Multi-section hydraulic oil cylinder

Abstract

The invention relates to the technical field of hydraulic oil cylinders, in particular to a multi-section type hydraulic oil cylinder which comprises a first oil-saving cylinder and a second oil-saving cylinder which are connected in series, a first cooling spiral pipe and a second cooling spiral pipe are designed, and a double-layer pipeline structure is adopted in a spiral pipeline, namely the first cooling spiral pipe and the second cooling spiral pipe. Fluid in the first outer pipeline and the second outer pipeline exchanges heat with fluid in the first inner pipeline and fluid in the second inner pipeline, the fluid in the first outer pipeline and the fluid in the second outer pipeline take away heat in the cylinder barrel, and the temperature of the fluid in the first outer pipeline and the temperature of the fluid in the second outer pipeline are reduced through heat exchange of the fluid in the first inner pipeline and the fluid in the second inner pipeline. The first cooling spiral pipe and the second cooling spiral pipe can be cooled continuously, the sustainable cooling effect is improved, meanwhile, the specific flow channel structures of the first cooling spiral pipe and the second cooling spiral pipe are designed, the heat exchange efficiency is improved, the oil cylinder is protected to be in the normal use state, and the service life of the oil cylinder is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic cylinders, and in particular to a multi-section hydraulic cylinder. Background Art

[0002] Aerial work lighting is a lighting device designed for aerial work environments. It is usually equipped with a liftable light pole to meet the lighting needs of different heights. This type of lighting has high brightness, a wide lighting range and good stability, which can ensure sufficient light during aerial work and improve work efficiency and safety. Aerial work lighting needs to provide lighting at different heights to adapt to different working environments. By lifting the light pole, the lighting height can be flexibly adjusted to ensure that the light can cover the required area. In aerial work environments, the stability and safety of lighting are crucial. The lifting light pole can ensure that the lighting equipment keeps a safe distance from the operator to avoid safety accidents caused by the fall of the lighting equipment. The hydraulic cylinder can provide stable power output, making the lifting and lowering process of the lifting rod smooth, which is very important for aerial work lighting because it needs to provide stable lighting at different heights.

[0003] The patent with application number CN201720832529.9 discloses a double-stroke limit hydraulic cylinder, which includes a cylinder head, a cylinder barrel, a piston rod, a first piston, a second piston and a cylinder bottom, wherein the cylinder head and the cylinder bottom are respectively fixed to the two ends of the cylinder barrel, the piston rod is movably arranged in the cylinder barrel, the first piston and the second piston are arranged on the piston rod at intervals and located in the cylinder barrel, the cross-sectional diameter of the first piston is greater than the cross-sectional diameter of the second piston, a first cavity is formed between the first piston and the cylinder head, a second cavity is formed between the second piston and the first piston, a third cavity is formed between the second piston and the cylinder bottom, and the first cavity, the second cavity and the third cavity are all connected to an oil pressure circuit. The above-mentioned double-stroke limit hydraulic cylinder can realize double-stroke limit of the piston rod. Not only is the structure simple and easy to implement; but also the cost is low and the operation is stable and reliable. However, in the use environment of high-altitude work lighting, the hydraulic cylinder will generate a lot of heat during operation, and because the metal heats up when it is at high altitude and exposed to direct sunlight in midsummer, coupled with the heat generated by the long-distance expansion and contraction of the cylinder, a large amount of heat will be generated during use. When the cylinder temperature is too high, it is easy to cause a cylinder explosion accident. Summary of the invention

[0004] The present invention provides a multi-section hydraulic cylinder, a first section cylinder and a second section cylinder connected in series, and by designing a first cooling spiral tube and a second cooling spiral tube, effective cooling is achieved when the multiple sections of the cylinders are connected in series, so as to protect the cylinders in a normal use state and increase the service life of the cylinders.

[0005] And design a specific flow channel structure to achieve cooling of the fluid through fluid flow control.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: a multi-section hydraulic cylinder, comprising a first section cylinder and a second section cylinder connected in series, the first section cylinder being provided with a first jacking oil inlet, a first jacking oil outlet, a first retraction oil inlet and a first retraction oil outlet, the second section cylinder being provided with a second jacking oil inlet, a second jacking oil outlet, a second retraction oil inlet and a second retraction oil outlet, the first jacking oil outlet being connected to the second jacking oil inlet, the first retraction oil outlet being connected to the second retraction oil inlet, the outer wall of the first section cylinder being covered with a first cooling spiral tube, and the second A second cooling spiral tube is wound around the outer wall of the fuel-saving cylinder, the first cooling spiral tube includes a first inner tube and a first outer tube, the second cooling spiral tube includes a second inner tube and a second outer tube, the first inner tube is connected to the second inner tube via a water pipe, the first outer tube is connected to the second outer tube via a water pipe, the first inner tube and the second inner tube are both connected to a first external water tank via a water pipe, the first outer tube and the second outer tube are both connected to a second external water tank via a water pipe, and the temperature of the fluid pumped out of the second external water tank is controlled to be lower than the temperature of the fluid pumped out of the first external water tank.

