Compact type double-acting oil cylinder and lateral moving frame

Abstract

The invention relates to the technical field of oil cylinders, and particularly discloses a compact type double-acting oil cylinder and a side moving frame. The cylinder barrels are arranged in the cylinder body, and oil ports are formed in the ends, close to each other, of the two cylinder barrels; the piston rod is slidably arranged in the cylinder barrel; the connectors are located at the ends, close to each other, of the two cylinder barrels, one ends of the connectors are located outside the cylinder barrels, the ends, close to each other, of the two connectors communicate with each other, and the other ends of the connectors are located inside the cylinder barrels and provided with one-way conduction assemblies. When the oil pressure in the cylinder barrels is increased or the piston rod abuts against the one-way conduction assembly, the two ends of the connectors communicate with each other, and oil in the oil inlet cylinder barrel flows into the oil outlet cylinder barrel through the two connectors. The two cylinder barrels are communicated, and pressure oil in the high-pressure cylinder barrel can flow into the low-pressure cylinder barrel, so that the high-pressure oil is prevented from being directly discharged out of a system through an overflow valve, the high-pressure oil is prevented from being instantly released, and the possibility of pressure impact caused by sudden pressure drop of the hydraulic system is reduced.

Description

Technical Field

[0001] This application relates to the field of hydraulic cylinder technology, and in particular to a compact double-acting hydraulic cylinder and a side-shifting frame. Background Technology

[0002] Forklifts typically have a side-shift carriage on their fork carriage. The side-shift carriage is mainly used for lateral movement of the forks and load to improve the forklift's maneuverability and efficiency in confined spaces. For example, in narrow aisles or loading / unloading platforms, the side-shift carriage can be used to move the forks left and right to precisely align pallets or goods, avoiding repeated adjustments to the forklift's position.

[0003] Lateral sliding of the side-shifting frame is typically driven by a double-acting hydraulic cylinder. A double-acting cylinder is a hydraulic actuator whose piston movement in both directions is driven by hydraulic oil pressure. In traditional double-acting cylinders, when the piston reaches its limit distance, the oil in the high-pressure chamber is directly discharged from the system through a relief valve. This direct pressure release from the relief valve causes a sudden drop in hydraulic system pressure, triggering a pressure shock, also known as water hammer. This pressure shock can easily damage hydraulic components, reduce the service life and stability of the hydraulic system, and affect the normal operation of the equipment. Summary of the Invention

[0004] To mitigate the impact of pressure shocks on equipment, this application provides a compact double-acting hydraulic cylinder and a side-shifting frame.

[0005] In a first aspect, this application provides a compact double-acting hydraulic cylinder, which adopts the following technical solution: A compact double-acting hydraulic cylinder, including a cylinder body; There are two cylinders, which are coaxially arranged inside the cylinder body, and each of the two cylinders has an oil port at one end that is close to the other. Two piston rods are provided and correspond to two cylinders. The piston rods are slidably disposed in the cylinders. When oil enters through the oil port on one of the cylinders, oil exits through the oil port on the other cylinder, so that the two piston rods move in the same direction. The connector has two parts, each corresponding to one of the two cylinders. The connector is located at one end of the two cylinders that are close to each other. One end of the connector is located outside the cylinder and the two ends of the connector that are close to each other are connected to each other. The other end of the connector is located inside the cylinder and is provided with a one-way conduction component. When the oil pressure in the cylinder increases or the piston rod abuts against the one-way conduction component, the two ends of the connector are connected to each other, so that the oil in the inlet cylinder flows into the outlet cylinder through the two connectors.

[0006] By adopting the above technical solution, the oil in the inlet cylinder can flow into the outlet cylinder through the two connectors, avoiding the direct discharge of high-pressure oil into the system through the relief valve. This prevents the sudden release of high-pressure oil from causing a sudden drop in hydraulic system pressure and resulting in pressure shock, reducing the possibility of damage to hydraulic components. It can also reduce hydraulic pressure fluctuations, improve the stability of the entire pressure system, and extend its service life.

