A core tube self-adapting guiding and telescopic hydraulic cylinder with self-compensation function

Abstract

The application discloses a core pipe self-adapting guiding and telescopic hydraulic cylinder with self-compensation function, which comprises a cylinder body assembly, a piston assembly, an ear ring assembly and a core pipe assembly. The ear ring assembly comprises an ear ring body and a hydraulic valve, the ear ring body is provided with an oil inlet and outlet hole and a first oil inlet channel, and the oil inlet and outlet hole is communicated with the first oil inlet channel through the hydraulic valve; the core pipe assembly comprises a floating core pipe, a first core pipe, a second core pipe and a guiding device, the floating core pipe, the first core pipe and the second core pipe are sequentially nested, and the guiding device is installed at the front end of the floating core pipe. Through the setting of the oil pipe seat, the second guiding sleeve and the guiding device, the floating core pipe can be effectively protected, limited and supported and guided, so that the floating core pipe is prevented from being damaged due to flexural deformation of the end face caused by back pressure during high-speed reciprocating operation of the hydraulic cylinder, and the safety of the floating core pipe is protected; through the setting of the hydraulic valve, the flow and pressure of the oil in the hydraulic cylinder can be regulated and controlled, so that the telescopic speed of the hydraulic cylinder is adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic cylinders, in particular to a telescopic hydraulic cylinder with a core tube adaptive guidance and a self-compensation function. Background Art

[0002] Currently, there are three types of telescopic systems for wheeled crane booms: single-cylinder, double-cylinder, and single-cylinder latch systems. The single-cylinder system is primarily used on 5-, 8-, 10-, and 12-ton wheeled cranes, while the single-cylinder latch system is primarily used on multi-section jibs (6 or more sections) wheeled cranes over 55 tons. The double-cylinder system is primarily used on wheeled cranes with capacities up to 100 tons, in addition to those using the single-cylinder and single-cylinder latch systems. Due to its high telescopic speed and high load-lifting efficiency, the double-cylinder system is highly sought after in the lifting market. Currently, large-tonnage double-cylinder cranes struggle to meet the growing demand for lifting cranes. Double-cylinder cranes utilize telescopic cylinders to drive the ropes, gradually extending and retracting the crane's telescopic boom, achieving varying boom lengths and fulfilling the boom's lifting function.

[0003] Due to the development trend of lightweight and intelligent cranes, in order to improve market comfort and lifting conditions, the output flow of the crane telescopic arm hydraulic system is large, and the telescopic arm extension and retraction speed is fast, which can reach 0.3m / s. Therefore, when the telescopic cylinder drives the rope row and the crane telescopic arm in operation, the telescopic cylinder runs at high speed and reciprocates. The floating core tube with the built-in piston rod also runs back and forth quickly. The end face back pressure is large, which accelerates the failure of the floating core tube, causing the core tube to deform and reduce the reliability of the hydraulic cylinder. When the hydraulic cylinder retracts, due to the large ratio of the large and small chamber areas of the hydraulic cylinder, reaching 5, the matching between the small chamber oil inlet and the large chamber oil return is poor. Due to the high-speed operation of the hydraulic cylinder, creeping and shaking faults often occur, which will accelerate the damage of the cylinder, hydraulic system and various parts of the host machine and reduce the service life of each part. Summary of the Invention

[0004] In view of this, the present invention provides a core tube adaptive guide and a telescopic hydraulic cylinder with self-compensation function, which can guide and limit the floating core tube to avoid deformation of the floating core tube due to high speed and high pressure. At the same time, it can also effectively prevent the hydraulic cylinder from shaking.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A telescopic hydraulic cylinder with a core tube self-adaptive guide and self-compensation function comprises a cylinder assembly, a piston assembly, an earring assembly and a core tube assembly.

