Large oil press main cylinder structure, press fitting tool and main cylinder pressing sleeve online replacement method

Abstract

The invention belongs to a main cylinder pressing sleeve of a large oil press in the technical field of large oil presses, and further relates to an online replacement method of the main cylinder pressing sleeve of the large oil press. The main cylinder body (1-21) falls to a working position, and the upper die device and the lower die device are dismantled; the main cylinder body (1-21) is locked at the highest position, and a T-shaped screw (1-6) of a connecting block (1-5) between the main cylinder body (1-21) and the lifting cylinder (4) is detached; the lifting oil cylinder (1-4) falls into a process hole of the lower beam (1-1) of the oil press; the main cylinder (1-2) is unlocked, the lifting cylinder (1-4) falls back to the lowest position along with the main cylinder body (1-21), and the pump is stopped; and the lifting oil cylinder (2-1) ascends and jacks up the main cylinder body (1-21). According to the online replacement method for the main cylinder pressing sleeve of the large oil press, the steps are simple, an online replacement mode is adopted when the main cylinder pressing sleeve of the oil press is replaced, the replacement efficiency of the main cylinder pressing sleeve is improved, and the problem that other parts are damaged in the replacement process of the main cylinder pressing sleeve is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-scale hydraulic presses, and more specifically, relates to a main cylinder sleeve of a large-scale hydraulic press. The present invention also relates to a press-fitting tool, and the present invention also relates to an online replacement method for the main cylinder sleeve of a large-scale hydraulic press. Background Art

[0002] In the process of wheel production, a large hydraulic press is needed to press and shape the wheel blank. Therefore, the hydraulic press is a key equipment for wheel production. The existing large hydraulic press adopts a three-beam, double-side column + prestressed tie rod type. The upper beam, movable crossbeam, and lower beam of the three beams are coaxial from top to bottom, and the lower surface of the upper beam, the upper surface of the lower beam, and the side columns are connected by abutment. Four prestressed tie rods pass through the upper surface of the upper beam, the lower surface of the lower beam, and the side columns, and are screwed through the locking nuts that are connected by abutment with the upper surface of the upper beam and the lower surface of the lower beam. The movable crossbeam is responsible for the main cylinder body of the hydraulic press (hereinafter referred to as the main cylinder body). An upper die device is fixedly installed on the lower surface of the main cylinder body, and a lower die device is fixedly installed on the upper surface of the lower beam. The upper and lower parts of the main cylinder body are square flanges, and the middle part is cylindrical. The square flange is chamfered and inlaid with X sliders. The X slider is slidably connected to the working slide on the side column of the hydraulic press to play a guiding role. The main cylinder body is slidably connected to the main cylinder plunger fixedly installed in the center of the upper beam. Lifting cylinders are arranged on both sides of the upper flange of the main cylinder body. The lifting cylinder column The plug is screwed to the connecting blocks fixed on both sides of the upper flange of the main cylinder body through T-screws. The lifting cylinder body is fixed on the side column. The lifting cylinder is responsible for the return stroke of the movable crossbeam. When the hydraulic press is pressing, oil is supplied to the main cylinder body, and relative movement is generated with the main cylinder plunger fixed on the upper beam, driving the movable crossbeam downward, driving the upper mold device to descend to the set position, and the upper and lower mold devices are closed to complete the forming of the wheel blank. After the pressing is completed, the main cylinder body stops supplying oil, and the lifting cylinder is supplied with oil to drive the movable crossbeam to rise to the original zero position. After the hydraulic press has been working for a period of time, due to the wear of the X slider and the horizontality of the master cylinder body, relative friction occurs between the master cylinder sleeve and the master cylinder plunger in the master cylinder body, causing wear of the master cylinder sleeve. When the wear reaches a certain amount, it will affect the service life of the seal of the master cylinder and even cause oil leakage in the master cylinder. The master cylinder sleeve needs to be replaced. The conventional replacement method is: the master cylinder body falls to the set position, the master cylinder body is supported, the pump is stopped, the master cylinder flange sleeve is separated from the master cylinder body, the master cylinder seal is removed, the upper beam locking nut of the prestressed pull rod of the hydraulic press is removed, and the master cylinder sleeve is lifted out. The upper beam and the main cylinder plunger, lift out the main cylinder flange sleeve, disassemble and assemble the main cylinder flange sleeve, install the components in reverse order according to the above order, and start the pump. This method of lifting the upper beam and the main cylinder plunger requires a high lifting height and requires the removal of the roof of the hydraulic press factory. The replacement efficiency is low, the workload is large, and the replacement cost is high, which affects the wheel production efficiency. In addition, this method of replacing the main cylinder sleeve will cause the well-pressed mating surfaces between the upper beam and the side column, the upper beam and the main cylinder plunger of the hydraulic press to be damaged, resulting in the possible collapse and damage of some load-bearing surfaces of the hydraulic press, affecting the safe service life of the hydraulic press.

