A two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function

Abstract

The present invention discloses a two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function, which includes a support head, a secondary plunger insurance nut, a primary plunger insurance nut, an upper joint, an outer cylinder, a primary plunger, a secondary plunger, a second inner cylinder, a first inner cylinder, a return oil pipe, an oil inlet pipe, a vertical calibration mechanism, a base, an inner cylinder, and a screw rod. The inner cylinder is sleeved in the base and can move relative to it. The base is sleeved in the first inner cylinder and can move relative to it. The first inner cylinder is sleeved in the second inner cylinder and can move relative to it. The second inner cylinder is sleeved in the secondary plunger and can move relative to it. The secondary plunger is sleeved in the primary plunger and can move relative to it. The present invention adopts an automated full-machine synchronous jacking form, which greatly reduces the labor intensity of maintenance personnel, shortens the maintenance and combat preparation time of military aircraft, and improves the economic benefits of civil aircraft.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic actuators, and in particular to a two-stage double-acting hydraulic cylinder with a mechanical insurance limit function. Background Art

[0002] Currently, at home and abroad, explosion-proof valves are added to the corresponding hydraulic systems of two-stage double-acting hydraulic cylinders to prevent pipe bursts, and hydraulic locks are added to prevent the creep of the hydraulic cylinders caused by the leakage of the hydraulic systems. However, for the field of aircraft ground support equipment involved in the present invention, the use of explosion-proof valves and hydraulic locks is not sufficient to eliminate the risks generated during the jacking and lowering processes of the aircraft.

[0003] In addition, there is a widespread problem of disordered lifting and lowering sequences of two-stage double-acting hydraulic cylinders at home and abroad. Especially in high-pressure usage environments, it is easy to have problems such as cylinder dropping caused by disordered usage sequences, thus posing safety hazards to the equipment and personnel in use.

[0004] Therefore, it is necessary to provide a brand-new two-stage double-acting hydraulic cylinder with a mechanical insurance limit function. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a two-stage double-acting hydraulic cylinder with a mechanical insurance limit function.

[0006] The present invention provides a two-stage double-acting hydraulic cylinder with a mechanical insurance limit function, and adopts the following technical solutions:

[0007] A two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function according to the present invention includes a support head 1, a secondary plunger insurance nut 4, a primary plunger insurance nut 5, an upper joint 6, an outer cylinder 7, a primary plunger 8, a secondary plunger 9, a second inner cylinder 10, a first inner cylinder 11, a return oil pipe 14, an inlet oil pipe 15, a vertical calibration mechanism 17, a base 18, an inner cylinder 19, and a screw 20. The inner cylinder 19 is sleeved in the base 18 and can move relative to it. The base 18 is sleeved in the first inner cylinder 11 and can move relative to it. The first inner cylinder 11 is sleeved in the second inner cylinder 10 and can move relative to it. The second inner cylinder 10 is sleeved in the secondary plunger 9 and can move relative to it. The secondary plunger 9 is sleeved in the primary plunger 8 and can move relative to it. The primary plunger 8 is sleeved in the outer cylinder 7 and can move relative to it. The inlet oil pipe 15 communicates with the inner cylinder 19, and the return oil pipe 14 communicates with the base 18. A screw 20 is sleeved in the inner cylinder 19, and the upper end of the screw 20 is fixedly connected to the support head 1. An upper joint 6 and a vertical calibration mechanism 17 are fixedly connected to the outside of the outer cylinder 7, and a connecting member 21 is also included. The secondary plunger insurance nut 4 is threadedly connected to the secondary plunger 9 through a trapezoidal nut, and the primary plunger insurance nut 5 is threadedly connected to the primary plunger 8 through a trapezoidal nut. A secondary plunger step surface is integrally protruded on the outer circle of the lower part of the secondary plunger 9, and a primary plunger step surface is integrally protruded on the inner circle of the upper part of the primary plunger 8. The bottom of the primary plunger 8 is fixedly connected to the bottom of the second inner cylinder 10 through the connecting member 21.

[0008] Preferably, the connecting member 21 is circular, its inner ring is fixedly connected to the outer circle of the second inner cylinder 10, and its outer ring is fixedly connected to the inner wall of the primary plunger 8.

[0009] More preferably, the connecting member 21 is circular, and a through hole 211 is opened on it. Its inner ring is fixedly connected to the outer circle of the second inner cylinder 10. The bottom of the primary plunger 8 is fixedly connected to the connecting member 21 through a bolt 212 passing through the through hole 211.

[0010] A further solution is that a protective cover 13 is fixedly connected under the base 18, and an opening for the return oil pipe 14 and the inlet oil pipe 15 to pass through is opened on it.

[0011] A pressure block 2 is also sleeved at the connection between the support head 1 and the screw 20, and a ratchet wrench 3 that can press the pressure block 2 to fix the support head 1 is sleeved outside the pressure block 2.

