An actuator with a mechanical lock structure for reducing the volume difference between two chambers

Abstract

The present invention discloses an actuator with a mechanical lock structure that reduces the volume difference between two chambers, comprising an outer cylinder. One end of the outer cylinder is connected with an end cover, and a lowering nozzle is provided on the end cover. The other end of the outer cylinder is provided with a retracting nozzle. A piston rod is arranged inside the outer cylinder, and a plunger rod is arranged inside the piston rod. One end of the plunger rod is connected with the end cover. A lock structure is arranged at the end of the piston rod extending into the interior of the outer cylinder. A cavity A is formed among the end cover, the plunger rod, the lock structure and the outer cylinder. The lowering nozzle is communicated with the cavity A. An internal thread is arranged at the outer end of the piston rod, and a limit nut and a double-ear bolt are connected to the internal thread. A moving piston is arranged on the plunger rod. A cavity B is formed among the moving piston, the plunger rod and the piston rod. The retracting nozzle is communicated with the cavity B. A sealing cover is arranged between the outer cylinder and the piston rod. A cavity C is formed among the lock structure, the piston rod, the sealing cover and the outer cylinder. An oil through hole is arranged on the piston rod. The present invention reduces the volume difference and output load difference between two chambers, reduces the fuel tank volume and saves the placement space.

Description

Technical Field

[0001] The invention belongs to the technical field of servo actuators, and particularly relates to an actuator cylinder with a reduced volume difference between two chambers and a mechanical lock structure. Background Art

[0002] As an actuator element of the operating motion mechanism of a hydraulic system or a pneumatic system, an actuator cylinder is widely used in modern aviation, aerospace, ships, and construction machinery. There is a retraction chamber and a lowering chamber inside the actuator cylinder, and a working load is output under hydraulic action. Generally, the retraction chamber of the actuator cylinder is the chamber with a piston rod, while the lowering chamber is the chamber without a piston rod. Therefore, the volume of the lowering chamber is larger, resulting in a large difference in volume between the two chambers, and a large difference in the values of the retraction load and the lowering load output. To provide the oil supply for the larger-volume lowering chamber of the hydraulic system, it is necessary to increase the volume of the on-board fuel tank, thereby increasing the weight of the fuel tank and the installation space of the fuel tank. Therefore, it is urgent to improve the existing actuator cylinder to meet the usage requirements. Summary of the Invention

[0003] To solve the above problems, the purpose of the present invention is to provide an actuator cylinder with a reduced volume difference between two chambers and a mechanical lock structure.

[0004] An actuator cylinder with a reduced volume difference between two chambers and a mechanical lock structure includes an outer cylinder. One end of the outer cylinder is connected with an end cap, and a sealing ring is provided at the connection. A lowering nozzle is provided on the end cap. The other end of the outer cylinder is provided with a retraction nozzle communicating with the inside of the outer cylinder. A piston rod is arranged inside the outer cylinder. The piston rod is a stepped shaft, and a stepped through hole is arranged inside the piston rod. A plunger rod is arranged inside the stepped through hole. One end of the plunger rod is connected with the end cap. A lock structure is arranged at the end of the piston rod extending into the inside of the outer cylinder. The lock structure is used for locking when the piston rod retracts and lowers. A cavity A is formed among the end cap, the plunger rod, the lock structure, and the outer cylinder. The lowering nozzle communicates with the cavity A. The outer end of the piston rod is provided with an internal thread, and a limit nut and a double-ear bolt are sequentially connected from the inside to the outside on the internal thread. A movement piston is arranged between the piston rod and the plunger rod. Sealing rings are arranged between the movement piston and the piston rod, and between the movement piston and the plunger rod. A cavity B is formed among the movement piston, the plunger rod, and the piston rod. The retraction nozzle communicates with the cavity B. A sealing cover is arranged between the outer cylinder and the piston rod. A locking nut is arranged on the outside of the sealing cover, and the locking nut is threadedly connected with the outer cylinder. Sealing rings are arranged between the sealing cover and the outer cylinder, and between the sealing cover and the piston rod. A cavity C is formed among the lock structure, the piston rod, the sealing cover, and the outer cylinder. An oil through hole is arranged on the piston rod, so that the cavity B and the cavity C communicate.

