Device and method for quickly loosening locking nut of column type hydraulic press

Abstract

The application discloses a device and method for quickly loosening locking nuts of a column hydraulic press, and the device is designed by analyzing the working principle of the hydraulic system of the equipment, loosening the locking nuts of the column hydraulic press by using the self-provided hydraulic system of the equipment, selecting a safe and reliable plugging position, designing a plug with an O-shaped sealing groove and a fastening mode of the plug according to the present situation of the plugging position, and performing reliability calculation. By considering the safety and reliability of plugging the super-high pressure working liquid and the convenience of the implementation process, the plugging position is selected at the oil inlet and outlet position of the lower cavity of the main cylinder. The design is a reliable design, can effectively use the self-provided hydraulic system of the column hydraulic press to reach the process requirement pressure, and achieves the purpose of quickly loosening the locking nuts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of column hydraulic press maintenance, and particularly relates to a device and method for quickly loosening locking nuts of a column hydraulic press. BACKGROUND

[0002] The column hydraulic press is a mechanical device using liquid pressure transmission according to Pascal's law. In the actual working process of the column hydraulic press, the oil pump sends the working liquid with pressure into the upper cavity of the main cylinder, the main cylinder piston drives the punch to move downward along the column, and the working liquid in the lower cavity of the main cylinder returns to the oil tank through the main cylinder return pipeline and the relevant valves of the hydraulic station. When the lower end surface of the upper punch contacts the workpiece placed on the workbench lining, the main cylinder piston will transmit the downward pressure of the working liquid to the workpiece, and at the same time, the workpiece will also generate an upward reaction force, which is transmitted to the upper cross beam. Since the upper cross beam is fixed by four columns, locking nuts and a machine base, the reaction force finally becomes the tensile force of the four columns. The greater the working liquid pressure provided by the oil pump, the greater the pressure applied to the workpiece, and the greater the tensile force borne by the columns. Under the tensile force of 300 tons, the four columns will deform by about 2-3 mm, i.e., the upper cross beam is separated from the upper end surface of the locking nut by 2-3 mm. At the moment of pressure release during the return stroke of the main cylinder, the upper cross beam will impact the upper end surface of the locking nut with great force under the action of the great tensile force. Under the working cycle of 1.5 minutes, the locking nut and the column thread will soon be damaged, causing equipment failure.

[0003] In the prior art, during maintenance, the overflow valve is first adjusted to control the output pressure of the oil pump, so that the output pressure of the oil pump is 5%-8% higher than the process requirement pressure. Under this pressure, the column elongation deformation is greater than the deformation during locking, so that the upper end surface of the locking nut and the contact surface of the upper cross beam are separated from the close contact, and the four locking nuts are quickly loosened by using a special wrench, so that a gap of 3-5 mm is generated between the upper end surface of the locking nut and the contact surface of the upper cross beam. The pressure is stopped, and the equipment is closed. At this time, the upper cross beam moves downward, the upper end surface of the upper cross beam and the locking nut generate a gap of 1-2 mm, the locking nut is removed, the upper cross beam is disassembled and lifted, and the main cylinder is disassembled and inspected.

[0004] However, during the long-term use of the equipment, due to the manufacturing defects of the main cylinder piston head or the defects of the sealing element, the working liquid in the upper and lower cavities of the main cylinder will appear the phenomenon of cavity mixing (internal leakage of the working liquid in the upper and lower cavities of the main cylinder), so that the actual working pressure cannot reach the set process requirement pressure. During the disassembly and maintenance of the main cylinder, the output pressure of the oil pump cannot reach the process requirement pressure by adjusting the overflow valve, and even is much lower than the process requirement pressure. At this time, various methods cannot loosen the four locking nuts.

[0005] According to the manufacturer's recommendations, the loosening method of destroying the four upper locking nuts of the upper cross beam can be used, but the damage to the four columns is inevitable during the destruction process, and slight negligence will also cause damage to the upper cross beam. These are the key stressed parts of the column hydraulic machine, and slight damage requires replacement of new parts. The column and upper cross beam are complex in processing and manufacturing, long in cycle, and high in precision requirements, which brings great economic losses to the society and enterprises. SUMMARY

[0006] The purpose of the present application is to provide a device and method for quickly loosening the locking nuts of a column hydraulic machine, which solves the problem of damage to the four columns and the upper cross beam during the repair process when the main cylinder of the column hydraulic machine leaks, causing great economic losses.