[0007] Among them, the cylinder body assembly includes a cylinder barrel, a cylinder bottom, an end cover, a first guide sleeve, a pressure cover and an oil pipe seat, the oil pipe seat is arranged inside the cylinder barrel and fixedly connected to the end cover, and the oil pipe seat is provided with a mounting groove; the earring assembly includes an earring body and a hydraulic valve, the hydraulic valve is installed on the earring body, the earring body is provided with oil inlet and outlet holes and a first oil inlet channel, and the oil inlet and outlet holes are connected to the first oil inlet channel through the hydraulic valve; the piston assembly includes a piston, a piston rod and a second guide sleeve, the rear end of the piston rod is threadedly connected to the piston, and the front end is threadedly connected to the earring body, a mounting through hole is provided in the middle of the piston, and the second guide sleeve is fixedly installed in the mounting through hole; the core tube assembly includes a floating core tube, a first core tube, and a second core tube and a guide device, the floating core tube, the first core tube and the second core tube are all inserted into the piston rod, wherein the floating core tube, the first core tube and the second core tube are nested in sequence, the rear end of the floating core tube is fixedly connected to the mounting groove, the guide device is installed at the front end of the floating core tube, the front ends of the first core tube and the second core tube are both in contact with the end face of the earring body, and the rear ends are both in contact with the front end face of the second guide sleeve, the rear end of the second core tube is also in contact with the rear end face and the inner wall of the piston, a first oil passage is constructed between the first core tube and the second core tube, the first oil passage is connected to the first oil inlet passage, and a second oil passage is provided on the second guide sleeve, the second oil passage connects the first oil passage and the internal space of the cylinder.

[0008] Preferably, the guide device includes a guide ring and a stop joint, the stop joint is installed at the front end of the floating core tube, a guide mounting groove is provided on the circumference of the stop structure, the guide ring is installed in the guide mounting groove, and the guide ring abuts against the inner wall of the floating core tube.

[0009] Preferably, a plurality of first step surfaces are gradually provided on the peripheral wall of the mounting through hole, and a plurality of second step surfaces cooperating with the plurality of first step surfaces are gradually provided on the circumference of the second guide sleeve.

[0010] Preferably, a plurality of sealing elements are provided between the second guide sleeve and the floating core tube.

[0011] Preferably, the earring body includes a first earring and a second earring, the first earring is threadedly connected to the front end of the piston rod, and the second earring is installed at the front end of the first earring through a connecting sleeve. An installation cavity is formed between the first earring and the second earring, and the hydraulic valve is inserted in the installation cavity. The first oil inlet channel is opened on the first earring, and the oil inlet and outlet holes are opened on the second earring.

[0012] Preferably, the hydraulic valve includes a valve end cover, a control piston, a valve core, a valve sleeve, a small spring, a one-way valve sleeve, a screw sleeve, a large spring and a screw plug; the valve end cover is arranged at the upper end of the valve sleeve, the control piston, the valve core and the small spring are arranged in sequence below the valve end cover, the screw sleeve is installed at the lower end of the valve sleeve and partially extends into the valve sleeve, a large spring is provided in the screw sleeve, the one-way valve sleeve is installed at the upper end of the screw sleeve, the upper end of the one-way valve sleeve abuts against the bottom of the small spring, the lower end extends into the screw sleeve and abuts against the upper end of the large spring, and the screw plug is installed at the lower end of the screw sleeve.

[0013] Preferably, a second oil inlet channel is also provided on the first earring, and a third oil passage is constructed between the second core tube and the inner wall of the piston rod. The second oil inlet channel is connected to the third oil passage, and the third oil passage is connected to the installation cavity above the hydraulic valve through an oil channel.

[0014] Preferably, the first earring is sleeved on the front end of the piston rod, and a sealing member is provided between the first earring and the outer side surface of the piston rod.

[0015] Preferably, a plurality of third step surfaces are gradually provided on the outer side surface of the piston rod, and a plurality of fourth step surfaces cooperating with the plurality of third step surfaces are gradually provided on the inner side surface of the first earring.

[0016] Compared with the prior art, the present application discloses a core tube adaptively guided and telescopic hydraulic cylinder with self-compensation function, which can effectively limit and guide the floating core tube by setting an oil pipe seat, a second guide sleeve and a guide device, thereby avoiding deformation and damage of the floating core tube due to high speed and high pressure during the movement process, thereby effectively protecting the safety of the floating core tube; by setting a hydraulic valve, the flow and pressure of the oil can be regulated to adjust the telescopic speed of the hydraulic cylinder, thereby effectively protecting the safety of the hydraulic cylinder.

[0017] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of the core tube adaptive guide and the telescopic hydraulic cylinder with self-compensation function disclosed in the embodiment of the present application;

[0019] Figure 2 yes Figure 1 Magnified view of area A in center.

