Telescopic oil cylinder of crane

Abstract

The utility model relates to the technical field of telescopic oil cylinders, in particular to a telescopic oil cylinder of a crane. According to the technical scheme, the hydraulic cylinder comprises a cylinder body, a piston rod and a movable head, a sealing piston is slidably connected into the cylinder body, the piston rod is fixed to the sealing piston, the end of the piston rod penetrates through the cylinder body and is fixedly provided with the movable head, a main oil hole is formed in the center of the piston rod, and auxiliary oil holes are formed in the piston rod and located on the periphery of the main oil hole. A main oil pipe and an auxiliary oil pipe are fixed to the positions, corresponding to the main oil hole and the auxiliary oil hole, of the movable head respectively, a rotating column is rotationally connected into the movable head, a connecting hole is formed in the rotating column and is of a T-shaped structure, and a one-way valve is installed at an opening in the middle of the connecting hole. By means of one-way flowing of the one-way valve, it can be guaranteed that hydraulic oil can only flow in the designated direction, the risk that the piston rod stretches out and draws back reversely due to overload is reduced, and use safety of the telescopic oil cylinder is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of telescopic oil cylinders, in particular to a telescopic oil cylinder for a crane. Background Art

[0002] Telescopic cylinder is a specially designed hydraulic cylinder with a structure consisting of multiple sleeves and pistons, which can achieve a larger stroke and a smaller installation space. It is often used in applications that require a larger stroke, such as lifting equipment, excavators, truck cranes, etc.

[0003] The main working principle of the telescopic cylinder is to use a hydraulic pump to drive the hydraulic oil to flow in a directional manner, thereby causing the piston rod to perform telescopic movement. In this process, the safety of the telescopic cylinder for the crane is extremely important. During use, if an overload occurs, it will cause the output end of the telescopic cylinder to move in the reverse direction, thereby causing accidental risks. However, if the hydraulic oil is in the cylinder and cannot flow in the reverse direction, even if an overload occurs, the output end of the cylinder will not move in the reverse direction if the hydraulic oil does not flow back, thereby ensuring safety in use. Therefore, it is necessary to design an anti-backflow structure. Utility Model Content

[0004] The utility model aims to solve the problems existing in the background technology and proposes a telescopic oil cylinder for a crane.

[0005] The technical solution of the utility model: a telescopic oil cylinder of a crane comprises a cylinder body, a piston rod and a movable head, a sealing piston is slidably connected in the cylinder body, the piston rod is fixed on the sealing piston, the end of the piston rod passes through the cylinder body and is fixed with a movable head, a main oil hole is opened at the center of the piston rod, a secondary oil hole is opened in the piston rod and located at the periphery of the main oil hole, a main oil pipe and a secondary oil pipe are respectively fixed on the movable head at positions corresponding to the main oil hole and the secondary oil hole, a rotating column is rotatably connected in the movable head, a connecting hole is opened in the rotating column, the connecting hole is a T-shaped structure, and a one-way valve is installed at the opening in the middle, a driving box is fixed on the outside of the movable head, a driving assembly is arranged in the driving box, the main oil hole passes through the sealing piston, and the secondary oil hole is located at the side wall on the front side of the sealing piston and an overflow hole is opened.

[0006] Preferably, three connecting holes are provided and are respectively located between the main oil hole and the main oil pipe and between the auxiliary oil hole and the auxiliary oil pipe.

[0007] Preferably, a sealing sleeve is fixed to the outer side wall of the rotating column to avoid the risk of hydraulic oil overflowing.

[0008] Preferably, the driving assembly includes a stepper motor and a transmission gear, the transmission gear is rotatably connected in a driving box, a driving shaft is fixed at the center position of the transmission gear, and the end of the driving shaft extends into the movable head and is fixedly connected to the center position of the rotating column.