[0012] Compared with the related technologies, the present invention has the following technical effects:

[0013] (a) The present invention adopts an automated full-machine synchronous jacking form, which greatly reduces the labor intensity of maintenance personnel, shortens the maintenance and preparation time of military aircraft, and improves the economic benefits of civil aircraft;

[0014] (b) It is applicable to various working conditions. 220V civil electricity can be used in the hangar, and 28V DC electricity on the power vehicle can be directly used when there is no power supply in the outfield;

[0015] (c) It effectively ensures the full-machine synchronous jacking of the aircraft, avoiding the aircraft from tilting during jacking and the generation of internal stress inside the aircraft due to the non-synchronization of each vertex;

[0016] (d) It is convenient to monitor the operating conditions of the main jack in real time, such as working pressure, oil temperature, jacking height, and instantaneous speed, which helps to detect the operating faults of the main jack in time and prevent the occurrence of accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present invention;

[0018] Figure 2 is a schematic diagram of the fully extended state of the secondary plunger 9 of the present invention;

[0019] Figure 3 is a schematic diagram of the fully extended state of the primary plunger 8 of the present invention;

[0020] Figure 4 is a schematic diagram of the position of the safety nut of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be further described below in conjunction with the drawings and embodiments.

[0022] As Figure 1As shown in the figure, a two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function according to the present invention includes a support head 1, a secondary plunger insurance nut 4, a primary plunger insurance nut 5, an upper joint 6, an outer cylinder 7, a primary plunger 8, a secondary plunger 9, a second inner cylinder 10, a first inner cylinder 11, a return oil pipe 14, an oil inlet pipe 15, a vertical calibration mechanism 17, a base 18, an inner cylinder 19, and a screw 20. The inner cylinder 19 is sleeved in the base 18 and can move relative to it. The base 18 is sleeved in the first inner cylinder 11 and can move relative to it. The first inner cylinder 11 is sleeved in the second inner cylinder 10 and can move relative to it. The second inner cylinder 10 is sleeved in the secondary plunger 9 and can move relative to it. The secondary plunger 9 is sleeved in the primary plunger 8 and can move relative to it. The primary plunger 8 is sleeved in the outer cylinder 7 and can move relative to it. The oil inlet pipe 15 communicates with the inner cylinder 19, and the return oil pipe 14 communicates with the base 18. A screw 20 is sleeved in the inner cylinder 19, and the upper end of the screw 20 is fixedly connected to the support head 1. An upper joint 6 and a vertical calibration mechanism 17 are fixedly connected to the outside of the outer cylinder 7, and a connecting member 21 is also included. The secondary plunger insurance nut 4 is threadedly connected to the secondary plunger 9 through a trapezoidal nut, and the primary plunger insurance nut 5 is threadedly connected to the primary plunger 8 through a trapezoidal nut. A secondary plunger step surface is integrally protruded on the outer circle of the lower part of the secondary plunger 9, and a primary plunger step surface is integrally protruded on the inner circle of the upper part of the primary plunger 8. The bottom of the primary plunger 8 is fixedly connected to the bottom of the second inner cylinder 10 through a connecting member 21. Embodiment 1

[0023] In this embodiment, the connecting member 21 is circular, its inner ring is fixedly connected to the outer circle of the second inner cylinder 10, and its outer ring is fixedly connected to the inner wall of the primary plunger 8.

[0024] A protective cover 13 is also fixedly connected under the base 18, and an opening for the return oil pipe 14 and the oil inlet pipe 15 to pass through is provided on it.

[0025] A pressing block 2 is also sleeved at the connection between the support head 1 and the screw 20, and a ratchet wrench 3 that can press the pressing block 2 to fix the support head 1 is sleeved outside the pressing block 2. Embodiment 2

[0026] In this embodiment, the connecting member 21 is annular, with a through hole 211 formed thereon, and its inner ring is fixedly connected to the outer circle of the second inner cylinder 10; the bottom of the first-stage plunger 8 is fixedly connected to the connecting member 21 through a bolt 212 passing through the through hole 211.

[0027] Before the aircraft synchronously descends until the landing gear touches the ground, the lateral force exerted by the aircraft on the jack is converted into the frictional force on the first-stage plunger 8. Since the gravity of the first-stage plunger 8 is insufficient to overcome the frictional force, the first-stage plunger 8 gets stuck. At the same time, when the landing gear of the aircraft touches the ground, since the lateral force on the jack sharply decreases, the frictional force generated by the first-stage plunger 8 due to the lateral force is insufficient to overcome its own gravity, resulting in the sudden drop of the first-stage plunger 8. At the same time as a loud impact sound occurs, it is likely to affect the personal safety of the operator.

[0028] After the first-stage plunger 8, the connecting member 21 and the second inner cylinder 10 are integrated in the present invention, the downward force of the hydraulic oil on the second inner cylinder 10 is transmitted to the first-stage plunger 8 through the connecting member 21 to overcome the frictional force exerted on the first-stage plunger 8 due to the side load of the jack, effectively avoiding the phenomenon that the first-stage plunger 8 gets stuck during the descent of the jack, thereby eliminating the risk of the first-stage plunger 8 falling.

