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

Abstract

The invention belongs to the technical field of engineering machinery and provides a telescopic oil cylinder, a multi-cylinder sequential telescopic hydraulic system and telescopic engineering machinery. The telescopic oil cylinder comprises a cylinder barrel, a piston rod and a first pipe core, a first rod inner channel extending in the axial direction is formed in the piston rod, the head end of the piston rod is further provided with a first external connection channel communicating with the first rod inner channel and the outside, the first pipe core is installed on the cylinder barrel, and one end of the first pipe core axially penetrates into the first rod inner channel from the bottom end of the piston rod. An oil passing hole is further formed in the circumferential wall of the first pipe core, an oil passing channel communicated with the oil passing hole and the first rod inner channel is formed in the first pipe core, and the oil passing hole is used for being exposed out of the bottom end of the piston rod when the piston rod extends to the preset length. Through cooperation of the channel in the first rod, the first pipe core and the oil passing hole and the oil passing channel in the first pipe core, sequential extending driving of the multiple oil cylinders can be achieved, dependence on a sequence valve is avoided, and therefore the purpose of reducing heating and energy consumption of a system is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery, and in particular relates to a telescopic oil cylinder, a multi-cylinder sequential telescopic hydraulic system and a telescopic engineering machinery. Background Art

[0002] The existing sequential telescopic hydraulic system realizes sequential telescopic operation by connecting sequential valves in series between multiple cylinders. Specifically, Figure 1 As shown, in the existing multi-stage oil cylinder, when the pressure oil enters from the rodless chamber oil port A of the first oil cylinder 01, it will act on the rodless chamber of the first oil cylinder 01, and at the same time act on the first sequence valve 04 through the oil channel C in the piston rod of the first oil cylinder 01. The system pressure reaches the load pressure of the first oil cylinder 01, but does not reach the opening pressure of the first sequence valve 04. The first sequence valve 04 cannot be opened, and the pressure oil cannot enter the second oil cylinder 02. The piston rod of the first oil cylinder 01 extends, and the oil in the rod chamber returns from the B port.

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

[0004] Because the load of each cylinder is different, in order to achieve sequential extension and retraction, it is necessary to set the pressure of each sequence valve through experiments, which makes debugging very troublesome. At the same time, when the system is working, a large part of the oil pressure is lost when the sequence valve is opened, causing the system to heat up or the end cylinder to be unable to extend. Summary of the invention

[0005] In view of the above-mentioned defects or shortcomings, the present invention provides a telescopic cylinder, a multi-cylinder sequential telescopic hydraulic system and a telescopic engineering machinery, aiming to solve the technical problem that the existing multi-stage cylinders need to use sequential valves to achieve sequential extension of multiple cylinders.

[0006] To achieve the above-mentioned purpose, the present invention provides a telescopic oil cylinder, wherein the telescopic oil cylinder includes a cylinder barrel, a piston rod and a first tube core, the piston rod is slidably arranged in the cylinder barrel and an axially extending first rod inner channel is provided in the rod, the head end of the piston rod is also provided with a first external channel connecting the first rod inner channel and the outside world, the first tube core is installed on the cylinder barrel and one end of the first tube core is axially inserted into the first rod inner channel from the bottom end of the piston rod, the first tube core is slidingly sealed with the bottom end of the piston rod, an oil hole is also provided on the peripheral wall of the first tube core, an oil passage connecting the oil hole and the first rod inner channel is provided in the first tube core, and the oil hole is used to be exposed from the bottom end of the piston rod when the piston rod is extended to a preset length.

[0007] In an embodiment of the present invention, a first oil inlet and return channel is provided at the bottom end of the cylinder barrel, an axially extending second rod inner channel is provided in the piston rod, a second external channel connecting the second rod inner channel and the outside is provided at the head end of the piston rod, and the telescopic oil cylinder also includes a second tube core, which is installed on the cylinder barrel and one end of which is connected to the first oil inlet and return channel, and the other end of the second tube core penetrates into the second rod inner channel from the bottom end of the piston rod, the second tube core connects the first oil inlet and return channel and the second rod inner channel, and the second tube core is in sliding sealing cooperation with the bottom end of the piston rod.

[0008] In an embodiment of the present invention, an independent oil inlet and return pipeline is also provided on the cylinder barrel, one end of the independent oil inlet and return pipeline is connected to the rod chamber of the cylinder barrel, and the other end is connected to the first oil inlet and return channel. A one-way valve is provided between the first oil inlet and return channel and the independent oil inlet and return pipeline, and the one-way valve is configured to be turned on when the hydraulic oil flows from the independent oil inlet and return pipeline to the first oil inlet and return channel and to be blocked in the reverse direction.

