Telescopic oil cylinder, multi-cylinder sequential telescopic hydraulic system and telescopic engineering machinery

Abstract

The present application belongs to the technical field of engineering machinery and provides a telescopic oil cylinder, a multi-cylinder sequential telescopic hydraulic system and a telescopic engineering machinery. The telescopic oil cylinder comprises a cylinder barrel, a piston rod and a first tube core. The piston rod is internally provided with an axially extending first rod internal passage. The head end of the piston rod is further provided with a first external passage which is in communication with the first rod internal passage and the external environment. The first tube core is installed on the cylinder barrel and axially penetrates into the first rod internal passage from the bottom end of the piston rod at one end. The peripheral wall of the first tube core is further provided with an oil passing hole. The first tube core is internally provided with an oil passing passage which is in communication with the oil passing hole and the first rod internal passage. The oil passing hole is used to be exposed from the bottom end of the piston rod when the piston rod is extended to a preset length. Through the cooperation of the first rod internal passage, the first tube core, the oil passing hole on the first tube core and the oil passing passage, the sequential extension driving between multiple oil cylinders can be realized, and the dependence on a sequence valve is eliminated, so that the purposes of reducing system heat generation and energy consumption are achieved.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a telescopic cylinder, a multi-cylinder sequential telescopic hydraulic system, and telescopic engineering machinery. Background Technology

[0002] Existing sequential telescopic hydraulic systems achieve sequential telescopic movement by connecting sequence valves in series between multiple cylinders, specifically, such as... Figure 1 As shown, in the existing multi-stage hydraulic cylinder, when pressurized oil enters from port A of the rodless chamber of the first hydraulic cylinder 01, it acts on the rodless chamber of the first hydraulic cylinder 01. Simultaneously, it acts on the first sequence valve 04 through the oil passage C in the piston rod of the first hydraulic cylinder 01. The system pressure reaches the load pressure of the first hydraulic cylinder 01, but does not reach the opening pressure of the first sequence valve 04. Therefore, the first sequence valve 04 cannot open, and the pressurized oil cannot enter the second hydraulic cylinder 02. The piston rod of the first hydraulic cylinder 01 extends, and the oil in the rod chamber returns from port B.

[0003] When the first cylinder 01 is fully extended, the system pressure rises, the first sequence valve 04 opens, and pressurized oil enters from port A1 of the rodless chamber of the second cylinder 02, acting on the rodless chamber of the second cylinder 02. Simultaneously, it acts on the second sequence valve 05 through the oil passage C1 in the piston rod of the second cylinder 02. The system pressure reaches the load pressure of the second cylinder 02, but not the opening pressure of the second sequence valve 02, so the second sequence valve 02 cannot open, and the pressurized oil cannot enter the third cylinder 03. The piston rod of the second cylinder 02 extends, and the oil in the rod chamber returns from port B1 through the oil passage D on the piston rod of the first cylinder 01 and port B of the rod chamber of the first cylinder 01. The extension principle of the third cylinder 03 is the same as that of the second cylinder 02.

[0004] Because each cylinder has a different load, achieving sequential extension and retraction requires setting the pressure of each sequence valve through testing, which is very troublesome. At the same time, a large part of the oil pressure is lost during system operation due to the opening of the sequence valves, causing the system to overheat or the end cylinder to fail to extend. Summary of the Invention

[0005] To address the aforementioned defects or deficiencies, this invention provides a telescopic cylinder, a multi-cylinder sequential telescopic hydraulic system, and telescopic engineering machinery, aiming to solve the technical problem that existing multi-stage cylinders require a sequence valve to achieve the sequential extension of multiple cylinders.

[0006] To achieve the above objectives, the present invention provides a telescopic hydraulic cylinder, wherein the telescopic hydraulic cylinder includes a cylinder barrel, a piston rod, and a first core tube. The piston rod is slidably disposed within the cylinder barrel and has an axially extending first internal channel within the rod. The head end of the piston rod also has a first external channel connecting the first internal channel tube and the outside. The first core tube is mounted on the cylinder barrel and one end extends axially into the first internal channel tube from the bottom end of the piston rod. The first core tube and the bottom end of the piston rod are slidably sealed together. The peripheral wall of the first core tube also has an oil passage hole. The first core tube has an oil passage connecting the oil passage hole and the first internal channel tube. The oil passage hole is used to protrude from the bottom end of the piston rod when the piston rod extends to a preset length.

[0007] In an embodiment of the present invention, the bottom end of the cylinder is provided with a first oil inlet and return channel, the piston rod is provided with an axially extending second rod inner channel, the head end of the piston rod is provided with a second external channel connecting the second rod inner channel and the outside, and the telescopic cylinder also includes a second core tube, the second core tube is installed on the cylinder and one end is connected to the first oil inlet and return channel, the other end of the second core tube passes through the second rod inner channel from the bottom end of the piston rod, the second core tube connects the first oil inlet and return channel and the second rod inner channel, and the second core tube is slidably sealed with the bottom end of the piston rod.

