Two-stage throttling structure for hydrostatic balancing between cylinder head and piston rod

Abstract

The utility model discloses a two-stage throttling structure for static pressure balance between cylinder head and piston rod, including the piston rod that goes through the cylinder head center hole and extends into the cylinder body, the cavity is formed to a plurality of in the inner wall surface circumferential interval concave of center hole, the through hole of the communication of cavity is set up and is used for installing the matching hole of throttling rod in the cylinder head, throttling rod is installed throttling screw no.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, and in particular to a two-stage throttling structure for static pressure balance between the cylinder head and the piston rod. Background Technology

[0002] For the piston rod in a hydraulic cylinder, while effectively supporting the piston rod to ensure its axial pushing and pulling action, it is also desirable to reduce friction and wear at the support location, and at the same time, reduce or even avoid bending caused by uneven force on the piston rod. By introducing hydrostatic technology into the guide structure of the hydraulic cylinder piston rod, circulating oil is injected between the contact surface of the piston rod and the guide structure to form an oil film that separates the two surfaces, thereby reducing friction and wear caused by contact.

[0003] In the prior art, the amount of oil circulating into the contact surface between the piston rod and the guide structure is difficult to control accurately. The uneven and unstable flow rate often leads to unstable oil film pressure, causing axial instability of the piston rod and local contact with the guide structure. Utility Model Content

[0004] To address the aforementioned issues, this application provides a rationally designed two-stage throttling structure for static pressure balance between the cylinder head and piston rod, thereby achieving reliable control of the amount of oil flowing into the cavity, ensuring accurate, uniform, and consistent oil quantity control, and helping to reduce or even avoid contact friction of the piston rod.

[0005] The technical solution adopted in this utility model is as follows: A two-stage throttling structure for static pressure balance between a cylinder head and a piston rod includes a piston rod extending axially through a central hole in the cylinder head into the cylinder body. Multiple cavities are formed by circumferential recesses along the inner wall of the central hole. A mounting hole communicating with the cavities is radially opened through the cylinder head, and a throttling rod is mounted in the mounting hole. The throttling rod has a through hole along its own axial direction, and a throttling screw one and a throttling screw two are sequentially installed in the through hole from the inside to the outside. A through hole is radially opened on the through hole at the outer end of the throttling screw two. The throttling screw one penetrates to form a throttling hole one, and the throttling screw two penetrates to form a throttling hole two. The orifice size of the throttling hole one facing the cavity is larger than the orifice size of the throttling hole two facing the cavity.

[0006] As a further improvement to the above technical solution: The number of mounting holes corresponds to the number of cavities, and the mounting holes and cavities are evenly spaced along the circumference of the cylinder head.

[0007] A pressure measuring hole is provided radially from the outside to the inside of the cylinder head and connects to the cavity. A pressure gauge is installed in the pressure measuring hole; multiple pressure gauges are arranged at intervals along the circumference of the cylinder head.

[0008] A plug is fitted at the outer opening of the fitting hole, and an circumferential groove is formed on the cylinder head end face facing the cylinder body. An extension hole is formed in the circumferential groove and connected to each fitting hole. The extension hole is connected to the internal through hole of the throttle rod through the fitting hole and the through hole.

[0009] The outer wall of the throttle rod is provided with a circumferential groove, and the middle part of the circumferential groove extends outward in a circumferential direction to form a convex ring. There is a gap between the outer wall of the convex ring and the inner wall of the mounting hole. The circumferential groove located on the inner side of the convex ring is directly connected to the extension hole, and the circumferential groove located on the outer side of the convex ring is directly connected to the through hole.

[0010] A sealing ring 1 is press-fitted between the cylinder head end face and the cylinder body end face located on the outer side of the circumferential groove, and a sealing ring 2 is press-fitted between the cylinder head end face and the cylinder body end face located on the inner side of the circumferential groove.

[0011] Along the axial direction of the central hole, the inner wall surfaces of the cylinder head on both sides of the cavity are respectively provided with oil return grooves in the circumferential direction. A return hole is provided in the radial direction through the cylinder head and connected to the oil return groove. The return holes of the two oil return grooves are connected by a connecting hole and led to the outside of the cylinder head. A plug is installed at the outer opening of the return hole.

