Large oil cylinder piston and piston rod locking assembly fixture

Abstract

The utility model discloses large -scale oil cylinder piston and piston rod's locking assembly fixture, including assembly drive arrangement, and assembly drive arrangement is provided with the central shaft, and the outside rotation cooperation of central shaft has the rotary element, and the cooperation end of rotary element is used for installing the piston, and the cooperation hole of central shaft can be inserted to the assembly of the assembly end of piston rod, and the cooperation hole is coaxial arrangement along the central axis of piston rod, when assembling, the vertical placement of piston rod makes its assembly end end face upward, and the upper coaxial sleeve of piston rod installs the piston, and the cooperation hole can form the circumferential limiting force and vertical support force of around its axis to the inserted part of central shaft, when the rotary element rotates relative to central shaft, can drive the rotation of piston relative to piston rod, and makes the assembly hole of piston can be screwed with the external thread of piston rod assembly end and is locked together, the utility model discloses can realize more accurate and smooth locking assembly with the aid of the dead weight of piston and piston rod, and then improves the assembly efficiency.

Description

Technical Field

[0001] This utility model relates to the field of assembly fixture technology, and in particular to a locking assembly fixture for large hydraulic cylinder pistons and piston rods. Background Technology

[0002] The assembly of large hydraulic cylinder pistons and piston rods typically involves interference fits and threaded connections. Interference fits are often achieved through hydraulic press fitting, while threaded connections are usually tightened using a torque wrench. In conventional threaded locking assemblies, manual pre-tightening is generally required to ensure easy rotation for several turns without noticeable jamming before using a torque wrench to complete the assembly. This avoids thread seizing or misalignment caused by forcing the screws in directly with a torque wrench. However, this also makes the assembly process cumbersome and less efficient. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a locking assembly fixture for large hydraulic cylinder pistons and piston rods, which can achieve more precise and smooth locking assembly by means of the self-weight of the piston and piston rod, thereby improving assembly efficiency.

[0004] Technical Solution: To achieve the above objectives, the present invention provides a locking assembly fixture for a large hydraulic cylinder piston and piston rod, comprising an assembly drive device. The assembly drive device is equipped with a central shaft, and a rotating component is rotatably fitted to the outside of the central shaft. The mating end of the rotating component is used to install the piston. The central shaft can be inserted into a mating hole at the assembly end of the piston rod, and the mating hole is coaxially arranged along the central axis of the piston rod. During assembly, the piston rod is placed vertically with its assembly end facing upwards, and the upper part of the piston rod is coaxially fitted with the piston. The mating hole can form a circumferential limiting force and a vertical supporting force around the axis of the inserted part of the central shaft. When the rotating component rotates relative to the central shaft, it can drive the piston to rotate relative to the piston rod, so that the internal thread of the piston's assembly hole can be tightly fitted with the external thread of the piston rod's assembly end.

[0005] Furthermore, the mating end of the rotating component is provided with a first mating component, which is vertically slidingly mated with at least two vertical extensions. Multiple vertical extensions are fixedly installed on the upper end face of the piston and are evenly distributed around the central axis of the piston.

[0006] Furthermore, the vertical extension adopts a bolt structure, the first mating part is provided with a corresponding vertical through hole, and the piston is provided with a corresponding threaded hole.

[0007] Furthermore, the first mating component is provided with multiple sets of vertical through holes, and the circumferential radii of the multiple sets of vertical through holes are different.

[0008] Furthermore, the first mating component and the rotating component are separately configured; the center of the first mating component is provided with a first mating hole, and the end of the rotating component is provided with a corresponding first mating part. The first mating part can be vertically inserted into the first mating hole, and the first mating hole can provide vertical support force and circumferential limiting force around the axis for the inserted part of the first mating part.

[0009] Furthermore, the first mating part and the annular surface of the first mating hole are engaged by a toothed structure.

[0010] Furthermore, a second mating component is fixedly installed on the end face of the piston rod assembly end. The second mating component has a second mating hole along its central axis, and the central shaft is inserted into the second mating hole.

[0011] Furthermore, the second mating hole is a countersunk hole with a polygonal cross-section, and the insertion end of the central shaft is machined to form an insertion section that is adapted to the structure of the second mating hole.

[0012] Beneficial effects: The locking assembly fixture for the large hydraulic cylinder piston and piston rod of this utility model has at least the following advantages:

[0013] 1. By inserting the central shaft into the mating hole at the end of the piston rod, and taking into account the self-weight effect of the piston rod when it is placed vertically, the circumferential rotational freedom and vertical lifting freedom of the central shaft are constrained. Then, by installing the piston relative to the rotating parts and providing uniform torque by the drive device, the purpose of assembling the piston relative to the piston rod is achieved.

[0014] 2. The insertion fit between the central shaft and the mating hole enables automatic alignment before the internal and external threads engage.

[0015] 3. The entire tightening process is completely hands-free. Since there is no manual contact, it is driven solely by the torque provided by the drive device and the weight of the piston. The threaded mating surfaces are subjected to balanced forces, with no forces acting in other directions, resulting in less resistance and a smoother tightening process.

