Spring hydraulic cylinder

Abstract

The utility model discloses a spring hydraulic cylinder relates to hydraulic transmission technical field. The hydraulic cylinder includes first outer casing body and second outer casing body through the thread connection. The oil port is equipped on the first outer casing body, and the piston body is slidably installed in it, and the spring is equipped between the piston body and the second outer casing body. The piston rod is connected on the piston body, and the piston rod stretches out from the guide port of second outer casing body. The utility model discloses the stroke limit of piston body is realized through setting the step at the connecting place of first outer casing body and second outer casing body, and the air muffler is installed in the exhaust port to reduce the noise, and the combined sealing guide structure that is composed of first guide ring, sealing ring and second guide ring is set up on the outer ring surface of piston body, improves the sealing reliability and motion stability, and the bushing and wiper ring are set up in the guide port, and the guide precision is improved and is effectively prevented the pollution. The utility model has the advantages of compact structure, reliable connection, long service life, and friendly working environment.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic actuator technology, specifically to a spring hydraulic cylinder with a compact structure, good sealing performance, and stable operation. Background Technology

[0002] A spring-loaded hydraulic cylinder is a common hydraulic actuator. It uses hydraulic pressure to extend the piston rod and relies on the built-in spring force to return it to its original position. It is widely used in applications requiring single-acting power, such as mold clamping and equipment braking.

[0003] Existing spring hydraulic cylinders have revealed some shortcomings during long-term use: First, the outer shell is mostly connected by bolts or clasps, resulting in poor overall rigidity and impact resistance, making it prone to loosening under frequent pressure fluctuations; second, the piston's sealing structure is relatively simple, making it susceptible to internal leakage due to wear, affecting operational stability; third, during the reciprocating motion of the piston rod, external contaminants such as dust and cutting fluid are easily introduced into the cylinder, accelerating the wear of seals and guide components; in addition, during the initial filling of the hydraulic cylinder, internal air is discharged through the ordinary vent, generating significant noise and affecting the working environment.

[0004] Therefore, providing a spring hydraulic cylinder with a compact structure, reliable connection, good sealing performance, strong anti-fouling ability and low operating noise is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this utility model is to overcome the defects of the prior art and provide a spring hydraulic cylinder that has a firm connection, reliable sealing, long service life and noise reduction function.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A spring-loaded hydraulic cylinder includes a first outer shell, a second outer shell, a piston rod, a piston body, and a spring. The first and second outer shells are directly connected by threads to form a rigid, integral cylinder. The first outer shell has an oil port for receiving hydraulic oil, and the piston body is slidably mounted within its inner cavity. The spring is positioned between the piston body and the second outer shell. One end of the piston rod is fixedly connected to the piston body, and the other end slides through a guide opening in the second outer shell and extends outward. An exhaust port for venting air from the cylinder is also provided on the side wall of the second outer shell.

[0008] As a further improvement of this utility model, after the first outer shell and the second outer shell are screwed together, an annular stepped surface is formed on the inner wall of their connection. This stepped surface constitutes a mechanical limit on the return stroke of the piston body, preventing it from excessively impacting the second outer shell.

[0009] As a further improvement of this utility model, an air silencer is fixedly installed inside the exhaust port. This air silencer can effectively reduce the exhaust airflow velocity, thereby significantly reducing the noise generated during exhaust.

[0010] As a further improvement of this utility model, three annular connecting grooves are sequentially formed along the axial direction on the outer ring surface of the piston body. A first guide ring, a sealing ring, and a second guide ring are respectively embedded in these three connecting grooves. The sealing ring is located in the middle and is responsible for preventing hydraulic oil leakage between the piston body and the inner wall of the first outer shell; the first guide ring and the second guide ring are distributed on both sides of the sealing ring, jointly providing support and guidance for the piston body, preventing uneven wear and jamming.

[0011] As a further improvement of this utility model, a bushing is fixedly installed inside the guide port. This bushing provides sliding support and guidance for the piston rod, reducing friction and wear. A scraper ring is also fixedly installed at the outer outlet of the guide port to scrape off contaminants adhering to the piston rod's surface when it retracts.

[0012] As a further improvement of this utility model, an O-ring is provided at the connection between the piston rod and the piston body to achieve static sealing and prevent hydraulic oil from leaking from this point.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] Reliable connection and compact structure: The first and second outer shells are directly connected by threads, eliminating the need for additional connectors, resulting in a more compact structure and stronger connection rigidity and impact resistance.

[0015] Good sealing performance and long service life: The piston body adopts a multi-combination sealing and guiding structure of "guide ring-sealing ring-guide ring", which not only ensures the reliability of dynamic sealing, but also disperses lateral forces through the guide rings on both sides, reducing wear and extending service life.

