic detection system, which comprises a piston rod, a cylinder barrel, and a V-group seal, a step seal, a Glyd ring and a dustproof ring which are sequentially arranged on the inner surface of the cylinder barrel, and a leakage detection port is arranged between the V-group seal and the step seal; the leakage detection system is composed of a manual ball valve connected with a leakage detection port, a pressure sensor, an electromagnetic ball valve, a detection oil tank and a flow meter. The V-group sealing compression amount adjusting assembly comprises a fixing nut, an adjusting screw rod and a wedge-shaped block, and the adjusting screw rod is rotated to drive the wedge-shaped block to move to achieve stepless adjustment of the compression amount. The control module processes sensor data through an industrial personal computer and controls an execution element. The system can monitor the sealing state in real time and automatically adjust the compression amount, and is mainly used for monitoring and maintaining the sealing performance of the super-long oil cylinder in the fields of large engineering machinery, maritime ships and the like.

Description

Technical Field

[0001] The present invention relates to the field of automatic detection and adjustment of external leakage of V-group seals of large oil cylinders. More specifically, the present invention relates to an automatic detection system and adjustment method for external leakage of V-group seals of large oil cylinders. Background Art

[0002] With the development of science and technology, the application of super-large and super-long cylinders in the fields of metallurgical forging equipment, maritime and offshore vessels, large-scale engineering construction, etc. is becoming more and more common. The design difficulty, reliability requirements, raw material production difficulty, processing difficulty, and surface processing difficulty of super-large and super-long cylinders are much higher than those of ordinary cylinders. The main cylinder of the pile frame of a pile-driving ship is a typical representative of super-large and super-long cylinders. It is the core component of a large pile-driving ship. It is mainly used for the pitching movement of the pile frame. The diameter of the cylinder exceeds 1.6m and the stroke exceeds 21m. As the key core component of the cylinder, the working performance of the seal is related to the normal operation of the cylinder. The V-group seal is the main seal of the super-large cylinder seal, and its importance is self-evident.

[0003] The long stroke of the main cylinder of a pile-driving vessel's pile frame can easily cause eccentric load failure of the cylinder seal. Prolonged exposure to the marine environment can lead to corrosion and other problems in the cylinder piston rod, leading to seal failure. Because the pile frame weighs thousands of tons and is difficult to repair, if the cylinder fails or stops working, it can render the pile-driving vessel unusable, requiring a long and expensive repair cycle. In severe cases, it can cause the boom to collapse, resulting in a serious safety incident.

[0004] At present, the monitoring of the main oil cylinder sealing system of the pile frame of the pile driving ship mainly relies on monitoring parameters such as the working pressure and stroke of the oil cylinder. Due to the high height of the piston rod of the main oil cylinder, it is impossible to detect the leakage of the oil cylinder in time, which may cause the oil cylinder to be unable to pull back the pile frame, posing a certain safety risk. In addition, when the current V-group seal leaks, it mainly relies on adjusting the number of gaskets to readjust the V-group seal compression. The adjustment process is relatively cumbersome, time-consuming and labor-intensive. At the same time, the V-group seal compression cannot be adjusted steplessly according to the seal leakage situation. Once over-adjusted, it is easy to cause the V-group seal to wear too quickly. Summary of the Invention

[0005] To achieve these objectives and other advantages, a preferred embodiment of the present invention provides an automatic leakage detection system for a large oil cylinder V-group seal, comprising a piston rod, a cylinder barrel, a V-group seal, a step seal, and a Gly ring sequentially mounted on the inner surface of the cylinder barrel along the extension direction of the cylinder, wherein a leakage detection port is provided between the V-group seal and the step seal; and further comprising a leakage detection system and a V-group seal compression adjustment assembly. The leak detection system includes: Connect the manual ball valve, pressure sensor and electromagnetic ball valve A of the leak detection port in sequence through pipelines; The oil tank is tested. The oil port on the lower side is connected to the electromagnetic ball valve A through a pipeline. A hydraulic test valve is installed on the side. The oil port on the upper side is connected to the electromagnetic ball valve B and the flow meter in sequence and then returned to the detection tank. The oil port on the bottom is connected to the electromagnetic ball valve B and the flow meter in sequence. Magnetic ball valve and transparent tube back to the test tank; V-group seal compression adjustment assembly, including: A fixing nut fixedly connected to the cylinder; The adjusting screw passes through the fixing nut and is connected to the wedge block through the pressure plate and the fastening nut. Screwing the adjusting screw in / out drives the wedge block to move axially to steplessly adjust the compression of the V group seal.