[0008] In an embodiment of the present invention, the cylinder is further provided with an independent inlet and return oil pipeline. One end of the independent inlet and return oil pipeline is connected to the rod chamber of the cylinder, and the other end is connected to the first inlet and return oil channel. A one-way valve is provided between the first inlet and return oil channel and the independent inlet and return oil pipeline. The one-way valve is configured to open when hydraulic oil flows from the independent inlet and return oil pipeline to the first inlet and return oil channel and to close in the reverse direction.

[0009] In an embodiment of the present invention, a hollow rod cavity is provided inside the piston rod. One end of the hollow rod cavity is connected to the rod cavity of the cylinder, and the other end is connected to the second external channel. A stroke valve is provided at the head of the piston rod. The working valve port of the stroke valve is connected to the hollow rod cavity and the second external channel. The stroke valve is configured to control the hollow rod cavity and the second external channel to conduct when the valve core of the stroke valve is displaced by a preset distance.

[0010] In an embodiment of the present invention, the hollow rod cavity is provided with an axially extending first cavity tube and a second cavity tube. The inner channel of the first rod is the cavity of the first cavity tube, and the inner channel of the second rod is the cavity of the second cavity tube. The first core tube is inserted from the bottom end of the piston rod and slides into the first cavity tube, and the second core tube is inserted from the bottom end of the piston rod and slides into the second cavity tube.

[0011] In an embodiment of the present invention, the cylinder includes a cylinder body and a cylinder base disposed at the bottom end of the cylinder body and used to seal the bottom opening of the cylinder body. The cylinder base includes a seat body and a rotary valve core coaxially rotatably disposed within the seat body. One end of the first tube core is fixedly installed on the side of the rotary valve core facing the cylinder body, and the other end of the first tube core extends into the inner channel of the first rod.

[0012] To achieve the above objectives, the present invention also provides a multi-cylinder sequential telescopic hydraulic system, which includes a primary cylinder, a secondary cylinder, and a rod chamber working channel. The primary cylinder can be a telescopic cylinder as described above. The rodless chamber of the secondary cylinder is connected to the first external channel of the primary cylinder. The rod chamber working channel is used to supply oil to and from the rod chambers of the primary and secondary cylinders.

[0013] In an embodiment of the present invention, the bottom end of the cylinder barrel of the first-stage cylinder is provided with a first inlet and return oil channel, the piston rod of the first-stage cylinder is provided with an axially extending second rod inner channel, and the head end of the piston rod is provided with a second external channel connecting the second rod inner channel and the outside. The second external channel is used to communicate with the rod chamber of the second-stage cylinder. The first-stage cylinder also includes a second core tube, which is installed on the cylinder barrel and one end is connected to the first inlet and return oil channel. The other end of the second core tube passes through the second rod inner channel from the bottom end of the piston rod. The cylinder barrel of the first-stage cylinder is also provided with an independent inlet and return oil pipeline, which connects the rod chamber of the cylinder barrel of the first-stage cylinder and the first inlet and return oil channel. A one-way valve is provided between the first inlet and return oil channel and the independent inlet and return oil pipeline. The working channel of the rod chamber includes the first inlet and return oil channel, the second rod inner channel, the second external channel, the second core tube, and the independent inlet and return oil pipeline.

[0014] In an embodiment of the present invention, the piston rod of the first-stage cylinder is provided with a hollow rod cavity. One end of the hollow rod cavity is connected to the rod chamber of the cylinder barrel of the first-stage cylinder, and the other end is connected to a second external channel. The head of the piston rod of the first-stage cylinder is provided with a stroke valve. The working valve port of the stroke valve is connected to the hollow rod cavity and the second external channel. The stroke valve is configured to control the hollow rod cavity to conduct through the second external channel when the valve core of the stroke valve is displaced by a preset distance. The valve core of the stroke valve is used to make transmission contact with the piston rod of the second-stage cylinder when the piston rod of the second-stage cylinder retracts to a preset position.

[0015] In an embodiment of the present invention, the secondary cylinder can be a telescopic cylinder as described above. In addition, the multi-cylinder sequential telescopic hydraulic system may also include a tertiary cylinder. The rodless chamber of the tertiary cylinder is connected to the first external channel of the secondary cylinder, and the working channel of the rod chamber is also used to supply oil to the rod chamber of the tertiary cylinder for oil inlet and outlet.

[0016] To achieve the above objectives, the present invention also provides a telescopic engineering machine, wherein the telescopic engineering machine includes a multi-cylinder sequential telescopic hydraulic system as described above.

[0017] Through the above technical solution, the telescopic hydraulic cylinder provided in the embodiments of the present invention has the following beneficial effects:

[0018] By controlling the oil intake of the rodless chamber of the telescopic cylinder, the piston rod of the telescopic cylinder can be pushed out. The extension of the piston rod causes the inner channel of the first rod to slide relative to the first core tube. When the piston rod extends to a certain position, the oil passage hole of the first core tube will leak out from the inner channel of the first rod and be placed in the rodless chamber. At this time, the pressure oil entering the rodless chamber from the outside can sequentially pass through the oil passage hole, oil passage, inner channel of the first rod, first external channel, and first external pipe to enter the rodless chamber of the next stage cylinder, realizing the extension drive of the next stage cylinder. In summary, the telescopic cylinder of the present invention, through the cooperation of the inner channel of the first rod, the first core tube, and the oil passage hole and oil passage on the first core tube, can only drive the extension of the next stage cylinder when the extension length of the piston rod of the telescopic cylinder reaches a preset length. This not only realizes the sequential extension drive between multiple cylinders, but also eliminates the dependence on the sequence valve, thereby reducing system heat generation and energy consumption.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a connection diagram of the sequential telescopic hydraulic system in the background technology;