[0007] As a preferred embodiment of the present invention, the first inner pipe is provided with a first inner water inlet and a first inner water outlet, and the first outer pipe is provided with a first outer water outlet and a first outer water inlet; the second cooling spiral pipe includes a second inner pipe and a second outer pipe, the second inner pipe is provided with a second inner water inlet and a second inner water outlet, and the second outer pipe is provided with a second outer water outlet and a second outer water inlet; wherein, the first inner water inlet is connected to the first external water tank, the first inner water outlet is connected to the second inner water inlet, the second inner water outlet is connected to the first external water tank, the first outer water inlet is connected to the second external water tank, the first outer water outlet is connected to the second outer water inlet, and the second outer water outlet is connected to the second external water tank; The first inner pipe is arranged at a side of the first outer pipe away from the nearest cylinder, and the second inner pipe is arranged at a side of the second outer pipe away from the nearest cylinder.

[0008] As a preferred embodiment of the present invention, the inner cavity of the first outer pipe and the outer wall of the first inner pipe form a first type of annular spacing space, and a spiral rib is provided on the inner wall of the first outer pipe close to the inner wall of the first outer pipe, and the spiral rib forms a first inner disturbance portion in the first type of annular spacing space; the inner cavity of the second outer pipe and the outer wall of the second inner pipe form a first type of annular spacing space, and a spiral rib is provided on the inner wall of the second outer pipe close to the inner wall of the second outer pipe, and the spiral rib forms a second inner disturbance portion in the second type of annular spacing space.

[0009] As a preferred embodiment of the present invention, the outer wall of the first inner pipe is provided with a plurality of arc-shaped shallow grooves, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral ribs; the outer wall of the second inner pipe is provided with a plurality of arc-shaped shallow grooves, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral ribs.

[0010] As a preferred embodiment of the present invention, a longitudinal protrusion arranged along the spiral direction of the first outer pipe is provided on the inner wall of the first outer pipe away from the cylinder, and the longitudinal protrusion forms a plurality of longitudinal corrugated grooves, and the longitudinal corrugated grooves form a first outer vortex portion in the first type of annular interval space; the first outer channel water outlet is arranged on the first outer pipe and is located on the side of the first inner disturbance portion; a longitudinal protrusion arranged along the spiral direction of the second outer pipe is provided on the inner wall of the second outer pipe away from the cylinder, and the longitudinal protrusion forms a plurality of longitudinal corrugated grooves, and the longitudinal corrugated grooves form a second outer vortex portion in the second type of annular interval space; the second outer channel water outlet is arranged on the outer pipe and is located on the side of the second inner disturbance portion.

[0011] As a preferred embodiment of the present invention, the longitudinal protrusion includes a uniform flat section and a disturbance enhanced section connected to each other, in the vertical direction, the uniform flat section is arranged below the disturbance enhanced section, the uniform flat section is a spiral rib structure with a uniform spiral lead, and the disturbance enhanced section is a spiral rib structure with a lead gradually decreasing upward.

[0012] As a preferred embodiment of the present invention, a disturbance groove is provided in the longitudinal corrugated groove, and the disturbance groove is a human-shaped groove.

[0013] As a preferred embodiment of the present invention, the ratio of the area of ​​the second inner disturbance portion to the area of ​​the first inner disturbance portion is 1:N+1, wherein N is the number of the second oil cylinders.

[0014] As a preferred embodiment of the present invention, the first oil cylinder and the second oil cylinder both include a cylinder barrel, a cylinder bottom, a cylinder cover, a piston and a piston rod, the piston rod is slidably arranged in the cylinder barrel, the piston is arranged between the piston rod and the cylinder barrel, an oil inlet pipe is arranged in the inner cavity of the piston rod, an enclosed inner retraction oil passage is formed between the oil inlet pipe and the inner cavity of the piston rod, an oil storage chamber is arranged between the piston and the cylinder bottom; an enclosed outer retraction oil passage is formed between the piston rod and the cylinder barrel, a spacer is arranged on the outer periphery of the piston rod near the piston, the thickness of the spacer is less than the thickness of the outer retraction oil passage, and the thickness of the spacer is 0.6-0.85 times the thickness of the outer retraction oil passage.