[0020] Reference numerals:

[0021] 11. Cylinder barrel; 12. Cylinder bottom; 13. End cover; 14. First guide sleeve; 15. Gland; 16. Oil pipe seat; 161. Mounting groove;

[0022] 21. Piston; 22. Piston rod; 23. Second guide sleeve; 231. Second oil passage;

[0023] 31. Earring body; 32. Hydraulic valve; 311. First earring; 312. Second earring; 321. Valve end cover; 322. Control piston; 323. Valve core; 324. Valve sleeve; 325. Small spring; 326. One-way valve sleeve; 327. Screw sleeve; 328. Large spring; 329. Screw plug; 3111. First oil inlet channel; 3112. Second oil inlet channel; 3121. Oil inlet and outlet holes;

[0024] 41. Floating core tube; 42. First core tube; 43. Second core tube; 44. Guide device; 441. Guide ring; 442. Stop joint;

[0025] 5. The first oil passage; 6. The third oil passage. DETAILED DESCRIPTION

[0026] The present invention discloses a core tube adaptively guided and telescopic hydraulic cylinder with self-compensating function, which can guide and limit the floating core tube 41 to avoid deformation of the floating core tube 41 due to high speed and high pressure. At the same time, it can also effectively prevent the hydraulic cylinder from shaking.

[0027] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0029] Reference below Figure 1 and Figure 2 The core tube adaptive guide and the telescopic hydraulic cylinder with self-compensation function in the embodiment of the present invention are described.

[0030] The embodiment of the present application discloses a telescopic hydraulic cylinder with a core tube adaptive guide and self-compensation function, including: a cylinder assembly, a piston assembly, an earring assembly and a core tube assembly.

[0031] Among them, the cylinder assembly includes a cylinder barrel 11, a cylinder bottom 12, an end cover 13, a first guide sleeve 14, a pressure cover 15 and an oil pipe seat 16. The oil pipe seat 16 is arranged inside the cylinder barrel 11 and fixedly connected to the end cover 13. The oil pipe seat 16 is provided with a mounting groove 161; the earring assembly includes an earring body 31 and a hydraulic valve 32. The hydraulic valve 32 is installed on the earring body 31. The earring body 31 is provided with oil inlet and outlet holes 3121 and a first oil inlet channel 3111. The oil inlet and outlet holes 3121 are connected to the first oil inlet channel 3111 through the hydraulic valve 32; the piston assembly includes a piston 21, a piston rod 22 and a second guide sleeve 23. The rear end of the piston rod 22 is threadedly connected to the piston 21, and the front end is threadedly connected to the earring body 31. A mounting through hole is provided in the middle of the piston 21, and the second guide sleeve 23 is fixedly installed in the mounting through hole; the core tube assembly includes a floating core tube 41, a first core tube 42 , the second core tube 43 and the guide device 44, the floating core tube 41, the first core tube 42 and the second core tube 43 are all arranged in the piston rod 22, wherein the floating core tube 41, the first core tube 42 and the second core tube 43 are nested in sequence, the rear end of the floating core tube 41 is fixedly connected to the mounting groove 161, the guide device 44 is installed at the front end of the floating core tube 41, the front ends of the first core tube 42 and the second core tube 43 are both in contact with the end face of the earring body 31, and the rear ends are both in contact with the front end face of the second guide sleeve 23, the rear end of the second core tube 43 is also in contact with the rear end face and inner wall of the piston 21, a first oil passage 5 is constructed between the first core tube 42 and the second core tube 43, the first oil passage 5 is connected to the first oil inlet channel 3111, and a second oil passage 231 is provided on the second guide sleeve 23, the second oil passage 231 connects the first oil passage 5 with the internal space of the cylinder 11.

[0032] In this embodiment, by providing the oil pipe seat 16, the second guide sleeve 23 and the guide device 44, the floating core tube 41 can be effectively limited and guided, thereby preventing the floating core tube 41 from being deformed and damaged due to high speed and high pressure during the movement process, thereby effectively protecting the safety of the floating core tube 41; by providing the hydraulic valve 32, the flow and pressure of the oil can be regulated to adjust the extension and retraction speed of the hydraulic cylinder, thereby effectively protecting the safety of the hydraulic cylinder.