[0009] In an embodiment of the present invention, a hollow rod cavity is provided in 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, and the working valve port of the stroke valve connects the hollow rod cavity and the second external channel. The stroke valve is configured to control the connection between the hollow rod cavity and the second external channel when the valve core of the stroke valve is displaced a preset distance.

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

[0011] In an embodiment of the present invention, the cylinder includes a cylinder body and a cylinder base arranged at the bottom end of the cylinder body and used to seal the bottom end opening of the cylinder body, the cylinder base includes a seat body and a rotating valve core coaxially rotatably arranged in the seat body, one end of the first tube core is fixedly installed on the side of the rotating valve core facing the cylinder body, and the other end of the first tube core extends into the channel inside the first rod.

[0012] To achieve the above-mentioned 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 the telescopic cylinder described above, the rodless chamber of the secondary cylinder is connected to the first external channel of the primary cylinder, and the rod chamber working channel is used to supply oil to and from the rod chambers of the primary cylinder and the secondary cylinder.

[0013] In an embodiment of the present invention, a first oil inlet and return channel is provided at the bottom end of the cylinder barrel of the first-level oil cylinder, an axially extending second rod inner channel is provided in the piston rod of the first-level oil cylinder, a second external channel connecting the second rod inner channel and the outside is provided at the head end of the piston rod, and the second external channel is used to connect with the rod chamber of the second-level oil cylinder. The first-level oil cylinder also includes a second pipe core, which is installed on the cylinder barrel and one end of which is connected with the first oil inlet and return channel, and the other end of the second pipe core penetrates into the second rod inner channel from the bottom end of the piston rod. An independent oil inlet and return pipeline is also provided on the cylinder barrel of the first-level oil cylinder, and the independent oil inlet and return pipeline is connected to the rod chamber of the cylinder barrel of the first-level oil cylinder and the first oil inlet and return channel, and a one-way valve is provided between the first oil inlet and return channel and the independent oil inlet and return pipeline; wherein, the rod chamber working channel includes the first oil inlet and return channel, the second rod inner channel, the second external channel, the second pipe core, and the independent oil inlet and return pipeline.

[0014] In an embodiment of the present invention, a hollow rod cavity is provided in the piston rod of the first-stage oil cylinder, one end of the hollow rod cavity is connected to the rod cavity of the cylinder barrel of the first-stage oil cylinder, and the other end is connected to the second external channel. A stroke valve is provided at the head of the piston rod of the first-stage oil cylinder, and the working valve port of the stroke valve connects the hollow rod cavity and the second external channel. The stroke valve is configured to control the connection between the hollow rod cavity and the second external channel when the valve core of the stroke valve is displaced a preset distance; wherein the valve core of the stroke valve is used to transmit contact with the piston rod of the second-stage oil cylinder when the piston rod of the second-stage oil cylinder is retracted to a preset position.

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

[0016] To achieve the above object, the present invention further provides a telescopic engineering machinery, wherein the telescopic engineering machinery comprises the multi-cylinder sequential telescopic hydraulic system described above.

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

[0018] By controlling the oil inflow into the rodless chamber of the telescopic oil cylinder, the piston rod of the telescopic oil cylinder can be pushed to extend, and the extension of the piston rod will cause the first rod inner channel to slide relative to the first tube core. When the piston rod is extended to a certain position, the oil hole of the first tube core will leak out from the first rod inner channel and be placed in the rodless chamber. At this time, the pressure oil entering the rodless chamber from the outside can pass through the oil hole, the oil channel, the first rod inner channel, the first external channel, and the first external pipeline in sequence to enter the rodless chamber of the next-level oil cylinder, thereby realizing the extension drive of the next-level oil cylinder. In summary, the telescopic oil cylinder of the present invention can only perform the extension drive of the next-level oil cylinder when the extension length of the piston rod of the telescopic oil cylinder reaches a preset length through the cooperation of the first rod inner channel, the first tube core, and the oil hole and oil channel on the first tube core. This not only realizes the sequential extension drive between multiple oil cylinders, but also gets rid of the dependence on the sequential valve, thereby achieving the purpose of reducing system heat and energy consumption.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide an understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0021] In the figure:

[0022] Figure 1 is a connection diagram of a sequential telescopic hydraulic system of the background technology;

[0023] Figure 2 is a schematic structural diagram of a telescopic oil cylinder according to an embodiment of the present invention;

[0024] Figure 3 is a structural schematic diagram of the bottom end of the telescopic oil cylinder according to an embodiment of the present invention;

[0025] Figure 4 is a connection diagram of a two-cylinder sequential telescopic hydraulic system according to an embodiment of the present invention;

[0026] Figure 5 Schematic diagram of the connection of a three-cylinder sequential telescopic hydraulic system according to an embodiment of the present invention.