[0015] As a preferred embodiment of the present invention, a gathering portion is recessed inwardly at the connection between the piston rod and the spacer sleeve, and a thickness of the gathering portion is equal to 2-3 times the distance from the spacer sleeve to the inner wall of the cylinder.

[0016] In summary, the present invention has the following beneficial effects.

[0017] 1. The first section of the oil cylinder and the second section of the oil cylinder connected in series solve the problem of lifting the lamp pole for the searchlight used for high-altitude operations. Due to high-altitude operations, multiple sections of oil cylinders need to be connected in series to realize the lifting function. By adopting a double-layer pipe structure in the spiral pipe, namely the first cooling spiral pipe and the second cooling spiral pipe, the fluid in the first outer pipe and the second outer pipe respectively exchanges heat with the fluid in the first inner pipe and the second inner pipe, and the fluid in the first outer pipe and the second outer pipe takes away the heat in the cylinder barrel. The heat exchange of the fluid in the first inner pipe and the second inner pipe reduces the temperature of the fluid in the first outer pipe and the second outer pipe, so that the first cooling spiral pipe and the second cooling spiral pipe can continuously cool down, thereby improving the sustainable cooling effect.

[0018] 2. During retraction, when the first oil cylinder retracts or the first oil cylinder retracts together with the second oil cylinder, the first cooling spiral tube does not move, and the second cooling spiral tube moves downward on the vertical plane. The potential energy of the fluid in the second cooling spiral tube (including the fluid in the second inner pipe and the fluid in the second outer pipe) is converted into mechanical energy (pressure energy), which is applied to the fluid in the connected first cooling spiral tube. Therefore, the area ratio of the second inner disturbance part to the first inner disturbance part is set to 1:N+1, where N is the number of the second oil cylinder. The first is that there is enough water in the first inner disturbance part to withstand the pushing force given by it, and at the same time, it flows from the first inner disturbance part to the second inner disturbance part. Due to the increase in potential energy, more thrust is required. When the design cross-section becomes smaller, the fluid can be lifted with less force.

[0019] 3. Set the thickness of the spacer. When the thickness of the spacer is too small, the graded push and retraction cannot be completed, and the effect of saving fuel and reducing pressure cannot be achieved. When a larger retraction thrust is needed, more hydraulic oil is needed. When the compression of the hydraulic oil is too large, and because the use environment of the technical solution of the present application is suitable for high-altitude work lighting, high-altitude work lighting usually needs to work for a long time at high altitudes, and the heat dissipation conditions may not be as good as on the ground. If the heat dissipation design is improper, heat accumulation will cause the equipment temperature to rise, further increasing the possibility of high-pressure cylinder explosion and increasing the cost of use. Once a fault occurs, it will affect normal production work and may even cause personnel safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the appearance structure of the first section of the oil cylinder in the present invention.

[0022] Figure 2 It is a cross-sectional schematic diagram of the first section of the oil cylinder in the retracted state in the present invention.

[0023] Figure 3 It is a cross-sectional schematic diagram of the first oil cylinder (excluding the first cooling spiral tube) in the present invention in the jacking state.

[0024] Figure 4 It is a cross-sectional schematic diagram of the second section of the oil cylinder in the retracted state in the present invention.

[0025] Figure 5 It is a cross-sectional schematic diagram of the second oil cylinder (excluding the second cooling spiral tube) in the present invention in the jacking state.

[0026] Figure 6 It is a schematic cross-sectional view of the first cooling spiral tube in the present invention.

[0027] Figure 7 It is a schematic vertical cross-sectional view of the first cooling spiral tube in the present invention.

[0028] Figure 8 It is a schematic diagram of the inner wall of the first outer pipe of the first cooling spiral pipe in the present invention.

[0029] Fig. 9 It is a schematic cross-sectional view of the second cooling spiral tube in the present invention.

[0030] Fig.10 It is a schematic vertical cross-sectional view of the second cooling spiral tube in the present invention.

[0031] Fig.11 It is a schematic diagram of the inner wall of the first outer pipe of the second cooling spiral pipe in the present invention.

[0032] Fig.12 This is a connection block diagram of the first cooling spiral tube, the second cooling spiral tube, the first external water tank and the second external water tank of the present invention.