[0007] To solve the above technical problems, the present application adopts the following technical solutions:

[0008] A device for quickly loosening the locking nuts of a column hydraulic machine, comprising a plug for plugging the oil inlet of the lower cavity of the main cylinder of the column hydraulic machine, the plug being a rectangular cuboid structure with a square longitudinal section.

[0009] A plurality of fixing bolts are provided on the plug, and all the fixing bolts are fixedly connected with the lower cavity of the main cylinder by penetrating the plug.

[0010] An annular sealing groove is formed on the plug with the longitudinal section center point as the center, a sealing ring is installed in the sealing groove, and the sealing ring has the same specification as the oil inlet.

[0011] The present application also has the following technical features:

[0012] Further, the plug material is selected from 45# steel or other alloy steel.

[0013] Further, the number of fixing bolts is four, which are distributed on the four corners of the plug.

[0014] Further, the plug is connected with the main cylinder through the fixing bolts.

[0015] A method for quickly loosening the locking nuts of a column hydraulic machine, the method is based on the device for quickly loosening the locking nuts of a column hydraulic machine described above:

[0016] Step 1, according to the thickness of the main oil pipe wall of the main cylinder of the column hydraulic machine, the maximum pressure provided by the hydraulic system of the column hydraulic machine and the area of the oil inlet, make the plug; use four fixing bolts to penetrate the plug.

[0017] According to the punch specification of the column hydraulic machine and the height requirement range of the column hydraulic machine allowed to press the workpiece, make auxiliary pads.

[0018] Step 2, place the auxiliary pad on the workbench of the column hydraulic machine, and make the center axis of the column hydraulic machine punch coincide with the center axis of the auxiliary pad.

[0019] Step 3, start the power supply of the column hydraulic machine, make the punch of the column hydraulic machine tightly press on the auxiliary pad, set the state at this time as the initial state, and turn off the power supply of the column hydraulic machine.

[0020] Step 4, remove the bolts connecting the lower cavity oil pipe of the main cylinder with the main cylinder, remove the lower cavity oil pipe of the main cylinder, and clean the contact surface.

[0021] Step 5, install the plug with a sealing ring, align the oil inlet of the lower cavity of the main cylinder of the column hydraulic machine, fix the plug and the main cylinder by all fixed bolts, and make the plug seal and block the oil inlet.

[0022] Step 6, adjust the pressure control system of the column hydraulic machine to make the oil pump output working liquid, control the output pressure to be 50% of the value, and observe whether the connection between the plug and the oil inlet leaks.

[0023] If leakage occurs, it indicates that the plug is not firmly installed or the sealing ring is not correctly installed, the column hydraulic machine is immediately stopped, and the initial state is restored; after waiting for 10 minutes, the installation of the plug and the sealing ring is checked and adjusted according to the actual situation, and after adjustment, step 5 is jumped to until no leakage occurs, and step 7 is executed.

[0024] If no leakage occurs, step 7 is executed.

[0025] Step 7, adjust the pressure regulating valve of the pressure control system of the column hydraulic machine, make the oil pump output liquid pressure, and increase the pressure by 10% of the value step by step each time, and check whether the connection between the plug and the oil inlet leaks after each pressure increase.

[0026] If leakage occurs, stop immediately, check the installation of the plug and adjust it, continue to increase the pressure by 10% of the value step by step after adjustment is completed, until the working liquid pressure output by the oil pump is greater than or equal to the value.

[0027] If no leakage occurs, continue to increase the pressure by 10% of the value step by step, until the working liquid pressure output by the oil pump is greater than or equal to the value.

[0028] When the working liquid pressure output by the oil pump is greater than or equal to the value, the initial state is restored, and the pressure at this time is recorded as the value, and step 8 is entered.

[0029] ​​​​​​​​Step 8, loosening the locking nut of the column hydraulic machine by two operators, one as the operating equipment operator, and the other as the loosening locking nut operator.

[0030] The operating equipment operator controls the main cylinder liquid pressure to rise to , and maintains for 5-10 seconds; during this period, the loosening locking nut operator loosens one locking nut, the operating equipment operator stops the main cylinder liquid pressure, and returns to the initial state, and waits for 3-5 minutes.

[0031] Step 9, repeating step 8 until all locking nuts are loosened and returned to the initial state, and the power of the column hydraulic machine is turned off.