[0022] Figure 2 This is a schematic diagram of the structure of the telescopic hydraulic cylinder according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the bottom end of the telescopic cylinder according to an embodiment of the present invention;

[0024] Figure 4 This is a connection diagram of a two-cylinder sequential telescopic hydraulic system according to an embodiment of the present invention;

[0025] Figure 5 This is a connection diagram of a three-cylinder sequential telescopic hydraulic system according to an embodiment of the present invention.

[0026] Background Art, Illustrations and Labeling

[0027] 01. First hydraulic cylinder; 02. Second hydraulic cylinder; 03. Third hydraulic cylinder; 04. First sequence valve; 05. Second sequence valve.

[0028] Explanation of reference numerals in the accompanying drawings of the embodiments of the present invention

[0029] 1. Cylinder barrel; 11. Cylinder body; 12. Cylinder base; 121. Base body; 122. Rotary valve core; 122a. Internal valve passage; 122b. Annular oil passage; 123. End cap; 13. Guide sleeve; 14. Independent inlet and return oil lines; 15. Check valve; 1a. First inlet and return oil passage; 1b. Second inlet and return oil passage; 2. Piston rod; 21. Piston body; 22. Rod body; 221. Hollow rod cavity; 2a. First external passage; 2 b. Second external channel; 2c. First working oil port; 2d. Second working oil port; 31. First cavity tube; 311. First rod internal channel; 32. Second cavity tube; 321. Second rod internal channel; 33. Stroke valve; 41. First core tube; 411. Oil passage hole; 42. Second core tube; 51. First external pipe; 52. Second external pipe; S1. First stage cylinder; S2. Second stage cylinder; S3. Third stage cylinder; W. Rodless chamber; Y. Rod chamber. Detailed Implementation

[0030] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] The telescopic hydraulic cylinder of the present invention will now be described with reference to the accompanying drawings.

[0032] like Figure 2 , Figure 4 and Figure 5 As shown, the telescopic cylinder provided by the present invention includes a cylinder barrel 1, a piston rod 2, and a first core tube 41.

[0033] The piston rod 2 is slidably disposed within the cylinder 1, dividing the inner cavity of the cylinder 1 into a rod chamber Y and a rodless chamber W. The rodless chamber W is located near the bottom end of the cylinder 1, and the rod chamber Y is located near the head end of the cylinder 1. The piston rod 2 has an axially extending first rod internal channel 311. The piston rod 2 extending out of the head end of the cylinder 1 also has a first external channel 2a connecting the first rod internal channel 311 and the outside. The first external channel 2a is used to connect to the pipeline of the rodless chamber W of the next stage cylinder. The first external channel 2a is located at the head end of the piston rod 2 to facilitate the connection of external pipelines.

[0034] The first core 41 is mounted on the cylinder 1. One end of the first core 41 axially passes through the rodless cavity W and the bottom end of the piston rod 2, and finally enters the inner channel 311 of the first rod. The first core 41 and the bottom end of the piston rod 2 are in sliding sealing fit, that is, the first core 41 can slide axially relative to the inner channel 311 of the first rod. An oil passage hole 411 is also provided on the peripheral wall of the first core 41, and an oil passage connecting the oil passage hole 411 and the inner channel 311 of the first rod is provided inside the first core 41. When the telescopic cylinder is in the retracted state, the oil passage hole 411 is located in the inner channel 311 of the first rod, and the oil passage hole 411 is used to protrude from the bottom end of the piston rod 2 when the piston rod 2 is extended to a preset length.

[0035] By connecting the first external channel 2a of the telescopic cylinder of the present invention to the rodless chamber W of the next stage cylinder, a multi-cylinder sequential telescopic hydraulic system with sequential extension function can be formed.

[0036] Specifically, by controlling the oil intake of the rodless chamber W of the telescopic cylinder, the piston rod 2 of the telescopic cylinder can be pushed out. The extension of the piston rod 2 will cause the first rod inner channel 311 to slide relative to the first tube 41. When the piston rod 2 extends to a certain position, the oil passage 411 of the first tube 41 will leak out from the first rod inner channel 311 and be placed in the rodless chamber W. At this time, the pressure oil entering the rodless chamber W from the outside can pass through the oil passage 411, the oil passage, the first rod inner channel 311, the first external channel 2a, and the first external pipe in sequence to enter the rodless chamber W of the next stage cylinder, thereby realizing the extension drive of the next stage cylinder. In summary, the telescopic cylinder of the present invention, through the cooperation of the first rod inner channel 311, the first tube core 41, and the oil passage hole 411 and oil passage on the first tube core 41, can drive the extension of the next stage cylinder only when the extension length of the piston rod 2 of the telescopic cylinder reaches the preset length. This not only realizes the sequential extension drive between multiple cylinders, but also eliminates the dependence on the sequence valve, thereby achieving the purpose of reducing system heat generation and energy consumption.