[0007] Optionally, a sealing ring is provided on the open side of the cylinder, the sealing ring abuts against the piston rod, and the piston rod and the inner wall of the cylinder are spaced apart.

[0008] By adopting the above technical solution, a sealing ring that abuts against the piston rod is set on the cylinder opening side, which can prevent oil leakage from the gap between the cylinder and the piston rod, ensuring sealing performance. The piston rod and the inner wall of the cylinder are spaced apart, which can reduce direct contact and friction between the two, reduce wear, and extend the service life of the components. In addition, the cylinder in this application only has a piston rod inside, and no piston is set at the end of the piston rod. Since the overall length is short, the piston is omitted and it is not easy to affect the stability of the piston rod sliding process. Furthermore, conventional oil cylinders have a sealing sleeve set at the end of the piston and a sealing sleeve set at the guide sleeve. There are many sealing parts, which can easily lead to internal leakage problems. However, in this application, the piston rod replaces the piston rod and piston combination form, so there is no need to pay attention to the problem of internal leakage. Only the sealing of the guide sleeve side needs to be checked, which reduces the probability of failure.

[0009] Optionally, the diameter of the piston rod is greater than four-fifths of the cylinder's inner diameter.

[0010] By adopting the above technical solution, the piston rod has a larger diameter, which can improve the load-bearing capacity of the piston rod and also improve the overall structural strength of the hydraulic cylinder.

[0011] Optionally, a sliding groove is provided on the cylinder body on the open side of the cylinder barrel, and an insert is slidably arranged in the sliding groove along the radial direction of the cylinder barrel. A dustproof ring is provided in the insert, and the dustproof ring is sleeved on the outside of the piston rod. The sealing ring abuts against the insert.

[0012] By adopting the above technical solution, the dustproof ring on the insert protects the outside of the piston rod, reducing the possibility of dust entering the cylinder. The insert can be slidably installed into the groove. Compared with the traditional method of installing the cylinder head by threaded connection, it can effectively reduce the total installation length, thereby ensuring the displacement of the piston rod.

[0013] Optionally, a sealing sleeve is provided at one end of the piston rod located inside the cylinder. The sealing sleeve has an annular cross-section and its length direction is along the axis of the piston rod. The sealing sleeve is flexible and can retract or extend along its own length direction. One end of the sealing sleeve is fixedly connected to the end of the piston rod, and the other end of the sealing sleeve is fixedly connected to the inner wall of the cylinder.

[0014] By adopting the above technical solution, when the piston rod moves, the sealing sleeve can retract or extend with the piston rod. The sealing sleeve is fixedly connected between the end of the piston rod and the inner wall of the cylinder. The sealing sleeve separates the side wall of the piston rod from the area inside the cylinder, so that the pressure oil in the cylinder cannot contact the side wall of the piston rod. Therefore, when the piston rod slides outward, it is not easy to carry out the pressure oil inside the cylinder, which can further ensure the sealing effect and ensure the stability of the hydraulic system inside the cylinder. Since the connection between the sealing sleeve and the inner wall of the cylinder always remains stationary and will not move with the piston rod, no wear will occur, thereby further ensuring the sealing effect of the sealing sleeve.

[0015] Optionally, the sealing sleeve is elastic.

[0016] By adopting the above technical solution, the piston rod can better adapt to the movement of the piston rod in the cylinder. When it retracts or extends with the movement of the piston rod, it can deform flexibly and is not easily damaged, maintaining the seal of the oil in the cylinder. In addition, when the movement of the piston rod causes the sealing sleeve to be stretched, some of the energy of the pressurized oil can be converted into the elastic potential energy of the sealing sleeve, thereby playing a certain buffering effect.

[0017] Optionally, the sealing sleeve includes an inner sleeve and an outer sleeve. The outer sleeve is coaxially spaced outside the inner sleeve. A connecting ring is fixedly connected between the end of the inner sleeve and the end of the outer sleeve. The inner sleeve, the outer sleeve, and the connecting rings at both ends together form a sealed cavity.

