A self-locking hydraulic cylinder

Abstract

The present invention relates to an in-cylinder self-locking hydraulic oil cylinder, comprising a cylinder barrel, a cylinder rod and a piston, wherein the piston has a piston inner cavity, and the piston inner cavity has two isolation pistons, which divide the piston inner cavity into a front inner cavity, a middle inner cavity and a rear inner cavity, and a locking ring assembly and a self-locking piston ring and a spring for driving the locking ring assembly are sleeved in the self-locking groove of the piston, and the end of the self-locking piston ring on one side of the locking ring assembly is provided with a notch for forming a self-locking piston oil cavity, and the front inner cavity is connected to the front cavity of the cylinder barrel through the first oil passage in the piston, the middle inner cavity is connected to the self-locking piston oil cavity through the second oil passage in the piston, and the rear inner cavity is connected to the rear cavity of the cylinder barrel through the third oil passage in the piston. The beneficial effects of the present invention are: the self-locking component of the hydraulic oil cylinder is located in the cylinder barrel, and the piston and the cylinder rod are unlocked and locked according to the actual oil pressure in the cylinder barrel, and the self-locking is more reliable.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic cylinders, in particular to an in-cylinder self-locking hydraulic oil cylinder. Background Art

[0002] A hydraulic cylinder usually includes a piston and a cylinder rod pushed by the piston. The hydraulic oil in the cylinder acts on the piston, driving the piston to move along the cylinder.

[0003] Cylinder self-locking is divided into oil circuit self-locking and mechanical self-locking. Oil circuit self-locking means adding a valve to maintain pressure so that the hydraulic oil of the cylinder does not return to the oil tank and the cylinder is filled with a certain pressure of oil. However, this pressure-maintaining self-locking is not very safe and reliable. If there is a leak, the cylinder rod will slowly return to its position. Mechanical self-locking means locking the cylinder rod through a mechanical structure to prevent the cylinder rod from moving when the cylinder fails. Mechanical self-locking is functionally divided into mechanical self-locking that can only self-lock in a specific position and mechanical self-locking that can self-lock in any position.

[0004] Chinese patent application CN105065363B discloses a high-precision lateral force-resistant self-locking wind power hydraulic cylinder with a mechanical self-locking mechanism, wherein the mechanical self-locking mechanism includes a self-locking ring assembly, a self-locking piston, a self-locking oil pipe and a clamping spring. When the main oil pressure decreases, the oil pressure of the self-locking oil pipe also decreases. The self-locking piston pushes the self-locking ring under the action of the clamping spring, so that the self-locking ring forms a clamping effect on the cylinder rod to achieve self-locking. When the main oil pressure is restored, the oil pressure of the self-locking oil pipe also increases, which generates pressure on the self-locking piston and overcomes the elastic force of the clamping spring, pushing the self-locking piston away from the self-locking piston axially, releasing the clamping effect of the self-locking ring on the cylinder rod, and achieving unlocking.

[0005] The disadvantage of the prior art is that the self-locking oil pipe needs to be connected to the main oil inlet pipe of the oil cylinder through a hydraulic valve and a pipeline, and these components are exposed and easily damaged by bumps, resulting in failure to unlock the oil cylinder.

[0006] In addition, the self-locking of the mechanical self-locking mechanism depends on the main oil pressure outside the cylinder. When the cylinder of the cylinder leaks and the main oil pressure is normal, the cylinder will not self-lock, resulting in failure of the cylinder self-locking. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an in-cylinder self-locking hydraulic oil cylinder to improve the reliability of self-locking.

[0008] The technical solution adopted by the present invention to solve its technical problem is: an in-cylinder self-locking hydraulic oil cylinder, including a cylinder barrel, a cylinder rod and a piston. The piston is located in the cylinder barrel and pushes the cylinder rod. The piston divides the inner cavity of the cylinder barrel into a front cavity and a rear cavity of the cylinder barrel. The piston has a piston inner cavity. There are two isolation pistons in the piston inner cavity, which divide the piston inner cavity into a front cavity, a middle cavity and a rear cavity. There is a circle of self-locking grooves on the piston. A locking ring assembly, a self-locking piston ring and a spring driving the locking ring assembly are sleeved in the self-locking groove. The locking ring assembly is locked. The tightening ring assembly and the spring are located on the front and rear sides of the self-locking piston ring. The spring pushes the self-locking piston ring to compress the locking ring assembly. The end of one side of the self-locking piston ring that compresses the locking ring assembly has a notch for forming a self-locking piston oil chamber. The front inner chamber is connected to the front chamber of the cylinder through the first oil passage in the piston, the middle inner chamber is connected to the self-locking piston oil chamber through the second oil passage in the piston, and the rear inner chamber is connected to the rear chamber of the cylinder through the third oil passage in the piston. The locking ring assembly includes an outer locking ring and an inner locking ring, and the outer locking ring and the inner locking ring are wedge-shaped.

[0009] In order to facilitate the installation of various self-locking components on the piston, the rear end of the piston is a detachable rear cover plate, and the rear ends of the piston cavity and the self-locking groove are closed by the rear cover plate.

[0010] The beneficial effects of the present invention are as follows: the self-locking component of the hydraulic oil cylinder is located in the cylinder barrel, and the piston and the cylinder rod are unlocked and locked according to the actual oil pressure in the cylinder barrel, so that the self-locking is more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0012] Figure 1 It is a structural schematic diagram of the present invention.