[0032] Further, in step 1, the thickness of the plug is 2-2.5 times the wall thickness of the main cylinder main oil pipe; or the thickness of the plug is calculated using the following formula:

[0033] F = σs × δ / k

[0034] wherein, F represents the pressure applied to the plug in the case of leakage of the working liquid in the main cylinder;

[0035] σs represents the yield limit of the selected material of the plug;

[0036] δ represents the thickness of the plug;

[0037] k represents the safety factor, k ε4,5.

[0038] Further, k the value of is 5.

[0039] Further, in step 1, the fixed bolt satisfies the following formula:

[0040] 4F min > × S

[0041] wherein, Fmin represents the minimum tensile load of a single bolt;

[0042] represents the maximum pressure that can be provided by the hydraulic system of the column hydraulic machine;

[0043] S represents the area enclosed by the sealing ring on the plug.

[0044] Further, in step 1, the parallelism of the upper and lower two planes of the auxiliary pad block is not greater than 0.1 mm.

[0045] Further, the auxiliary pad block is made of 45# steel or other alloy steel.

[0046] Compared with the prior art, the present application has the following technical effects:

[0047] (I) The device for quickly loosening the locking nut of the column type hydraulic machine of the present application is characterized in that a plug with sufficient strength is designed, fixing bolts are arranged at four corners of the plug, and a sealing ring with the same specification as the oil outlet is arranged at the center of the plug.

[0048] The plug is mainly used to generate elongation deformation of the column by force transmission through the pressure generated by the hydraulic system of the oil press, so as to loosen the locking nut, and therefore the plug can only be used to block the oil passage of the lower cavity of the main cylinder. In the design process of the column type hydraulic machine, according to the function of the oil pipe connected to the lower cavity of the main cylinder, the liquid pressure borne by the pipe is small, and when the working liquid leaks most seriously in the upper and lower cavities of the main cylinder, it is assumed that the pressure borne by the upper and lower cavities of the main cylinder is almost the same, so the pressure is much higher than the pressure designed for the oil pipe connected to the lower cavity of the main cylinder, and therefore the blocking position must be selected in the main cylinder. This design is a reliable design, which can effectively make the output pressure of the oil pump reach the process requirement pressure and achieve the purpose of loosening the locking nut.

[0049] (II) The method for quickly loosening the locking nut of the column type hydraulic machine of the present application is characterized in that the auxiliary pad block is used to press the auxiliary pad block by the punch of the press, the oil pipe connected to the lower cavity of the main cylinder is then disassembled, and the plug is installed, so that the liquid pressure borne by the lower cavity of the main cylinder during disassembly is not greater than the designed pressure, and the equipment is prevented from being damaged; at the same time, the working liquid pressure is gradually increased to ensure that no leakage or other abnormal conditions occur at the plug, so that the safety of the entire device is ensured, and the device is suitable for large-scale use and promotion in industry. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 is a schematic view of the plug structure of the present application;

[0051] Figure 2 is a schematic view of the vertical direction sectional structure of the plug of the present application;

[0052] Figure 3 is a schematic view of the connection relationship between the plug and the column type hydraulic machine of the present application.

[0053] The meanings of the reference numerals in the drawings are as follows: 1, plug; 2, column type hydraulic machine; 3, main cylinder; 4, lower cavity of the main cylinder; 5, oil inlet; 6, sealing ring; 7, fixing bolt. DETAILED DESCRIPTION

[0054] The following gives the specific embodiments of the present application, it is necessary to explain that the present application is not limited to the following specific examples, any equivalent transformation based on the technical scheme of the present application falls within the protection scope of the present application.

[0055] A device for quickly loosening the locking nut of a column hydraulic press, comprising a plug 1, the plug 1 is a cuboid structure with a square longitudinal section;

[0056] The plug 1 is used to block the main cylinder 3 of the column hydraulic press 2, and the blocking position is selected as the oil inlet 5 of the lower cavity 4 of the main cylinder;

[0057] An annular sealing groove is formed on the plug 1 with the center point of the longitudinal section as the center, a sealing ring 7 is installed in the sealing groove, and the sealing ring 7 has the same specification as the oil inlet 5; A plurality of fixing bolts 6 are arranged on the plug 1, and all the fixing bolts 6 are connected with the lower cavity 4 of the main cylinder in a sealing and fixed manner.