[0018] By adopting the above technical solution, air is stored in the sealed cavity. When the piston rod moves and the sealing sleeve is squeezed, the sealing sleeve can expand outward. Thus, a portion of the energy of the pressurized oil can be converted into the elastic potential energy of the sealing sleeve, further playing a buffering role and protecting the internal structure of the cylinder.

[0019] Optionally, a buckle is fixedly connected to the connecting ring at the end away from the piston rod, and an mounting ring is coaxially fixedly connected to the inner wall of the cylinder, with a slot for the buckle to be inserted into the mounting ring.

[0020] By adopting the above technical solution, when the piston rod is slid into the cylinder, the connecting ring can slide into the cylinder along with it until the buckle on the connecting ring is inserted into the groove on the mounting ring, thereby making the sealing sleeve stably installed on the inner wall of the cylinder and ensuring the normal operation of the sealing sleeve; the combination of buckle and groove makes the installation process of the sealing sleeve relatively simple.

[0021] Secondly, this application provides a side-shifting frame, which adopts the following technical solution: A side-shifting frame includes any of the compact double-acting hydraulic cylinders described above. A pin is provided at one end of the piston rod outside the cylinder barrel, and the end of the pin away from the piston rod is hemispherical. A frame is provided on the outside of the cylinder body, and an abutment groove is provided on the frame. The ends of the two pins away from the piston rod abut against the abutment groove.

[0022] By adopting the above technical solution, a pin is set at the outer end of the piston rod, and the end away from the piston rod is hemispherical. In conjunction with the abutment groove on the frame, it is conducive to flexible and stable transmission of power, enabling the frame to achieve smooth lateral sliding. When the side beams at the edge of the frame are inclined, the lateral drive of the frame can also be smoothly achieved through the combination of the pin and the abutment groove, thus making it more adaptable.

[0023] Optionally, the piston rod has a mounting groove at one end outside the cylinder, the pin is located in the mounting groove, the pin and the inner wall of the mounting groove are spaced apart, and an abutment ring is provided in the mounting groove. The abutment ring is elastic, the outer wall of the abutment ring abuts against the inner wall of the mounting groove, and the inner wall of the abutment ring abuts against the pin.

[0024] By adopting the above technical solution, the elastic abutment ring tightens and fixes the pin in the mounting groove, making the connection between the pin and the inner wall of the mounting groove flexible rather than rigid. Therefore, during the movement of the frame, it is not easy to apply radial force to the piston rod through the pin, so that the piston rod will not be subjected to unilateral force, resulting in hydraulic oil leakage. The sealing ring is also not subjected to additional pressure, which can ensure the service life of the oil cylinder. In addition, the flexible connection can also play a certain buffering role, reducing the force on the piston rod, thereby further protecting the oil cylinder.

[0025] In summary, this application includes the following beneficial technical effects: 1. By setting up connectors and one-way guide components, the oil in the inlet cylinder flows into the outlet cylinder through the two connectors, avoiding the direct discharge of high-pressure oil from the system through the relief valve. This prevents the instantaneous release of high-pressure oil, reduces the possibility of pressure shock caused by a sudden drop in hydraulic system pressure, and reduces the possibility of damage to hydraulic components.

[0026] 2. By replacing the traditional piston rod and piston mechanism in hydraulic cylinders with a piston rod, a sealing structure is only required at the guide sleeve, eliminating the need to worry about internal leakage. Only the seal on the guide sleeve side needs to be checked, reducing the probability of failure.