[0016] 4. The modular fixture structure can effectively improve the efficiency of batch assembly, and the fixture is more versatile, which can meet the assembly needs of piston structures in a larger size range. Attached Figure Description

[0017] Figure 1 This is an assembly diagram of one embodiment of the locking assembly fixture of this utility model;

[0018] Figure 2 This is a schematic diagram of the relative assembly of the first mating part, the second mating part, the piston, and the piston rod. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] As attached Figure 1-2 The aforementioned locking assembly fixture for the large hydraulic cylinder piston and piston rod includes an assembly drive device 1. The assembly drive device 1 is provided with a central shaft 11, and a rotating component 12 is rotatably fitted on the outer side of the central shaft 11. The mating end of the rotating component 12 can movably mount the piston 3, allowing the piston 3 to slide closer to or away from the mating end of the rotating component 12. The central shaft 11 can be inserted into a mating hole at the assembly end of the piston rod 4, and the mating hole is coaxially arranged along the central axis of the piston rod 4. During assembly, the piston rod 4 is placed vertically with its assembly end facing upward, and the upper part of the piston rod 4 is coaxially fitted with the piston 3. The mating hole can form a circumferential limiting force and a vertical supporting force around the axis of the inserted part of the central shaft 11. When the rotating component 12 rotates relative to the central shaft 11, it can drive the piston 3 to rotate relative to the piston rod 4, so that the internal thread of the assembly hole of the piston 3 can be tightly fitted with the external thread of the assembly end of the piston rod 4.

[0021] The main body of the assembly drive device 1 can be an electric torque wrench, which is driven by a drive motor and the rotating parts are rotated by a gearbox, making it more convenient and flexible to use.

[0022] Considering the large size and weight of the components in a large hydraulic cylinder, to avoid misalignment of the threads during assembly due to their own weight, the piston rod is first placed vertically with the threaded end facing upwards. The piston 3 is then fitted onto the upper part of the external thread. Next, the assembly drive device 1 is installed. First, the piston 3 is installed relative to the rotating component 12, and then the end of the central shaft 11 is inserted relative to the mating hole, ensuring that the starting ends of the internal and external threads used for assembly and locking are aligned. When fully inserted, the assembly drive device 1 is positioned on the upper end of the piston rod, supported and limited by the central shaft. Because the piston rod is heavy and vertically placed on a horizontal surface, it provides a circumferential limit to the central shaft 11, preventing it from rotating around its own axis. At this point, the rotating component 12 is driven to rotate, causing the piston 3 to rotate at a uniform speed under the applied uniform torque force. Under its own weight, it gradually engages with the external thread on the upper part of the piston rod until the piston is fully locked in place relative to the piston rod. Throughout the assembly process, the piston rod is placed stably on the ground, and only the piston 3 moves vertically downward while rotating. The rotating part that drives the piston 3 to rotate also rotates within a fixed horizontal plane, thus making the locking process stable and reliable.

[0023] The rotating component 12 has a first mating component 2 at its mating end. The first mating component 2 is vertically slidably engaged with at least two vertical extensions 21. Multiple vertical extensions 21 are fixedly mounted on the upper end face of the piston 3 and are evenly distributed around the central axis of the piston 3. When installing the piston 3 relative to the rotating component 12, multiple vertical extensions are first installed on the piston. Then, the first mating component 2 is simultaneously fitted with multiple vertical extensions, ensuring that the central shaft is vertically aligned with the mating hole. This ensures that after the central shaft is inserted into the mating hole, the starting end of the piston's internal thread and the piston rod's external thread are perfectly aligned. During subsequent rotational locking, as the piston rotates downwards, multiple vertical extensions slide vertically with the first mating component 2, guiding the vertical movement of the piston. During the process, the vertical sliding relationship between the first mating part 2 and the vertical extension part 21 plays a good stabilizing role in the rotation locking process, ensuring that the piston always maintains a vertical downward movement state, avoiding lateral tilting and thus preventing misalignment. Furthermore, since the relative pressure between the threaded mating surfaces mainly comes from the piston's own weight, and the piston always rotates and descends in a horizontal state, its own weight is evenly distributed, preventing excessive pressure on any side and increasing resistance, making the tightening process very smooth.

[0024] Preferably, the vertical extension 21 adopts a bolt structure, and the first mating part 2 is provided with a corresponding matching vertical through hole, i.e., a threaded through hole, and the piston 3 is provided with a corresponding matching threaded hole. This makes the fixed installation of the vertical extension 21 relative to the piston more convenient and quick. After being fully locked in place, simply pull out the assembly drive device 1 vertically and then remove the vertical extension 21 on the piston to obtain the assembled piston structure. The pulled-out assembly drive device 1 can then be used for the assembly of other piston structures. When performing batch assembly of large hydraulic cylinder piston structures, its flexibility and convenience are highlighted, eliminating the need for time-consuming and laborious operations such as handling or clamping large piston structures, thus significantly improving assembly efficiency.