[0012] The fitting hole is a stepped hole structure with a larger end and a smaller inner end. The inner end of the throttle rod installed in the fitting hole is limited by the step, and the outer end of the throttle rod is pressed and limited by the clamping part installed in the fitting hole.

[0013] The inner end of the throttling rod extends inward to form a flange, and the two end faces of the throttling screw are fitted and limited by the flange.

[0014] A sealing groove is provided circumferentially at the end of the center hole away from the cylinder body, and a sealing ring is installed in the sealing groove.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The throttling rod in the mounting hole of this utility model serves as the final channel for oil to flow into the cavity. By setting a throttling structure on the channel, especially a two-stage throttling with gradually decreasing throttling orifice, reliable control of the amount of oil flowing into the cavity is achieved, ensuring accurate, uniform and consistent oil volume control, ensuring the formation of a reliable and stable oil film, and helping to reduce or even avoid contact friction of the piston rod. This utility model also has the following advantages: The pressure drop and flow rate of the oil are generated by the first throttle screw and the second throttle screw in sequence. This can effectively ensure the uniformity and consistency of the amount of oil flowing into each cavity of the piston rod while adapting to changes in external load, and effectively ensure the formation of a stable oil film in the circumference of the piston rod. External oil flows into the cavity through the throttle rod and secondary throttle. The oil in the cavity flows into the return oil groove through the gap between the piston rod and the cylinder head, and finally flows out through the return oil hole and the connecting hole, forming a continuous and cyclical flow of oil. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the present invention.

[0017] Figure 2 This is a cross-sectional view of the present invention.

[0018] Figure 3 This is a cross-sectional view of the throttling rod of this utility model.

[0019] Figure 4 This is a cross-sectional view of the cylinder head of this utility model.

[0020] Figure 5 This is a cross-sectional view of the cylinder head of this utility model from another section.

[0021] The components are: 1. Piston rod; 2. Cylinder head; 3. Pressure gauge; 4. Cylinder body; 5. Plug; 6. Clamping component; 7. Throttling rod; 8. Throttling screw one; 9. Throttling screw two; 10. Sealing ring one; 11. Sealing ring two; 12. Sealing ring three; 20. Center hole; 21. Cavity; 22. Mounting hole; 23. Circumferential groove; 24. Oil return hole; 25. Pressure test hole; 26. Oil return groove; 27. Connecting hole; 28. Sealing groove; 221. Extension hole; 71. Through hole; 72. Circular groove; 73. Raised ring; 74. Flange; 75. Through hole; 81. Throttling orifice one; 91. Throttling orifice two. Detailed Implementation

[0022] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0023] like Figure 1 , Figure 2 and Figure 3 As shown, the two-stage throttling structure for static pressure balance between the cylinder head and piston rod in this embodiment includes a piston rod 1 extending axially through the central hole 20 of the cylinder head 2 into the cylinder body 4. Multiple cavities 21 are formed circumferentially at intervals along the inner wall of the central hole 20. A fitting hole 22 communicating with the cavity 21 is opened radially through the cylinder head 2. A throttling rod 7 is fitted in the fitting hole 22. A through hole 71 is opened along its own axial direction on the throttling rod 7. A throttling screw 8 and a throttling screw 9 are installed sequentially from the inside to the outside in the through hole 71. A through hole 75 is opened radially on the through hole 71 located at the outer end of the throttling screw 9. The throttling screw 8 passes through the throttling hole 81, and the throttling screw 9 passes through the throttling hole 91. The orifice size of the throttling hole 81 facing the cavity 21 is larger than the orifice size of the throttling hole 91 facing the cavity 21.

[0024] In this embodiment, the throttling rod 7 in the fitting hole 22 serves as the final channel for oil to flow into the cavity 21. By setting a throttling structure on the channel, especially a two-stage throttling with gradually decreasing throttling orifice, reliable control of the amount of oil flowing into the cavity 21 can be achieved.