[0033] For example Figure 1As shown, when the hydraulic cylinder extends, the hydraulic oil input from the oil inlet and outlet holes 3121 enters the first oil inlet channel through the hydraulic valve 32, and enters the first oil passage through the first oil inlet channel, and then enters the internal space of the cylinder body. The end cover 13 of the hydraulic cylinder is subjected to a leftward force under the continuously increasing oil pressure, and finally the cylinder assembly moves to the left as a whole under the action of the oil pressure, and the hydraulic cylinder extends. During the extension process, the hydraulic valve 32 can adjust the flow and pressure of the oil under the control of the control unit to ensure that the hydraulic cylinder can be extended stably and avoid shaking of the hydraulic cylinder. At the same time, the floating core tube 41 can adaptively guide during the extension and retraction process under the joint action of the oil pipe seat 16, the second guide sleeve 23 and the guide device 44, thereby effectively avoiding the occurrence of offset and shaking, and thereby preventing the floating core tube 41 from being deformed due to high speed and high pressure and causing damage.

[0034] Furthermore, the design in which the front and rear ends of the piston rod 22 are respectively threadedly connected to the earring body 31 and the piston 21 realizes a welding-free processing technology, effectively solving the problem of difficult to ensure the positioning accuracy of the piston rod of the existing hydraulic cylinder due to the earrings and pistons welded at the front and rear ends.

[0035] Furthermore, the front and rear ends of the first core tube 42 and the second core tube 43 are respectively in contact with the end face of the earring body 31 and the rear end face of the second guide sleeve 23, wherein the rear end of the second core tube 43 is also in contact with the rear end face and inner wall of the piston 21. This processing technology of fixing the end faces in contact realizes a welding-free processing technology, which can effectively avoid the oil leakage problem caused by welding; for example Figure 1 As shown, two mating grooves nested in sequence are provided on the rear end face of the earring body 31, and the front ends of the first core tube 42 and the second core tube 43 are respectively provided with mating supports that abut the bottom surfaces of the two mating grooves, and a sealing member is provided between the mating supports and the inner walls of the mating grooves; the front ends of the first core tube 42 and the second core tube 43 are also provided with mating supports, wherein the rear end face of the second guide sleeve 23 is provided with a mating groove that cooperates with the mating support of the first core tube 42, and a sealing member is provided between the mating support of the first core tube 42 and the inner wall of the mating groove, the rear end face of the mating support of the second core tube 43 abuts against the front end face of the second guide sleeve 23, and abuts against the inner wall surface of the piston 21 in the circumferential direction, and a sealing member is provided between the two, and an annular flange is also provided on the mating support of the second core tube 43, and the rear end face of the annular flange abuts against the front end face of the piston 21.

[0036] In some embodiments, for example Figure 1As shown, the guide device 44 includes a guide ring 441 and a stop joint 442. The stop joint 442 is installed at the front end of the floating core tube 41. A guide mounting groove 161 is provided on the circumference of the stop structure. The guide ring 441 is installed in the guide mounting groove 161. The guide ring 441 abuts against the inner wall of the floating core tube 41.

[0037] The setting of the stop joint 442 can effectively prevent the floating core tube 41 from moving, thereby enhancing the stability of the floating core tube 41 during movement; the guide ring 441 can continuously guide the floating core tube 41 during the movement of the floating core tube 41, thereby effectively preventing the floating core tube 41 from deflecting and making the movement smoother.

[0038] In some embodiments, for example Figure 1 As shown, a plurality of first stepped surfaces are gradually arranged on the peripheral wall of the mounting hole, and a plurality of second stepped surfaces are gradually arranged on the circumference of the second guide sleeve 23 to cooperate with the plurality of first stepped surfaces. The provision of the first stepped surfaces and the second stepped surfaces can serve as an auxiliary positioning function, making the installation of the second guide sleeve 23 more convenient and quick.

[0039] In some embodiments, for example Figure 1 As shown, multiple seals are provided between the second guide sleeve 23 and the floating core tube 41. The provision of multiple seals can effectively prevent oil from leaking into the floating core tube 41 during its movement, thus avoiding a drop in oil pressure in the cylinder and ensuring the stability of the hydraulic cylinder during its extension and retraction process.