[0013] In the figure, 1. cylinder barrel, 2. cylinder rod, 3. piston, 3-1. rear cover plate, 4. isolation piston, 5. locking ring assembly, 5-1. outer locking ring, 5-2. inner locking ring, 6. self-locking piston ring, 6-1. notch, 7. spring, 8-1. first oil channel, 8-2. second oil channel, 8-3. third oil channel, 9. front oil port, 10. rear oil port. DETAILED DESCRIPTION

[0014] like Figure 1 The shown embodiment is a self-locking hydraulic cylinder, comprising a cylinder barrel 1, a cylinder rod 2 and a piston 3. The piston 3 is located in the cylinder barrel 1 and pushes the cylinder rod 2. The piston 3 divides the inner cavity of the cylinder barrel 1 into a front cavity and a rear cavity. The front end and the rear end of the cylinder barrel 1 are provided with a front oil port 9 and a rear oil port 10 for passing hydraulic oil to the front cavity and the rear cavity of the cylinder barrel. The piston 3 has a piston cavity, and the piston cavity is provided with two isolation pistons 4, which divide the piston cavity into a front cavity, a middle cavity and a rear cavity.

[0015] A circle of self-locking groove is provided on the piston 3, and a locking ring assembly 5 and a self-locking piston ring 6 and a spring 7 for driving the locking ring assembly 5 are sleeved in the self-locking groove. The locking ring assembly 5 and the spring 7 are located on the front and rear sides of the self-locking piston ring 6. The spring 7 pushes the self-locking piston ring 6 to press the locking ring assembly 5. The end of the self-locking piston ring 6 on the side that presses the locking ring assembly 5 has a notch 6-1 for forming a self-locking piston oil chamber.

[0016] The front inner chamber is connected to the front chamber of the cylinder through the first oil passage 8-1 in the piston 3, the middle inner chamber is connected to the self-locking piston oil chamber through the second oil passage 8-2 in the piston 3, and the rear inner chamber is connected to the rear chamber of the cylinder through the third oil passage 8-3 in the piston 3.

[0017] The locking ring assembly 5 comprises an outer locking ring 5-1 and an inner locking ring 5-2, and the outer locking ring 5-1 and the inner locking ring 5-2 are wedge-fitted.

[0018] The rear end of the piston 3 is a detachable rear cover plate 3-1, which is fixed by bolts, and the rear end of the piston cavity and the self-locking groove is closed by the rear cover plate 3-1.

[0019] The working process is as follows: when the front oil port 9 is connected to oil, the main oil pressure is in the front chamber of the cylinder, and the main oil pressure acts on the isolation piston 4 on the front side through the first oil channel 8-1. The isolation piston 4 presses the hydraulic oil in the middle inner chamber into the self-locking piston oil chamber through the second oil channel 8-2, pushing the self-locking piston ring 6 to overcome the pressure of the spring 7 and move away from the locking ring assembly 5. The locking ring assembly 5 is dispersed, the piston is unlocked, and the main oil pressure will push the piston 3 to move backward, causing the cylinder rod 2 to retract.

[0020] When oil flows through the rear oil port 10, the main oil pressure is in the rear chamber of the cylinder barrel. The main oil pressure acts on the isolation piston 4 on the rear side through the third oil channel 8-3. The isolation piston 4 presses the hydraulic oil in the middle inner chamber into the self-locking piston oil chamber through the second oil channel 8-2, pushing the self-locking piston ring 6 to overcome the pressure of the spring 7 and move away from the locking ring assembly 5. The locking ring assembly 5 is dispersed, the piston 3 is unlocked, and the main oil pressure will push the piston 3 to move forward, causing the cylinder rod 2 to extend.

[0021] When the oil supply is lost, the cylinder 1 leaks, or the front oil port 9 and the rear oil port 10 are blocked, there is no main oil pressure in the front cavity and the rear cavity of the cylinder, and the self-locking piston ring 6 will be pressed toward the locking ring assembly 5 under the action of the spring 7. The inner locking ring 5-2 and the outer locking ring 5-1 are squeezed against each other through the wedge surface, generating pressure on the inner wall of the cylinder 1 and the outer wall of the piston 3, thereby locking the piston 3.

Claims

1. An in-cylinder self-locking hydraulic cylinder, comprising a cylinder barrel (1), a cylinder rod (2) and a piston (3), wherein the piston (3) is located in the cylinder barrel (1) and pushes the cylinder rod (2), and the piston (3) divides the inner cavity of the cylinder barrel (1) into a cylinder barrel front cavity and a cylinder barrel rear cavity, wherein: The piston (3) has a piston inner cavity, and two isolation pistons (4) are arranged in the piston inner cavity, which divide the piston inner cavity into a front inner cavity, a middle inner cavity and a rear inner cavity. A circle of self-locking grooves is provided on the piston (3), and a locking ring assembly (5) and a self-locking piston ring (6) and a spring (7) for driving the locking ring assembly (5) are sleeved in the self-locking groove. The locking ring assembly (5) and the spring (7) are located at the front and rear sides of the self-locking piston ring (6). The spring (7) pushes the self-locking piston ring (6) to press the locking ring assembly (5). The end of the self-locking piston ring (6) on the side pressing the locking ring assembly (5) has a notch (6-1) for forming a self-locking piston oil chamber. The front inner cavity is communicated with the front cavity of the cylinder through a first oil passage (8-1) in the piston (3), the middle inner cavity is communicated with the self-locking piston oil cavity through a second oil passage (8-2) in the piston (3), and the rear inner cavity is communicated with the rear cavity of the cylinder through a third oil passage (8-3) in the piston (3). The locking ring assembly (5) comprises an outer locking ring (5-1) and an inner locking ring (5-2), and the outer locking ring (5-1) and the inner locking ring (5-2) are wedge-matched.

2. The in-cylinder self-locking hydraulic cylinder according to claim 1 is characterized in that: The rear end of the piston (3) is a detachable rear cover plate (3-1), and the inner cavity of the piston and the rear end of the self-locking groove are sealed by the rear cover plate (3-1).

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