[0027] 3. A sealing sleeve is provided at one end of the piston rod inside the cylinder. On the one hand, it can prevent the pressurized oil in the cylinder from directly contacting the outer wall of the piston rod, so that the pressurized oil is not easily carried out when the piston rod slides outward. On the other hand, it can also play a buffering role, further protecting the oil cylinder. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the hydraulic cylinder in Embodiment 1 of this application; Figure 2 This is a cross-sectional view of the hydraulic cylinder in Embodiment 1 of this application; Figure 3 This is a cross-sectional view of another state of the hydraulic cylinder in Embodiment 1 of this application; Figure 4 yes Figure 2 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the overall structure of the side-shifting frame in Embodiment 1 of this application; Figure 6 This is a cross-sectional view of the side-shifting frame in Embodiment 1 of this application; Figure 7 yes Figure 6 Enlarged view of point B in the middle; Figure 8 This is a cross-sectional view of Embodiment 2 of this application; Figure 9 yes Figure 8 Enlarged diagram of point C in the middle.

[0029] Reference numerals: 1. Cylinder block; 11. Slide groove; 2. Cylinder barrel; 21. Oil port; 22. Mounting ring; 3. Piston rod; 31. Mounting groove; 4. Connector; 41. One-way conduction assembly; 5. Sealing ring; 6. Insert; 61. Dustproof ring; 7. Sealing sleeve; 71. Inner sleeve; 72. Outer sleeve; 73. Connecting ring; 731. Snap-fit; 74. Cavity; 8. Pin; 9. Frame; 91. Upper crossbeam; 92. Lower crossbeam; 93. Side beam; 931. Abutment groove; 10. Abutment ring; 12. Mounting seat; 13. Support sleeve. Detailed Implementation

[0030] The following combination Figures 1-9 This application will be described in further detail.

[0031] Example 1 This application discloses a compact double-acting hydraulic cylinder. (Refer to...) Figure 1 and Figure 2 The compact double-acting hydraulic cylinder includes a cylinder body 1, two cylinder barrels 2 coaxially disposed inside the cylinder body 1, two piston rods 3 corresponding to the cylinder barrels 2, and two connectors 4 corresponding to the cylinder barrels 2. Each of the two cylinder barrels 2 has an oil port 21 at one end closest to each other; one oil port 21 is for oil inlet, and the other oil port 21 is for oil outlet. When the direction of movement of the piston rod 3 changes, the oil port 21 that was originally for oil inlet is now for oil outlet, and the oil port 21 that was originally for oil outlet is now for oil inlet; that is, the state of oil inlet / outlet at each oil port 21 is switched.

[0032] One end of the piston rod 3 is slidably disposed within the corresponding cylinder 2, while the other end of the piston rod 3 is located outside the cylinder 2. A connector 4 is located at the end of the two cylinders 2 that are close to each other. One end of the connector 4 is located outside the cylinder 2, and the two ends of the connector 4 that are close to each other are interconnected. The other end of the connector 4 is located inside the cylinder 2 and is equipped with a one-way flow assembly 41. The one-way flow assembly 41 can be in the form of a one-way valve, and its function is to control the flow direction of the oil. In this embodiment, the one-way flow assembly 41 includes a sealing block and a spring.

[0033] The connector 4 has an internal connection hole, one end of which is open, and the other end of which houses a sealing block and a spring. Normally, the spring presses the sealing block against the opening of the connection hole, closing one end. When the cylinder 2 corresponding to this connector 4 is in an oil-filled state, the oil pressure in the cylinder 2 increases. This oil pressure causes the sealing block to overcome the spring's elasticity and slide inward, keeping both ends of the connection hole open. Furthermore, when the piston rod 3 slides inward into the cylinder 2 until its end abuts against the sealing block, the piston rod 3 can also push the sealing block against the spring's elasticity and slide it into the connection hole, thus connecting both ends of the connection hole.