[0005] For example, to reduce weight, a through hole one is provided in the plunger rod along the axial direction. One end of the through hole one is provided with internal threads. A counterbore is provided in the middle of the end cap. A connecting screw rod (the connecting screw rod is a countersunk screw rod) is provided in the counterbore. The other end of the connecting screw rod is connected to the internal threads of the plunger rod. A fastening nut and a locking nut are further provided in the counterbore from the inside to the outside. A sealing ring is provided between the fastening nut and the counterbore. A sealing ring is also provided at the connection between the connecting screw rod and the plunger rod.

[0006] For example, to facilitate locking when the piston rod is retracted and extended, the locking structure includes a fastening nut, a left locking circlip, a moving piston, a right locking circlip, a left bushing, a right bushing, a steel ball and a support sleeve. The stepped portion inside the piston rod serves as a limiting step. The support sleeve is provided at the end of the piston rod and is fixed by the fastening nut. Sealing rings are provided between the support sleeve and the piston rod and between the support sleeve and the plunger rod. The fastening nut is threadedly connected to the piston rod. The moving piston is provided on the piston rod. The left locking circlip and the right locking circlip are respectively provided at both ends of the moving piston. The left locking circlip is arranged between the fastening nut and the moving piston. The right locking circlip is arranged at the stepped portion of the piston rod (the piston rod is a stepped shaft). A through hole two is provided on the wall of the piston rod. The steel ball is provided in the through hole two and is pressed by the moving piston. Two blind holes are provided at one end of the moving piston in contact with the piston rod. When the piston rod contracts, the steel ball is located in the blind hole at the right end. When the piston rod extends, during the process of the moving piston moving to the right, the blind hole at the left end of the moving piston moves to the position of the steel ball, so that the steel ball is in the blind hole at the left end. The left bushing and the right bushing are both provided between the piston rod and the plunger rod. Springs are provided between the left bushing and the support sleeve and between the right bushing and the limiting step. The steel ball presses on the connection between the left bushing and the right bushing.

[0007] For example, to facilitate the flow of oil and lubricate the parts at the same time, through holes three are provided on both the left bushing and the right bushing. An oil passage hole is provided on the piston rod at the end where the locking structure is installed.

[0008] For example, to facilitate clamping the left locking circlip and the right locking circlip, left and right steps are provided on the inner wall of the outer cylinder for locking the left locking circlip and the right locking circlip respectively, and the left and right steps are communicated.

[0009] For example, to facilitate limiting the moving piston, a limiting ring is provided at the end of the plunger rod; to facilitate limiting the piston rod, a limiting nut is provided on the double-ear bolt.

[0010] For example, to ensure the reliable connection of the limiting nut, a locking screw is provided on the limiting nut.

[0011] The actuating cylinder of the present invention reduces the volume difference between the two chambers and has a mechanical locking structure. Compared with the prior art, its beneficial effects are as follows: 1. By arranging a plunger rod in the middle of the piston rod and connecting the plunger rod to the end cover, the volume of the lowering chamber (i.e., cavity A) is reduced. The retracting chamber is divided into cavity B and cavity C, and the oil passage hole on the piston rod enables cavity B and cavity C to communicate, thereby increasing the volume of the retracting chamber (but generally reducing the volume difference between the lowering chamber and the retracting chamber), expanding the hydraulic action area, and increasing the output load during retraction; 2. The oil passage hole is arranged on the piston rod at one end of the locking structure, which not only ensures the communication between cavity B and cavity C, but also lubricates the left and right bushings and the spring; 3. The structure of the present invention is compact. By reducing the volume difference between the retracting chamber and the lowering chamber, the difference between the retracting load and the lowering load output is reduced, the volume of the fuel tank is reduced, and the installation space is saved. At the same time, the setting of the locking structure ensures the reliable locking of the piston rod of the actuating cylinder after retraction and lowering, with stable performance, convenient installation and operation, meeting the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described in detail below with reference to the accompanying drawings.

[0013] Figure 1 is a schematic structural diagram of the actuating cylinder of the present invention that reduces the volume difference between the two chambers and has a mechanical locking structure;

[0014] Figure 2 is Figure 1 a partial enlarged view;

[0015] Figure 3 is a three-dimensional structural diagram of the actuating cylinder of the present invention that reduces the volume difference between the two chambers and has a mechanical locking structure.