[0006] Preferably, it also includes an industrial computer; When the pressure sensor detection value P1 ≥ threshold value P0, the industrial computer controls the electromagnetic ball valve A and electromagnetic ball valve B to open, and calculates the leakage amount Q by detecting the oil tank level change rate △S1 / △t or the flow meter measured value Q2 S ; Leakage Q S The calculation includes the following steps: S1. Leakage status monitoring When the pressure sensor detection value P1 ≥ threshold value P0, the leakage detection process is triggered, the industrial computer controls the electromagnetic ball valve A and electromagnetic ball valve B to open, and the oil flows into the detection tank; When the pressure sensor detection value P1 is less than the threshold value P0, it is determined that there is no leakage and the electromagnetic ball valve remains closed; S2. Leakage calculation Working condition 1: Slight leakage: Use the tank level sensor to measure the liquid level change rate ΔS1 / Δt, and calculate the leakage amount Q1=ΔS1 / Δt×A, where ΔS1 / Δt is the liquid level change rate and A is the cross-sectional area of ​​the test tank; Working condition 2: Excessive leakage: When the leakage Q1 exceeds the flow meter detection accuracy Q d , close the electromagnetic ball valve B and open the electromagnetic ball valve C to quickly drain the oil; Working condition 3: Leakage can be measured within an appropriate range: leakage Q2 can be directly read through the flow meter; Final leakage: take the maximum value Q S =max(Q1, Q2) as the basis for evaluation; S3. Leakage threshold judgment and alarm Comparison of leakage value Q S and seal leakage threshold Qn; If Q S ≤Qn, maintain the current adjusting screw screw length Ln; If Q S=max(Q1, Q2)>Qn, indicating that the seal leakage exceeds the limit and affects the use, triggering the sound and light alarm, then adjust Stepless adjustment of the screw; Preferably, the detection oil tank is hinged to the cylinder barrel of the oil cylinder, and when the oil cylinder posture changes, the detection oil tank can always be in In vertical posture.

[0007] Preferably, the stepless adjustment of the adjusting screw specifically includes the following steps: S41. Through the sealing performance test, measure the actual leakage Q under different screw screw lengths Ln S , establish Ln-Q S Mapping relationship curve; S42, corresponding to each actual leakage amount Q S In Ln-Q S Use the mapping relationship curve to find the corresponding target screw insertion length Ln; S43. Generate a compression adjustment instruction based on the obtained target screw insertion length Ln, so that the actual screw insertion length is consistent with the target screw insertion length.

[0008] On the other hand, a preferred embodiment of the present invention further provides a V-group seal detection and adjustment method, comprising the following steps: S1, real-time monitoring of the leak detection port pressure P1, if P1 is less than the standard value P0, start the leak detection process, if P1 ≥ P0 Execute S2 when S2. Obtain the actual leakage Q through the liquid level sensor or flow meter S , if Q S >Qn, execute S3; S3, adjust the screw length Ln and leakage Q S The mapping relationship table; S4, drive the adjusting screw to rotate to Lt, completing the stepless adjustment of the compression amount, where , where a n For leakage Quantity correction factor.

[0009] The present application at least includes the following beneficial effects: the present application provides a large oil cylinder V group seal leakage automatic detection system and adjusting method, through accurate measurement of the large oil cylinder piston rod V group seal leakage amount, combined with the trend analysis of the V group seal leakage amount, the sealing performance of the large oil cylinder piston rod V group seal is quantitatively evaluated, so as to solve the problem that the sealing performance of the large oil cylinder piston rod V group seal cannot be accurately grasped, and the use safety of the large oil cylinder is significantly improved; through the V group compression amount adjusting mechanism designed for the first time, combined with the leakage data, the V group seal compression amount is quickly and steplessly adjusted, the oil cylinder maintenance time is reduced, and the service life of the V group seal is improved.

