Multi-rod plunger long-stroke hollow hydraulic cylinder

Abstract

The utility model provides a multi-rod plunger long-stroke hollow hydraulic cylinder which comprises an annular cylinder body, the annular cylinder body comprises an oil inlet cavity, an oil port communicated with the oil inlet cavity is formed in the annular cylinder body, a plurality of groups of holes which are evenly distributed in the annular direction at intervals are formed in the end of the annular cylinder body, plunger rods are arranged in the multiple groups of holes in a sliding and penetrating mode along the axes of the holes, and the plunger rods are connected with the oil inlet cavity. Outer guide assemblies are arranged on the annular cylinder body in a sliding mode along the axes of the plunger rods, the outer guide assemblies are fixedly connected with the ends, extending out of the annular cylinder body, of the multiple sets of plunger rods, inner guide assemblies are arranged in the multiple sets of holes, and the inner guide assemblies conduct inner guide on the plunger rods. When the hydraulic cylinder is used, stress is more uniform, unbalance loading resistance and lateral force resistance are higher, the hydraulic cylinder is particularly suitable for the working condition of a long-stroke hydraulic cylinder, and the service life of the hydraulic cylinder is greatly prolonged. And meanwhile, the hollow structure of the hydraulic cylinder facilitates penetration of a mandrel and is used for load lifting working conditions, and the application range of the hydraulic cylinder is expanded.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic cylinders, in particular to a multi-rod plunger long-stroke hollow hydraulic cylinder. Background Art

[0002] A plunger hydraulic cylinder is a single-acting cylinder. Its hydraulic power can only be applied in one direction, and the plunger's return stroke usually relies on gravity or an external force. Due to its simple structure, single-acting plunger hydraulic cylinders are commonly used to achieve movement in applications with unidirectional loads, such as lifting large metallurgical machinery, horizontally pushing heavy equipment, and raising the barrel of a military gun.

[0003] For example, the Chinese invention patent with publication number CN104454756B provides a self-returning plunger hydraulic cylinder, which includes an annular cylinder body with a cylindrical structure and a plunger extending into the interior of the annular cylinder body; the plunger is a cylindrical structure, and one end of which is closed outside the annular cylinder body; it also includes a piston rod, one end of which is fixedly connected to the annular cylinder body, and the other end extends to the interior of the plunger, forming a closed cavity inside the plunger, and vacuuming the closed cavity.

[0004] Another example is the Chinese utility model patent with publication number CN212868088U, which provides a long-stroke plunger hydraulic cylinder, including a cylinder barrel and a plunger. A cylinder cover is provided at the end of the cylinder barrel to close the cylinder barrel, one end of the plunger is arranged in the cylinder barrel, and a plunger ring is provided at the end of the plunger arranged in the cylinder barrel; a guide rail is provided in the cylinder barrel, and a guide slider is provided on the end of the plunger arranged in the cylinder barrel. The plunger slides and moves in the cylinder barrel, and the guide slider cooperates with the guide rail.

[0005] By analyzing the above patents and combining them with existing technologies, it is found that most of the existing hydraulic cylinders are single-plunger structures, and most of the application scenarios of single-plunger hydraulic cylinders are non-vertical installations. When the mass of the plunger is large, the plunger rod is unevenly stressed, and the overall structure of the hydraulic cylinder is easily bent downward due to the weight of the plunger, resulting in unilateral wear of the seals and guides. Especially for the use of long-stroke hydraulic cylinders, there are often eccentric loads and lateral forces, which also cause unilateral wear of the seals and guides of the single-plunger hydraulic cylinder, causing oil leakage in the hydraulic cylinder seal, greatly reducing the service life of the hydraulic cylinder. In addition, since the plunger hydraulic cylinder is single-chamber controlled, the piston rod can usually only be extended for jacking conditions. When used for load lifting conditions, it is usually achieved by using an external auxiliary arm, which has a bulky structure. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model proposes a multi-rod, long-stroke hollow hydraulic cylinder. This solves the technical issues identified in the background art above, such as unilateral wear of seals and guides caused by eccentric loading and lateral forces in existing non-vertically mounted and long-stroke plunger hydraulic cylinders. Furthermore, the hollow structure of this hydraulic cylinder facilitates the insertion of a core shaft, making it suitable for load-lifting applications, thus expanding its application range.