[0003] There is a technology in the prior art named "A method for replacing the guide sleeve of a hydraulic cylinder forging a large press" and with a publication (announcement) number of "CN117680966A". This technology involves a method for replacing the guide sleeve of a hydraulic cylinder forging a large press. The method is to separate the hydraulic cylinder plunger and the cylinder body online according to the assembly characteristics of the hydraulic cylinder, and to disassemble and assemble the guide sleeve online. The specific method is as follows: Online separation of the plunger and the cylinder body before the return cylinder is removed: operate the return cylinder to descend, and the hydraulic cylinder plunger descends with the movable crossbeam to the minimum stroke of the return cylinder. At this time, place sleepers, gaskets, and jacks on the inner side of the column to support the movable crossbeam, remove the return cylinder, and place sleepers, gaskets, and jacks at the original position of the return cylinder to support the movable crossbeam; online separation of the plunger and the cylinder body after the return cylinder is removed: operate the hydraulic jack, and continuously remove the gaskets and sleepers until the distance between the hydraulic cylinder plunger and the cylinder body meets the working space for disassembly and assembly of the guide sleeve; online disassembly and installation of the guide sleeve. This method is efficient and convenient, and can greatly shorten the operation time and reduce the operation cost.

[0004] However, this technology does not involve the technical problems and technical solutions of the present application. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a method for online replacement of the main cylinder sleeve of a large hydraulic press is provided, which has simple steps and adopts an online replacement method when replacing the main cylinder sleeve of the hydraulic press, thereby improving the replacement efficiency of the main cylinder sleeve and reducing the damage to other components caused during the replacement process of the main cylinder sleeve.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0007] The present invention is an online replacement method for a main cylinder sleeve of a large hydraulic press, and the replacement steps of the online replacement method for a main cylinder sleeve of a large hydraulic press are as follows:

[0008] S1. The main cylinder body falls to the working position, and the upper die device and the lower die device are removed;

[0009] S2: The master cylinder body is locked to the highest position, and the T-screw of the connecting block between the master cylinder body and the lifting cylinder is removed;

[0010] S3: The lifting cylinder falls into the process hole of the lower beam of the hydraulic press;

[0011] S4: The master cylinder is unlocked, the lifting cylinder falls back to the lowest position along with the master cylinder body, and the pump stops;

[0012] S5: The lifting cylinder rises and lifts up the main cylinder body;

[0013] S6: Remove the main cylinder flange press-fit assembly, the connecting blocks 1-5 between the main cylinder body and the lifting cylinder, and hang the main cylinder flange press-fit assembly on the upper beam of the hydraulic press with a hand chain hoist;

[0014] S7: The main cylinder body descends to the set working position along with the lifting cylinder and falls on the steel support frame, and the lifting cylinder continues to descend to the lowest position;

[0015] S8: The master cylinder flange press sleeve assembly is lifted out through the longitudinal gap between the master cylinder body and the master cylinder plunger, and the master cylinder press sleeve is replaced and lifted in;

[0016] S9: Install the components on the master cylinder body in reverse order according to the above steps.

[0017] In step S2, remove the T-screw of the connection block between the main cylinder body and the lifting cylinder: remove the two Haver protective rings at the bottom of the connection block; remove the T-screw nut at the top of the connection block; the lifting cylinder falls back to expose the spherical pad, and pull out the T-screw; the lifting cylinder rises and returns to the top lifting position, and the main cylinder is locked.

[0018] Step S5, when the lifting cylinder lifts the main cylinder body: open the valve on the lifting cylinder valve block of the hydraulic station, the pump starts to load, and the lifting cylinder slowly rises. When the top cap above the piston rod hits the lower surface of the main cylinder body, the lifting cylinder is raised again to lift the main cylinder body; close the valve on the valve block of the lifting cylinder of the hydraulic station, and observe whether the main cylinder body has a downward slip phenomenon. If so, check the hydraulic circuit and eliminate the source of the fault; when the main cylinder body remains stable, stop the pump.