[0058] By considering the safety and reliability of blocking the super-high pressure working liquid, and the convenience of the implementation process, the blocking position is selected at the oil inlet and outlet of the lower cavity of the main cylinder. This design is a reliable design, which can effectively use the self-contained hydraulic system of the column hydraulic press to reach the process requirement pressure, and achieve the purpose of quickly loosening the locking nut.

[0059] As a preferred scheme, the material of the plug 1 is selected from 45# steel or other alloy steel to ensure that the strength of the plug 1 meets the standard.

[0060] As a preferred scheme, the sealing surface of the plug 1 and the sealing surface of the main cylinder are sealed by an "O" sealing ring to improve the reliability of the sealing.

[0061] A method for quickly loosening the locking nut of a column hydraulic press, the method is based on the device for quickly loosening the locking nut of the column hydraulic press described above.

[0062] Step 1, according to the thickness of the main oil pipe wall of the main cylinder 3 of the column hydraulic press 2, the maximum pressure that can be provided by the hydraulic system of the column hydraulic press 2 and the area of the oil inlet 5, the plug 1 is made; 4 fixing bolts 6 are used to penetrate the plug 1.

[0063] According to the punch specification of the column hydraulic press 2 and the height requirement range of the column hydraulic press 2 allowed to press the workpiece, a cuboid auxiliary pad with a rectangular cross section is made.

[0064] Step 2, place the auxiliary pad on the workbench of the column hydraulic press 2, and make the center axis of the punch of the column hydraulic press 2 coincide with the center axis of the auxiliary pad.

[0065] Step 3, start the power supply of the column hydraulic press 2, make the punch of the column hydraulic press 2 tightly press on the auxiliary pad, set the state at this time as the initial state, and turn off the power supply of the column hydraulic press 2.

[0066] Step 4, remove the main cylinder lower cavity oil pipe 4 and the main cylinder 3 connection part bolt, remove the main cylinder lower cavity 4 oil pipe, wipe the contact surface clean.

[0067] Step 5, install the plug 1 sealing ring 7, align the main cylinder lower cavity 4 oil inlet 5 of the column hydraulic press 2, through all the fixed bolt 6 fixed connection plug 1 and the main cylinder 3, so that the plug 1 sealing plugging oil inlet 5.

[0068] By using the auxiliary pad, the upper punch of the press is compacted, and the main cylinder lower cavity connection oil pipe is removed, the plug is installed, which ensures that the main cylinder lower cavity is not subjected to liquid pressure greater than the design pressure during the implementation process, and avoids damage to the equipment and safety accidents.

[0069] Step 6, adjust the pressure control system of the column hydraulic press 2 to make the oil pump output working liquid, control the output pressure to 50% of the design value, and observe whether the plug 1 and the oil inlet 5 connection place leak.

[0070] If there is leakage, it means that the plug 1 is not installed firmly or the sealing ring 7 is not installed correctly, immediately stop the column hydraulic press 2, and restore to the initial state; wait for 10 min, remove and check the installation of the plug 1 and the sealing ring 7, and adjust according to the actual situation, repeat step 5 after adjustment until no leakage occurs, and execute step 7.

[0071] If there is no leakage, execute step 7.

[0072] Step 7, adjust the pressure regulating valve of the pressure control system of the column hydraulic press 2, so that the liquid pressure output by the oil pump is increased by 10% of the design value at each step, and the leakage of the plug 1 and the oil inlet 5 connection place is checked after each pressure increase.

[0073] If there is leakage, stop immediately, check the installation of the plug 1 and adjust, continue to increase the pressure by 10% of the design value after adjustment is completed, until the working liquid pressure output by the oil pump≥ the design value. If there is no leakage, continue to increase the pressure by 10% of the design value, until the working liquid pressure output by the oil pump≥ the design value.

[0074] When the working liquid pressure output by the oil pump≥ the design value, restore to the initial state, and record the pressure at this time as the design value, enter step 8.

[0075] When the working liquid pressure output by the oil pump≥ the design value, restore to the initial state, and record the pressure at this time as the design value, enter step 8.

[0076] ​​​​​​​In the step-by-step boosting mode, it can clearly reflect whether there is leakage or other abnormal conditions at the connection of the plug 1, and ensure the smooth progress of the disassembly work.

[0077] Step 8, loosen the locking nuts of the column hydraulic press by two operators, one as the operating equipment personnel, and the other as the locking nut loosening personnel.

[0078] The operating equipment personnel controls the liquid pressure of the main cylinder 3 to rise to , and keep for 5-10 seconds; during this period, the locking nut loosening personnel loosens one locking nut, the operating equipment personnel stops the liquid pressurization of the main cylinder 3, and returns to the initial state, and waits for 3-5 minutes.