[0040] In some embodiments, for example Figure 1 As shown, the earring body 31 includes a first earring 311 and a second earring 312. The first earring 311 is threadedly connected to the front end of the piston rod 22, and the second earring 312 is installed at the front end of the first earring 311 through a connecting sleeve. An installation cavity is formed between the first earring 311 and the second earring 312, and the hydraulic valve 32 is inserted into the installation cavity. The first oil inlet channel 3111 is opened on the first earring 311, and the oil inlet and outlet holes 3121 are opened on the second earring 312.

[0041] In this embodiment, for example Figure 2As shown, the hydraulic valve 32 includes a valve end cover 321, a control piston 322, a valve core 323, a valve sleeve 324, a small spring 325, a one-way valve sleeve 326, a screw sleeve 327, a large spring 328 and a screw plug 329; the valve end cover 321 is arranged at the upper end of the valve sleeve 324, the control piston 322, the valve core 323 and the small spring 325 are arranged below the valve end cover 321 in sequence, the screw sleeve 327 is installed at the lower end of the valve sleeve 324 and partially extends into the valve sleeve 324, a large spring 328 is provided in the screw sleeve 327, the one-way valve sleeve 326 is installed at the upper end of the screw sleeve 327, the upper end of the one-way valve sleeve 326 abuts against the bottom of the small spring 325, the lower end extends into the screw sleeve 327 and abuts against the upper end of the large spring 328, and the screw plug 329 is installed at the lower end of the screw sleeve 327.

[0042] In some embodiments, for example Figure 1 As shown, a second oil inlet channel 3112 is also provided on the first earring 311, and a third oil passage 6 is constructed between the second core tube 43 and the inner wall of the piston rod 22. The second oil inlet channel 3112 is connected to the third oil passage 6, and the third oil passage 6 is connected to the installation cavity above the hydraulic valve 32 through the oil channel. The rear end of the third oil inlet channel is closed by the front end face of the piston 21.

[0043] In this embodiment, when the hydraulic cylinder retracts, oil is introduced into the second oil inlet channel 3112, and the oil enters the third oil passage 6. When the third oil passage 6 is filled with oil, the oil pressure acts on the front end surface of the piston 21 and pushes the piston 21 backward. At this time, under the combined action of the oil pressure in the third oil passage 6 and the load on the hydraulic cylinder, the oil in the internal space of the cylinder body flows back to the valve sleeve 324 along the second oil passage 231, the first oil passage 5, and the first oil inlet channel 3111. The valve sleeve 324 cannot be opened in one direction due to the function of the one-way valve, thereby preventing the oil from flowing back from the oil inlet and outlet holes 3121. The oil is continuously input into the third oil passage 6 through the second oil inlet channel 3112, thereby causing the oil pressure in the third oil passage 6 and the installation cavity above the hydraulic valve 32 to continuously increase. When the oil pressure in the installation cavity above the hydraulic valve 32 reaches 10 MPa, the oil can push the control piston 322 to move downward, so that the control piston 322 pushes the valve core 323 and reversely opens the valve sleeve 324, so that the oil in the internal space of the cylinder body can pass through the hydraulic valve 32 and flow back from the inlet and outlet oil holes 3121. The above design can reduce the retraction speed of the hydraulic cylinder, avoid the retraction speed being too fast causing the piston rod 22 to shake, or the piston rod 22 to have too much impact when it retracts to the bottom, causing the entire vehicle to vibrate, which can effectively reduce the wear and tear of the hydraulic cylinder and extend the service life of the hydraulic cylinder.

[0044] In this embodiment, the first earring 311 is sleeved on the front end of the piston rod 22 , and a seal is provided between the first earring 311 and the outer side surface of the piston rod 22 .

[0045] Furthermore, the outer surface of the piston rod 22 is gradually provided with multiple third stepped surfaces, and the inner surface of the first earring 311 is gradually provided with multiple fourth stepped surfaces that cooperate with the third stepped surfaces. The provision of the third and fourth stepped surfaces can assist in positioning, making the installation of the first earring 311 more convenient and quick.