[0019] In step S7, when the main cylinder body falls to the set working position with the lifting cylinder: a support frame is placed under the main cylinder body, and the height of the support frame is the set height of the main cylinder lowering position; after the connecting block is removed, the lifting cylinder has no rod chamber oil entering, first open the throttle valve controlling the oil cylinder on the lifting cylinder valve block, loosen it one circle first, and observe whether the main cylinder body falls, if the main cylinder body does not fall, open the total oil return throttle valve on the valve block, loosen it one circle first, and observe whether the main cylinder body falls, if the main cylinder body does not fall, open the total oil return safety overflow valve on the valve block until the main cylinder body slowly falls, and adjust the opening degree of each valve appropriately according to the descending speed of the main cylinder body on site; when the lower plane of the main cylinder body falls onto the support frame, the lifting cylinder has oil entering the rod chamber, and after driving the lifting cylinder piston rod back to the zero position, the pump is stopped and the energy is cut off.

[0020] Step S8, when disassembling and assembling the main cylinder sleeve: lift the main cylinder flange sleeve assembly through the longitudinal gap between the main cylinder body and the main cylinder plunger to the designated position, and remove the main cylinder sleeve; process the mating surfaces of the main cylinder flange and the main cylinder sleeve to the tolerance matching accuracy required by the design; process the main cylinder sleeve according to the tolerance matching accuracy requirements of the main cylinder flange and the main cylinder sleeve; assemble the main cylinder sleeve by the frozen pressing method, cool the main cylinder sleeve with liquid nitrogen and assist in assembling the main cylinder sleeve with the pressing tooling, the pressing tooling includes a support plate, an adjusting screw, a pressing plate, and an adjusting nut, the pressing plate is connected to the upper part of the main cylinder sleeve, and the pressing plate is also connected to the lower end of the adjusting nut, threaded holes are processed at both ends of the support plate, and the threaded holes are connected to the lower part of the adjusting screw.

[0021] When the press-fitting tool is press-fitted, the master cylinder flange is first placed on the press-fitting tool support plate, and the adjusting screw is connected to the support plate. During this period, the master cylinder press sleeve is cooled to the set assembly process size with liquid nitrogen, and then the master cylinder press sleeve is hoisted to the mating surface with the master cylinder flange, and the pressing plate is hoisted to the upper surface of the master cylinder press sleeve. The adjusting screw passes through the through holes at both ends of the pressing plate, and the adjusting nut is rotated to drive the pressing plate downward, thereby driving the master cylinder press sleeve to be squeezed into the master cylinder flange, protecting the pressing surface from indentations when the guide sleeve is press-fitted.

[0022] The contact parts of the two ends of the pressing plate of the pressing tool and the guide sleeve are inlaid with concave positioning blocks, and the positioning blocks ride on the main cylinder pressing sleeve.

[0023] The positioning block is made of nylon, copper, rubber or plastic.

[0024] The lifting oil cylinder rises to lift the main cylinder body by 45mm-55mm.

[0025] The present invention also relates to a main cylinder structure of a large hydraulic press, including a lower beam of the hydraulic press, a main cylinder, an upper beam of the hydraulic press, a lifting cylinder, a connecting block, a T-screw, a lifting cylinder, and a support frame. The main cylinder includes a main cylinder body, a main cylinder flange, a main cylinder sleeve, and a main cylinder plunger.

[0026] The present invention also relates to a large-scale hydraulic press main cylinder sleeve pressing tooling, the pressing tooling 4 includes a support plate, an adjusting screw, a pressure plate, and an adjusting nut. The pressure plate is connected to the upper part of the main cylinder sleeve, and the pressure plate is also connected to the lower end of the adjusting nut. Threaded holes are processed at both ends of the support plate, and the threaded holes are connected to the lower part of the adjusting screw.