[0027] BACKGROUND ART DESCRIPTION OF REFERENCE NUMERALS

[0028] 01, first oil cylinder; 02, second oil cylinder; 03, third oil cylinder; 04, first sequence valve; 05, second sequence valve.

[0029] DESCRIPTION OF NUMBERS FOR THE EMBODIMENTS OF THE PRESENT INVENTION

[0030] 1. Cylinder barrel; 11. Cylinder body; 12. Cylinder base; 121. Seat body; 122. Rotating valve core; 122a. Valve internal conducting channel; 122b. Annular oil channel; 123. End cover; 13. Guide sleeve; 14. Independent oil inlet and return pipeline; 15. Check valve; 1a. First oil inlet and return channel; 1b. Second oil inlet and return channel; 2. Piston rod; 21. Piston body; 22. Rod body; 221. Hollow rod cavity; 2a. First external channel; 2 b, second external channel; 2c, first working oil port; 2d, second working oil port; 31, first cavity tube; 311, first rod inner channel; 32, second cavity tube; 321, second rod inner channel; 33, travel valve; 41, first tube core; 411, oil hole; 42, second tube core; 51, first external pipeline; 52, second external pipeline; S1, first-stage oil cylinder; S2, second-stage oil cylinder; S3, third-stage oil cylinder; W, rodless chamber; Y, rod chamber. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] The telescopic cylinder of the present invention will be described below with reference to the accompanying drawings.

[0033] like Figure 2 , Figure 4 and Figure 5 As shown, the telescopic oil cylinder provided by the present invention includes a cylinder barrel 1, a piston rod 2 and a first tube core 41.

[0034] The piston rod 2 is slidably arranged in the cylinder barrel 1 and divides the inner cavity of the cylinder barrel 1 into a rod cavity Y and a rodless cavity W. The rodless cavity W is close to the bottom end of the cylinder barrel 1, and the rod cavity Y is close to the head end of the cylinder barrel 1. The piston rod 2 is provided with an axially extending first rod inner channel 311. The head end of the piston rod 2 extending out of the cylinder barrel 1 is also provided with a first external channel 2a connecting the first rod inner channel 311 and the outside world. The first external channel 2a is used to connect with the rodless cavity W pipeline of the next-level oil cylinder. The first external channel 2a is arranged at the head end of the piston rod 2, so as to facilitate external pipeline connection.

[0035] The first tube core 41 is installed on the cylinder barrel 1. One end of the first tube core 41 axially passes through the rodless cavity W and the bottom end of the piston rod 2, and finally penetrates into the first rod inner channel 311. The first tube core 41 and the bottom end of the piston rod 2 are slidingly sealed, that is, the first tube core 41 can slide axially relative to the first rod inner channel 311. An oil hole 411 is also provided on the peripheral wall of the first tube core 41, and an oil passage connecting the oil hole 411 and the first rod inner channel 311 is provided in the first tube core 41. The oil hole 411 is located in the first rod inner channel 311 when the telescopic cylinder is in the retracted state, and the oil hole 411 is used to be exposed from the bottom end of the piston rod 2 when the piston rod 2 is extended to a preset length.

[0036] By connecting the first external channel 2a of the telescopic oil cylinder of the present invention with the rodless chamber W of the next-stage oil cylinder, a multi-cylinder sequential telescopic hydraulic system with a sequential extension function can be formed.

[0037] Specifically, by controlling the oil inflow into the rodless chamber W of the telescopic oil cylinder, the piston rod 2 of the telescopic oil cylinder can be pushed to extend, and the extension of the piston rod 2 will cause the first rod inner channel 311 to slide relative to the first tube core 41. When the piston rod 2 is extended to a certain position, the oil hole 411 of the first tube core 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 hole 411, the oil channel, the first rod inner channel 311, the first external channel 2a, and the first external pipeline in sequence to enter the rodless chamber W of the next-level oil cylinder, thereby realizing the extension drive of the next-level oil 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 hole 411 and the oil channel on the first tube core 41, can only drive the next-level cylinder to extend when the extension length of the piston rod 2 of the telescopic cylinder reaches a preset length. It not only realizes the sequential extension drive between multiple cylinders, but also gets rid of the dependence on the sequential valve, thereby achieving the purpose of reducing system heat and energy consumption.