[0025] The first mating component 2 is provided with multiple sets of vertical through holes, and the circumferential radius of the multiple sets of vertical through holes is different. If each set contains two vertical through holes, the two vertical through holes are symmetrical about the piston axis. The vertical through holes with different radii can meet the installation requirements of pistons of different sizes, thereby improving the overall versatility of the fixture.

[0026] The first mating component 2 and the rotating component 12 are separately configured; the center of the first mating component 2 is provided with a first mating hole 22, and the end of the rotating component 12 is provided with a first mating part 13. The first mating part 13 can be vertically inserted into the first mating hole 22, and the first mating hole 22 can form a vertical support force and a circumferential limiting force around the axis for the inserted part of the first mating part 13.

[0027] This allows the first mating part 2 and the main driving part of the assembly drive device 1 to be used as a common part. When performing batch assembly operations, the vertical extension 21 can be fixedly installed on each piston 3 first. When it is time to assemble, the first mating part 2 is inserted relative to the multiple vertical extensions 21, and then a special torque wrench is inserted relative to the mating hole at the end of the piston rod of the first mating part 2. The assembly operation can be performed immediately. After completion, the common part can be pulled out in sequence for the assembly of the next piston structure. The disassembly of the vertical extension 21 relative to the assembled piston structure can be carried out independently, which further improves the efficiency of batch assembly.

[0028] Preferably, the annular surfaces of the first mating part 13 and the first mating hole 22 are engaged by a toothed structure.

[0029] A second mating component 5 is fixedly installed on the assembly end face of the piston rod 4. The second mating component 5 has a second mating hole 51 along its central axis, and the central shaft 11 is inserted into the second mating hole 51. The second mating hole 51 mainly prevents the piston and piston rod from rotating together. By making it a detachable independent module, it is unnecessary to directly create a mating hole on the piston rod, making the piston structure more functionally appropriate. During assembly, while installing the vertical extension 21 on the piston 3, the second mating component 5 can be installed on the corresponding piston rod.

[0030] Preferably, the second mating hole 51 is a countersunk hole with a polygonal cross section, and the insertion end of the central shaft 11 is machined to form an insertion section 14 that is adapted to the structure of the second mating hole 51.

[0031] The above are merely preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A locking assembly fixture for the piston and piston rod of a large hydraulic cylinder, characterized in that: The assembly includes an assembly drive device (1), which is provided with a central shaft (11). A rotating part (12) is rotatably fitted on the outside of the central shaft (11). The mating end of the rotating part (12) is used to install a piston (3). The central shaft (11) can be inserted into the mating hole of the assembly end of the piston rod (4). The mating hole is coaxially arranged along the central axis of the piston rod (4). During assembly, the piston rod (4) is placed vertically with its assembly end facing upwards. The piston (3) is coaxially fitted onto the upper part of the piston rod (4). The mating hole can form a circumferential limiting force and a vertical supporting force around the axis of the insertion part of the central shaft (11). When the rotating part (12) rotates relative to the central shaft (11), it can drive the piston (3) to rotate relative to the piston rod (4), so that the internal thread of the assembly hole of the piston (3) can be screwed tightly into the external thread of the assembly end of the piston rod (4).

2. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 1, characterized in that: The rotating part (12) is provided with a first mating part (2) at its mating end. The first mating part (2) is vertically slidably mated with at least two vertical extensions (21). Multiple vertical extensions (21) are fixedly installed on the upper end face of the piston (3) and are evenly arranged around the central axis of the piston (3).

3. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 2, characterized in that: The vertical extension (21) adopts a bolt structure, the first mating part (2) is provided with a corresponding vertical through hole, and the piston (3) is provided with a corresponding threaded hole.

4. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 3, characterized in that: The first mating part (2) is provided with multiple sets of vertical through holes, and the circumferential arrangement radius of the multiple sets of vertical through holes is different.

5. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 2, characterized in that: The first mating part (2) and the rotating part (12) are separately arranged; the center of the first mating part (2) is provided with a first mating hole (22), and the end of the rotating part (12) is provided with a first mating part (13). The first mating part (13) can be vertically inserted into the first mating hole (22), and the first mating hole (22) can form a vertical support force and a circumferential limiting force around the axis for the inserted part of the first mating part (13).

6. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 5, characterized in that: The first mating part (13) and the annular surface of the first mating hole (22) are engaged by a toothed structure.

7. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 5, characterized in that: The piston rod (4) is fixedly mounted on the end face of the assembly end. The second mating part (5) is provided with a second mating hole (51) along its central axis. The central shaft (11) is inserted into the second mating hole (51).

8. The locking assembly fixture for the piston and piston rod of a large hydraulic cylinder according to claim 7, characterized in that: The second mating hole (51) is a countersunk hole with a polygonal cross section, and the insertion end of the central shaft (11) is machined to form an insertion section (14) that is adapted to the structure of the second mating hole (51).

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