[0027] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows:

[0028] The online replacement method for the main cylinder sleeve of a large hydraulic press described in the present invention is as follows: 1. When replacing the main cylinder sleeve of the hydraulic press, the main cylinder body of the hydraulic press is disassembled from top to bottom, and the main cylinder flange sleeve assembly is lifted out to replace the main cylinder sleeve. The main cylinder flange sleeve assembly with the replaced main cylinder sleeve is reinstalled to the center of the hydraulic press, and installed from bottom to top along the center line of the hydraulic press, thereby improving the replacement efficiency of the main cylinder sleeve, reducing the damage to other parts during the replacement of the cylinder guide sleeve, increasing the safe service life of the hydraulic press, saving replacement costs, ensuring installation accuracy, and providing operating specifications for the replacement of the main cylinder sleeve of the hydraulic press. 2. The lifting cylinder adopts a long-stroke hydraulic cylinder, which can be lifted and lowered in one go without the need to add a transition lifting rod. The up and down movement speed of the main cylinder body is controllable, and the resistance is small during operation. A pad is provided on the head of the lifting cylinder plunger to protect the piston rod head from deformation and damage caused by abnormal external forces. 3. The main cylinder sleeve is assembled by freezing press fitting, and the press fitting tool assists in assembly. Press fitting is quick and convenient. An arc groove is provided under the press plate of the press fitting tool, which is convenient for press fitting and positioning of the main cylinder sleeve. A positioning block made of nylon is inlaid in the arc groove and in contact with the main cylinder sleeve to protect the main cylinder sleeve from indentation when it is pressed into the main cylinder flange. The online replacement method for the main cylinder sleeve of a large hydraulic press of the present invention has simple steps. When replacing the main cylinder sleeve of the hydraulic press, an online replacement method is adopted, which improves the replacement efficiency of the main cylinder sleeve and reduces the damage to other parts during the replacement of the main cylinder sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following is a brief description of the contents and symbols in the drawings of this specification:

[0030] Figure 1 It is a schematic diagram of the main structure of the large-scale hydraulic press of the present invention;

[0031] Figure 2 This is a schematic diagram of the axial structure of the large-scale hydraulic press of the present invention;

[0032] Figure 3 It is a schematic diagram of the axial structure of the main cylinder of the large-scale hydraulic press according to the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of the press-fitting tooling of the present invention when in use;

[0034] Figure 5 It is a structural schematic diagram of the press-fitting tooling of the present invention;

[0035] The marks in the accompanying drawings are respectively: 1-1, 1-2, main cylinder; 1-3, 1-4, lifting cylinder; 1-5, connecting block; 1-6, T-screw; 1-21, main cylinder body; 1-22, main cylinder flange; 1-23, main cylinder pressing sleeve; 1-24, main cylinder plunger; 2-1, lifting cylinder; 2-2, top cap; 3, support frame; 4, pressing tool; 4-1, support plate; 4-2, adjusting screw; 4-3, pressing plate; 4-4, adjusting nut. DETAILED DESCRIPTION

[0036] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings:

[0037] As attached Figure 1 -Attached Figure 3 As shown, the present invention is an online replacement method for a main cylinder sleeve of a large hydraulic press, and the replacement steps of the online replacement method for a main cylinder sleeve of a large hydraulic press are as follows:

[0038] S1. The main cylinder body 1-21 falls to the working position, and the upper die device and the lower die device are removed; S2: The main cylinder body 1-21 is locked to the highest position, and the T-screw 1-6 of the connecting block 1-5 between the main cylinder body 1-21 and the lifting cylinder 1-4 is removed; S3: The lifting cylinder 2-1 falls into the process hole of the lower beam 1-1 of the hydraulic press; S4: The main cylinder 1-2 is unlocked, and the lifting cylinder 1-4 falls back to the lowest position with the main cylinder body 1-21, and the pump is stopped; S5: The lifting cylinder 2-1 rises and lifts the main cylinder body 1-21; S6: Remove the main cylinder flange press fittings and the main cylinder The connecting block 1-5 between the cylinder body 1-21 and the lifting cylinder 1-4, and the main cylinder flange press-fit assembly are hung on the upper beam 1-3 of the hydraulic press by a hand chain hoist; S7: the main cylinder body 1-21 is lowered to the set working position along with the lifting cylinder 2-1, and falls on the steel support frame 3, and the lifting cylinder 2-1 continues to descend to the lowest position; S8: the main cylinder flange press-fit assembly is lifted out through the longitudinal gap between the main cylinder body 1-21 and the main cylinder plunger 1-24, and the main cylinder press sleeve 1-23 is replaced and lifted in; S9: the parts on the main cylinder body 1-21 are installed in reverse order according to the above steps. The above steps propose an improved technical solution for the deficiencies in the existing technology. The beneficial effects of the method of the present invention are: 1. When replacing the main cylinder sleeve of the hydraulic press, the main cylinder body of the hydraulic press is disassembled from top to bottom, the main cylinder flange sleeve assembly is lifted out to replace the main cylinder sleeve, and the main cylinder flange sleeve assembly with the replaced main cylinder sleeve is reinstalled to the center of the hydraulic press, and installed from bottom to top along the center line of the hydraulic press, thereby improving the efficiency of replacing the main cylinder sleeve, reducing the damage to other parts during the replacement of the cylinder guide sleeve, increasing the safe service life of the hydraulic press, saving replacement costs, ensuring installation accuracy, and providing operating specifications for the replacement of the main cylinder sleeve of the hydraulic press. 2. The lifting cylinder adopts a long-stroke hydraulic cylinder, which can be lifted and lowered in one go without the need to add a transition lifting rod. The up and down movement speed of the main cylinder body is controllable, and the resistance is small during operation. The piston head of the lifting cylinder is provided with a pad to protect the piston rod head from deformation and damage caused by abnormal external forces. 3. The main cylinder sleeve is assembled by freezing press fitting, and the press fitting tool assists in assembly. Press fitting is quick and convenient. An arc groove is provided under the press plate of the press fitting tool, which is convenient for press fitting and positioning of the main cylinder sleeve. A positioning block made of nylon is inlaid in the arc groove and in contact with the main cylinder sleeve to protect the main cylinder sleeve from indentation when it is pressed into the main cylinder flange. The online replacement method for the main cylinder sleeve of a large hydraulic press described in the present invention has simple steps and adopts an online replacement method when replacing the main cylinder sleeve of the hydraulic press, thereby improving the replacement efficiency of the main cylinder sleeve and reducing the damage to other parts during the replacement of the main cylinder sleeve.