[0034] Reference Figure 2Therefore, when oil enters through port 21 on the left cylinder 2, oil exits through port 21 on the right cylinder 2, and both piston rods 3 move to the left simultaneously. When the left piston rod 3 moves to its limit position, the right piston rod 3 abuts against the sealing block. At this time, the left cylinder 2 is still in the oil-in-water state, so the oil pressure inside the left cylinder 2 is relatively large, and the two ends of the connector 4 in this cylinder 2 are in a connected state; the right piston rod 3 pushes the sealing block to move, which can make the two ends of the connector 4 in the right cylinder 2 also in a connected state, so the two connectors 4 are connected to each other. Since the oil pressure in the left cylinder 2 is higher than that in the right cylinder 2, the pressurized oil in the left cylinder 2 can flow into the right cylinder 2 through the two connectors 4. Then the pressurized oil in the right cylinder 2 is discharged outward through the oil port 21, avoiding the direct discharge of high-pressure oil into the system through the relief valve. This avoids the pressure shock caused by the instantaneous release of high-pressure oil and reduces the possibility of damage to hydraulic components. Therefore, this application utilizes the oil communication between the two cylinders 2 to balance pressure changes and make the hydraulic system more stable and reliable.

[0035] Reference Figure 3 When oil enters through port 21 on the right cylinder 2, oil exits through port 21 on the left cylinder 2, and both piston rods 3 move to the right simultaneously. When the right piston rod 3 reaches its limit position, the left piston rod 3 abuts against the sealing block. At this time, the right cylinder 2 is still in the oil-in-water state, so the oil pressure inside the right cylinder 2 is relatively large, and the two ends of the connector 4 in this cylinder 2 are in a connected state. The left piston rod 3 pushes the sealing block to move, which can also make the two ends of the connector 4 in the left cylinder 2 in a connected state, so the two connectors 4 are connected to each other. Since the oil pressure in the right cylinder 2 is relatively large at this time, and is greater than the oil pressure in the left cylinder 2, the pressurized oil in the right cylinder 2 can flow into the left cylinder 2 through the two connectors 4, and then the pressurized oil in the left cylinder 2 is discharged out through port 21, thereby reducing hydraulic pressure fluctuations, improving the stability of the entire pressure system and extending its service life.

[0036] Reference Figure 4 Furthermore, a support sleeve 13 is provided on the open side of the cylinder 2. The support sleeve 13 is fitted onto the outside of the piston rod 3. The support sleeve 13 is used to support the piston rod 3 and restrict the sliding direction of the piston rod 3. The diameter of the piston rod 3 is slightly smaller than the inner diameter of the cylinder 2. The distance between the outer wall of the piston rod 3 and the inner wall of the cylinder 2 is 2mm. Therefore, the piston rod 3 and the cylinder 2 are spaced apart, which can reduce the friction between the piston rod 3 and the inner wall of the cylinder 2 and extend the service life. The larger rod diameter design can also improve the load-bearing capacity of the piston rod 3 and enhance the working stability of the hydraulic cylinder.

[0037] A sealing ring 5 is also provided at one end of the support sleeve 13. The sealing ring 5 is sleeved on the outside of the piston rod 3, and the inner wall of the sealing ring 5 abuts against the piston rod 3. The sealing ring 5 can prevent hydraulic oil leakage and ensure the sealing of the cylinder. In addition, since the part of the piston rod 3 located in the cylinder 2 is contaminated with oil, when the piston rod 3 slides outward, the sealing ring 5 can scrape off the oil on the piston rod 3, thereby keeping the part of the piston rod 3 that slides out of the cylinder 2 clean.

[0038] Reference Figure 1 and Figure 4 Both ends of the cylinder body 1 are provided with sliding grooves 11, each corresponding to a cylinder 2. The sliding grooves 11 are located on the open side of the cylinder 2 and are arranged radially along the cylinder 2. An insert 6 is slidably disposed in the sliding groove 11, and a dustproof ring 61 is engaged in the insert 6. The dustproof ring 61 is sleeved on the outside of the piston rod 3, with its inner wall abutting against the outer wall of the piston rod 3. The dustproof ring 61 prevents dust, impurities, etc., from entering the cylinder 2, contaminating the hydraulic oil, and damaging internal components. Both the dustproof ring 61 and the insert 6 are located on the side of the sealing ring 5 away from the support sleeve 13, and the insert 6 abuts against the sealing ring 5. Therefore, the insert 6 can restrict the axial movement of the sealing ring 5 and the support sleeve 13, improving the stability of the sealing ring 5 and the support sleeve 13 after installation. Because the insert 6 is slidably inserted into the sliding groove 11, the installation process of the insert 6 is simple and the total installation length can be reduced.