[0079] Step 9, repeat step 8 until all locking nuts are loosened and return to the initial state, and the punch of the column hydraulic press 2 leaves the auxiliary pad, and the power of the column hydraulic press 2 is turned off.

[0080] If leakage occurs, stop immediately, check the installation of the plug 1 and adjust, and then repeat step 6 until no leakage occurs.

[0081] As a preferred solution, in step 1, the thickness of the plug 1 is 2-2.5 times the wall thickness of the main oil pipe of the main cylinder 3; or the plug thickness is calculated using the following formula:

[0082] F = σs × δ / k

[0083] wherein, F represents the pressure applied to the plug in the case of leakage of the working liquid in the main cylinder; F is the force on the plug, that is, F = P 设 ×S； The lower cavity 4 of the main cylinder is sealed, and the upper cavity of the main cylinder is pressurized to P 设 In this state, due to the leakage of the upper and lower cavities in the main cylinder, the liquid pressure of the lower cavity is also P 设 , S is the force area of the plug, that is, S The value is the area surrounded by the sealing ring 7 on the plug 1;

[0084] σs represents the yield limit of the selected material of the plug;

[0085] δ represents the thickness of the plug;

[0086] k represents the safety factor, k ∈(4, 5).

[0087] In use, the pressure intensity borne by the plug 1 is equal to the wall thickness of the main cylinder 3, the thickness of the plug 1 is set to 2-2.5 times of the wall thickness of the main cylinder 3, and the strength of the plug 1 can be completely guaranteed.

[0088] As a preferred solution, k The value of 5 further guarantees the strength of the plug 1.

[0089] As a preferred solution, four fixed bolts 6 satisfying the following standards are selected:

[0090] 4F min > × S

[0091] Among them, Fmin The minimum tensile load of a single bolt is represented;

[0092] The highest pressure that can be provided by the hydraulic system of the column hydraulic press is represented;

[0093] S The area surrounded by the sealing ring on the plug is represented.

[0094] As a preferred solution, in step 1, the parallelism of the upper and lower two planes of the auxiliary pad block is not greater than 0.1 mm, so that the stress of the column is uniform, and the equipment is not damaged.

[0095] As a preferred solution, the material of the auxiliary pad block is selected from 45# steel or other alloy steel, so that the strength is guaranteed.

[0096] The device and method for quickly loosening the locking nut of the column hydraulic press have been used in a company, the locking screw is no longer damaged according to the manufacturer's suggestion, the disassembly and maintenance time of the equipment is greatly saved, and the social and economic benefits are remarkable.

[0097] Compared with the original destructive disassembly, the disassembly and maintenance time is saved for about 3 months; the use of the present application makes the faulty equipment recover the use performance within 2 days, avoids the need to re-produce and process the column, the locking nut, the upper cross beam and other main equipment parts after the column is damaged, saves a large amount of manpower, cost and social resources, and solves the imminent problem in the production process of the enterprise.