[0039] In step S2, remove the T-screw 1-6 of the connection block 1-5 between the main cylinder body 1-21 and the lifting cylinder 1-4: remove the two Haversian protective rings at the bottom of the connection block 1-5; remove the T-screw nut at the top of the connection block 1-5; the lifting cylinder 1-4 falls back to expose the spherical pad, and the T-screw 1-6 is pulled out; the lifting cylinder 1-4 rises and returns to the top lifting position, and the main cylinder 1-2 is locked. The above steps further limit step S2 to reliably realize the removal of the T-screw 1-6 of the connection block 1-5. After the detection, the lifting cylinder 1-4 rises and returns to the top lifting position to achieve the locking of the main cylinder 1-2.

[0040] In step S5, when the lifting cylinder 2-1 lifts up the main cylinder body 1-21: open the valve on the valve block of the lifting cylinder 2-1 of the hydraulic station, the pump starts to load, and the lifting cylinder 2-1 slowly rises. When the top cap 2-2 above the piston rod hits the lower surface of the main cylinder body 1-21, the lifting cylinder 2-1 is raised again to lift up the main cylinder body 1-21; close the valve on the valve block of the lifting cylinder 2-1 of the hydraulic station, and observe whether the main cylinder body 1-21 slides down. If so, check the hydraulic circuit and eliminate the source of the fault; when the main cylinder body 1-21 remains stable, stop the pump. The above steps further define step S5 to reliably realize that the lifting cylinder 2-1 lifts up the main cylinder body 1-21.

[0041] In step S7, when the main cylinder body 1-21 falls to the set working position along with the lifting cylinder 2-1: place the support frame 3 under the main cylinder body 1-21, and the height of the support frame 3 is the set height of the lowering position of the main cylinder 1-2; after the connecting block 1-5 is removed, the rodless cavity of the lifting cylinder 2-1 is filled with oil, first open the throttle valve of the control cylinder on the valve block of the lifting cylinder 2-1, loosen it a circle, and observe whether the main cylinder body 1-21 falls. If the main cylinder body 1-21 does not fall, open the total return valve on the valve block. The oil throttle valve is loosened one turn first to observe whether the main cylinder body 1-21 descends. If the main cylinder body 1-21 does not descend, open the total oil return safety overflow valve on the valve block until the main cylinder body 1-21 slowly descends. According to the descending speed of the main cylinder body 1-21, adjust the opening of each valve appropriately on site; when the lower plane of the main cylinder body 1-21 descends to the support frame 3, oil enters the rod chamber of the lifting cylinder 2-1, and after driving the piston rod of the lifting cylinder 2-1 back to the zero position, the pump is stopped and the energy is cut off. The above steps further limit the S7 step to ensure that the main cylinder body 1-21 descends to the set working position with the lifting cylinder 2-1, and the control is reliable.