[0016] As shown in the figure, 1 - outer cylinder, 2 - piston rod, 3 - plunger rod, 4 - right lock retaining ring, 5 - moving piston, 6 - left lock retaining ring, 7 - fastening nut, 8 - end cover, 9 - lowering nozzle, 10 - locking nut, 11 - fastening nut, 12 - connecting screw, 13 - support sleeve, 14 - left bushing, 15 - steel ball, 16 - right bushing, 17 - spring, 18 - moving piston, 19 - retracting nozzle, 20 - anti-loosening screw, 21 - limit nut, 22 - sealing cover, 23 - locking nut, 24 - double-ear bolt, 25 - limit nut, 26 - limit ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0018] It should be noted that the structures, ratios, sizes, etc. depicted in the accompanying drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have any substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "outer", "inner", "left", "right", etc. cited in this specification are only for the convenience of description and clarification, and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope for the implementation of the present invention.

[0019] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "provided with" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] It should be noted that the term "comprising" or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device.

[0021] Such as Figure 1 、 3As shown in the figure, an actuating cylinder with a mechanical lock structure for reducing the volume difference between two chambers includes an outer cylinder 1. One end of the outer cylinder 1 is connected to an end cap 8, and a sealing ring is provided at the connection. A lowering nozzle 9 is provided on the end cap 8. The other end of the outer cylinder 1 is provided with a retracting nozzle 19 communicating with the inside of the outer cylinder 1. A piston rod 2 is arranged inside the outer cylinder 1. The piston rod 2 is a stepped shaft, including a large end and a small end. The diameter of the large end is greater than that of the small end. A stepped through hole is provided inside the piston rod 2, including a large hole and a small hole. The diameter of the large hole is greater than that of the small hole. The large end corresponds to the large hole, and the small end corresponds to the small hole. A plunger rod 3 is arranged in the stepped through hole. One end of the plunger rod 3 is connected to the end cap 8. A lock structure is provided at the end of the piston rod 2 extending into the inside of the outer cylinder 1. The lock structure is arranged on the small end and is used for locking when the piston rod 2 retracts and lowers. A cavity A is formed between the end cap, the plunger rod 3, the lock structure and the outer cylinder 1. The lowering nozzle communicates with the cavity A. The outer end (i.e., the large end) of the piston rod 2 is provided with an internal thread. An adjusting nut 21 and a double-ear bolt 24 are sequentially connected to the internal thread from the inside to the outside. A blind hole is provided inside the double-ear bolt 24. The adjusting nut 21 is provided with an external thread. The external thread of the adjusting nut 21 is connected to the internal thread of the piston rod 2. A through hole four is provided in the middle of the adjusting nut 21. The plunger rod 3 passes through the through hole four and extends into the blind hole of the double-ear bolt 24. A moving piston 18 is arranged between the piston rod 2 and the plunger rod 3. The moving piston 18 is arranged in the large hole and is limited by the adjusting nut 21. Sealing rings are provided between the moving piston 18 and the piston rod 2, and between the moving piston 18 and the plunger rod 3. A cavity B is formed among the moving piston 18, the plunger rod 3 and the piston rod 2. The retracting nozzle communicates with the cavity B. A sealing cover 22 is arranged between the outer cylinder 1 and the piston rod 2. A locking nut 23 is provided on the outside of the sealing cover 22. The sealing cover 22 is fixed on the outer cylinder 1 through the locking nut 23. The locking nut 23 is threadedly connected to the outer cylinder 1. Sealing rings are provided between the sealing cover 22 and the outer cylinder 1, and between the sealing cover 22 and the piston rod 2. A cavity C is formed among the lock structure, the piston rod 2, the sealing cover 22 and the outer cylinder 1. An oil through hole is provided on the piston rod 2, so that the cavity B and the cavity C communicate with each other.

[0022] For example, to reduce the weight, a through hole one is provided along the axial direction of the plunger rod 3. One end of the through hole one is provided with an internal thread. A counterbore is provided in the middle of the end cap 8. A connecting screw 12 (the connecting screw 12 is a counterbore screw) is arranged in the counterbore. The other end of the connecting screw 12 is connected to the internal thread of the plunger rod 3. A fastening nut 11 and a locking nut 10 are further provided in the counterbore from the inside to the outside. A sealing ring is provided between the fastening nut 11 and the counterbore. A sealing ring is also provided at the connection between the connecting screw 12 and the plunger rod 3.