[0010] Other advantages, objects, and features of the present application will be understood by those skilled in the art from the following description, and will be further understood by those skilled in the art through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a structural entity diagram of the large oil cylinder V group seal leakage automatic detection system of the present application.

[0012] Figure 2 It is Figure 1 It is a local enlarged view of A in the middle.

[0013] Figure 3 It is a tool control system composition of the present application. DETAILED DESCRIPTION

[0014] The present application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present application according to the description.

[0015] The following description is used to disclose the present application so that those skilled in the art can implement the present application. The preferred embodiments in the following description are only as examples, and other obvious modifications can be thought by those skilled in the art. The basic principles of the present application defined in the following description can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0016] Those skilled in the art should understand that in the disclosure of the present application, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation of the present application.

[0017] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0018] like Figure 1-2 As shown, a preferred embodiment of the present invention provides an automatic detection system for external leakage of a V-group seal of a large oil cylinder, comprising a piston rod 1, a cylinder barrel 2, a V-group seal 3, a step seal 4, a Gly ring 5, and a dust seal 6 sequentially installed on the inner surface of the cylinder barrel 2 along the extension direction of the oil cylinder, wherein a leakage detection port 7 is provided between the V-group seal 3 and the step seal 4; The leak detection system includes: Connect the manual ball valve, pressure sensor 9 and electromagnetic ball valve A10 of the leak detection port in sequence through pipelines; The oil port on the lower side of the test tank 11 is connected to the electromagnetic ball valve A10 through a pipeline. A hydraulic detection sensor 12 is installed on the side. The oil port on the upper side is connected to the electromagnetic ball valve B13 and the flow meter 14 in sequence and then returns to the test tank. The oil port on the bottom is connected to the electromagnetic ball valve C15 and the transparent tube in sequence and then returns to the test tank. V-group seal compression adjustment assembly, including: A fixing nut 19 fixedly connected to the cylinder; The adjusting screw 20 passes through the fixing nut 19 and is connected to the wedge block 23 through the pressure plate 21 and the fastening nut 22. The adjusting screw 20 is screwed in / out to drive the wedge block 23 to move axially to steplessly adjust the compression amount of the V group seal 3; A control module including an industrial computer 24; When the pressure sensor detection value P1 ≥ threshold value P0, the industrial computer controls the electromagnetic ball valve A10 and the electromagnetic ball valve B13 to open, and calculates the leakage amount Q by detecting the oil tank level change rate △S1 / △t or the flow meter measured value Q2. S .

[0019] In the above technical solution, the detection oil tank 11 is connected to each solenoid valve through a pipeline, and a hydraulic detection sensor 12 is installed on its side to measure the liquid level change. The V group seal compression adjustment assembly includes a fixed nut 19, an adjusting screw 20, a pressure plate 21, a fastening nut 22 and a wedge block 23. By rotating the adjusting screw 20, the wedge block 23 can be driven to move to adjust the compression of the V group seal 3. The core of the control module is the industrial computer 24, which is responsible for processing sensor data and controlling the actions of each actuator. When the system is working, the pressure value P1 of the leakage detection port 7 is first monitored by the pressure sensor 9. When P1 exceeds the preset threshold value P0, the industrial computer 24 controls the electromagnetic ball valve A 10 and the electromagnetic ball valve B 13 to open, allowing the leaked oil to enter the detection oil tank 11. The hydraulic detection sensor 12 monitors the changes in the tank liquid level in real time, and the industrial computer 24 calculates the leakage amount Q1 based on the liquid level change rate. When the leakage amount is large, the flowmeter 14 directly measures the return oil flow Q2 as the leakage amount Q S At the same time, the industrial computer 24 determines whether the sealing compression needs to be adjusted according to the leakage amount. If adjustment is required, the adjusting screw 20 is controlled to rotate the corresponding angle, and the wedge block 23 is used to push the V-group sealing support block to move, thereby achieving stepless adjustment of the compression amount.