[0007] To achieve the above objectives, the present invention provides the following technical solutions: a multi-rod plunger long-stroke hollow hydraulic cylinder, comprising:

[0008] An annular cylinder body, the annular cylinder body including an oil inlet chamber, an oil port communicating with the oil inlet chamber is formed on the annular cylinder body, and a plurality of groups of holes evenly spaced annularly and communicating with the oil inlet chamber are formed on the end of the annular cylinder body;

[0009] The plunger rod is provided with the same number as the holes and is respectively slidably provided along its axis through the plurality of holes;

[0010] An external guide assembly, fixedly connected to the ends of the multiple groups of plunger rods, and guiding the plunger rods outward along the outer cylinder wall of the annular cylinder body; and

[0011] There are multiple sets of inner guide components, which are respectively arranged in the multiple sets of holes and connected with the multiple sets of plunger rods to guide the plunger rods internally.

[0012] In a preferred embodiment, the annular cylinder comprises:

[0013] a first cylinder head, wherein a second cylinder head is provided on one side of the first cylinder head and arranged in parallel with each other;

[0014] an inner cylinder barrel, both ends of which are sealed and fixedly connected to the first cylinder head and the second cylinder head respectively; and

[0015] The outer cylinder barrel has two ends respectively sealed and fixedly connected to the first cylinder head and the first cylinder head, and is sleeved on the inner cylinder barrel to form an annular cavity for the plunger rod to move.

[0016] In a preferred embodiment, the first cylinder head and the second cylinder head are annular, and the inner cylinder barrel is hollow and communicates with the center holes of the first cylinder head and the second cylinder head to cooperate to form a core shaft hole.

[0017] In a preferred embodiment, the outer guide assembly includes an outer guide sleeve, which is cylindrical and slidably sleeved on the annular cylinder along its axis, and the ends of multiple groups of plunger rods are fixedly connected to the outer guide sleeve.

[0018] In a preferred embodiment, the inner guide assembly includes:

[0019] An inner guide sleeve is disposed in the oil inlet chamber and communicates with the hole, and the plunger rod is slidably disposed in the inner guide sleeve; and

[0020] A sealing member is arranged in the inner guide sleeve and contacts the outer wall of the plunger rod to seal the gap between the plunger rod and the inner guide sleeve.

[0021] In a preferred embodiment, a mounting flange is provided at the end of the annular cylinder.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. When the hydraulic cylinder is in use, the oil port is connected to the external hydraulic system pressure oil, and oil is supplied to the oil inlet chamber through the oil port to drive multiple plunger rods to move synchronously under the action of the external guide assembly. The hydraulic cylinder decomposes the traditional single plunger rod into multiple, and seals and guides the multiple plunger rods respectively through the cooperation of multiple groups of internal guide assemblies, so that the force of the hydraulic cylinder is more uniform during use, and the plunger rod has no contact with the inside of the oil inlet chamber. Only the surface of the plunger rod needs to be fine-machined to ensure the sealing performance, which reduces the processing difficulty and has a longer sealing life. The overall movement of the multiple groups of plunger rods is guided by the external guide assembly, and the ability to resist off-center load and lateral force is stronger, so that when it is not installed vertically, it is not easy for the plunger rod to bend downward due to its own weight, which effectively avoids the unilateral wear of the contact surface caused by uneven force when the plunger rod contacts the annular cylinder body, greatly improving the service life of the hydraulic cylinder. Especially for the use of long-stroke hydraulic cylinders, since the internal and external guide methods increase the piston rod rigidity and the ability to resist side loads and lateral forces, the stroke of the hydraulic cylinder can be made longer and the service life of the hydraulic cylinder is also improved.

[0024] 2. The annular cylinder body of this hydraulic cylinder, formed by the first and second cylinder heads, inner and outer cylinders, forms an annular cavity. This allows the hydraulic cylinder to pass the mandrel of a mechanical device through the mandrel hole, enabling load lifting. The mandrel hole can also be used to route cables or other components. Compared to traditional external cables, this hydraulic cylinder protects the cables during routing, reducing wear on the moving parts of the cables during use, effectively extending the cable's lifespan and enhancing the appearance and practicality of the mechanical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0026] Figure 1 A cross-sectional view of a multi-rod plunger long-stroke hollow hydraulic cylinder provided by the utility model;

[0027] Figure 2 The utility model is a cross-sectional schematic diagram of a multi-rod plunger long-stroke hollow hydraulic cylinder.

[0028] Reference numerals:

[0029] 1. First cylinder head; 2. Mounting flange; 3. Outer cylinder barrel; 4. Outer guide sleeve; 5. Plunger rod; 6. Core shaft hole; 7. Inner guide sleeve; 8. Oil port; 9. Second cylinder head; 10. Inner cylinder barrel. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technicians in this field can make some non-essential improvements and adjustments to the present invention based on the above application content.

