Telescopic hydraulic cylinder with core tube self-adaptive guiding function and self-compensation function

Abstract

The invention discloses a telescopic hydraulic cylinder with a core tube self-adaptive guiding function and a self-compensation function. The telescopic hydraulic cylinder comprises a cylinder body assembly, a piston assembly, a lug ring assembly and a core tube assembly. The lug ring assembly comprises a lug ring body and a hydraulic valve, an oil inlet and outlet hole and a first oil inlet channel are formed in the lug ring body, and the oil inlet hole is communicated with the first oil inlet channel through the hydraulic valve; the core tube assembly comprises a floating core tube, a first core tube, a second core tube and a guide device, the floating core tube, the first core tube and the second core tube are sequentially arranged in a nested mode, and the guide device is installed at the front end of the floating core tube. By arranging the oil pipe seat, the second guide sleeve and the guide device, the floating core pipe can be effectively protected, limited, supported and guided, so that the situation that the floating core pipe is bent, deformed and damaged due to the fact that the end face is subjected to back pressure in the high-speed reciprocating operation process of the hydraulic cylinder is avoided, and the safety of the floating core pipe is protected; and the flow and pressure of oil in the hydraulic cylinder can be regulated and controlled by arranging the hydraulic valve, so that the telescopic speed of the hydraulic cylinder is adjusted.

Description

Technical Field

[0001] The 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] At present, there are three types of telescopic systems for the whole arm of wheeled cranes, namely, single-cylinder rope row telescopic system, double-cylinder rope row telescopic system, and single-cylinder latch telescopic system. The single-cylinder rope row telescopic system is mainly used in 5-ton, 8-ton, 10-ton, and 12-ton wheeled cranes, and the single-cylinder latch telescopic system is mainly used in multi-section arm (6-section arm and above) wheeled cranes with more than 55 tons. The double-cylinder rope row telescopic system is mainly used for wheeled cranes other than the single-cylinder rope row telescopic system and the single-cylinder latch telescopic system, with a maximum tonnage of 100 tons. Due to the fast telescopic operation speed and high hoisting telescopic efficiency of the double-cylinder rope row telescopic system crane, it is deeply loved by the hoisting market. At present, large-tonnage double-cylinder rope row structure cranes are difficult to meet the development of the hoisting crane market. The double-cylinder rope row telescopic system crane is realized by driving the rope row through the telescopic oil cylinder to complete the extension and retraction of the crane telescopic arm step by step, so as to achieve different arm lengths for the whole machine, thereby realizing the hoisting function of the boom.

[0003] Due to the development trend of lightweight and intelligent cranes, in order to improve the market comfort and hoisting working 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 to operate, the telescopic cylinder runs at high speed and reciprocates, and 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 chambers of the hydraulic cylinder, which reaches 5, the matching of 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 and reduce the service life of each part. Summary of the invention

[0004] In view of this, the present invention provides a core tube adaptively guiding and 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: A telescopic hydraulic cylinder with a core tube self-adaptive guide and self-compensation function comprises a cylinder body assembly, a piston assembly, an earring assembly and a core tube assembly.

[0006] 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 a mounting groove is arranged on the oil pipe seat; 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. 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 arranged 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 in the installation 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 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 arranged on the second guide sleeve, the second oil passage connects the first oil passage and the internal space of the cylinder.

[0007] 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 installation groove is provided on the circumference of the stop structure, the guide ring is installed in the guide installation groove, and the guide ring abuts against the inner wall of the floating core tube.

[0008] Preferably, 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.

[0009] Preferably, a plurality of sealing elements are provided between the second guide sleeve and the floating core tube.

[0010] 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, 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, 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.

[0011] 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 arranged 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.

[0012] Preferably, a second oil inlet channel is also provided on the first earring, and a third oil passage 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 passage channel, and the third oil passage channel is connected to the installation cavity above the hydraulic valve through an oil channel.

[0013] 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.

[0014] Preferably, 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 cooperating with the plurality of third step surfaces are gradually arranged on the inner side surface of the first earring.

[0015] Compared with the prior art, the present application discloses a core tube adaptively guiding 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.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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; Figure 2 yes Figure 1 Magnified view of area A.

[0018] Reference numerals: 11. Cylinder barrel; 12. Cylinder bottom; 13. End cover; 14. First guide sleeve; 15. Gland; 16. Oil pipe seat; 161. Mounting groove; 21. Piston; 22. Piston rod; 23. Second guide sleeve; 231. Second oil passage; 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. Check 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; 41. floating core tube; 42. first core tube; 43. second core tube; 44. guide device; 441. guide ring; 442. stop joint; 5. The first oil passage; 6. The third oil passage. DETAILED DESCRIPTION

[0019] The present invention discloses a core tube adaptively guided and telescopic hydraulic cylinder with self-compensation 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, and at the same time, can effectively prevent the hydraulic cylinder from shaking.