[0023] For example, as Figure 2As shown in the figure, for the convenience of locking the piston rod 2 when it is retracted and extended, the locking structure includes a fastening nut 7, a left locking ring 6, a moving piston 5, a right locking ring 4, a left bushing 14, a right bushing 16, a steel ball 15 and a support sleeve 13. The step inside the piston rod 2 serves as a limiting step. The support sleeve 13 is arranged at the end of the piston rod 2 and fixed to the end of the piston rod 2 by the fastening nut 7. Sealing rings are provided between the support sleeve 13 and the piston rod 2, and between the support sleeve 13 and the plunger rod 3. The fastening nut 7 is threadedly connected to the piston rod 2. The moving piston 5 is arranged on the piston rod 2. Sealing rings are provided between the moving piston 5 and the outer cylinder 1, and between the moving piston 5 and the piston rod 2. The left locking ring 6 and the right locking ring 4 are respectively arranged at both ends of the moving piston 5. The left locking ring 6 is arranged between the fastening nut 7 and the moving piston 5, and the right locking ring 4 is arranged at the step of the piston rod 2 (the piston rod is a stepped shaft). A through hole two is provided on the wall of the piston rod 2. The steel ball 15 is arranged in the through hole two and pressed by the moving piston 5. Two blind holes are provided at one end of the moving piston 5 in contact with the piston rod 2. When the piston rod 2 contracts, the steel ball 15 is located in the blind hole at the right end. When the piston rod 2 extends, during the process of the moving piston 5 moving to the right, the blind hole at the left end of the moving piston 5 moves to the position of the steel ball 15, so that the steel ball 15 is in the blind hole at the left end. At this time, the moving piston 5 presses the right locking ring 4. The left bushing 14 and the right bushing 16 are both arranged between the piston rod 2 and the plunger rod 3. The left bushing 14 and the right bushing 16 are both sleeved on the plunger rod 3. Springs 17 are provided between the left bushing 14 and the support sleeve 13, and between the right bushing 16 and the limiting step, so that the left bushing 14 and the right bushing 16 are pressed against each other, thereby pressing the steel ball 15 to lock the moving piston 5 through the steel ball 15. The steel ball 15 presses at the connection of the left bushing 14 and the right bushing 16.

[0024] For example, for the convenience of oil flow and lubrication of parts at the same time, through holes three are provided on both the left bushing 14 and the right bushing 16. The oil through hole is arranged on the piston rod 2 at the end where the locking structure is installed, that is, on the small end of the piston rod 2.

[0025] For example, to facilitate clamping the left locking ring 6 and the right locking ring 4, the inner wall of the outer cylinder 1 is provided with a left step and a right step, which are respectively used to lock the left locking ring 6 and the right locking ring 4. The left step and the right step are connected. The left step is arranged at one end of the end cover 8, and the right step is arranged at one end of the sealing cover 22.

[0026] For example, a limiting ring 26 is provided at the end of the plunger rod 3. The outer diameter of the limiting ring 26 is smaller than the aperture of the through hole four of the limiting nut 21, so that the limiting ring 26 can limit the movement piston 18; for the convenience of limiting the piston rod 2, a limiting nut 25 is provided on the double-ear bolt 24.

[0027] For example, to ensure the reliable connection of the limiting nut 21, a locking screw 20 is provided on the limiting nut 21.

[0028] The present invention is achieved in the following manner:

[0029] Hydraulic oil is introduced through the lowering nozzle 9. The hydraulic oil enters the cavity A, pushing the locking structure to move to the right. The piston rod 2 moves to the right, causing the left locking collar 6 to slide from the left step to the right end, achieving unlocking. During the process of the moving piston 5 moving to the right, the blind hole at its left end moves to the position of the steel ball 15, causing the moving piston 5 to squeeze the right locking collar 4. When the right locking collar 4 moves to the right step, the right locking collar 4 slides into the right step, achieving locking. During the process of the piston rod 2 moving to the right, the piston rod 2 drives the limit nut 21 and the double-ear bolt 24 to move to the right together. When the bottom of the large hole contacts the moving piston 18, it drives the moving piston 18 to move to the right together until the right locking collar 4 is locked, completing the extension of the piston rod 2.