[0031] Example:

[0032] like Figure 1 、 2 As shown, the utility model provides a multi-rod plunger long-stroke hollow hydraulic cylinder, including an annular cylinder body, the annular cylinder body including an oil inlet chamber, an oil port 8 connected to the oil inlet chamber is opened on the annular cylinder body, and a plurality of groups of holes arranged evenly in annular space and connected to the oil inlet chamber are opened at the end of the annular cylinder body. The annular cylinder body includes a first cylinder head 1, a second cylinder head 9, an inner cylinder barrel 10 and an outer cylinder barrel 3. The first cylinder head 1 and the second cylinder head 9 are arranged in parallel with each other, and the ends of the inner cylinder barrel 10 and the outer cylinder barrel 3 are sealed and fixedly connected to the first cylinder head 1 and the first cylinder head 1 respectively. The outer cylinder barrel 3 is sleeved on the inner cylinder barrel 10 and forms an annular cavity for the movement of the plunger rod 5. The first cylinder head 1 and the second cylinder head 9 are annular, and the inner cylinder barrel 10 is a hollow structure and is connected to the center holes of the first cylinder head 1 and the second cylinder head 9 to form a core shaft hole 6.

[0033] It is installed in the use area, and a mounting flange 2 is provided at the end of the annular cylinder body to facilitate the installation of the hydraulic cylinder. The cable or core shaft can be passed through the core shaft hole 6 formed by the first cylinder head 1 and the second cylinder head 9 and the inner cylinder barrel 10. The core shaft is used for load lifting conditions, and when the cable is passed through, the cable can be protected and the aesthetics of the equipment can be improved.

[0034] like Figure 1 、 2As shown, in this embodiment, there are also plunger rods 5 with the same number of holes, and multiple groups of plunger rods 5 are respectively slidably arranged along their axes and penetrated into the multiple groups of holes. An outer guide assembly is slidably arranged on the annular cylinder body along the axes of the plunger rods 5. The outer guide assembly is fixedly connected to one end of the multiple groups of plunger rods 5 extending out of the annular cylinder body. The outer guide assembly includes an outer guide sleeve 4, which is cylindrical and slidably sleeved on the annular cylinder body along its axis. The ends of the multiple groups of plunger rods 5 are fixedly connected to the outer guide sleeve 4.

[0035] The outer guide sleeve 4 can slide on the annular cylinder body along its axis, thereby externally guiding and positioning the movement of multiple groups of plunger rods 5, improving the anti-bending performance of the hydraulic cylinder and improving the anti-eccentric load capability and reliability of the hydraulic cylinder.

[0036] like Figure 1 As shown, in this embodiment, multiple groups of holes are each provided with an inner guide assembly connected to multiple groups of plunger rods 5, guiding the plunger rods 5. The inner guide assembly includes an inner guide sleeve 7 disposed within the oil inlet chamber and communicating with the holes. The plunger rods 5 slide through the inner guide sleeve 7. The inner guide sleeve 7 is provided with a seal that contacts the outer wall of the plunger rod 5 and seals the gap between the plunger rod 5 and the inner guide sleeve 7.

[0037] The arrangement of multiple inner guide sleeves 7, in conjunction with the arrangement of outer guide sleeves 4, increases the guide contact area of ​​the plunger rod 5, further improving the seal life and the plunger rod's 5 anti-bending performance. This makes it particularly suitable for long-stroke hydraulic cylinders, broadening their application range and reducing their cost. Furthermore, the plunger rod 5 does not contact the annular cylinder body, and there is no requirement for the two to fit together. Therefore, only fine machining of the plunger rod 5 surface is required to ensure sealing performance, reducing machining difficulty and lowering material and processing costs.