[0033] In the figure: 1, cylinder barrel, 2, cylinder bottom, 3, cylinder head, 4, piston, 5, piston rod, 6, oil inlet pipe, 7, inner retraction oil passage, 8, outer retraction oil passage, 9, spacer, 10, gathering part, 11, first lifting oil inlet, 12, first lifting oil outlet, 13, first retraction oil inlet, 14, first retraction oil outlet, 15, second lifting oil inlet, 16, second lifting oil outlet, 17, second retraction oil inlet, 18, second retraction oil outlet, 19, oil storage chamber, 20, spacer oil inlet passage, 21, rod oil inlet passage, 22, first external water tank, 23, second external water tank; a, first oil cylinder, a1, first cooling spiral tube, a2, first inner pipeline, a3, first an outer pipe, a4, a first inner channel water inlet, a5, a first inner channel water outlet, a6, a first outer channel water outlet, a7, a first outer channel water inlet, a8, a first inner disturbance portion, a9, a first outer vortex portion; b, a second oil cylinder, b1, a second cooling spiral tube, b2, a second inner pipe, b3, a second outer pipe, b4, a second inner channel water inlet, b5, a second inner channel water outlet, b6, a second outer channel water outlet, b7, a second outer channel water inlet, b8, a second inner disturbance portion, b9, a second outer vortex portion; l, spiral ribs; z, longitudinal protrusions, z1, longitudinal corrugated grooves, z2, uniform and gentle sections, z3, disturbance enhancement sections, z4, disturbance grooves; g, shallow grooves. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings.

[0035] Embodiment 1

[0036] The first section of the oil cylinder a and at least one second section of the oil cylinder b connected in series solve the problem of lifting and lowering the lamp pole used for high-altitude operation searchlights. Due to high-altitude operations, multiple sections of oil cylinders need to be connected in series to realize the lifting function. Moreover, when the high-altitude searchlight is used, the descending and retraction distance is too large. During the retraction process, kinetic energy generates heat and the potential energy of the lamp pole is converted into kinetic energy and frictional heat, which will generate excessive heat and gas, which is easy to explode and cause safety accidents.

[0037] See attached Figure 1 To Attachment Fig.12As shown (where the dotted line with an arrow is the direction of fluid flow), at least a first section of oil cylinder a and a second section of oil cylinder b are connected in series. Among them, the number of second section of oil cylinder b is at least 1. The first section of oil cylinder a is provided with a first jacking oil inlet 11, a first jacking oil outlet 12, a first retracting oil inlet 13 and a first retracting oil outlet 14, and the second section of oil cylinder b is provided with a second jacking oil inlet 15, a second jacking oil outlet 16, a second retracting oil inlet 17 and a second retracting oil outlet 18. The first jacking oil outlet 12 is connected to the second jacking oil inlet 15, and the first retracting oil outlet 14 is connected to the second retracting oil inlet 17. When the second-section oil cylinder b is in the series state, the second lifting oil outlet 16 and the second retracting oil outlet 18 are in a blocked state. When there is a second second-section oil cylinder b, the second lifting oil outlet 16 is connected to the second lifting oil inlet 15 of the next second-section oil cylinder b, and the second retracting oil outlet 18 is connected to the second retracting oil inlet 17 of the next second-section oil cylinder b. When there is only one second-section oil cylinder b, the second lifting oil outlet 16 and the second retracting oil outlet 18 are blocked.

[0038] A multi-section hydraulic cylinder comprises a first section cylinder a and a second section cylinder b which are connected in series. The first section cylinder a is provided with a first lifting oil inlet 11, a first lifting oil outlet 12, a first retracting oil inlet 13 and a first retracting oil outlet 14. The second section cylinder b is provided with a second lifting oil inlet 15, a second lifting oil outlet 16, a second retracting oil inlet 17 and a second retracting oil outlet 18. The first lifting oil outlet 12 is connected to the second lifting oil inlet 15, the first retracting oil outlet 14 is connected to the second retracting oil inlet 17. The outer wall of the first section cylinder a is covered with a first cooling spiral tube a1, and the outer wall of the second section cylinder b is covered with a The second cooling spiral tube b1, the first cooling spiral tube a1 includes a first inner tube a2 and a first outer tube a3, the second cooling spiral tube b1 includes a second inner tube b2 and a second outer tube b3, the first inner tube a2 is connected to the second inner tube b2 through a water pipe, the first outer tube a3 is connected to the second outer tube b3 through a water pipe, the first inner tube a2 and the second inner tube b2 are both connected to the first external water tank 22 through a water pipe, the first outer tube a3 and the second outer tube b3 are both connected to the second external water tank 23 through a water pipe, and the temperature of the fluid pumped out of the second external water tank 23 is controlled to be lower than the temperature of the fluid pumped out of the first external water tank 22. By adopting a double-layer pipe structure in the spiral pipes, namely the first cooling spiral pipe a1 and the second cooling spiral pipe b1, the fluids in the first outer pipe a3 and the second outer pipe b3 exchange heat with the fluids in the first inner pipe a2 and the second inner pipe b2 respectively, and the fluids in the first outer pipe a3 and the second outer pipe b3 take away the heat in the cylinder. The heat exchange of the fluids in the first inner pipe a2 and the second inner pipe b2 reduces the temperature of the fluids in the first outer pipe a3 and the second outer pipe b3, so that the first cooling spiral pipe a1 and the second cooling spiral pipe b1 can sustainably cool down, thereby improving the sustainable cooling effect.