[0009] Preferably, the stepper motor is fixed on the outer wall of the driving box, a threaded rod is inside the driving box and rotatably connected to the position corresponding to the stepper motor, a toothed plate is inside the driving box and slidably connected to the periphery of the transmission gear, the toothed plate is meshed with the transmission gear, the threaded rod passes through the toothed plate and is threadedly connected to the toothed plate, and the output end of the stepper motor is fixed at the end of the threaded rod.

[0010] Compared with the prior art, the utility model has the following beneficial technical effects: utilizing the one-way flow of the one-way valve can ensure that the hydraulic oil can only flow in the specified direction, reducing the risk of reverse extension and retraction of the piston rod caused by overload, and improving the safety of the telescopic cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the partially cutaway structure of the front side of the utility model;

[0012] Figure 2 This is a schematic diagram of the internal structure of the movable head of the utility model;

[0013] Figure 3 This is a schematic diagram of the cross-sectional structure of the movable head of the utility model from top view;

[0014] Figure 4 This is a schematic diagram of the internal structure of the drive box of the utility model.

[0015] Figure numerals: 1. cylinder body; 2. piston rod; 21. main oil hole; 22. auxiliary oil hole; 23. overflow hole; 24. sealing piston; 3. movable head; 31. main oil pipe; 32. auxiliary oil pipe; 33. rotating column; 34. connecting hole; 35. one-way valve; 36. sealing sleeve; 4. drive box; 41. stepping motor; 42. transmission gear; 43. driving shaft; 44. gear plate; 45. threaded rod. DETAILED DESCRIPTION

[0016] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0017] Example

[0018] like Figure 1-4As shown, a telescopic oil cylinder for a crane proposed by the utility model comprises a cylinder body 1, a piston rod 2 and a movable head 3, a sealing piston 24 is slidably connected in the cylinder body 1, the piston rod 2 is fixed on the sealing piston 24, the end of the piston rod 2 passes through the cylinder body 1 and is fixed with the movable head 3, a main oil hole 21 is opened at the center of the piston rod 2, a secondary oil hole 22 is opened in the piston rod 2 and is located outside the main oil hole 21, a main oil pipe 31 and a secondary oil pipe 32 are respectively fixed on the movable head 3 and at positions corresponding to the main oil hole 21 and the secondary oil hole 22, and a rotating connection is provided in the movable head 3. There is a rotating column 33, a connecting hole 34 is opened in the rotating column 33, the connecting hole 34 is a T-shaped structure, and a one-way valve 35 is installed at the opening in the middle position, a driving box 4 is fixed to the outside of the movable head 3, a driving assembly is arranged in the driving box 4, the main oil hole 21 passes through the sealing piston 24, the auxiliary oil hole 22 is located on the side wall of the front side of the sealing piston 24, and an overflow hole 23 is opened, there are three connecting holes 34, and they are respectively located between the main oil hole 21 and the main oil pipe 31 and between the auxiliary oil hole 22 and the auxiliary oil pipe 32, and a sealing sleeve 36 is fixed to the outer wall of the rotating column 33.

[0019] The driving assembly includes a stepper motor 41 and a transmission gear 42. The transmission gear 42 is rotatably connected in the driving box 4. A driving shaft 43 is fixed at the center position of the transmission gear 42. The end of the driving shaft 43 extends into the movable head 3 and is fixedly connected to the center position of the rotating column 33. The stepper motor 41 is fixed to the outer wall of the driving box 4. A threaded rod 45 is rotatably connected in the driving box 4 and at a position corresponding to the stepper motor 41. A toothed plate 44 is slidably connected in the driving box 4 and located at the periphery of the transmission gear 42. The toothed plate 44 is meshed with the transmission gear 42. The threaded rod 45 passes through the toothed plate 44 and is threadedly connected to the toothed plate 44. The output end of the stepper motor 41 is fixed to the end of the threaded rod 45.