[0020] This implementation utilizes a multi-stage seal system and an intelligent detection system to achieve real-time monitoring and automatic adjustment of the cylinder's sealing status. The dual detection mechanism of a pressure sensor and flow meter ensures accurate leakage measurement, while the screw-wedge adjustment mechanism provides precise compression control. The entire system boasts a compact design and rapid response, effectively preventing safety incidents caused by seal failure.

[0021] In another technical solution, the leakage amount Q S The calculation includes the following steps: S1. Leakage status monitoring When the pressure sensor detection value P1 ≥ threshold value P0, the leakage detection process is triggered, the industrial computer controls the electromagnetic ball valve A and electromagnetic ball valve B to open, and the oil flows into the detection tank; When the pressure sensor detection value P1 is less than the threshold value P0, it is determined that there is no leakage and the electromagnetic ball valve remains closed; S2. Leakage calculation Working condition 1: Slight leakage: Use the tank level sensor to measure the liquid level change rate ΔS1 / Δt, and calculate the leakage amount Q1=ΔS1 / Δt×A, where ΔS1 / Δt is the liquid level change rate and A is the cross-sectional area of ​​the test tank; Working condition 2: Excessive leakage: When the leakage Q1 exceeds the flow meter detection accuracy Q d , close the electromagnetic ball valve B and open the electromagnetic ball valve C to quickly drain the oil; Working condition 3: Leakage can be measured within an appropriate range: leakage Q2 can be directly read through the flow meter; Final leakage: take the maximum value Q S =max(Q1, Q2) as the basis for evaluation; S3. Leakage threshold judgment and alarm Comparison of leakage value Q S and seal leakage threshold Qn; If Q S ≤Qn, maintain the current adjustment screw screw length Ln; If Q S =max(Q1, Q2)>Qn, indicating that the seal leakage exceeds the limit and affects the use, triggering the sound and light alarm, then adjust Stepless adjustment of the screw; In the above embodiment, under working condition 1 with a slight leakage, when the pressure sensor 9 detects a leakage and the leakage amount is small, the industrial computer 24 opens the electromagnetic ball valve A 10 and the electromagnetic ball valve B 13 to allow the leaked oil to enter the detection tank 11. The hydraulic detection sensor 12 measures the liquid level change, and the industrial computer 24 calculates the leakage amount Q1 based on the product of the liquid level rise height per unit time and the cross-sectional area of ​​the tank. This measurement method has a high sensitivity to tiny leaks. When the leakage continues and causes the liquid level in the detection tank 11 to reach the upper limit Smax (excessive leakage), the system automatically switches to working condition 2, opens the electromagnetic ball valve C 15 to discharge the oil back to the detection tank, and remeasures after the liquid level drops to the lower limit Smin until the liquid level drops to a reasonable range, and then switches to working condition 3. Under working condition 3, the leakage amount is within a reasonable range. At this time, the electromagnetic ball valve C 15 is kept closed, and all the leaked oil flows through the flow meter 14, and the flow value Q2 is directly read as the leakage amount Q S The system prioritizes high-precision measurement using Condition 1, automatically upgrading to Condition 3 when the leakage exceeds the liquid level measurement range. Condition 2 serves as a transitional state, ensuring that the system does not lose measurement data during the transition. This hierarchical measurement strategy ensures both sensitivity for detecting small leaks and accurate measurement of large flow rates, significantly expanding the system's measurement range.

[0022] This implementation achieves precise leakage measurement across the full range through an intelligent operating mode switching mechanism. The system automatically selects the optimal measurement method based on the actual leakage situation, eliminating the need for manual intervention. This improves measurement accuracy while ensuring continuous and stable system operation.

[0023] In another technical solution, the detection oil tank is hinged to the cylinder barrel of the oil cylinder, and when the cylinder posture changes, the detection oil tank can always be in a vertical posture. The detection oil tank is connected to the fixed plate and the ball joint, and the fixed plate is fixed to the cylinder barrel of the oil cylinder.