[0039] The first inner channel water inlet a4 is connected to the first external water tank 22 through a water pipe and a water pump, and the fluid in the first external water tank 22 is pumped into the first cooling spiral tube a1 through the water pump and the water pipe. The second inner channel water outlet b5 is connected to the first external water tank 22 through a water pipe and a water pump, and the water pump pumps the fluid that has completed the heat absorption work in the second cooling spiral tube b1 to the first external water tank 22.

[0040] The first inner pipe a2 is provided with a first inner water inlet a4 and a first inner water outlet a5, and the first outer pipe a3 is provided with a first outer water outlet a6 and a first outer water inlet a7. The second cooling spiral pipe b1 includes a second inner pipe b2 and a second outer pipe b3, the second inner pipe b2 is provided with a second inner water inlet b4 and a second inner water outlet b5, and the second outer pipe b3 is provided with a second outer water outlet b6 and a second outer water inlet b7. Among them, the first inner water inlet a4 is connected to the first external water tank 22, the first inner water outlet a5 is connected to the second inner water inlet b4, the second inner water outlet b5 is connected to the first external water tank 22, the first outer water inlet a7 is connected to the second water tank, the first outer water outlet a6 is connected to the second outer water inlet b7, and the second outer water outlet b6 is connected to the second external water tank 23.

[0041] The first inner pipe a2 is arranged on the side of the first outer pipe a3 away from the nearest cylinder 1, and the second inner pipe b2 is arranged on the side of the second outer pipe b3 away from the nearest cylinder 1. During retraction, when the first section oil cylinder a retracts or the first section oil cylinder a and the second section oil cylinder b retract together, the first cooling spiral pipe a1 does not move, and the second cooling spiral pipe b1 moves downward on the vertical plane. The potential energy of the fluid in the second cooling spiral pipe b1 (including the fluid in the second inner pipe b2 and the fluid in the second outer pipe b3) is converted into mechanical energy (pressure energy), which is applied to the fluid pushing force in the connected first cooling spiral pipe a1, so the area ratio of the second inner disturbance part b8 to the first inner disturbance part a8 is set to 1:N+1, where N is the number of the second section oil cylinders b. The first is that there is enough water in the first inner disturbance part a8 to withstand the pushing force given by it. At the same time, it flows from the first inner disturbance part a8 to the second inner disturbance part b8. Due to the increase in potential energy, more thrust is required. When the designed cross-section becomes smaller, the fluid can be lifted with less force.

[0042] The inner cavity of the first outer pipe a3 and the outer wall of the first inner pipe a2 form a first type of annular space, and a spiral rib 1 is provided on the inner wall of the first outer pipe a3 near the inner wall of the first outer pipe a3, and the spiral rib 1 forms a first inner disturbance part a8 in the first type of annular space. The inner cavity of the second outer pipe b3 and the outer wall of the second inner pipe b2 form a first type of annular space, and a spiral rib 1 is provided on the inner wall of the second outer pipe b3 near the inner wall of the second outer pipe b3, and the spiral rib 1 forms a second inner disturbance part b8 in the second type of annular space. By adding a spiral rib structure to the inner wall of the spiral pipe, the presence of the rib can not only strengthen the disturbance of the water flow, but also effectively increase the heat exchange inside. Enhance turbulent flow and improve the heat transfer efficiency between the fluid and the inner wall of the pipe.