[0046] Other structures and operations of the core tube adaptive guide and the telescopic hydraulic cylinder with self-compensation function according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0047] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A core tube adaptive telescopic hydraulic cylinder, characterized in that: include: Cylinder assembly, piston assembly, earring assembly and core tube assembly; The cylinder assembly includes a cylinder barrel, a cylinder bottom, an end cover, a first guide sleeve, a gland, and an oil pipe seat. The oil pipe seat is arranged inside the cylinder barrel and fixedly connected to the end cover. The oil pipe seat is provided with a mounting groove. The earring assembly includes an earring body and a hydraulic valve, wherein the hydraulic valve is mounted on the earring body, and the earring body is provided with oil inlet and outlet holes and a first oil inlet channel, wherein the oil inlet and outlet holes are connected to the first oil inlet channel through the hydraulic valve; The piston assembly includes a piston, a piston rod and a second guide sleeve. The rear end of the piston rod is threadedly connected to the piston, and the front end is threadedly connected to the earring body. A mounting hole is provided in the middle of the piston, and the second guide sleeve is fixedly installed in the mounting hole. The core tube assembly includes a floating core tube, a first core tube, a second core tube and a guide device, wherein the floating core tube, the first core tube and the second core tube are all inserted into the piston rod, wherein the floating core tube, the first core tube and the second core tube are nested in sequence, the rear end of the floating core tube is fixedly connected to the mounting groove, the guide device is installed at the front end of the floating core tube, the front ends of the first core tube and the second core tube are both abutted against the end face of the earring body, and the rear ends are both abutted against the front end face of the second guide sleeve, the rear end of the second core tube is also abutted against the rear end face and inner wall of the piston, a first oil passage is constructed between the first core tube and the second core tube, the first oil passage is connected to the first oil inlet passage, and a second oil passage is provided on the second guide sleeve, and the second oil passage connects the first oil passage and the internal space of the cylinder.

2. The core tube adaptive telescopic hydraulic cylinder according to claim 1, characterized in that: The guide device includes a guide ring and a stop joint. The stop joint is installed at the front end of the floating core tube. A guide installation groove is provided on the circumference of the stop joint. The guide ring is installed in the guide installation groove. The guide ring abuts against the inner wall of the floating core tube.

3. The core tube adaptive telescopic hydraulic cylinder according to claim 1, characterized in that: A plurality of first step surfaces are gradually arranged on the peripheral wall of the mounting through hole, and a plurality of second step surfaces cooperating with the plurality of first step surfaces are gradually arranged on the circumference of the second guide sleeve.

4. The core tube adaptive telescopic hydraulic cylinder according to claim 1, characterized in that: A plurality of sealing elements are provided between the second guide sleeve and the floating core tube.

5. The core tube adaptive telescopic hydraulic cylinder according to claim 1, characterized in that: The earring body includes a first earring and a second earring, the first earring is threadedly connected to the front end of the piston rod, and the second earring is installed at the front end of the first earring through a connecting sleeve. An installation cavity is formed between the first earring and the second earring, and the hydraulic valve is inserted into the installation cavity. The first oil inlet channel is opened on the first earring, and the oil inlet and outlet holes are opened on the second earring.

6. The core tube adaptive telescopic hydraulic cylinder according to claim 5, characterized in that: The hydraulic valve comprises a valve end cover, a control piston, a valve core, a valve sleeve, a small spring, a one-way valve sleeve, a screw sleeve, a large spring and a screw plug; The valve end cover is arranged at the upper end of the valve sleeve, the control piston, the valve core and the small spring are arranged in sequence below the valve end cover, the screw sleeve is installed at the lower end of the valve sleeve and partially extends into the valve sleeve, a large spring is provided in the screw sleeve, the one-way valve sleeve is installed at the upper end of the screw sleeve, the upper end of the one-way valve sleeve abuts against the bottom of the small spring, the lower end extends into the screw sleeve and abuts against the upper end of the large spring, and the screw plug is installed at the lower end of the screw sleeve.

7. The core tube adaptive telescopic hydraulic cylinder according to claim 6, characterized in that: A second oil inlet channel is also provided on the first earring, and a third oil channel is constructed between the second core tube and the inner wall of the piston rod. The second oil inlet channel is connected to the third oil channel, and the third oil channel is connected to the installation cavity above the hydraulic valve through an oil channel.

8. The core tube adaptive telescopic hydraulic cylinder according to claim 5, characterized in that: The first earring is sleeved on the front end of the piston rod, and a sealing member is provided between the first earring and the outer side surface of the piston rod.

9. The core tube adaptive telescopic hydraulic cylinder according to claim 6, characterized in that: A plurality of third step surfaces are gradually arranged on the outer side surface of the piston rod, and a plurality of fourth step surfaces that match the plurality of third step surfaces are gradually arranged on the inner side surface of the first earring.

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