[0042] Step S8, when disassembling and assembling the master cylinder sleeve 1-23: lift the master cylinder flange sleeve assembly through the longitudinal gap between the master cylinder body 1-21 and the master cylinder plunger 1-24 to the designated position, and remove the master cylinder sleeve 1-23; process the mating surfaces of the master cylinder flange 1-22 and the master cylinder sleeve 1-23 to the tolerance matching accuracy required by the design; process the master cylinder sleeve 1-23 according to the tolerance matching accuracy requirements of the master cylinder flange 1-22 and the master cylinder sleeve 1-23; assemble the master cylinder sleeve 1-23 by the frozen pressing method, and cool the master cylinder sleeve with liquid nitrogen to assist with the pressing tooling to assemble the master cylinder sleeve. As shown in the attached figure Figure 4 , Attachment Figure 5 As shown, the press tool 4 includes a support plate 4-1, an adjusting screw 4-2, a press plate 4-3, and an adjusting nut 4-4. The press plate 4-3 is connected to the upper part of the main cylinder sleeve 1-23, and the press plate 4-3 is also connected to the lower end of the adjusting nut 4-4. The support plate 4-1 has threaded holes at both ends, and the threaded holes are connected to the lower part of the adjusting screw 4-2. The above steps further define step S5 to realize the disassembly and assembly of the main cylinder sleeve 1-23, and the disassembly and assembly requires the use of a press tool.

[0043] When the press-fitting tool 4 is press-fitted, the main cylinder flange 1-22 is first placed on the support plate 4-1 of the press-fitting tool 4, and the adjusting screw 4-2 is connected to the support plate 4-1. During this period, the main cylinder sleeve 1-23 is cooled to the set assembly process size with liquid nitrogen, and then the main cylinder sleeve 1-23 is hoisted to the mating surface with the main cylinder flange 1-22, and the pressing plate 4-3 is hoisted to the upper surface of the main cylinder sleeve 1-23. The adjusting screw 4-2 passes through the through holes at both ends of the pressing plate 4-3, and the adjusting nut 4-4 is rotated to drive the pressing plate 4-3 downward, driving the main cylinder sleeve 1-23 to be squeezed into the main cylinder flange, and the pressing surface of the protective guide sleeve 1-16 is not indented when it is press-fitted. The above structure further limits the steps when the press-fitting tool 4 is used, ensuring that the main cylinder sleeve 1-23 is squeezed into the main cylinder flange during press-fitting, and the pressing surface of the protective guide sleeve 1-16 is not indented when it is press-fitted.

[0044] The two ends of the press tooling press plate 4-3 are inlaid with concave positioning blocks 4-5 at the contact parts with the guide sleeve 1-16, and the positioning blocks 4-5 ride on the main cylinder press sleeve 1-23. In the above structure, when the main cylinder press sleeve 1-23 is assembled, the concave positioning blocks 4-5 play a reliable positioning role.

[0045] The positioning block 4-5 is made of nylon, copper, rubber or plastic. With the above structure, the positioning block 4-5 will not damage the contact surface of the main cylinder sleeve 1-23 when in use.

[0046] The lifting oil cylinder 2-1 rises to lift the main cylinder body 1-21 by 45mm-55mm. The above structure has different lifting heights according to different models of products, which is limited to a range.

[0047] The present invention also relates to a main cylinder structure of a large hydraulic press, including a lower beam 1-1 of the hydraulic press, a main cylinder 1-2, an upper beam 1-3 of the hydraulic press, a lifting cylinder 1-4, a connecting block 1-5, a T-screw 1-6, a lifting cylinder 2-1, and a support frame 3. The main cylinder 1-2 includes a main cylinder body 1-21, a main cylinder flange 1-22, a main cylinder sleeve 1-23, and a main cylinder plunger 1-24. The replacement method of the present invention is aimed at the main cylinder structure of a large hydraulic press of the above structure, which effectively guarantees the replacement effect and protects the product.

[0048] The present invention also relates to a large-scale hydraulic press main cylinder sleeve press tooling, the press tooling 4 comprises a support plate 4-1, an adjusting screw 4-2, a pressure plate 4-3, and an adjusting nut 4-4, the pressure plate 4-3 is connected to the upper part of the main cylinder sleeve 1-23, and the pressure plate 4-3 is also connected to the lower end of the adjusting nut 4-4, and threaded holes are processed at both ends of the support plate 4-1, and the threaded holes are connected to the lower part of the adjusting screw 4-2. With the above structure, when the main cylinder sleeve 1-23 is press-fitted, the press tooling is used, and the press-fitting is reliable.