[0037] In an embodiment of the present invention, the first external pipe 51 refers to the pipe connecting the first external channel 2a and the rodless chamber W of the next stage hydraulic cylinder.

[0038] Understandably, cylinder 1 needs to be equipped with a second inlet / outlet channel 1b for supplying oil to and from the rodless chamber W of the telescopic cylinder, ensuring that hydraulic oil can smoothly enter the rodless chamber W of the telescopic cylinder. When the telescopic cylinder forms a multi-cylinder sequential telescopic hydraulic system with other cylinders, a rod chamber working channel is also required for supplying oil to and from the rod chamber Y of the telescopic cylinder and the next-stage cylinder. The rod chamber working channel can be integrated into the telescopic cylinder or be an external pipeline.

[0039] Taking an integrated rod-type working channel as an example, such as Figure 2 , Figure 4 and Figure 5As shown, in an embodiment of the present invention, a first oil inlet / outlet channel 1a may be provided at the bottom end of the cylinder 1, a second rod inner channel 321 extending axially may be provided inside the piston rod 2, and a second external channel 2b connecting the second rod inner channel 321 and the outside may be provided at the head end of the piston rod 2. The second external channel 2b is used to connect with the rod chamber Y of the next stage cylinder. For example, the second external channel 2b can be connected to the rod chamber Y of the next stage cylinder through a second external pipe 52.

[0040] like Figure 2 , Figure 4 and Figure 5 As shown, the telescopic cylinder may further include a second core 42. The second core 42 is mounted on the cylinder barrel 1 and one end is connected to the first oil inlet / return channel 1a. The other end of the second core 42 passes through the bottom end of the piston rod 2 into the second rod inner channel 321. The second core 42 connects the first oil inlet / return channel 1a and the second rod inner channel 321, and the second core 42 is in sliding sealing fit with the bottom end of the piston rod 2. The first oil inlet / return channel 1a, the second rod inner channel 321, the second external channel 2b, and the second core 42 together form the rod chamber working channel of the next-stage cylinder.

[0041] After the telescopic cylinder extends to its final position, it drives the extension of the next-stage cylinder. During the extension process of the next-stage cylinder, the hydraulic oil in the rod chamber Y of the next-stage cylinder can sequentially return through the second external pipe 52, the second external channel 2b, the second rod internal channel 321, and the first inlet and return oil channel 1a. By returning oil to the rod chamber Y of the next-stage cylinder, the normal extension of the cylinder is ensured. Integrating the working channel of the rod chamber into the telescopic cylinder increases the integration of the piping.

[0042] like Figure 2 As shown, for the return oil of the rod chamber Y of the telescopic cylinder, an independent inlet and return oil pipeline 14 can be installed on the cylinder barrel 1 of the telescopic cylinder. One end of the independent inlet and return oil pipeline 14 can be connected to the rod chamber Y of the cylinder barrel 1, and the other end can be connected to the first inlet and return oil channel 1a. A one-way valve 15 needs to be installed between the first inlet and return oil channel 1a and the independent inlet and return oil pipeline 14. The one-way valve 15 is configured to open when hydraulic oil flows from the independent inlet and return oil pipeline 14 to the first inlet and return oil channel 1a and close in the reverse direction. By installing the one-way valve 15, the oil flowing back from the rod chamber Y of the next stage cylinder to the first inlet and return oil channel 1a can be prevented from flowing into the independent inlet and return oil pipeline 14.

[0043] like Figure 1 As shown, in the existing sequential telescopic system composed of multi-stage hydraulic cylinders, each hydraulic cylinder can only achieve the action of the cylinder with the smaller force first or the simultaneous action of three hydraulic cylinders, and cannot achieve sequential retraction.

[0044] To achieve sequential retraction among multiple hydraulic cylinders, the present invention further improves the structure of the telescopic hydraulic cylinder.

[0045] like Figure 2 , Figure 3 and Figure 4 As shown, in an embodiment of the present invention, the piston rod 2 is provided with a hollow rod cavity 221. One end of the hollow rod cavity 221 is connected to the rod cavity Y of the cylinder 1, and the other end is connected to the second external channel 2b. The head of the piston rod 2 is provided with a stroke valve 33. The working valve port of the stroke valve 33 is connected to the hollow rod cavity 221 and the second external channel 2b. The stroke valve 33 is configured to control the hollow rod cavity 221 to conduct with the second external channel 2b when the valve core of the stroke valve 33 is displaced by a preset distance. By setting the position of the valve core of the stroke valve 33, the valve core can be pushed to move when the next stage cylinder retracts to a preset position (such as retracting to the end), so that the hollow rod cavity 221 and the second external channel 2b are connected.

[0046] like Figure 2 , Figure 3 and Figure 4 As shown, in an embodiment of the present invention, the head end of the piston rod 2 is also provided with a first working port 2c and a second working port 2d, which are respectively corresponding to the two working ports of the stroke valve 33. The first working port 2c is connected to the second external channel 2b, and the second working port 2d is connected to the hollow rod cavity 221. By controlling the displacement of the valve core, the first working port 2c and the second working port 2d can be made to connect the hollow rod cavity 221 to the second external channel 2b.