[0024] In the above embodiment, the detection oil tank 11 is connected to the fixed plate 17 through a ball joint 18, and the fixed plate 17 is firmly mounted on the cylinder 2. The ball joint 18 structure allows the detection oil tank 11 to rotate freely in multiple directions. When the oil cylinder is working, the angle of the cylinder 2 may change as the piston rod 1 extends and retracts. At this time, under the action of gravity, the detection oil tank 11 will automatically adjust its posture through the ball joint 18 and always remain in a vertical state. This design ensures that the measurement reference of the hydraulic detection sensor 12 is always consistent with the direction of gravity, avoiding liquid level measurement errors caused by the tilt of the oil tank. The ball joint 18 needs to provide sufficient rotational freedom while maintaining the stability of the connection to prevent the detection oil tank 11 from shaking during operation. The connection between the fixed plate 17 and the cylinder 2 is fixed with high-strength bolts to ensure the rigidity of the overall structure. The pipeline connection of the detection oil tank 11 uses a flexible hose to adapt to its posture changes.

[0025] This embodiment solves the measurement benchmark issue under dynamic cylinder conditions. A simple mechanical structure enables adaptive leveling of the detection tank 11, ensuring accurate level measurement. This mechanism requires no additional power or control system, relying solely on gravity for automatic adjustment, resulting in a simple structure and high reliability.

[0026] In another technical solution, when Q S When the leakage threshold Qn is exceeded, it means that the seal leakage exceeds the limit and affects the use. According to the adjustment screw screw length Ln and the leakage amount Q S The mapping relationship table generates a compression adjustment instruction, and then adjusts the compression of the V group seal according to the compression adjustment instruction.

[0027] The adjusting screw 20 is driven by a servo motor and is precisely adjusted according to the calculated rotation angle. The rotation of the screw 20 drives the wedge block 23 to move axially, and the wedge surface pushes the V-group seal support block 25 to produce displacement, thereby changing the compression of the V-group seal 3. This embodiment realizes closed-loop control of the seal compression amount. Through quantitative relationships and automatic adjustment mechanisms, the traditional manual gasket adjustment method is replaced, greatly improving the adjustment accuracy and efficiency. The system can intelligently determine the optimal compression amount based on the actual leakage situation, which not only ensures the sealing effect, but also avoids premature wear of the seal caused by excessive compression.

[0028] In another technical solution, when Q S When the leakage threshold Qn is exceeded, the industrial computer controls the audible and visual alarm to sound an alarm. This implementation utilizes a multi-level alarm strategy to ensure that operators are promptly notified of any sealing anomalies. This combined audible and visual alarm system improves alarm reliability and effectively conveys alarm information even in harsh environments. The system supports customizable alarm parameters to meet the needs of diverse application scenarios.

[0029] In another technical solution, the stepless adjustment of the adjusting screw specifically includes the following steps: S41. Through the sealing performance test, measure the actual leakage Q under different screw screw lengths Ln S , establish Ln-Q S Mapping relationship curve; S42, corresponding to each actual leakage amount Q S In Ln-Q S Use the mapping relationship curve to find the corresponding target screw insertion length Ln; S43. Generate a compression adjustment instruction based on the obtained target screw insertion length Ln, so that the actual screw insertion length is consistent with the target screw insertion length.

[0030] On the other hand, a preferred embodiment of the present invention provides a V-group seal detection and adjustment method, comprising the following steps: S1, real-time monitoring of the leak detection port pressure P1, if P1 is less than the standard value P0, start the leak detection process, if P1 ≥ P0 Execute S2 when S2. Obtain leakage Q through liquid level sensor or flow meter S , if Q S >Qn, execute S3; S3, adjust the screw length Ln and leakage Q S The mapping relationship table; S4, drive the adjusting screw to rotate to Lt, completing the stepless adjustment of the compression amount, where , where a n For leakage Quantity correction factor.