[0030] After the piston rod 2 extends, hydraulic oil is introduced through the retracting nozzle 19. The hydraulic oil enters the cavity C, pushing the locking structure to move to the left. The piston rod 2 moves to the left, causing the right locking collar 4 to slide from the right step to the left end, achieving unlocking. During the process of the moving piston 5 moving to the left, the blind hole at its right end moves to the position of the steel ball 15, causing the moving piston to squeeze the left locking collar 6. When the left locking collar 6 moves to the left step, the left locking collar 6 slides into the left step, achieving locking. While the piston rod 2 moves to the left, the hydraulic oil enters the cavity B from the cavity C through the oil passage hole on the piston rod 2, pushing the moving piston 18 to move to the right until it is limited by the limit nut 21, and then moves to the left together with the limit nut 21 until the left collar 6 is locked, completing the retraction of the piston rod 2.

[0031] Other details not elaborated in the present invention are all well-known conventional techniques in the art.

[0032] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention all fall within the protection scope of the present invention.

Claims

1. An actuating cylinder with a mechanical lock structure for reducing the volume difference between two chambers, comprising an outer cylinder, one end of the outer cylinder is connected with an end cover, a lowering nozzle is arranged on the end cover, a retracting nozzle is arranged at the other end of the outer cylinder, and a piston rod is arranged in the outer cylinder, characterized in that: The piston rod is a stepped shaft with a stepped through hole inside. A plunger rod is arranged in the stepped through hole. One end of the plunger rod is connected to the end cover. A locking structure is provided at the end of the piston rod extending into the inner part of the outer cylinder. A cavity A is formed among the end cover, the plunger rod, the locking structure and the outer cylinder. The lowering nozzle is communicated with the cavity A. An internal thread is provided at the outer end of the piston rod. A limit nut and a double-ear bolt are sequentially connected to the internal thread from inside to outside. A moving piston is arranged between the piston rod and the plunger rod. A cavity B is formed among the moving piston, the plunger rod and the piston rod. The retracting nozzle is communicated with the cavity B. A sealing cover is arranged between the outer cylinder and the piston rod. A locking nut is provided on the outer side of the sealing cover. The locking nut is threadedly connected to the outer cylinder. A cavity C is formed among the locking structure, the piston rod, the sealing cover and the outer cylinder. An oil through hole is provided on the piston rod to communicate the cavity B and the cavity C; Wherein, the locking structure includes a fastening nut, a left locking ring, a moving piston, a right locking ring, a left bushing, a right bushing, steel balls and a support sleeve. The step in the piston rod serves as a limit step. The support sleeve is arranged at the end of the piston rod and fixed by the fastening nut. The fastening nut is threadedly connected to the piston rod. The moving piston is arranged on the piston rod. The left locking ring and the right locking ring are respectively arranged at both ends of the moving piston. A through hole II is provided on the piston rod wall. The steel balls are arranged in the through hole II and pressed by the moving piston. The left bushing and the right bushing are both arranged between the piston rod and the plunger rod. Springs are provided between the left bushing and the support sleeve and between the right bushing and the limit step. The steel balls press on the connection part of the left bushing and the right bushing; Through holes III are provided on both the left bushing and the right bushing. The oil through hole is provided on the piston rod at the end where the locking structure is installed.

2. The actuating cylinder for reducing the volume difference between two chambers and having a mechanical locking structure as claimed in claim 1, wherein: The plunger rod is provided with a through hole I along the axial direction.

3. The actuator with a mechanical lock structure for reducing the volume difference between two chambers as described in claim 2, wherein: A counterbore is provided in the middle of the end cover. A connecting screw rod is arranged in the counterbore. The other end of the connecting screw rod is connected to the plunger rod. A fastening nut and a locking nut are further provided in the counterbore from inside to outside.

4. The actuating cylinder with a mechanical locking structure for reducing the volume difference between two chambers as claimed in claim 1, wherein: Left and right steps are provided on the inner wall of the outer cylinder for locking the left and right locking rings respectively.

5. The actuating cylinder with a mechanical locking structure for reducing the volume difference between two chambers as claimed in claim 1, wherein: A limit ring is provided at the end of the plunger rod.

6. The actuator with a mechanical lock structure for reducing the volume difference between two chambers as claimed in claim 1, wherein: A limit nut is provided on the double-ear bolt.

7. The actuator with a mechanical locking structure for reducing the volume difference between two chambers according to any one of claims 1-6, characterized in that: A lock prevention screw is provided on the limit nut.

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