[0047] Taking the retraction of the next-stage hydraulic cylinder into position as an example, which actuates the valve core. Figure 2 , Figure 3 and Figure 4 As shown, in the multi-cylinder sequential telescopic hydraulic system composed of a telescopic cylinder and a next-stage cylinder, during retraction, the first oil inlet and return channel 1a is controlled to receive oil. Due to the presence of the one-way valve 15, the pressure oil in the first oil inlet and return channel 1a can only enter the rod chamber Y of the next-stage cylinder through the first oil inlet and return channel 1a, the second core 42, the second rod inner channel 321, the second external channel 2b, and the second external pipe, thereby driving the next-stage cylinder to retract. When the next-stage cylinder retracts, the hydraulic oil in the rodless chamber W of the next-stage cylinder can return through the first external pipe, the first external channel 2a, the first rod inner channel 311, the oil passage of the first core 41, the oil passage hole 411 of the first core 41, the rodless chamber W of the telescopic cylinder, and the second oil inlet and return channel 1b of the telescopic cylinder.

[0048] When the next-stage hydraulic cylinder retracts to its final position, it will push the valve core to switch to the valve position that connects the hollow rod cavity 221 and the second external channel 2b. After the hollow rod cavity 221 and the second external channel 2b are connected, the pressure oil from the first inlet and return oil channel 1a will pass through the first inlet and return oil channel 1a, the second core 42, the second rod inner channel 321, and the hollow rod cavity 221 to enter the rod cavity Y of the telescopic hydraulic cylinder, thereby realizing the retraction drive of the telescopic hydraulic cylinder.

[0049] In summary, the telescopic cylinder of the present invention, by providing an empty rod chamber that connects the rod chamber Y and the second external channel 2b, and by providing a stroke valve 33, can realize the sequential retraction of the telescopic cylinder and the next stage cylinder.

[0050] In an embodiment of the present invention, the stroke valve 33 can also be an electrically controlled valve. When the next stage cylinder retracts to its position, the stroke valve 33 can be controlled by the controller to achieve the sequential retraction function.

[0051] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the piston rod 2 includes a piston body 21 and a rod body 22. The piston body 21 is slidably disposed within the cylinder 1 and divides the inner cavity of the cylinder 1 into a rod chamber Y and a rodless chamber W. The rod body 22 is detachably mounted on the piston rod 2 and its head extends from the head end of the cylinder 1. The piston rod 2 and the head end of the cylinder 1 are also provided with guide sleeves 13 to guide the extension and retraction of the rod body 22.

[0052] like Figure 1 and Figure 2 As shown, in embodiments of the present invention, the first rod inner channel 311, the second rod inner channel 321, and the hollow rod cavity 221 can be formed in many ways. For example, the rod body 22 can be a hollow tube, with a hollow rod cavity 221 inside. The hollow rod cavity 221 contains an axially extending first cavity tube 31 and a second cavity tube 32. The first rod inner channel 311 is the cavity of the first cavity tube 31, and the second rod inner channel 321 is the cavity of the second cavity tube 32. The piston body 21 also has two axially penetrating through holes, which are respectively aligned with the first cavity tube 31 and the second cavity tube 32. The first core 41 is inserted through one of the through holes of the piston rod 2 and slides into the first cavity tube 31, while the second core 42 is inserted through the other through hole of the piston rod 2 and slides into the second cavity tube 32. The cavity tube and the detachable piston rod 2 facilitate the assembly of the telescopic cylinder, while the cavity tube ensures that the first rod inner channel 311, the second rod inner channel 321, and the hollow rod cavity 221 are independent of each other.

[0053] Of course, in the embodiments of the present invention, the first inner channel 311, the second inner channel 321, and the hollow rod cavity 221 can also be independent and axially extending channels.

[0054] In an embodiment of the present invention, the first core 41, the second core 42 and the piston body 21 need to be in sealed contact to avoid oil leakage between the channels.

[0055] In an embodiment of the present invention, a channel for the rod cavity Y of the telescopic cylinder can be formed on the peripheral wall of the rod body 22.

[0056] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the cylinder 1 includes a cylinder body 11 and a cylinder base 12 disposed at the bottom end of the cylinder body 11 and used to seal the bottom opening of the cylinder body 11. The cylinder base 12 includes a seat body 121 and a rotary valve core 122 coaxially rotatably disposed within the seat body 121. One end of the first tube core 41 is fixedly installed on the side of the rotary valve core 122 facing the cylinder body 11, and the other end extends into the inner channel 311 of the first rod. Similarly, the installation method of the second tube core 42 can be the same as that of the first tube core 41. By installing the first tube core 41 and the second tube core 42 on the rotary valve core 122, the piston rod 2 can drive the first tube core 41 and the second tube core 42 to rotate together within the cylinder 1, thereby facilitating the assembly of the telescopic cylinder and preventing damage to the tube cores when the piston rod 2 is hoisted and aligned.

[0057] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, since the second core 42 needs to be connected to the first inlet and return oil channel 1a, an internal valve conduction channel 122a and an annular oil passage 122b need to be provided on the rotary valve core 122 to maintain the connection between the second core 42 and the first inlet and return oil channel 1a when the rotary valve core 122 rotates.