[0029] During use, in the ascending process, the hydraulic oil enters the inside of the hydraulic cylinder through the oil inlet pipe 15 to drive the second-stage plunger 9, the inner cylinder 19 and its accessories to rise until the second-stage plunger 9 is fully extended, as Figure 2 shown. Then the stepped surface of the second-stage plunger 9 drives the stepped surface of the first-stage plunger 8 to rise, thereby realizing the rise of the first-stage plunger 8 until it is fully raised, as Figure 3 shown. During the ascending process, the second-stage plunger safety nut 4 and the second-stage plunger 9 are connected by a trapezoidal transmission thread, and the first-stage plunger safety nut 5 and the first-stage plunger 8 are connected by a trapezoidal transmission thread. Therefore, during the ascending process of the hydraulic cylinder, by manually rotating the first-stage plunger safety nut 8, the clearance between it and the second-stage plunger can be kept within the range of 10 - 15 mm, and by rotating the second-stage plunger safety nut, the clearance between it and the upper support can be kept within the range of 10 - 15 mm, as Figure 4 shown. When phenomena such as pipe burst, leakage in the hydraulic system and impact inside the valve block occur, after the hydraulic cylinder drops slightly, mechanical limits will be generated by the first-stage plunger safety nut 5 and the second-stage plunger safety nut 4, effectively preventing the event of plane crash and casualties caused by the rapid descent of the hydraulic cylinder.

[0030] Descending process. The hydraulic oil enters the secondary plunger 9 finally through the return oil pipe 14, the base 18, the first inner cylinder 11 and the second inner cylinder 10, forcing it to descend. While the secondary plunger 9 is descending, the second inner cylinder 10 converts the oil pressure into a downward acting force and transmits it to the primary plunger 8 through the connecting piece 21, causing the primary plunger to descend as the secondary plunger 9 descends, making the two-stage double-acting hydraulic cylinder in the present invention orderly and solving the problem of disordered sequence commonly existing in domestic and foreign two-stage double-acting hydraulic cylinders.

[0031] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function, comprising a support head (1), a secondary plunger insurance nut (4), a primary plunger insurance nut (5), an upper joint (6), an outer cylinder (7), a primary plunger (8), a secondary plunger (9), a second inner cylinder (10), a first inner cylinder (11), a return oil pipe (14), an inlet oil pipe (15), a vertical calibration mechanism (17), a base (18), an inner cylinder (19), and a screw rod (20). The inner cylinder (19) is sleeved in the base (18) and can move relative to it. The base (18) is sleeved in the first inner cylinder (11) and can move relative to it. The first inner cylinder (11) is sleeved in the second inner cylinder (10) and can move relative to it. The second inner cylinder (10) is sleeved in the secondary plunger (9) and can move relative to it. The secondary plunger (9) is sleeved in the primary plunger (8) and can move relative to it. The primary plunger (8) is sleeved in the outer cylinder (7) and can move relative to it. The inlet oil pipe (15) is communicated with the inner cylinder (19), and the return oil pipe (14) is communicated with the base (18). A screw rod (20) is sleeved in the inner cylinder (19), and the upper end of the screw rod (20) is fixedly connected to the support head (1). An upper joint (6) and a vertical calibration mechanism (17) are fixedly connected to the outside of the outer cylinder (7). It is characterized in that: It further includes a connecting member (21); the secondary plunger safety nut (4) is threadedly connected to the secondary plunger (9) through a trapezoidal nut, and the primary plunger safety nut (5) is threadedly connected to the primary plunger (8) through a trapezoidal nut; a secondary plunger step surface is integrally protruded on the outer circumference of the lower part of the secondary plunger (9), and a primary plunger step surface is integrally protruded on the inner circumference of the upper part of the primary plunger (8); the bottom of the primary plunger (8) is fixedly connected to the bottom of the second inner cylinder (10) through the connecting member (21).

2. The two-stage double-acting hydraulic cylinder with a mechanical insurance limit function according to claim 1, wherein: The connecting member (21) is annular, its inner ring is fixedly connected to the outer circumference of the second inner cylinder (10), and its outer ring is fixedly connected to the inner wall of the primary plunger (8).

3. A two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function as described in claim 1, characterized in that: The connecting member (21) is annular, and a through hole (211) is provided thereon. Its inner ring is fixedly connected to the outer circumference of the second inner cylinder (10); the bottom of the primary plunger (8) is fixedly connected to the connecting member (21) through a bolt (212) passing through the through hole (211).

4. A two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function according to any one of claims 1-3, characterized in that: A protective cover (13) is further fixedly connected under the base (18), and an opening is provided thereon for the return oil pipe (14) and the inlet oil pipe (15) to pass through.

5. The two-stage double-acting hydraulic cylinder with a mechanical insurance and limit function as claimed in claim 1, wherein: A pressing block (2) is further sleeved at the connection between the support head (1) and the screw rod (20), and a ratchet wrench (3) that can press the pressing block (2) to fix the support head (1) is sleeved outside the pressing block (2).

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