[0039] When assembling the hydraulic cylinder, first fix the connector 4 to the end of the cylinder barrel 2, and then fix the cylinder barrel 2 inside the cylinder body 1. Next, install the support sleeve 13 and the sealing ring 5 in sequence, and then slide the insert 6 into the slide groove 11 so that the insert 6 abuts against the sealing ring 5, and the dustproof ring 61 in the insert 6 is coaxial with the sealing ring 5. Then, insert the piston rod 3 into the cylinder barrel 2. The overall assembly process is relatively simple.

[0040] The implementation principle of Example 1 is as follows: In the working state, one cylinder 2 is in the oil inlet state and the other cylinder 2 is in the oil outlet state, so that the two piston rods 3 slide in the same direction. When the piston rod 3 in the oil inlet cylinder 2 moves to the limit position, the piston rod 3 in the oil outlet cylinder 2 also moves to the limit position. At this time, under the action of the oil pressure inside the oil inlet cylinder 2 and the pushing action of the piston rod 3 in the oil outlet cylinder 2, the two joints 4 are in a state of mutual connection. Therefore, the pressurized oil in the oil inlet cylinder 2 can flow into the oil outlet cylinder 2 through the joint 4, and the pressurized oil in the oil outlet cylinder 2 is discharged outward through the oil port 21. This avoids the high pressure oil being directly discharged from the system through the overflow valve, thereby avoiding the pressure shock caused by the instantaneous release of high pressure oil, reducing the possibility of damage to hydraulic components, reducing hydraulic pressure fluctuations, improving the stability of the entire pressure system and extending its service life.

[0041] Reference Figure 5 and Figure 6 This embodiment also discloses a side-shifting frame, including the aforementioned double-acting hydraulic cylinder. A mounting base 12 is fixedly provided on the outer side of the cylinder body 1. Two mounting bases 12 are provided and located at both ends of the cylinder body 1. The mounting bases 12 mainly support the cylinder body 1 and are used to install on the fork carriage of a forklift, thus facilitating overall lifting and lowering.

[0042] Reference Figure 6 and Figure 7 Each piston rod 3 has a pin 8 at one end outside the cylinder 2, with the end of the pin 8 furthest from the piston rod 3 being hemispherical. A frame 9 is provided on the outer side of the cylinder body 1, comprising an upper crossbeam 91, a lower crossbeam 92, and side beams 93. The upper and lower crossbeams 91 and 92 are arranged in parallel at intervals and are horizontally positioned, while the side beams 93 are vertically positioned and fixedly connected to both ends of the upper crossbeam 91. The distance between the two side beams 93 is greater than the length of the cylinder body 1, and the cylinder body 1 and piston rod 3 are located between the two side beams 93. Arc-shaped abutment grooves 931 are formed on the sides of the two side beams 93 that are close to each other, and the ends of the two pins 8 furthest from the piston rod 3 abut against the corresponding abutment grooves 931. During use, the hemispherical end of the pin 8 and the arc-shaped abutment groove 931 are always in abutment. Therefore, when the two piston rods 3 move to the left, the frame 9 moves to the left, and when the two piston rods 3 move to the right, the frame 9 moves to the right. The crossbeam can be used to mount the forks, so when the frame 9 moves, the forks move horizontally, thereby accurately aligning the pallet or goods and avoiding repeated adjustments to the forklift's position.