[0058] In an embodiment of the present invention, an end cap 123 is also provided on the side of the cylinder base 12 facing away from the cylinder barrel 1.

[0059] To achieve the above objectives, the present invention also provides a multi-cylinder sequential telescopic hydraulic system. The multi-cylinder sequential telescopic hydraulic system includes a primary cylinder S1, a secondary cylinder S2, and a rod-side working channel. The primary cylinder S1 can be a telescopic cylinder as described above, and the secondary cylinder S2 can be the telescopic cylinder of the present invention or a conventional cylinder. During connection, the rodless chamber W of the secondary cylinder S2 needs to be connected to the first external channel 2a of the primary cylinder S1. The multi-cylinder sequential telescopic hydraulic system also needs to be provided with a rod-side working channel for the inlet and outlet oil flow of the rod-side chambers Y of the primary cylinder S1 and the secondary cylinder S2.

[0060] Specifically, such as Figure 2 and Figure 4 As shown, taking a two-cylinder sequential telescopic hydraulic system consisting of a telescopic cylinder and a regular cylinder as an example, the two cylinders refer to the first-stage cylinder S1 and the second-stage cylinder S2, respectively. The first-stage cylinder S1 is the telescopic cylinder of this invention.

[0061] When the two-cylinder sequential extension hydraulic system needs to extend sequentially, oil is first supplied to the second inlet / return oil channel 1b of the first-stage cylinder S1. The pressurized oil in the second inlet / return oil channel 1b first enters the rodless chamber W of the first-stage cylinder S1 to drive the piston rod 2 of the first-stage cylinder S1 to extend. When the first-stage cylinder S1 extends, the oil in the rod chamber Y of the first-stage cylinder S1 can return through the independent inlet / return oil line 14 and the first inlet / return oil channel 1a.

[0062] When the piston rod 2 of the first-stage cylinder S1 extends to a preset length (the preset length can refer to the first-stage cylinder S1 extending to its full position), the oil passage 411 leaks out from the first rod inner channel 311 and is placed in the rodless chamber W of the first-stage cylinder S1. At this time, the pressurized oil in the rodless chamber W of the first-stage cylinder S1 can sequentially pass through the oil passage 411, the oil passage, the first rod inner channel 311, the first external channel 2a, and the first external pipe 51 into the rodless chamber W of the second-stage cylinder S2, thereby realizing the extension drive of the second-stage cylinder S2. When the second-stage cylinder S2 extends, the oil in the rod chamber Y of the second-stage cylinder S2 can sequentially return through the second external pipe 52, the second external channel 2b, the second rod inner channel 321, and the first inlet and return oil channel 1a.

[0063] Through the above operations, the first-stage hydraulic cylinder S1 and the second-stage hydraulic cylinder S2 can be extended sequentially.

[0064] When the two-cylinder sequential telescopic hydraulic system needs to retract, oil is first introduced into the first inlet / return channel 1a of the first-stage cylinder S1. Due to the presence of the check valve 15, the pressurized oil in the first inlet / return channel 1a first passes through the first inlet / return channel 1a, the second core 42, the second rod inner channel 321, the second external channel 2b, and the second external pipe 52 to enter the rod chamber Y of the second-stage cylinder S2, thereby driving the second-stage cylinder S2 to retract. The hydraulic oil in the rodless chamber W of the second-stage cylinder S2 can return through the first external pipe 51, the first external channel 2a, the first rod inner channel 311, the oil passage of the first core 41, the oil passage hole 411 of the first core 41, the rodless chamber W of the telescopic cylinder, and the second inlet / return channel 1b of the telescopic cylinder.

[0065] After the secondary cylinder S2 retracts to its final position, the piston rod 2 of the secondary cylinder S2 will push the valve core of the stroke valve 33 to actuate. At this time, the hollow rod cavity 221 will be connected to the second external channel 2b. After the hollow rod cavity 221 is connected to the second external channel 2b, the pressure oil of the first inlet and return oil channel 1a will pass through the first inlet and return oil channel 1a, the second core 42, the second rod inner channel 321, and the hollow rod cavity 221 to enter the rod cavity Y of the telescopic cylinder, thereby realizing the retraction drive of the telescopic cylinder.

[0066] Through the above operations, the secondary hydraulic cylinder S2 and the primary hydraulic cylinder S1 can be retracted sequentially.

[0067] Taking a three-cylinder sequential telescopic hydraulic system consisting of two telescopic cylinders and one ordinary cylinder as an example, such as... Figure 2 and Figure 5 As shown, the three cylinders refer to the first-stage hydraulic cylinder S1, the second-stage hydraulic cylinder S2, and the third-stage hydraulic cylinder S3, respectively. The first-stage hydraulic cylinder S1 and the second-stage hydraulic cylinder S2 are both telescopic hydraulic cylinders of the present invention.

[0068] The first external channel 2a and the second external channel 2b of the first-stage hydraulic cylinder S1 are connected to the first inlet and return oil channels 1a and 1b of the second-stage hydraulic cylinder S2 through two external pipes, respectively. The first external channel 2a and the second external channel 2b of the second-stage hydraulic cylinder S2 are connected to the rodless chamber W and the rod chamber Y of the third-stage hydraulic cylinder S3 through two external pipes, respectively.