[0038] In the embodiment of the present invention, the first external pipeline 51 refers to a pipeline connecting the first external channel 2a and the rodless chamber W of the next stage oil cylinder.

[0039] It is understandable that the cylinder barrel 1 needs to be provided with a second oil inlet and return passage 1b for supplying oil to and from the rodless chamber W of the telescopic oil cylinder, so as to ensure that the hydraulic oil can smoothly enter the rodless chamber W of the telescopic oil cylinder. When the telescopic oil cylinder and other oil cylinders form a multi-cylinder sequential telescopic hydraulic system, a rod chamber working passage needs to be provided to supply oil to and from the rod chamber Y of the telescopic oil cylinder and the next-level oil cylinder. The rod chamber working passage can be integrated in the telescopic oil cylinder or can be an external pipeline.

[0040] Take the integrated rod cavity working channel as an example. Figure 2 , Figure 4 and Figure 5As shown, in the embodiment of the present invention, the bottom end of the cylinder barrel 1 may be provided with a first oil inlet and return channel 1a, the piston rod 2 may be provided with an axially extending second rod inner channel 321, and the head end of the piston rod 2 may be provided with a second external channel 2b connecting the second rod inner channel 321 and the outside, and the second external channel 2b is used to connect with the rod chamber Y of the next-stage oil cylinder. For example, the second external channel 2b can be connected with the rod chamber Y of the next-stage oil cylinder through a second external pipe 52.

[0041] like Figure 2 , Figure 4 and Figure 5 As shown, the telescopic oil cylinder may also include a second tube core 42, which is mounted on the cylinder barrel 1 and one end of which is connected to the first oil inlet and return channel 1a, and the other end of the second tube core 42 penetrates from the bottom end of the piston rod 2 into the second rod inner channel 321, the second tube core 42 connects the first oil inlet and return channel 1a and the second rod inner channel 321, and the second tube core 42 is in sliding sealing cooperation with the bottom end of the piston rod 2. Among them, the first oil inlet and return channel 1a, the second rod inner channel 321, the second external channel 2b, and the second tube core 42 constitute the rod chamber working channel of the next-level oil cylinder.

[0042] After the telescopic oil cylinder is extended to the right position, the extension drive of the next oil cylinder will be carried out. During the extension process of the next oil cylinder, the hydraulic oil in the rod chamber Y of the next oil cylinder can be returned through the second external pipe 52, the second external channel 2b, the second rod internal channel 321, and the first oil inlet and return channel 1a in sequence, and the oil is returned to the rod chamber Y of the next oil cylinder, thereby ensuring the normal extension of the oil cylinder. Integrating the working channel of the rod chamber on the telescopic oil cylinder can increase the integration of the pipeline.

[0043] like Figure 2 As shown, for the oil return of the rod chamber Y of the telescopic oil cylinder, an independent oil inlet and return pipeline 14 can be set on the cylinder barrel 1 of the telescopic oil cylinder. One end of the independent oil inlet and return pipeline 14 can be connected to the rod chamber Y of the cylinder barrel 1, and the other end is connected to the first oil inlet and return channel 1a. A one-way valve 15 needs to be set between the first oil inlet and return channel 1a and the independent oil inlet and return pipeline 14. The one-way valve 15 is configured to be conductive when the hydraulic oil flows from the independent oil inlet and return pipeline 14 to the first oil inlet and return channel 1a, and to be cut off in the reverse direction. By setting the one-way valve 15, the oil flowing back from the rod chamber Y of the next-level oil cylinder to the first oil inlet and return channel 1a can be prevented from flowing to the independent oil inlet and return pipeline 14.

[0044] like Figure 1 As shown, in the existing sequential telescopic system composed of multiple cylinders, each cylinder can only realize that the cylinder with less force moves first or three cylinders move at the same time, and sequential retraction cannot be achieved.

[0045] In order to realize the sequential retraction of multiple oil cylinders, the present invention further improves the structure of the telescopic oil cylinders.

[0046] like Figure 2 , Figure 3 and Figure 4 As shown, in the embodiment of the present invention, a hollow rod chamber 221 is provided in the piston rod 2, one end of the hollow rod chamber 221 is connected to the rod chamber Y of the cylinder 1, and the other end is connected to the second external channel 2b. A travel valve 33 is provided at the head of the piston rod 2, and the working valve port of the travel valve 33 connects the hollow rod chamber 221 and the second external channel 2b. The travel valve 33 is configured to control the hollow rod chamber 221 to be connected to the second external channel 2b when the valve core of the travel valve 33 is displaced by a preset distance. By setting the position of the valve core of the travel valve 33, the valve core can be pushed to move when the next-level oil cylinder retracts to a preset position (such as retracted to the full position), so that the hollow rod chamber 221 is connected to the second external channel 2b.