[0025] In this embodiment, the pressure drop and flow rate regulation of the flowing oil are generated by the first throttle screw 8 and the second throttle screw 9 in sequence. This can effectively ensure the uniformity and consistency of the amount of oil flowing into each cavity 21 of the piston rod 1 while adapting to changes in external load, and effectively ensure the formation of a stable oil film in the circumference of the piston rod 1.

[0026] In this embodiment, the oil flows into the cavity 21 through the throttle rod 7 and forms an oil film around the piston rod 1. The oil film separates the outer wall of the piston rod 1 from the inner wall of the cylinder head 2, effectively offsetting and balancing the radial load, so that the piston rod 1 is in a similar suspended equilibrium state, thereby avoiding contact friction and wear.

[0027] In this embodiment, by setting the orifice size of the first throttling orifice 81 facing the cavity 21 to be larger than the orifice size of the second throttling orifice 91 facing the cavity 21, that is, setting the liquid outlet size of the first throttling orifice 81 to be larger than the liquid outlet size of the second throttling orifice 91, the oil achieves secondary throttling after flowing through the first throttling orifice 81 and the second throttling orifice 91, thus ensuring the throttling effect.

[0028] The number of mounting holes 22 corresponds to the number of cavities 21. The mounting holes 22 and cavities 21 are evenly spaced along the circumference of the cylinder head 2, thereby effectively ensuring the stability and reliability of the oil film formed on the piston rod 1.

[0029] In this embodiment, four sets of fitting holes 22 and cavities 21 can be evenly spaced along the circumference of the cylinder head 2 to form four corresponding sets of oil injections in the upper, lower, left, and right directions, which facilitates the realization and maintenance of the "suspended" piston rod 1.

[0030] A pressure measuring hole 25 is provided radially through the cylinder head 2 from the outside to the inside and connects to the cavity 21. A pressure gauge 3 is installed in the pressure measuring hole 25. Multiple pressure gauges 3 are arranged at intervals along the circumference of the cylinder head 2. Thus, the pressure gauges 3 can effectively detect and provide feedback on the real-time oil pressure in the circumference of the piston rod 1.

[0031] In this embodiment, pressure gauges 3 can be installed for each cavity 21.

[0032] like Figure 4As shown, a plug 5 is fitted at the outer opening of the fitting hole 22 to ensure the sealing at the outer opening; an circumferential groove 23 is provided on the end face of the cylinder head 2 facing the cylinder body 4, and an extension hole 221 is provided in the circumferential groove 23 to connect with each fitting hole 22. The extension hole 221 is connected to the internal through hole 71 of the throttle rod 7 through the fitting hole 22 and the through hole 75 to realize the oil supply to the contact surface between the piston rod 1 and the cylinder head 2.

[0033] like Figure 3 As shown, the outer wall of the throttle rod 7 has a circumferential groove 72, and the middle part of the circumferential groove 72 extends outward in the circumferential direction to form a convex ring 73. There is a gap between the outer wall of the convex ring 73 and the inner wall of the mounting hole 22. The circumferential groove 72 located inside the convex ring 73 is directly connected to the extension hole 221, and the circumferential groove 72 located outside the convex ring 73 is directly connected to the through hole 75.

[0034] In this embodiment, the circumferential groove 72 and the central convex ring 73 are provided in conjunction with the extension hole 221 and the through hole 75, so that the oil flowing from the extension hole 221 to the lower part of the circumferential groove 72 passes over the convex ring 73 and then flows into the through hole 75 through the upper part of the circumferential groove 72, which creates a pressure drop on the oil and helps to regulate and accurately control the flow rate.

[0035] A sealing ring 10 is press-fitted between the end face of the cylinder head 2 located outside the circumferential groove 23 and the end face of the cylinder body 4, and a sealing ring 11 is press-fitted between the end face of the cylinder head 2 located inside the circumferential groove 23 and the end face of the cylinder body 4.

[0036] In this embodiment, the circumferential groove 23 and the extension hole 221 for oil supply flow are located between the sealing ring 10 and the sealing ring 11, so as to achieve sealing and flow restriction of oil between the contact surfaces of the cylinder head 2 and the cylinder body 4, and ensure stable and consistent oil supply.

[0037] In this embodiment, an oil passage communicating with the circumferential groove 23 can be opened on the cylinder 4 according to actual needs to achieve oil supply.