[0069] During extension, oil is first introduced into the second inlet / return oil channel 1b of the first-stage cylinder S1. The pressurized oil in the second inlet / return oil channel 1b first enters the rodless chamber W of the first-stage cylinder S1 to drive the piston rod 2 of the first-stage cylinder S1 to extend. During extension, the oil in the rod chamber Y of the first-stage cylinder S1 can return through the independent inlet / return oil pipeline 14 of the first-stage cylinder S1 and the first inlet / return oil channel 1a of the first-stage cylinder S1.

[0070] When the piston rod 2 of the first-stage cylinder S1 extends to a preset length (the preset length can refer to the first-stage cylinder S1 extending to its full position), the oil passage 411 leaks out from the first rod inner channel 311 and is placed in the rodless chamber W of the first-stage cylinder S1. At this time, the pressure oil in the rodless chamber W of the first-stage cylinder S1 can sequentially pass through the oil passage 411, the oil passage, the first rod inner channel 311, the first external channel 2a, the first external pipe, and the second inlet and return oil channel 1b of the second-stage cylinder S2 into the rodless chamber W of the second-stage cylinder S2, thus realizing the extension of the second-stage cylinder S2. When the second-stage cylinder S2 extends, the hydraulic oil in the rod chamber Y of the second-stage cylinder S2 can enter the second external channel 2b of the first-stage cylinder S1 through the independent inlet and return oil pipe 14 of the second-stage cylinder S2 and the first inlet and return oil channel 1a of the second-stage cylinder S2, and then return through the second rod inner channel 321 and the first inlet and return oil channel 1a of the first-stage cylinder S1.

[0071] After the secondary cylinder S2 extends to its position, the pressure oil in the rodless chamber W of the secondary cylinder S2 can sequentially pass through the oil passage 411 of the secondary cylinder S2, the oil passage, the first rod inner passage 311, the first external passage 2a, the first external pipe, and the rodless chamber W of the tertiary cylinder S3, thereby enabling the extension of the tertiary cylinder S3.

[0072] The principle of sequential retraction in a three-cylinder sequential telescopic hydraulic system is the same as that in a two-cylinder sequential telescopic hydraulic system, and will not be repeated here.

[0073] In embodiments of the present invention, the multi-cylinder sequential telescopic hydraulic system may also be composed of more telescopic cylinders connected in series.

[0074] To achieve the above objectives, the present invention also provides a telescopic engineering machine, wherein the telescopic engineering machine includes a multi-cylinder sequential telescopic hydraulic system as described above. The telescopic engineering machine can be a crane, a telescopic boom aerial work platform, etc. Since the telescopic engineering machine adopts all the technical solutions of the above embodiments, it at least has the beneficial effects brought about by the above embodiments, and will not be repeated here.

[0075] In the description of this invention, it should be understood that 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Although embodiments of the present invention have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A telescopic hydraulic cylinder, characterized in that, The telescopic cylinder includes: Cylinder (1); The piston rod (2) is slidably disposed in the cylinder (1) and has an axially extending first rod inner channel (311) inside the rod. The head end of the piston rod (2) is also provided with a first external channel (2a) connecting the first rod inner channel (311) and the outside. The first core (41) is installed on the cylinder (1) and one end of it is axially inserted into the inner channel (311) of the first rod from the bottom end of the piston rod (2). The first core (41) is slidably sealed to the bottom end of the piston rod (2). The peripheral wall of the first core (41) is also provided with an oil passage (411). The first core (41) is provided with an oil passage connecting the oil passage (411) and the inner channel (311) of the first rod. The oil passage (411) is used to be exposed from the bottom end of the piston rod (2) when the piston rod (2) extends to a preset length. The cylinder (1) includes a cylinder body (11) and a cylinder base (12) disposed at the bottom end of the cylinder body (11) and used to block the bottom opening of the cylinder body (11). The cylinder base (12) includes a seat body (121) and a rotary valve core (122) coaxially rotatably disposed in the seat body (121). The seat body (121) is provided with a first oil inlet and return channel (1a). The rotary valve core (122) is provided with an internal valve conduction channel (122a) and an annular oil passage (122b). The annular oil passage (122b) is used to keep the first oil inlet and return channel (1a) connected to the internal valve conduction channel (122a) when the rotary valve core (122) rotates. The piston rod (2) is provided with an axially extending second rod inner channel (321). The head end of the piston rod (2) is provided with a second external channel (2b) connecting the second rod inner channel (321) and the outside. The telescopic cylinder also includes a second core (42). One end of the second core (42) is disposed on the rotary valve core (122) and connected to the valve inner conduction channel (122a). The other end passes through the second rod inner channel (321) from the bottom end of the piston rod (2).

2. The telescopic hydraulic cylinder according to claim 1, characterized in that, The second core (42) is in sliding sealing fit with the bottom end of the piston rod (2).

3. The telescopic hydraulic cylinder according to claim 2, characterized in that, The cylinder (1) is also provided with an independent inlet and return oil pipeline (14). One end of the independent inlet and return oil pipeline (14) is connected to the rod chamber (Y) of the cylinder (1), and the other end is connected to the first inlet and return oil channel (1a). A one-way valve (15) is provided between the first inlet and return oil channel (1a) and the independent inlet and return oil pipeline (14). The one-way valve (15) is configured to open when hydraulic oil flows from the independent inlet and return oil pipeline (14) to the first inlet and return oil channel (1a) and close in the reverse direction.