[0020] Embodiments of the present invention are described in detail below, 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 should not be construed as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] 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.

[0023] The embodiment of the present application discloses a telescopic hydraulic cylinder with a core tube adaptive guidance and self-compensation function, including: a cylinder body assembly, a piston assembly, an earring assembly and a core tube assembly.

[0024] 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 , a second core tube 43 and a guide device 44, the floating core tube 41, the first core tube 42 and the second core tube 43 are all inserted into 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 in 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 abutted against the end face of the earring body 31, and the rear ends are both abutted against the front end face of the second guide sleeve 23, the rear end of the second core tube 43 is also abutted against the rear end face and the 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, and the second oil passage 231 connects the first oil passage 5 with the internal space of the cylinder barrel 11.

[0025] 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, thereby effectively protecting the safety of the floating core tube 41; by providing the hydraulic valve 32, the flow rate 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.

[0026] For example Figure 1As shown, when the hydraulic cylinder is extended, 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 body assembly moves to the left as a whole under the action of the oil pressure, and the hydraulic cylinder is extended. 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 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 deviation and shaking, and thus preventing the floating core tube 41 from being deformed and damaged due to high speed and high pressure.

[0027] 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 the difficulty in ensuring the positioning accuracy of the piston rod of the existing hydraulic cylinder due to the earrings and pistons welded on the front and rear ends.

[0028] 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 surface of the earring body 31 and the rear end surface of the second guide sleeve 23, wherein the rear end of the second core tube 43 is also in contact with the rear end surface and the inner wall of the piston 21. This processing technology of fixing the end surfaces 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 matching 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 provided with matching support members respectively abutting against the bottom surfaces of the two matching grooves, and a sealing member is provided between the matching support member and the inner wall of the matching groove; the front ends of the first core tube 42 and the second core tube 43 are also provided with matching support members, wherein a matching groove matching with the matching support member of the first core tube 42 is provided on the rear end face of the second guide sleeve 23, and a sealing member is provided between the matching support member of the first core tube 42 and the inner wall of the matching groove, the rear end face of the matching support member 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 matching support member 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.

[0029] 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 installation groove 161 is provided on the circumference of the stop structure. The guide ring 441 is installed in the guide installation groove 161. The guide ring 441 abuts against the inner wall of the floating core tube 41.

[0030] 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.

[0031] In some embodiments, for example Figure 1 As shown, a plurality of first step surfaces are gradually arranged on the peripheral wall of the installation 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 23. The arrangement of the first step surface and the second step surface can play a role in auxiliary positioning, making the installation of the second guide sleeve 23 more convenient and quick.

[0032] 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 the oil from leaking into the floating core tube 41 during its movement, and avoid the oil pressure in the cylinder from dropping, thereby ensuring the stability of the hydraulic cylinder during its extension and retraction process.

[0033] 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. 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. 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.

[0034] 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 arranged 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.

[0035] 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, the third oil passage 6 is connected to the installation cavity above the hydraulic valve 32 through the oil channel, and the rear end of the third oil inlet channel is closed by the front end face of the piston 21.

[0036] 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, thereby allowing the oil in the internal space of the cylinder body to pass through the hydraulic valve 32 and flow back from the oil inlet and outlet holes 3121. The above design can reduce the retraction speed of the hydraulic cylinder, avoid the piston rod 22 shaking due to the retraction speed being too fast, or the piston rod 22 having too much impact when it retracts to the bottom, causing the entire vehicle to vibrate, and can effectively reduce the wear and tear of the hydraulic cylinder and extend the service life of the hydraulic cylinder.

[0037] In this embodiment, the first earring 311 is sleeved on the front end of the piston rod 22 , and a sealing member is provided between the first earring 311 and the outer side surface of the piston rod 22 .

[0038] Furthermore, a plurality of third step surfaces are gradually arranged on the outer side surface of the piston rod 22, and a plurality of fourth step surfaces cooperating with the plurality of third step surfaces are gradually arranged on the inner side surface of the first earring 311. The arrangement of the third step surface and the fourth step surface can play a role in assisting positioning, making the installation of the first earring 311 more convenient and quick.

[0039] 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.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0041] Although the 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 present invention, and that the scope of the present 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 comprises a cylinder barrel, a cylinder bottom, an end cover, a first guide sleeve, a gland and an oil pipe seat, wherein the oil pipe seat is arranged inside the cylinder barrel and fixedly connected to the end cover, and a mounting groove is arranged on the oil pipe seat; The earring assembly comprises 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 with the first oil inlet channel through the hydraulic valve; The piston assembly comprises 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, 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, a second oil passage is provided on the second guide sleeve, and the second oil passage connects the first oil passage with 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 structure, the guide ring is installed in the guide installation groove, and 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 arranged 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, 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, 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.

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 arranged 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 passage 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 passage channel, and the third oil passage 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 arranged 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 matching with the plurality of third step surfaces are gradually arranged on the inner side surface of the first earring.

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