Claims

1. A method for quick loosening of the locking nut of a column hydraulic press, said method being based on a device for quick loosening of the locking nut of a column hydraulic press, comprising a plug (1) for plugging the oil inlet (5) of the lower cavity (4) of the main cylinder (3) of a column hydraulic press (2), characterized in that, The plug (1) is a cuboid structure with a square longitudinal section; The plug (1) is provided with a plurality of fixing bolts (6), and all the fixing bolts (6) are fixedly connected with the lower cavity (4) of the main cylinder by penetrating the plug (1); The plug (1) is provided with a ring-shaped sealing groove with the center point of the longitudinal section as the center, and the sealing groove is provided with a sealing ring (7); the sealing ring (7) has the same specification as the oil inlet (5), and the plug (1) is characterized by comprising the following steps: Step 1: according to the thickness of the main oil pipe wall of the main cylinder (3) of the column hydraulic machine (2), the maximum pressure provided by the hydraulic system of the column hydraulic machine (2) and the area of the oil inlet (5), the plug (1) is made; four fixing bolts (6) penetrate the plug (1); According to the punch specification of the column hydraulic machine (2) and the height requirement range of the column hydraulic machine (2) allowed to press the workpiece, the auxiliary pad is made; Step 2: place the auxiliary pad on the workbench of the column hydraulic machine (2), and make the center axis of the punch of the column hydraulic machine (2) coincide with the center axis of the auxiliary pad; Step 3: start the power supply of the column hydraulic machine (2), make the punch of the column hydraulic machine (2) tightly press on the auxiliary pad, set the state at this time as the initial state, and turn off the power supply of the column hydraulic machine (2); Step 4: remove the bolts at the connection part of the oil pipe of the lower cavity (4) of the main cylinder and the main cylinder (3), remove the oil pipe of the lower cavity (4) of the main cylinder, and wipe the contact surface clean; Step 5: after the plug (1) is installed with the sealing ring (7), align the oil inlet (5) of the lower cavity (4) of the main cylinder of the column hydraulic machine (2), and fix the plug (1) and the main cylinder (3) by all the fixing bolts (6), so that the plug (1) seals and blocks the oil inlet (5); Step 6, adjust the control system of the hydraulic press (2) to make the oil pump output working fluid, control the output pressure to be 50% of the pressure of the oil tank, and observe whether the joint between the plug (1) and the oil inlet (5) leaks fluid. Step 6, adjust the control system of the hydraulic press (2) to make the oil pump output working fluid, control the output pressure to be 50% of the pressure of the oil tank, and observe whether the joint between the plug (1) and the oil inlet (5) leaks fluid wherein, represents the corresponding pressure of the column hydraulic press (2) when the lock nut is locked. If liquid leakage occurs, it indicates that the plug (1) is not firmly installed or the sealing ring (7) is not correctly installed, the column hydraulic machine (2) is immediately stopped, and the initial state is restored; after waiting for 10 minutes, the installation of the plug (1) and the sealing ring (7) is checked and adjusted according to the actual situation, and after adjustment, step 5 is jumped to until step 7 is executed after no liquid leakage occurs; If there is no liquid leakage, step 7 is executed; Step 7, adjust the pressure regulating valve of the pressure control system of the column hydraulic press (2), so that the oil pump output liquid pressure is gradually increased at intervals of 10% of the original pressure, and after each pressure increase, check whether the plug (1) and the oil inlet (5) are connected. leakage; If leakage occurs, stop the machine immediately, check the installation of the plug (1) and make adjustments. After adjustment, continue the operation. The pressure is increased gradually in increments of 10% until the hydraulic pressure output by the oil pump is ≥ value; If no leakage occurs, continue to gradually increase the pressure by 10% of the value of until the oil pump output working hydraulic pressure is greater than or equal to the value of P2. When the oil pump output working hydraulic pressure ≥ , the initial state is restored, and the pressure at this time is recorded as , and step 8 is entered. Step 8: two operators cooperate to loosen the locking nuts of the column hydraulic machine, one of whom is an operating equipment operator; the other is a loosening locking nut operator; The operator controls the liquid pressure of the main cylinder (3) to rise to , and maintains it for 5-10 seconds. During this period, the operator loosens one of the locking nuts, and the operator stops the liquid pressure of the main cylinder (3) and restores it to the initial state, and waits for 3-5 minutes. Step 9: repeat step 8 until all the locking nuts are loosened, and then return to the initial state and turn off the power supply of the column hydraulic machine (2).

2. The method of claim 1, wherein, The material of the plug (1) is selected from 45# steel or other alloy steel.

3. The method of claim 1, wherein, The number of the fixing bolts (6) is four, which are distributed on the four corners of the plug (1).

4. The method of claim 1, wherein, In step 1, the thickness of the plug (1) is 2-2.5 times the thickness of the main oil pipe wall of the main cylinder (3); or the plug thickness is calculated using the following formula: F = σs × δ / k wherein F Pc represents the pressure applied to the plug in the case of leakage of the master cylinder working fluid σs represents the yield limit of the selected material of the plug; δ represents the thickness of the plug; k represents a safety factor, k ∈4,5.

5. The method of claim 4, wherein, k the value of 5.

6. The method of claim 5, wherein, In step 1, the fixing bolts (6) satisfy the following formula: 4F min > × S wherein, Fmin represents the minimum tensile load of a single bolt; represents the maximum pressure that can be provided by the hydraulic system of the hydraulic press; S represents the area enclosed by the seal ring on the plug.

7. The method of claim 6, wherein, In step 1, the parallelism between the upper and lower planes of the auxiliary pad is not greater than 0.1 mm.

8. The method of claim 7, wherein, The material of the auxiliary pad is selected from 45# steel or other alloy steel.

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