[0043] The outer wall of the first inner pipe a2 is provided with a plurality of arc-shaped shallow grooves g, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral rib l. The outer wall of the second inner pipe b2 is provided with a plurality of arc-shaped shallow grooves g, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral rib l. The spiral flow channel on the inner wall of the vortex pipe can be designed as a series of shallow grooves, the shape of which can make the water flow produce a vortex effect (similar to the effect of enhancing heat exchange) when flowing along the pipe. This design can not only increase the contact area between the fluid and the pipe wall, but also improve the efficiency of heat exchange. Make the water flow produce more disturbances and improve heat transfer.

[0044] The inner wall of the first outer pipe a3 is provided with a longitudinal protrusion z arranged along the spiral direction of the first outer pipe a3 on the side away from the cylinder 1, and the longitudinal protrusion z forms a plurality of longitudinal corrugated grooves z1, and the longitudinal corrugated grooves z1 form a first outer vortex portion a9 in the first type of annular interval space. The first outer channel water outlet a6 is arranged on the first outer pipe a3 and is located on the side of the first inner disturbance portion a8. The inner wall of the second outer pipe b3 is provided with a longitudinal protrusion z arranged along the spiral direction of the second outer pipe b3 on the side away from the cylinder 1, and the longitudinal protrusion z forms a plurality of longitudinal corrugated grooves z1, and the longitudinal corrugated grooves z1 form a second outer vortex portion b9 in the second type of annular interval space. The second outer channel water outlet b6 is arranged on the outer pipe and is located on the side of the second inner disturbance portion b8. The structure increases the disturbance formed by the fluid by adding corrugations to the inner wall of the pipe, which helps to improve the efficiency of the heat exchange. The corrugated structure can be arranged along the spiral direction of the pipe, with longitudinal corrugations. Each corrugation disrupts the laminar flow state of the water flow, so that the fluid generates vortices during the flow process, thereby enhancing the heat exchange. Increase the contact area between the fluid and the pipe wall and improve the heat exchange coefficient.

[0045] The longitudinal protrusion z includes a uniform and gentle section z2 and a disturbance enhanced section z3 which are connected to each other. In the vertical direction, the uniform and gentle section z2 is arranged below the disturbance enhanced section z3. The uniform and gentle section z2 is a spiral rib structure with a uniform spiral lead, and the disturbance enhanced section z3 is a spiral rib l structure with a lead gradually decreasing upward.

[0046] A disturbance groove z4 is provided in the longitudinal corrugated groove z1, and the disturbance groove z4 is a human-shaped groove. By designing the disturbance groove z4, the fluid can flow smoothly when pumping water to the first outer pipe a3 or the second outer pipe b3, ensuring efficient execution of subsequent heat transfer.

[0047] The ratio of the area of ​​the second inner disturbance portion b8 to the area of ​​the first inner disturbance portion a8 is 1:N+1, where N is the number of the second section oil cylinders b.

[0048] The first section oil cylinder a and the second section oil cylinder b both include a cylinder barrel 1, a cylinder bottom 2, a cylinder cover 3, a piston 4, and a piston rod 5. The piston rod 5 is slidably arranged in the cylinder barrel 1. A piston 4 is arranged between the piston rod 5 and the cylinder barrel 1. An oil inlet pipe 14 is arranged in the inner cavity of the piston rod 5. An enclosed inner retraction oil channel 7 is formed between the oil inlet pipe 14 and the inner cavity of the piston rod 5. An oil storage chamber 19 is arranged between the piston 4 and the cylinder bottom 2. The oil storage chamber 19 is always filled with hydraulic oil to facilitate the smooth progress of subsequent lifting and retraction pushing work.

[0049] The thickness of the spacer sleeve 9 is less than the thickness of the outer retraction oil passage 8, and the thickness of the spacer sleeve 9 is 0.6-0.85 times the thickness of the outer retraction oil passage 8. The specific thickness ratio is calculated based on the telescopic distance of the overall oil cylinder. When the thickness of the spacer sleeve 9 is too small, the graded push retraction cannot be completed, and the effect of saving oil and reducing pressure cannot be achieved. When a larger retraction thrust is required, more hydraulic oil is required. When the hydraulic oil is compressed too much, and because the use environment of the technical solution of this application is suitable for high-altitude work lighting, high-altitude work lighting usually needs to work for a long time at high altitudes, and the heat dissipation conditions may not be as good as on the ground. If the heat dissipation design is improper, heat accumulation will cause the equipment temperature to rise, further increasing the possibility of high-pressure cylinder explosion and increasing the cost of use. Once a failure occurs, it will affect normal production work and may even cause personnel safety hazards.