[0047] 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 oil port 2c and a second working oil port 2d corresponding to the two working oil ports of the travel valve 33 respectively, the first working oil port 2c is connected to the second external channel 2b, and the second working oil port 2d is connected to the hollow rod cavity 221. By controlling the displacement of the valve core, the first working oil port 2c and the second working oil port 2d can be made conductive, thereby realizing the connection between the hollow rod cavity 221 and the second external channel 2b.

[0048] Take the action of pushing the valve core when the next-level oil cylinder retracts to the correct position as an example. Figure 2 , Figure 3 and Figure 4 As shown, when the multi-cylinder sequential telescopic hydraulic system composed of a telescopic cylinder and a next-level cylinder retracts, the first oil inlet and return channel 1a is first controlled to enter the 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 pass through the first oil inlet and return channel 1a, the second tube core 42, the second rod inner channel 321, the second external channel 2b, and the second external pipeline to enter the rod chamber Y of the next-level cylinder, thereby driving the next-level cylinder to retract. When the next-level cylinder retracts, the hydraulic oil in the rodless chamber W of the next-level cylinder can return oil through the first external pipeline, the first external channel 2a, the first rod inner channel 311, the oil passage channel of the first tube core 41, the oil passage hole 411 of the first tube core 41, the rodless chamber W of the telescopic cylinder, and the second oil inlet and return channel 1b of the telescopic cylinder.

[0049] When the next-stage oil cylinder retracts to the 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 in the first oil inlet and return channel 1a will pass through the first oil inlet and return channel 1a, the second tube core 42, the second rod inner channel 321, and the hollow rod cavity 221 into the rod cavity Y of the telescopic oil cylinder, thereby realizing the retraction drive of the telescopic oil cylinder.

[0050] In summary, the telescopic cylinder of the present invention can realize the sequential retraction of the telescopic cylinder and the next-stage cylinder by providing an empty rod chamber connected to the rod chamber Y and the second external channel 2b and providing a stroke valve 33.

[0051] In the embodiment of the present invention, the stroke valve 33 may also be an electrically controlled valve. When the next-stage oil cylinder is retracted to its position, the stroke valve 33 is controlled by a controller to actuate, thereby realizing a sequential retraction function.

[0052] like Figure 1 and Figure 2 As shown, in the 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 in the cylinder barrel 1 and divides the inner cavity of the cylinder barrel 1 into a rod cavity Y and a rodless cavity W. The rod body 22 is detachably mounted on the piston rod 2 and the head end extends from the head end of the cylinder barrel 1. The piston rod 2 and the head end of the cylinder barrel 1 are also provided with a guide sleeve 13 to guide the extension and retraction of the rod body 22.

[0053] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, there are many ways to form the first rod inner channel 311, the second rod inner channel 321, and the hollow rod cavity 221. For example, the rod body 22 can be a hollow tube, the rod body 22 is provided with a hollow rod cavity 221, the hollow rod cavity 221 is provided with 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 first rod inner channel 311 is the cavity of the second cavity tube 32. The piston body 21 is also provided with two axially penetrating through holes, and the two through holes are respectively aligned with the first cavity tube 31 and the second cavity tube 32. The first tube core 41 penetrates from one of the through holes of the piston rod 2 and slides into the first cavity tube 31, and the second tube core 42 penetrates from 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 oil cylinder, and the cavity tube can ensure that the first rod inner channel 311, the second rod inner channel 321 and the hollow rod cavity 221 are independent of each other.

[0054] Of course, in the embodiment of the present invention, the first rod inner channel 311, the second rod inner channel 321, and the hollow rod cavity 221 may also be channels that are independent of each other and extend axially.

[0055] In the embodiment of the present invention, the first tube core 41 , the second tube core 42 and the piston body 21 need to be in sealed contact to avoid oil cross-talk between the channels.

[0056] In the embodiment of the present invention, a hole having a rod cavity Y of the telescopic oil cylinder may be opened on the peripheral wall of the rod body 22 .

[0057] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the cylinder barrel 1 includes a barrel body 11 and a cylinder base 12 disposed at the bottom end of the barrel body 11 and used to block the bottom end opening of the barrel 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, one end of the first tube core 41 is fixedly mounted on the side of the rotary valve core 122 facing the barrel body 11, and the other end extends into the first rod inner channel 311. Similarly, the installation method of the second tube core 42 can be the same as the installation method 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 be allowed to drive the first tube core 41 and the second tube core 42 to rotate together in the cylinder barrel 1, thereby facilitating the assembly of the telescopic oil cylinder and preventing damage to the tube core when the piston rod 2 is hoisted and twisted.