[0043] Furthermore, a mounting groove 31 is coaxially formed at one end of the piston rod 3 located outside the cylinder 2. The pin 8 is coaxially inserted into the mounting groove 31, with the pin 8 and the inner wall of the mounting groove 31 spaced apart. An abutment ring 10, an O-ring, is provided in the mounting groove 31, thus possessing elasticity. The outer wall of the abutment ring 10 abuts against the inner wall of the mounting groove 31, and the inner wall of the abutment ring 10 abuts against the pin 8, thus the abutment ring 10 is in a taut state, capable of fixing the pin 8 in the mounting groove 31. The connection between the pin 8 and the mounting groove 31 is flexible rather than rigid; therefore, during the horizontal movement of the frame 9, the pin 8 will not exert radial force on the piston rod 3, and the sealing ring 5 will not bear additional pressure, extending the service life of the hydraulic cylinder.

[0044] Example 2 Reference Figure 8 and Figure 9The difference between this embodiment and Embodiment 1 is that, in this embodiment, a sealing sleeve 7 is provided at one end of the piston rod 3 located inside the cylinder 2. The sealing sleeve 7 has an annular cross-section, and its length is along the axis of the piston rod 3. One end of the sealing sleeve 7 is fixedly connected to the end of the piston rod 3, and the other end is fixedly connected to the inner wall of the cylinder 2. The sealing sleeve 7 is flexible, so it can retract or extend when the piston rod 3 moves. The sealing sleeve 7 is fixedly connected between the end of the piston rod 3 and the inner wall of the cylinder 2, thus separating the side wall of the piston rod 3 from the internal area of ​​the cylinder 2, preventing the pressurized oil in the cylinder 2 from contacting the outer wall of the piston rod 3. Therefore, it is less likely for the pressurized oil to be carried out when the piston rod 3 slides outward, thereby enhancing the sealing performance of the cylinder.

[0045] The sealing sleeve 7 is elastic and can be stretched and deformed under tension to better adapt to the movement of the piston rod 3. The sealing sleeve 7 includes an inner sleeve 71 and an outer sleeve 72. The outer sleeve 72 is coaxially spaced outside the inner sleeve 71. Connecting rings 73 are fixedly connected between the ends of the inner sleeve 71 and the ends of the outer sleeve 72. Two connecting rings 73 are provided, located at the two ends of the inner sleeve 71 respectively. A sealed cavity 74 is formed between the inner sleeve 71, the outer sleeve 72, and the connecting rings 73 at both ends. Air is stored in the cavity 74. When the piston rod 3 moves, the sealing sleeve 7 in one cylinder 2 is stretched, which provides a certain buffering effect. The sealing sleeve 7 in the other cylinder 2 is compressed, and the compressed sealing sleeve 7 expands outward and bulges, also providing a certain buffering effect. This allows the piston rod 3 to dissipate some energy after moving to its limit position, enhancing the buffering effect and further reducing the impact between the piston rod 3 and the one-way conduction assembly 41.

[0046] Furthermore, a snap fastener 731 is fixedly connected to the connecting ring 73 at the end away from the piston rod 3. Multiple snap fasteners 731 are arranged in a circumferential array. An mounting ring 22 is coaxially fixedly connected to the inner wall of the cylinder 2, and the mounting ring 22 has a slot for inserting the snap fastener 731. Therefore, through the cooperation of the snap fastener 731 and the slot, the sealing sleeve 7 can be easily installed on the inner wall of the cylinder 2, ensuring a secure connection. In addition, an elastic ring made of rubber can be fixedly glued to the connecting ring 73 where the snap fastener 731 is located. This elastic ring provides a sealing effect, so that after the snap fastener 731 is inserted into the slot, the elastic ring is compressed, enhancing the sealing effect between the sealing sleeve 7 and the mounting ring 22.