[0049] The innovative features of the online replacement method for the main cylinder sleeve of a large hydraulic press of the present invention are as follows: 1. When replacing the main cylinder sleeve of the hydraulic press, an online replacement method is adopted, which improves the replacement efficiency of the main cylinder sleeve, reduces the damage to other parts during the replacement process of the main cylinder sleeve, and provides operating specifications for the replacement of the main cylinder sleeve of the hydraulic press. 2. The lifting cylinder adopts a long-stroke hydraulic cylinder, and the up and down movement speed of the cylinder body of the main cylinder of the hydraulic press is controllable, with small resistance during operation. A pad is provided on the head of the lifting cylinder plunger to protect the piston rod head from deformation and damage caused by abnormal external force. 3. The main cylinder sleeve is assembled by freezing pressing, and liquid nitrogen cooling is used to assist in the main cylinder pressing assembly with a pressing tool. The force application is simple and convenient. Nylon pressing blocks are inlaid at both ends of the pressing plate of the pressing tool and the contact part with the main cylinder sleeve to protect the pressing surface from indentations when the main cylinder sleeve is pressed into the main cylinder flange.

[0050] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for online replacement of a main cylinder sleeve of a large hydraulic press, characterized in that: The replacement steps of the online replacement method for the main cylinder sleeve of a large hydraulic press are as follows: S1. The main cylinder body (1-21) falls to the working position, and the upper mold device and the lower mold device are removed; S2: The main cylinder body (1-21) is locked to the highest position, and the T-screw (1-6) of the connecting block (1-5) between the main cylinder body (1-21) and the lifting cylinder (4) is removed; S3: The lifting cylinder (1-4) falls into the process hole of the lower beam (1-1) of the hydraulic press; S4: The master cylinder (1-2) is unlocked, the lifting cylinder (1-4) falls back to the lowest position along with the master cylinder body (1-21), and the pump stops; S5: The lifting cylinder (2-1) rises and lifts up the main cylinder body (1-21); S6: Remove the main cylinder flange press-fit assembly, the connecting block (1-5) between the main cylinder body (1-21) and the lifting cylinder (1-4), and hang the main cylinder flange press-fit assembly on the upper beam 1-3 of the hydraulic press by a hand chain hoist; S7: The main cylinder body (1-21) descends to the set working position along with the lifting cylinder (2-1) and falls on the steel support frame (3), and the lifting cylinder continues to descend to the lowest position; S8: The master cylinder flange press-fit assembly is lifted out through the longitudinal gap between the master cylinder body (1-21) and the master cylinder plunger (1-24), and the master cylinder press sleeve (1-23) is replaced and lifted in; S9: Install the components on the master cylinder body (1-21) in reverse order according to the above steps.

2. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 1 is characterized in that: In step S2, the T-screw (1-6) of the connecting block (1-5) between the main cylinder body (1-21) and the lifting cylinder (1-4) is removed: the two Haversian protective rings at the bottom of the connecting block (1-5) are removed; the T-screw nut at the top of the connecting block (1-5) is removed; the lifting cylinder (1-4) falls back to expose the spherical pad, and the T-screw (1-6) is pulled out; the lifting cylinder (1-4) rises and returns to the jacking position, and the main cylinder (1-2) is locked.

3. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 1 or 2, characterized in that: In step S5, when the lifting cylinder (1-4) lifts up the main cylinder body (1-21): open the valve on the valve block of the lifting cylinder (2-1) of the hydraulic station, the pump starts to load, and the lifting cylinder (2-1) slowly rises. When the top cap (2-2) above the piston rod hits the lower surface of the main cylinder body (1-21), the lifting cylinder (2-1) is raised again to lift up the main cylinder body (1-21); close the valve on the valve block of the lifting cylinder (2-1) of the hydraulic station, and observe whether the main cylinder body (1-21) slides down. If so, check the hydraulic circuit and eliminate the fault source; when the main cylinder body (1-21) remains stable, stop the pump.

4. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 1 or 2, characterized in that: In step S7, when the main cylinder body (1-21) falls to the set working position along with the lifting cylinder (2-1), a support frame (3) is placed under the main cylinder body (1-21), and the height of the support frame (3) is the set height of the lowering position of the main cylinder (1-2); after the connecting block (1-5) is removed, the lifting cylinder (2-1) does not have oil entering the rod chamber, first open the throttle valve of the control cylinder on the valve block of the lifting cylinder (2-1), loosen it once, and observe whether the main cylinder body (1-21) falls. If the main cylinder body (1-21) does not fall, open the valve block. Loosen the total oil return throttle valve once and observe whether the main cylinder body (1-21) descends. If the main cylinder body (1-21) does not descend, open the total oil return safety relief valve on the valve block until the main cylinder body (1-21) slowly descends. According to the descending speed of the main cylinder body (1-21), adjust the opening of each valve appropriately on site. When the lower plane of the main cylinder body (1-21) descends and falls onto the support frame (3), oil enters the rod chamber of the lifting cylinder (2-1), and after driving the piston rod of the lifting cylinder (2-1) back to the zero position, the pump is stopped and the energy is cut off.

5. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 1 or 2, characterized in that: Step S8, when disassembling and assembling the master cylinder sleeve (1-23): lift the master cylinder flange sleeve assembly through the longitudinal gap between the master cylinder body (1-21) and the master cylinder plunger (1-24) to a designated position, and remove the master cylinder sleeve (1-23); process the mating surfaces of the master cylinder flange (1-22) and the master cylinder sleeve (1-23) to the tolerance matching accuracy required by the design; process the master cylinder sleeve (1-23) according to the tolerance matching accuracy requirements of the master cylinder flange (1-22) and the master cylinder sleeve (1-23); The main cylinder sleeve (1-23) is assembled by freezing and pressing, and the main cylinder sleeve is cooled by liquid nitrogen and assisted by a pressing tool. The pressing tool (4) includes a support plate (4-1), an adjusting screw (4-2), a pressing plate (4-3), and an adjusting nut (4-4). The pressing plate (4-3) is connected to the upper part of the main cylinder sleeve (1-23), and the pressing plate (4-3) is also connected to the lower end of the adjusting nut (4-4). Threaded holes are processed at both ends of the support plate (4-1), and the threaded holes are connected to the lower part of the adjusting screw (4-2).

6. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 5 is characterized in that: When the press-fitting tool (4) is press-fitted, the main cylinder flange (1-22) is first placed on the support plate (4-1) of the press-fitting tool (4), and the adjusting screw (4-2) is connected to the support plate (4-1). During this period, the main cylinder pressing sleeve (1-23) is cooled to the set assembly process size with liquid nitrogen, and then the main cylinder pressing sleeve (1-23) is hoisted to the mating surface with the main cylinder flange (1-22), and the pressing plate (4-3) is hoisted to the upper surface of the main cylinder pressing sleeve (1-23). ​​The adjusting screw (4-2) passes through the through holes at both ends of the pressing plate (4-3), and the adjusting nut (4-4) is rotated to drive the pressing plate (4-3) downward, thereby driving the main cylinder pressing sleeve (1-23) to be squeezed into the main cylinder flange, so as to protect the pressing surface of the guide sleeve (1-16) from being indented when press-fitting.

7. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 6 is characterized in that: The contact parts of the two ends of the press-fitting tooling press plate (4-3) and the guide sleeve (1-16) are inlaid with concave positioning blocks (4-5), and the positioning blocks (4-5) ride on the main cylinder press sleeve (1-23).

8. The method for online replacement of the main cylinder sleeve of a large hydraulic press according to claim 7 is characterized in that: The positioning blocks (4-5) are made of nylon, copper, rubber or plastic.

9. A main cylinder structure of a large hydraulic press, characterized in that: The invention comprises a hydraulic press lower beam (1-1), a main cylinder (1-2), a hydraulic press upper beam (1-3), a lifting cylinder (1-4), a connecting block (1-5), a T-screw (1-6), a lifting cylinder (2-1), and a support frame (3). The main cylinder (1-2) comprises a main cylinder body (1-21), a main cylinder flange (1-22), a main cylinder sleeve (1-23), and a main cylinder plunger (1-24).

10. A large-scale hydraulic press main cylinder sleeve press fitting tool, characterized in that: The press fitting tool (4) comprises a support plate (4-1), an adjusting screw rod (4-2), a press plate (4-3), and an adjusting nut (4-4); the press plate (4-3) is connected to the upper part of the main cylinder press sleeve (1-23); the press plate (4-3) is also connected to the lower end of the adjusting nut (4-4); threaded holes are processed at both ends of the support plate (4-1), and the threaded holes are connected to the lower part of the adjusting screw rod (4-2).

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