[0058] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, since the second tube core 42 needs to be connected to the first oil inlet and return channel 1a, it is necessary to set an in-valve conducting channel 122a and an annular oil channel 122b on the rotating valve core 122 to maintain the conduction between the second tube core 42 and the first oil inlet and return channel 1a when the rotating valve core 122 rotates.

[0059] In the embodiment of the present invention, an end cover 123 is further provided on the side of the cylinder base 12 facing away from the cylinder barrel 1 .

[0060] To achieve the above-mentioned purpose, the present invention further provides a multi-cylinder sequential telescopic hydraulic system, which includes a primary oil cylinder S1, a secondary oil cylinder S2 and a rod chamber working channel. The primary oil cylinder S1 can be the telescopic oil cylinder described above, and the secondary oil cylinder S2 can be the telescopic oil cylinder of the present invention or a common oil cylinder. When connected, the rodless chamber W of the secondary oil cylinder S2 needs to be connected to the first external channel 2a of the primary oil cylinder S1, and the multi-cylinder sequential telescopic hydraulic system also needs to be provided with a rod chamber working channel for supplying and returning oil to the rod chamber Y of the primary oil cylinder S1 and the secondary oil cylinder S2.

[0061] Specifically, Figure 2 and Figure 4 As shown, a two-cylinder sequential telescopic hydraulic system consisting of a telescopic cylinder and a common cylinder is taken as an example, the two cylinders refer to the primary cylinder S1 and the secondary cylinder S2 respectively, and the primary cylinder S1 is the telescopic cylinder of the present invention.

[0062] When the two-cylinder sequential telescopic hydraulic system needs to be extended sequentially, the oil inlet of the second oil inlet and return channel 1b of the first-stage oil cylinder S1 is controlled first, and the pressure oil of the second oil inlet and return channel 1b will first enter the rodless chamber W of the first-stage oil cylinder S1 to drive the piston rod 2 of the first-stage oil cylinder S1 to extend. When the first-stage oil cylinder S1 is extended, the oil in the rod chamber Y of the first-stage oil cylinder S1 can be returned through the independent oil inlet and return pipeline 14 and the first oil inlet and return channel 1a.

[0063] When the piston rod 2 of the primary oil cylinder S1 is extended to a preset length (the preset length may refer to the primary oil cylinder S1 being extended to the desired position), the oil hole 411 will leak out from the first rod inner channel 311 and be placed in the rodless chamber W of the primary oil cylinder S1. At this time, the pressure oil in the rodless chamber W of the primary oil cylinder S1 can sequentially pass through the oil hole 411, the oil passage, the first rod inner channel 311, the first external channel 2a, and the first external pipe 51 to enter the rodless chamber W of the secondary oil cylinder S2, thereby realizing the extension drive of the secondary oil cylinder S2. When the secondary oil cylinder S2 is extended, the oil in the rod chamber Y of the secondary oil cylinder S2 can sequentially pass through the second external pipe 52, the second external channel 2b, the second rod inner channel 321, and the first oil inlet and return channel 1a for oil return.

[0064] Through the above operations, the first-stage oil cylinder S1 and the second-stage oil cylinder S2 can be extended in sequence.

[0065] When the two-cylinder sequential telescopic hydraulic system needs to retract, the first oil inlet and return channel 1a of the first-stage oil cylinder S1 is controlled to enter the oil. Due to the presence of the one-way valve 15, the pressure oil in the first oil inlet and return channel 1a will first pass through the first oil inlet and return channel 1a, the second tube core 42, the second rod inner channel 321, the second external channel 2b, and the second external pipeline 52 to enter the rod chamber Y of the second-stage oil cylinder S2, thereby driving the second-stage oil cylinder S2 to retract. The hydraulic oil in the rodless chamber W of the second-stage oil cylinder S2 can be returned through the first external pipeline 51, the first external channel 2a, the first rod inner channel 311, the oil passage channel of the first tube core 41, the oil passage hole 411 of the first tube core 41, the rodless chamber W of the telescopic oil cylinder, and the second oil inlet and return channel 1b of the telescopic oil cylinder.

[0066] After the secondary oil cylinder S2 is retracted to the position, the piston rod 2 of the secondary oil cylinder S2 will push the valve core of the travel valve 33 to move, and at this time the hollow rod chamber 221 will be connected with the second external channel 2b. After the hollow rod chamber 221 is connected with the second external channel 2b, the pressure oil of the first oil inlet and return channel 1a will pass through the first oil inlet and return channel 1a, the second tube core 42, the second rod inner channel 321, and the hollow rod chamber 221 to enter the rod chamber Y of the telescopic oil cylinder, thereby realizing the retraction drive of the telescopic oil cylinder.