[0016] Strong anti-fouling capability: A scraper ring is installed at the guide port outlet, which can effectively prevent external contaminants from entering the cylinder, protecting the internal seals and guide components, and is suitable for harsh working conditions.

[0017] Smooth operation and low noise: An air muffler is installed at the exhaust port to eliminate exhaust whine and improve the working environment. At the same time, the mechanical stroke limit step reduces impact during piston return, resulting in smoother operation. Attached Figure Description

[0018] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0019] Reference numerals: 1. Second outer casing; 2. Piston rod; 3. Piston body; 4. First outer casing; 5. Spring; 6. Bushing; 7. Air muffler; 8. Wiper ring; 9. First guide ring; 10. Sealing ring; 11. Second guide ring; 12. O-ring. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention. Figure 1 As shown, the spring hydraulic cylinder provided by this utility model consists of a first outer shell 4 and a second outer shell 1 connected by threads. The first outer shell 4 has an oil port (not shown in the figure) for connecting to the hydraulic system. The piston body 3 is installed in the inner hole of the first outer shell 4 and can slide along its inner wall. The piston rod 2 is connected to the piston body 3 by threads, and an O-ring 12 is installed at their mating surface to ensure reliable static sealing.

[0021] Three annular grooves are sequentially machined on the outer circumference of the piston body 3, from the side closest to the piston rod towards the spring side, where a first guide ring 9, a sealing ring 10, and a second guide ring 11 are respectively installed. The sealing ring 10 (such as a Y-ring or Glyd ring) is responsible for the main seal, preventing pressurized oil from leaking from one side of the piston to the other. The first guide ring 9 and the second guide ring 11 (such as guide strips made of polytetrafluoroethylene or polymer materials) are responsible for supporting the piston body 3, allowing it to slide smoothly within the cylinder and avoiding direct metal-to-metal contact that could cause wear and jamming.

[0022] The end of the second outer casing 1 is machined with a precision guide hole, into which a bushing 6 made of wear-resistant material (such as copper-based alloy or engineering plastic) is press-fitted to guide the piston rod 2 and ensure the straightness of its extension and retraction. On the outside of the guide hole, a wiper ring 8 (such as a polyurethane dust scraper ring) is installed to scrape off dust, moisture and other contaminants adhering to the surface of the piston rod 2 when it retracts.

[0023] The second outer casing 1 has an exhaust port machined on its side wall and is equipped with an air muffler 7. When the hydraulic cylinder is used for the first time or refilled with oil after maintenance, the air accumulated inside can be discharged through this exhaust port, and the air muffler 7 can effectively reduce exhaust noise.

[0024] Spring 5 is installed in the cavity between piston body 3 and second outer shell 1. When hydraulic oil enters the rodless chamber of first outer shell 4 through the oil port, the pressurized oil pushes piston body 3, compresses spring 5, and piston rod 2 extends outward to perform its function. When the oil pressure is released, the compressed spring 5 releases its energy, pushing piston body 3 to move in the opposite direction, causing piston rod 2 to retract and achieve reset. At the end of the reset stroke, piston body 3 contacts the stepped surface formed at the connection between first outer shell 4 and second outer shell 1, thereby achieving mechanical limiting.

[0025] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A spring hydraulic cylinder, comprising a first outer shell (4), a second outer shell (1), a piston rod (2), a piston body (3), and a spring (5), wherein the first outer shell (4) and the second outer shell (1) are connected by threads, characterized in that: An oil port is provided on the first outer shell (4). A piston body (3) is slidably installed inside the first outer shell (4). A spring (5) is provided between the piston body (3) and the second outer shell (1). A piston rod (2) is fixedly connected to the piston body (3). A guide port is provided on the second outer shell (1). The piston rod (2) slides out of the guide port. An exhaust port is provided on the side wall of the second outer shell (1).

2. A spring hydraulic cylinder according to claim 1, characterized in that: A step is formed at the connection between the first outer shell (4) and the second outer shell (1) to limit the stroke of the piston body (3).

3. A spring hydraulic cylinder according to claim 1, characterized in that: An air silencer (7) is fixedly installed inside the exhaust port.

4. A spring hydraulic cylinder according to claim 1, characterized in that: The piston body (3) has three connecting grooves sequentially opened on its outer ring surface, and a first guide ring (9), a sealing ring (10), and a second guide ring (11) are respectively installed in the connecting grooves.

5. A spring hydraulic cylinder according to claim 1, characterized in that: A bushing (6) is fixedly installed inside the guide port, and a wiper ring (8) is fixedly installed at the outlet of the guide port.

6. A spring hydraulic cylinder according to claim 1, characterized in that: An O-ring (12) is provided between the piston rod (2) and the piston body (3).

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