[0050] The connection between the piston rod 5 and the spacer sleeve 9 is inwardly recessed to provide a gathering portion 10 , and the thickness of the gathering portion 10 is equal to 2-3 times the distance from the spacer sleeve 9 to the inner wall of the cylinder barrel 1 .

[0051] The central axis of the spacer oil inlet channel 20 and the central axis of the rod body oil inlet channel 21 are arranged in parallel, and the central axis of the spacer oil inlet channel 20 is located in the rod body oil inlet channel 21. The spacer oil inlet channel 20 and the spacer oil inlet channel 20 are arranged to overlap only partially in area under horizontal projection, so that the hydraulic oil can smoothly enter the gap between the spacer 9 and the piston rod 5 after passing through the spacer oil inlet channel 20 and fill it, when the spacer oil inlet channel 20 and the spacer oil inlet channel 20 overlap under horizontal projection, the hydraulic oil may directly enter the inner retraction oil channel 7 through the spacer oil inlet channel 20 after passing through the spacer oil inlet channel 20, so that the retraction work cannot be performed efficiently. Furthermore, when the hydraulic oil fills the gap between the spacer 9 and the piston rod 5, this part of the hydraulic oil is tested for pressure on the part of the piston 4 between the spacer 9 and the piston rod 5 in the process of continuous hydraulic oil entering in the later stage, pushing the piston 4 to retract, which is equivalent to the secondary use of the hydraulic oil, improving the retraction push effect.

[0052] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "front and back", "left and right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the invention.

[0053] Of course, in the present technical solution, those skilled in the art should understand that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0054] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art under the technical guidance of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A multi-section hydraulic cylinder, comprising a first section cylinder (a) and a second section cylinder (b) connected in series, wherein the first section cylinder (a) is provided with a first lifting oil inlet (11), a first lifting oil outlet (12), a first retracting oil inlet (13) and a first retracting oil outlet (14), and the second section cylinder (b) is provided with a second lifting oil inlet (15), a second lifting oil outlet (16), a second retracting oil inlet (17) and a second retracting oil outlet (18), the first lifting oil outlet (12) is connected to the second lifting oil inlet (15), and the first retracting oil outlet (14) is connected to the second retracting oil inlet (17), characterized in that: The first oil cylinder (a) has an outer wall covered with a first cooling spiral tube (a1) wound around it, and the second oil cylinder (b) has an outer wall covered with a second cooling spiral tube (b1) wound around it, the first cooling spiral tube (a1) includes a first inner tube (a2) and a first outer tube (a3), the second cooling spiral tube (b1) includes a second inner tube (b2) and a second outer tube (b3), the first inner tube (a2) is connected to the second inner tube (b2) via a water pipe, the first outer tube (a3) ​​is connected to the second outer tube (b3) via a water pipe, the first inner tube (a2) and the second inner tube (b2) are both connected to a first external water tank (22) via a water pipe, the first outer tube (a3) ​​and the second outer tube (b3) are both connected to a second external water tank (23) via a water pipe, and the temperature of the fluid pumped out of the second external water tank (23) is controlled to be lower than the temperature of the fluid pumped out of the first external water tank (22).

2. A multi-section hydraulic cylinder according to claim 1, characterized in that: The first inner pipe (a2) is provided with a first inner water inlet (a4) and a first inner water outlet (a5), and the first outer pipe (a3) ​​is provided with a first outer water outlet (a6) and a first outer water inlet (a7); the second cooling spiral pipe (b1) comprises a second inner pipe (b2) and a second outer pipe (b3), the second inner pipe (b2) is provided with a second inner water inlet (b4) and a second inner water outlet (b5), and the second outer pipe (b3) is provided with a second outer water outlet (b6) and a second outer water inlet (b7). b7); wherein the first inner water inlet (a4) is connected to the first external water tank (22), the first inner water outlet (a5) is connected to the second inner water inlet (b4), the second inner water outlet (b5) is connected to the first external water tank (22), the first outer water inlet (a7) is connected to the second external water tank (23), the first outer water outlet (a6) is connected to the second outer water inlet (b7), and the second outer water outlet (b6) is connected to the second external water tank (23); The first inner pipe (a2) is arranged on a side of the first outer pipe (a3) ​​away from the nearest cylinder (1), and the second inner pipe (b2) is arranged on a side of the second outer pipe (b3) away from the nearest cylinder (1).