[0067] Through the above operations, the secondary oil cylinder S2 and the primary oil cylinder S1 can be retracted in sequence.

[0068] Take the three-cylinder sequential telescopic hydraulic system consisting of two telescopic cylinders and one ordinary cylinder as an example. Figure 2 and Figure 5 As shown, the three cylinders refer to the primary cylinder S1, the secondary cylinder S2 and the tertiary cylinder S3 respectively. Both the primary cylinder S1 and the secondary cylinder S2 are telescopic cylinders of the present invention.

[0069] The first external channel 2a and the second external channel 2b of the first-stage oil cylinder S1 are connected to the first oil inlet and return channel 1a and the second oil inlet and return channel 1b of the second-stage oil cylinder S2 through two external pipes, respectively. The first external channel 2a and the second external channel 2b of the second-stage oil cylinder S2 are connected to the rodless chamber W and the rod chamber Y of the third-stage oil cylinder S3 through two external pipes, respectively.

[0070] When extending, the oil inlet of the second oil inlet and return channel 1b of the primary oil cylinder S1 is controlled first, and the pressure oil of the second oil inlet and return channel 1b will first enter the rodless chamber W of the primary oil cylinder S1 to drive the piston rod 2 of the primary oil cylinder S1 to extend. When the primary oil cylinder S1 is extended, the oil in the rod chamber Y of the primary oil cylinder S1 can be returned through the independent oil inlet and return pipeline 14 of the primary oil cylinder S1 and the first oil inlet and return channel 1a of the primary oil cylinder S1.

[0071] When the piston rod 2 of the primary oil cylinder S1 is extended to a preset length (the preset length may refer to the primary oil cylinder S1 being extended to the full length), the oil hole 411 will leak out from the first rod inner channel 311 and be placed in the rodless chamber W of the primary oil cylinder S1. At this time, the pressure oil in the rodless chamber W of the primary oil cylinder S1 can enter the rodless chamber W of the secondary oil cylinder S2 through the oil hole 411 of the primary oil cylinder S1, the oil passage, the first rod inner channel 311, the first external channel 2a, the first external pipeline, and the second oil inlet and return channel 1b of the secondary oil cylinder S2 in sequence, thereby extending the secondary oil cylinder S2. When the secondary oil cylinder S2 is extended, the hydraulic oil in the rod chamber Y of the secondary oil cylinder S2 can enter the second external channel 2b of the primary oil cylinder S1 through the independent oil inlet and return pipeline 14 of the secondary oil cylinder S2 and the first oil inlet and return channel 1a of the secondary oil cylinder S2, and then return the oil through the second rod inner channel 321 and the first oil inlet and return channel 1a of the primary oil cylinder S1 in sequence.

[0072] After the secondary cylinder S2 is extended into place, the pressure oil in the rodless chamber W of the secondary cylinder S2 can pass through the oil hole 411 of the secondary cylinder S2, the oil channel, the first rod inner channel 311, the first external channel 2a, the first external pipeline, and the rodless chamber W of the tertiary cylinder S3 in sequence to realize the extension of the tertiary cylinder S3.

[0073] The principle of sequential retraction of the three-cylinder sequential telescopic hydraulic system is the same as that of the two-cylinder sequential telescopic hydraulic system, and will not be repeated here.

[0074] In an embodiment of the present invention, the multi-cylinder sequential telescopic hydraulic system may also be composed of more telescopic cylinders connected in series.

[0075] To achieve the above object, the present invention further provides a telescopic engineering machine, wherein the telescopic engineering machine comprises the multi-cylinder sequential telescopic hydraulic system described above. The telescopic engineering machine may be a crane, a telescopic boom aerial work vehicle, etc. Since the telescopic engineering machine adopts all the technical solutions of the above embodiments, it at least has the beneficial effects brought by the above embodiments, which will not be repeated here.

[0076] In the description of the present invention, it should be understood that 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0077] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] 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.