4. The telescopic hydraulic cylinder according to claim 3, characterized in that, The piston rod (2) is provided with a hollow rod cavity (221). One end of the hollow rod cavity (221) is connected to the rod cavity (Y) of the cylinder (1), and the other end is connected to the second external channel (2b). The head of the piston rod (2) is provided with a stroke valve (33). The working valve port of the stroke valve (33) is connected to the hollow rod cavity (221) and the second external channel (2b). The stroke valve (33) is configured to control the hollow rod cavity (221) and the second external channel (2b) to conduct when the valve core of the stroke valve (33) is displaced by a preset distance.

5. The telescopic hydraulic cylinder according to claim 4, characterized in that, The hollow rod cavity (221) is provided with an axially extending first cavity tube (31) and second cavity tube (32). The first rod inner channel (311) is the cavity of the first cavity tube (31), and the second rod inner channel (321) is the cavity of the second cavity tube (32). The first tube core (41) is inserted from the bottom end of the piston rod (2) and slides into the first cavity tube (31). The second tube core (42) is inserted from the bottom end of the piston rod (2) and slides into the second cavity tube (32).

6. The telescopic hydraulic cylinder according to any one of claims 1 to 5, characterized in that, One end of the first tube core (41) is fixedly installed on the side of the rotary valve core (122) facing the cylinder body (11), and the other end of the first tube core (41) extends into the inner channel (311) of the first rod.

7. A multi-cylinder sequential telescopic hydraulic system, characterized in that, The multi-cylinder sequential telescopic hydraulic system includes: The first-stage hydraulic cylinder (S1) is the telescopic hydraulic cylinder according to any one of claims 1 to 6; A secondary hydraulic cylinder (S2), wherein the rodless chamber (W) of the secondary hydraulic cylinder (S2) is connected to the first external channel (2a) of the primary hydraulic cylinder (S1); and The rod chamber working channel is used to supply oil to and from the rod chamber (Y) of the first-stage cylinder (S1) and the second-stage cylinder (S2).

8. The multi-cylinder sequential telescopic hydraulic system according to claim 7, characterized in that, The first-stage cylinder (S1) has a first inlet / outlet oil channel (1a) at the bottom of the cylinder barrel (1). The piston rod (2) of the first-stage cylinder (S1) has an axially extending second rod inner channel (321). The head end of the piston rod (2) has a second external channel (2b) connecting the second rod inner channel (321) and the outside. The second external channel (2b) is used to communicate with the rod chamber (Y) of the second-stage cylinder (S2). The first-stage cylinder (S1) also includes a second core (42), which is mounted on the cylinder barrel (1). One end is connected to the first oil inlet and return channel (1a), and the other end of the second core (42) passes through the second rod inner channel (321) from the bottom end of the piston rod (2). The cylinder (1) of the first-stage cylinder (S1) is also provided with an independent oil inlet and return pipeline (14). The independent oil inlet and return pipeline (14) is connected to the rod chamber (Y) of the cylinder (1) of the first-stage cylinder (S1) and the first oil inlet and return channel (1a). A one-way valve (15) is provided between the first oil inlet and return channel (1a) and the independent oil inlet and return pipeline (14). The rod cavity working channel includes the first oil inlet and return channel (1a), the second rod inner channel (321), the second external channel (2b), the second core (42), and the independent oil inlet and return pipeline (14).

9. The multi-cylinder sequential telescopic hydraulic system according to claim 8, characterized in that, The piston rod (2) of the first-stage cylinder (S1) is provided with a hollow rod cavity (221). One end of the hollow rod cavity (221) is connected to the rod cavity (Y) of the cylinder (1) of the first-stage cylinder (S1), and the other end is connected to the second external channel (2b). The head of the piston rod (2) of the first-stage cylinder (S1) is provided with a stroke valve (33). The working valve port of the stroke valve (33) is connected to the hollow rod cavity (221) and the second external channel (2b). The stroke valve (33) is configured to control the hollow rod cavity (221) and the second external channel (2b) to be connected when the valve core of the stroke valve (33) is displaced by a preset distance. The valve core of the stroke valve (33) is used to make transmission contact with the piston rod (2) of the secondary cylinder (S2) when the piston rod (2) of the secondary cylinder (S2) retracts to the preset position.

10. The multi-cylinder sequential telescopic hydraulic system according to claim 7, characterized in that, The secondary cylinder (S2) is a telescopic cylinder as described in any one of claims 1 to 6. The multi-cylinder sequential telescopic hydraulic system further includes a tertiary cylinder (S3). The rodless chamber (W) of the tertiary cylinder (S3) is connected to the first external channel (2a) of the secondary cylinder (S2). The working channel of the rod chamber is also used to supply oil to and from the rod chamber (Y) of the tertiary cylinder (S3).

11. A telescopic engineering machine, characterized in that, Includes the multi-cylinder sequential telescopic hydraulic system according to any one of claims 7 to 10.

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