3. A multi-section hydraulic cylinder according to claim 2, characterized in that: The inner cavity of the first outer pipe (a3) ​​and the outer wall of the first inner pipe (a2) form a first type of annular space, and a spiral rib (l) is provided on the inner wall of the first outer pipe (a3) ​​close to the inner wall of the first outer pipe (a3), and the spiral rib (l) forms a first inner disturbance portion (a8) in the first type of annular space; the inner cavity of the second outer pipe (b3) and the outer wall of the second inner pipe (b2) form a first type of annular space, and a spiral rib (l) is provided on the inner wall of the second outer pipe (b3) close to the inner wall of the second outer pipe (b3), and the spiral rib (l) forms a second inner disturbance portion (b8) in the second type of annular space.

4. A multi-section hydraulic cylinder according to claim 3, characterized in that: The outer wall of the first inner pipe (a2) is provided with a plurality of arc-shaped shallow grooves, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral rib (l); the outer wall of the second inner pipe (b2) is provided with a plurality of arc-shaped shallow grooves, and the distance between the upper and lower arc-shaped shallow grooves is adapted to the lead setting of the spiral rib (l).

5. A multi-section hydraulic cylinder according to claim 2, characterized in that: The inner wall of the first outer pipe (a3) ​​is provided with a longitudinal protrusion (z) arranged along the spiral direction of the first outer pipe (a3) ​​on the side away from the cylinder (1), and the longitudinal protrusion (z) forms a plurality of longitudinal corrugated grooves (z1), and the longitudinal corrugated grooves (z1) form a first outer vortex portion (a9) in the first type of annular interval space; the first outer channel water outlet (a6) is provided on the first outer pipe (a3) ​​and is located on the side of the first inner disturbance portion (a8); the inner wall of the second outer pipe (b3) is provided with a longitudinal protrusion (z) arranged along the spiral direction of the second outer pipe (b3) on the side away from the cylinder (1), and the longitudinal protrusion (z) forms a plurality of longitudinal corrugated grooves (z1), and the longitudinal corrugated grooves (z1) form a second outer vortex portion (b9) in the second type of annular interval space; the second outer channel water outlet (b6) is provided on the outer pipe and is located on the side of the second inner disturbance portion (b8).

6. A multi-section hydraulic cylinder according to claim 5, characterized in that: The longitudinal protrusion (z) comprises a uniform flat section (z2) and a disturbance enhancement section (z3) which are connected to each other. In the vertical direction, the uniform flat section (z2) is arranged below the disturbance enhancement section (z3). The uniform flat section (z2) is a spiral rib structure with a uniform spiral lead, and the disturbance enhancement section (z3) is a spiral rib (l) structure with a lead that gradually decreases upward.

7. A multi-section hydraulic cylinder according to claim 6, characterized in that: A disturbance groove (z4) is provided in the longitudinal corrugated groove (z1), and the disturbance groove (z4) is a human-shaped groove.

8. The multi-section hydraulic cylinder according to claim 3, characterized in that: The ratio of the area of ​​the second inner disturbance portion (b8) to the area of ​​the first inner disturbance portion (a8) is (N+1):1, where N is the number of the second oil cylinders (b).

9. The multi-section hydraulic cylinder according to claim 1, characterized in that: The first oil-section cylinder (a) and the second oil-section cylinder (b) both comprise a cylinder barrel (1), a cylinder bottom (2), a cylinder cover (3), a piston (4) and a piston rod (5); the piston rod (5) is slidably arranged in the cylinder barrel (1); the piston (4) is arranged between the piston rod (5) and the cylinder barrel (1); an oil inlet pipe (6) is arranged in the inner cavity of the piston rod (5); an enclosed inner retraction oil passage (7) is formed between the oil inlet pipe (6) and the inner cavity of the piston rod (5); an oil storage chamber is arranged between the piston (4) and the cylinder bottom (2); an enclosed outer retraction oil passage (8) is formed between the piston rod (5) and the cylinder barrel (1); a spacer (9) is arranged on the outer circumference of the piston rod (5) near the piston (4); the thickness of the spacer (9) is less than the thickness of the outer retraction oil passage (8), and the thickness of the spacer (9) is 0.6 to 0.85 times the thickness of the outer retraction oil passage (8).

10. A multi-section hydraulic cylinder according to claim 9, characterized in that: A gathering portion (10) is provided inwardly at the connection between the piston rod (5) and the spacer sleeve (9), and the thickness of the gathering portion (10) is equal to 2-3 times the distance from the spacer sleeve (9) to the inner wall of the cylinder barrel (1).

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