[0047] The above are optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A compact double-acting hydraulic cylinder, characterized in that: include: Cylinder block (1); There are two cylinders (2) and they are coaxially arranged inside the cylinder body (1). Each of the two cylinders (2) has an oil port (21) at one end that is close to the other. Two piston rods (3) are provided and correspond to the two cylinders (2). The piston rods (3) are slidably disposed in the cylinders (2). When oil enters through the oil port (21) on one of the cylinders (2), oil exits through the oil port (21) on the other cylinder (2), so that the two piston rods (3) move in the same direction. There are two connectors (4) corresponding to the two cylinders (2). The connectors (4) are located at the ends of the two cylinders (2) that are close to each other. One end of the connector (4) is located outside the cylinder (2) and the ends of the two connectors (4) that are close to each other are connected to each other. The other end of the connector (4) is located inside the cylinder (2) and is provided with a one-way guide assembly (41) so that when the oil pressure in the cylinder (2) increases or the piston rod (3) abuts against the one-way guide assembly (41), the two ends of the connector (4) are connected to each other, so that the oil in the cylinder (2) that is inlet flows into the cylinder (2) that is outlet through the two connectors (4).

2. A compact double-acting hydraulic cylinder according to claim 1, characterized in that: A sealing ring (5) is provided on the open side of the cylinder (2), the sealing ring (5) abuts against the piston rod (3), and the piston rod (3) and the inner wall of the cylinder (2) are spaced apart.

3. A compact double-acting hydraulic cylinder according to claim 2, characterized in that: The diameter of the piston rod (3) is greater than four-fifths of the inner diameter of the cylinder (2).

4. A compact double-acting hydraulic cylinder according to claim 2, characterized in that: A sliding groove (11) is provided on the cylinder body (1) on the opening side of the cylinder barrel (2). A insert (6) is slidably arranged in the sliding groove (11) along the radial direction of the cylinder barrel (2). A dustproof ring (61) is provided in the insert (6). The dustproof ring (61) is sleeved on the outside of the piston rod (3). The sealing ring (5) abuts against the insert (6).

5. A compact double-acting hydraulic cylinder according to claim 1, characterized in that: The piston rod (3) is provided with a sealing sleeve (7) at one end inside the cylinder (2). The sealing sleeve (7) has a circular cross-section and its length direction is along the axis of the piston rod (3). The sealing sleeve (7) is flexible and can be retracted or extended along its own length direction. One end of the sealing sleeve (7) is fixedly connected to the end of the piston rod (3), and the other end of the sealing sleeve (7) is fixedly connected to the inner wall of the cylinder (2).

6. A compact double-acting hydraulic cylinder according to claim 5, characterized in that: The sealing sleeve (7) is elastic.

7. A compact double-acting hydraulic cylinder according to claim 6, characterized in that: The sealing sleeve (7) includes an inner sleeve (71) and an outer sleeve (72). The outer sleeve (72) is coaxially spaced outside the inner sleeve (71). A connecting ring (73) is fixedly connected between the end of the inner sleeve (71) and the end of the outer sleeve (72). The inner sleeve (71), the outer sleeve (72) and the connecting rings (73) at both ends together form a sealed cavity (74).

8. A compact double-acting hydraulic cylinder according to claim 7, characterized in that: A buckle (731) is fixedly connected to the connecting ring (73) at the end away from the piston rod (3), and an mounting ring (22) is fixedly connected to the inner wall of the cylinder (2) on the same axis. The mounting ring (22) has a slot for the buckle (731) to be inserted.

9. A lateral shifting frame, characterized in that: The compact double-acting hydraulic cylinder according to any one of claims 1-8 is provided with a pin (8) at one end of the piston rod (3) outside the cylinder barrel (2), and the end of the pin (8) away from the piston rod (3) is hemispherical. A frame (9) is provided on the outside of the cylinder body (1), and an abutment groove (931) is provided on the frame (9). The ends of the two pins (8) away from the piston rod (3) abut against the abutment groove (931).

10. A lateral shifting frame according to claim 9, characterized in that: The piston rod (3) has an installation groove (31) at one end outside the cylinder (2). The pin (8) is located in the installation groove (31). The pin (8) and the inner wall of the installation groove (31) are spaced apart. An abutment ring (10) is provided in the installation groove (31). The abutment ring (10) is elastic. The outer wall of the abutment ring (10) abuts against the inner wall of the installation groove (31). The inner wall of the abutment ring (10) abuts against the pin (8).

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