[0031] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An automatic detection system for external leakage of V-group seals of large oil cylinders, characterized by: It includes a piston rod, a cylinder, a V-group seal, a Step seal, and a Gly ring installed on the inner surface of the cylinder in sequence along the extension direction of the cylinder, wherein a leakage detection port is provided between the V-group seal and the Step seal; it also includes a leakage detection system and a V-group seal compression adjustment component; The leak detection system includes: Connect the manual ball valve, pressure sensor and electromagnetic ball valve A of the leakage detection port in sequence through pipelines; The oil port on the lower side of the test tank is connected to the electromagnetic ball valve A through a pipeline. A hydraulic detection sensor is installed on the side. The oil port on the upper side is connected to the electromagnetic ball valve B and the flow meter in sequence and then returns to the test tank. The oil port on the bottom is connected to the electromagnetic ball valve and the transparent tube in sequence and then returns to the test tank. V-group seal compression adjustment assembly, including: A fixing nut fixedly connected to the cylinder; The adjusting screw passes through the fixing nut and is connected to the wedge block through the pressure plate and the fastening nut. Screwing the adjusting screw in / out drives the wedge block to move axially to steplessly adjust the compression of the V group seal.

2. The large oil cylinder V group seal external leakage automatic detection system according to claim 1 is characterized in that: It also includes industrial computers; When the pressure sensor detection value P1 ≥ threshold value P0, the industrial computer controls the electromagnetic ball valve A and electromagnetic ball valve B to open, and calculates the leakage amount Q by detecting the oil tank level change rate △S1 / △t or the flow meter measured value Q2 S ; Leakage Q S The calculation includes the following steps: S1. Leakage status monitoring When the pressure sensor detection value P1 ≥ threshold value P0, the leakage detection process is triggered, the industrial computer controls the electromagnetic ball valve A and electromagnetic ball valve B to open, and the oil flows into the detection tank; When the pressure sensor detection value P1 is less than the threshold value P0, it is determined that there is no leakage and the electromagnetic ball valve remains closed; S2. Leakage calculation Working condition 1: Slight leakage: Use the tank level sensor to measure the liquid level change rate ΔS1 / Δt, and calculate the leakage amount Q1=ΔS1 / Δt×A, where ΔS1 / Δt is the liquid level change rate and A is the cross-sectional area of ​​the test tank; Working condition 2: Excessive leakage: When the leakage Q1 exceeds the flow meter detection accuracy Q d , close the electromagnetic ball valve B and open the electromagnetic ball valve C to quickly drain the oil; Working condition 3: Leakage can be measured within an appropriate range: leakage Q2 can be directly read through the flow meter; Final leakage: take the maximum value Q S =max(Q1, Q2) as the basis for evaluation; S3. Leakage threshold judgment and alarm Comparison of leakage value Q S and seal leakage threshold Qn; If Q S ≤Qn, maintain the current adjustment screw screw length Ln; If Q S =max(Q1, Q2)>Qn, indicating that the seal leakage exceeds the limit and affects the use, triggering the sound and light alarm, then adjust Stepless adjustment of the screw.

3. The large oil cylinder V group seal external leakage automatic detection system according to claim 1 is characterized in that: Place The detection oil tank and the cylinder barrel of the oil cylinder are hinged, and when the posture of the oil cylinder changes, the detection oil tank can always be in a vertical posture.

4. The large oil cylinder V group seal external leakage automatic detection system according to claim 2 is characterized in that: tune The stepless adjustment of the joint screw specifically includes the following steps: S41. Through the sealing performance test, measure the actual leakage Q under different screw screw lengths Ln S , establish Ln-Q S Mapping relationship curve; S42, corresponding to each actual leakage amount Q S In Ln-Q S Use the mapping relationship curve to find the corresponding target screw insertion length Ln; S43. Generate a compression adjustment instruction based on the obtained target screw insertion length Ln, so that the actual screw insertion length is consistent with the target screw insertion length.

5. A V-group seal detection and adjustment method according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, real-time monitoring of the leak detection port pressure P1, if P1 is less than the standard value P0, start the leak detection process, if P1 ≥ P0 Execute S2 when S2. Obtain the actual leakage Q through the liquid level sensor or flow meter S , if Q S >Qn, execute S3; S3, adjust the screw length Ln and leakage Q S The mapping relationship table; S4, drive the adjusting screw to rotate to Lt, completing the stepless adjustment of the compression amount, where , where a n For leakage Quantity correction factor.

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