[0020] In this embodiment, firstly, the entire device is connected to an external power source, and the main oil pipe 31 and the auxiliary oil pipe 32 are installed on the hydraulic pump. The hydraulic pump is used to drive the hydraulic oil to flow. When the hydraulic oil passes through the connecting hole 34 from the main oil pipe 31 and then enters the main oil hole 21, it can directly enter the cylinder body 1, thereby pushing the sealing piston 24 and the piston rod 2 to extend. In the event of an overload, since a one-way valve 35 is installed in the connecting hole 34, the hydraulic oil in the main oil hole 21 will not flow back into the main oil pipe 31, so it will not cause the piston rod 2 to move in the opposite direction. On the contrary, when the piston rod 2 needs to be contracted, the rotating column 33 can be rotated. This causes the position of the one-way valve 35 in the entire connecting hole 34 to change. After a right-angle rotation, the one-way fluidity of the one-way valve 35 changes, causing the hydraulic oil in the main oil hole 21 to flow unidirectionally into the main oil pipe 31. At this time, the hydraulic oil in the auxiliary oil pipe 32 is injected into the auxiliary oil hole 22 and flows out from the overflow hole 23, pushing the sealing piston 24 inward to achieve normal contraction. During the driving process of the rotating column 33, the output end of the stepping motor 41 is used to drive the threaded rod 45 to rotate, causing the tooth plate 44 to slide, and finally driving the transmission gear 42 and the driving shaft 43 to rotate, thereby realizing the rotation drive of the rotating column 33.

[0021] The above-mentioned specific embodiments are only several preferred embodiments of the present invention. Based on the technical solution of the present invention and the relevant inspiration of the above-mentioned embodiments, those skilled in the art can make various alternative improvements and combinations to the above-mentioned specific embodiments.

Claims

1. A telescopic oil cylinder for a crane, comprising a cylinder body (1), a piston rod (2) and a movable head (3), characterized in that: A sealing piston (24) is slidably connected in the cylinder body (1), the piston rod (2) is fixed on the sealing piston (24), the end of the piston rod (2) passes through the cylinder body (1) and is fixed with a movable head (3), a main oil hole (21) is opened at the center of the piston rod (2), a secondary oil hole (22) is opened in the piston rod (2) and is located outside the main oil hole (21), and a main oil pipe (31) and a secondary oil pipe (32) are respectively fixed on the movable head (3) at positions corresponding to the main oil hole (21) and the secondary oil hole (22). (32), a rotating column (33) is rotatably connected inside the movable head (3), a connecting hole (34) is provided inside the rotating column (33), the connecting hole (34) is a T-shaped structure, and a one-way valve (35) is installed at the opening in the middle position, a driving box (4) is fixed outside the movable head (3), a driving assembly is arranged inside the driving box (4), the main oil hole (21) passes through the sealing piston (24), and the auxiliary oil hole (22) is located on the side wall of the front side of the sealing piston (24) and is provided with an overflow hole (23).

2. The crane telescopic cylinder according to claim 1, characterized in that: Three connecting holes (34) are provided and are respectively located between the main oil hole (21) and the main oil pipe (31) and between the auxiliary oil hole (22) and the auxiliary oil pipe (32).

3. The crane telescopic cylinder according to claim 1, characterized in that: A sealing sleeve (36) is fixed to the outer side wall of the rotating column (33).

4. The crane telescopic cylinder according to claim 1, characterized in that: The driving assembly comprises a stepping motor (41) and a transmission gear (42), wherein the transmission gear (42) is rotatably connected in a driving box (4), a driving shaft (43) is fixed at the center of the transmission gear (42), and an end of the driving shaft (43) extends into the movable head (3) and is fixedly connected to the center of a rotating column (33).

5. The crane telescopic cylinder according to claim 4, characterized in that: The stepper motor (41) is fixed to the outer wall of the driving box (4); a threaded rod (45) is rotatably connected to a position corresponding to the stepper motor (41) in the driving box (4); a toothed plate (44) is slidably connected to the outer periphery of the transmission gear (42) in the driving box (4); the toothed plate (44) is meshed with the transmission gear (42); the threaded rod (45) passes through the toothed plate (44) and is threadedly connected to the toothed plate (44); and the output end of the stepper motor (41) is fixed to the end of the threaded rod (45).

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