[0079] Although the embodiments of the present invention have been described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A telescopic cylinder, characterized in that: The telescopic cylinder comprises: Cylinder (1); A piston rod (2) is slidably disposed in the cylinder (1) and is provided with a first rod inner channel (311) extending axially therein, and a first external channel (2a) is further provided at the head end of the piston rod (2) for connecting the first rod inner channel (311) with the outside; A first tube core (41) is mounted on the cylinder barrel (1) and one end of which axially penetrates into the first rod inner channel (311) from the bottom end of the piston rod (2). The first tube core (41) is in sliding sealing cooperation with the bottom end of the piston rod (2). An oil hole (411) is also provided on the peripheral wall of the first tube core (41). An oil passage connecting the oil hole (411) and the first rod inner channel (311) is provided in the first tube core (41). The oil hole (411) is used to be exposed from the bottom end of the piston rod (2) when the piston rod (2) is extended to a preset length.

2. The telescopic cylinder according to claim 1, characterized in that: The bottom end of the cylinder barrel (1) is provided with a first oil inlet and return passage (1a), the piston rod (2) is provided with an axially extending second rod inner passage (321), the head end of the piston rod (2) is provided with a second external passage (2b) connecting the second rod inner passage (321) and the outside, the telescopic oil cylinder also includes a second tube core (42), the second tube core (42) is mounted on the cylinder barrel (1) and one end of the second tube core (42) is connected to the first oil inlet and return passage (1a), the other end of the second tube core (42) penetrates into the second rod inner passage (321) from the bottom end of the piston rod (2), the second tube core (42) is used to connect the first oil inlet and return passage (1a) and the second rod inner passage (321), and the second tube core (42) is in sliding sealing cooperation with the bottom end of the piston rod (2).

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

4. The telescopic cylinder according to claim 3, characterized in that: A hollow rod chamber (221) is provided in the piston rod (2), one end of the hollow rod chamber (221) is connected to the rod chamber (Y) of the cylinder (1), and the other end is connected to the second external channel (2b). A travel valve (33) is provided at the head of the piston rod (2), and a working valve port of the travel valve (33) connects the hollow rod chamber (221) and the second external channel (2b). The travel valve (33) is configured to control the hollow rod chamber (221) and the second external channel (2b) to be connected when the valve core of the travel valve (33) moves a preset distance.

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

6. The telescopic cylinder according to any one of claims 1 to 5, characterized in that: The cylinder barrel (1) comprises a barrel body (11) and a cylinder base (12) arranged at the bottom end of the barrel body (11) and used to seal the bottom end opening of the barrel body (11); the cylinder base (12) comprises a seat body (121) and a rotary valve core (122) coaxially rotatably arranged in the seat body (121); one end of the first tube core (41) is fixedly mounted on a side of the rotary valve core (122) facing the barrel body (11); the other end of the first tube core (41) extends into the first rod inner channel (311).

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

8. The multi-cylinder sequential telescopic hydraulic system according to claim 7, characterized in that: The bottom end of the cylinder barrel (1) of the first-stage oil cylinder (S1) is provided with a first oil inlet and return channel (1a); the piston rod (2) of the first-stage oil cylinder (S1) 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 second external channel (2b) is used to communicate with the rod chamber (Y) of the second-stage oil cylinder (S2); the first-stage oil cylinder (S1) further comprises a second tube core (42), and the second tube core (42) is mounted on the cylinder barrel (1). One end of the second pipe core (42) is connected to the first oil inlet and return passage (1a), and the other end of the second pipe core (42) penetrates into the second rod inner passage (321) from the bottom end of the piston rod (2). An independent oil inlet and return pipeline (14) is also provided on the cylinder barrel (1) of the first oil cylinder (S1). The rod chamber (Y) of the independent oil inlet and return pipeline (14) connected to the cylinder barrel (1) of the first oil cylinder (S1) is connected to the first oil inlet and return passage (1a). A one-way valve (15) is provided between the first oil inlet and return passage (1a) and the independent oil inlet and return pipeline (14); The rod chamber working channel includes the first oil inlet and return channel (1a), the second rod inner channel (321), the second external channel (2b), the second pipe 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: A hollow rod chamber (221) is provided in the piston rod (2) of the first-stage oil cylinder (S1), one end of the hollow rod chamber (221) is connected to the rod chamber (Y) of the cylinder barrel (1) of the first-stage oil cylinder (S1), and the other end is connected to the second external channel (2b). A travel valve (33) is provided at the head of the piston rod (2) of the first-stage oil cylinder (S1), and a working valve port of the travel valve (33) connects the hollow rod chamber (221) and the second external channel (2b). The travel valve (33) is configured to control the hollow rod chamber (221) to be connected to the second external channel (2b) when the valve core of the travel valve (33) is displaced by a preset distance; The valve core of the travel valve (33) is used for transmission contact with the piston rod (2) of the secondary oil cylinder (S2) when the piston rod (2) of the secondary oil cylinder (S2) is retracted to a preset position.

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

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

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