[0038] Specific usage and beneficial effects of this utility model:

[0039] When in use, the hydraulic cylinder connects the oil port 8 to the pressure oil of the external hydraulic system, and supplies oil to the oil inlet chamber through the oil port 8, so as to drive multiple plunger rods 5 to move synchronously under the action of the external guide assembly. The hydraulic cylinder decomposes the traditional single plunger rod 5 into multiple ones, and seals and guides the multiple plunger rods 5 respectively through the cooperation of multiple groups of internal guide assemblies, so that the force of the hydraulic cylinder is more uniform during use, and the plunger rod 5 has no contact with the inside of the oil inlet chamber. It is only necessary to fine-tune the surface of the plunger rod 5 to ensure the sealing performance, which reduces the processing difficulty and has a longer sealing life; the overall movement of the plunger rod 5 is guided by the outer guide sleeve 4, and the ability to resist off-center load and lateral force is stronger, so that when it is not installed vertically and used, it is not easy for the plunger rod 5 to bend downward due to its own weight, which effectively avoids the uneven force when the plunger rod 5 contacts the annular cylinder body, resulting in unilateral wear of the contact surface, thereby greatly improving the service life of the hydraulic cylinder. Especially for the use of long-stroke hydraulic cylinders, since the internal and external guide methods increase the piston rod rigidity and the ability to resist side loads and lateral forces, the stroke of the hydraulic cylinder can be made longer and the service life of the hydraulic cylinder is also improved.

[0040] The annular cylinder body in the hydraulic cylinder is formed by the cooperation of the first cylinder head 1, the second cylinder head 9, the inner cylinder 10 and the outer cylinder 3 to form an annular cavity structure. When in use, the hydraulic cylinder can pass the core shaft of the mechanical equipment through the core shaft hole 6, which can be used for load lifting conditions, expanding the scope of use of the plunger hydraulic cylinder. The core shaft hole 6 can also be used to thread cables or other components. Compared with traditional external cables, this hydraulic cylinder can protect the cables when threading them, reducing wear on the moving part of the cables when the hydraulic cylinder is in use, effectively extending the service life of the cables, and making the appearance of the mechanical equipment more beautiful and practical.

[0041] The above shows and describes the basic principles, main features, and advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments. It is obvious to those skilled in the art that modifications or improvements can be made based on the present invention. Therefore, such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A multi-rod plunger long-stroke hollow hydraulic cylinder, characterized in that: Includes: An annular cylinder body, the annular cylinder body includes an oil inlet chamber, an oil port (8) is provided on the annular cylinder body and is connected to the oil inlet chamber, and a plurality of holes are provided at the end of the annular cylinder body and are evenly spaced in an annular direction and are connected to the oil inlet chamber; The plunger rod (5) is provided with the same number of groups as the holes, and is respectively slidably provided along its axis and penetrates into the plurality of groups of holes; An external guide assembly is fixedly connected to the ends of the plurality of plunger rods (5) and guides the plunger rods (5) externally along the outer cylinder wall of the annular cylinder body; and There are multiple sets of inner guide components, which are respectively arranged in the multiple sets of holes and connected to the multiple sets of plunger rods (5) to guide the plunger rods (5) internally.

2. A multi-rod plunger long-stroke hollow hydraulic cylinder according to claim 1, characterized in that: The annular cylinder comprises: A first cylinder head (1), wherein a second cylinder head (9) is provided on one side of the first cylinder head (1) and arranged in parallel with each other; An inner cylinder (10), both ends of which are sealed and fixedly connected to the first cylinder head (1) and the first cylinder head (1); and The outer cylinder (3) has two ends sealed and fixedly connected to the first cylinder head (1) and the first cylinder head (1), and is sleeved on the inner cylinder (10) to form an annular cavity for the plunger rod (5) to move.

3. The multi-rod plunger long-stroke hollow hydraulic cylinder according to claim 2, characterized in that: The first cylinder head (1) and the second cylinder head (9) are annular in shape, and the inner cylinder barrel (10) is hollow and communicates with the center holes of the first cylinder head (1) and the second cylinder head (9) to cooperate to form a core shaft hole (6).

4. The multi-rod plunger long-stroke hollow hydraulic cylinder according to claim 1, characterized in that: The outer guide assembly comprises an outer guide sleeve (4), which is cylindrical and is slidably sleeved on the annular cylinder along its axis. The ends of multiple groups of plunger rods (5) are fixedly connected to the outer guide sleeve (4).

5. The multi-rod plunger long-stroke hollow hydraulic cylinder according to claim 1, characterized in that: The inner guide assembly includes: An inner guide sleeve (7) is disposed in the oil inlet chamber and communicates with the hole, and the plunger rod (5) is slidably inserted into the inner guide sleeve (7); and A sealing member is arranged in the inner guide sleeve (7) and contacts the outer wall of the plunger rod (5) to seal the gap between the plunger rod (5) and the inner guide sleeve (7).

6. The multi-rod plunger long-stroke hollow hydraulic cylinder according to claim 1, characterized in that: The end of the annular cylinder is provided with a mounting flange (2).

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