[0038] In this embodiment, sealing ring 10 and sealing ring 11 can be respectively disposed outside the circumferential groove 23 on its inner and outer sides; of course, they can also be disposed adjacent to the circumferential groove 23, for example... Figure 2 The middle sealing ring 10 is attached to the side of the circumferential groove 23 to achieve and ensure that the oil flows through the circumferential groove 23 toward the extension hole 221.

[0039] like Figure 5As shown, along the axial direction of the central hole 20, the inner wall surfaces of the cylinder head 2 on both sides of the cavity 21 are respectively provided with oil return grooves 26 in the circumferential direction. A return hole 24 is provided in the radial direction through the cylinder head 2 and connected to the oil return groove 26. The oil return holes 24 of the two oil return grooves 26 are connected through the connecting hole 27 and led to the outside of the cylinder head 2. A plug is installed at the outer opening of the oil return hole 24.

[0040] In this embodiment, external oil flows into the cavity 21 through the throttle rod 7 and the secondary throttle. The oil in the cavity 21 flows into the return oil groove 26 through the gap between the piston rod 1 and the cylinder head 2, and finally flows out from the return oil groove 26 through the return oil hole 24 and the connecting hole 27, forming a continuous and cyclical flow of oil.

[0041] The mounting hole 22 is a stepped hole structure with a large end and a small inner end. The inner end of the throttle rod 7 installed in the mounting hole 22 is limited by the step, and the outer end of the throttle rod 7 is pressed and limited by the clamping member 6 installed in the mounting hole 22, so as to realize the reliable installation of the throttle rod 7 in the mounting hole 22.

[0042] In this embodiment, the clamping member 6 can be threaded and fitted into the fitting hole 22 to clamp and fix the throttle rod 7.

[0043] In this embodiment, the clamping member 6 can be an axially penetrating nut structure, which can clamp and fix the throttle rod 7 at its installation position.

[0044] The plug 5 located at the large end of the fitting hole 22 on the outside of the clamping member 6 can be fitted into the fitting hole 22 with a threaded structure.

[0045] The inner end of the throttle rod 7 extends inward to form a flange 74. The end face of the second throttle screw 9 fits against the flange 74 and is limited, thus realizing and ensuring the reliable and consistent installation position of the second throttle screw 9 and the first throttle screw 8 inside the throttle rod 7.

[0046] In this embodiment, the first throttle screw 8 and the second throttle screw 9 can be threaded and fitted into the through hole 71 of the throttle rod 7.

[0047] In this embodiment, the throttling hole 81 opened in the throttling screw 8 and the throttling hole 91 opened in the throttling screw 9 can both be configured as variable diameter holes or stepped holes with larger outer diameters and smaller inner diameters, so as to achieve pressure drop and flow control when the oil flows through.

[0048] A sealing groove 28 is provided circumferentially at the end of the center hole 20 away from the cylinder body 4. A sealing ring 12 is installed in the sealing groove 28 to achieve and ensure the sealing installation between the piston rod 1 and the cylinder body 4.

[0049] In actual operation, a filter element, such as a filter screen, can be installed in the oil flow channel, such as at the through hole 75 of the throttle rod 7, and / or between the contact surfaces of the throttle screw 8 and the throttle screw 9, to filter the flowing oil, thereby helping to ensure and improve the reliability and service life of the secondary throttle structure, ensure the stability of the formed oil film, and ensure the reliable use of the piston rod 1.

[0050] This invention employs a two-stage throttling method to reliably control the amount of oil flowing into the cavity, ensuring accurate, uniform, and consistent oil volume control, guaranteeing the formation of a reliable and stable oil film, and helping to reduce or even avoid contact friction of the piston rod.

[0051] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0052] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. A two-stage throttling structure for static pressure balance between a cylinder head and a piston rod, comprising a piston rod (1) extending axially through a central hole (20) in the cylinder head (2) into the cylinder body (4), characterized in that: Multiple cavities (21) are formed by circumferentially recessed along the inner wall of the central hole (20). A fitting hole (22) communicating with the cavity (21) is opened radially through the cylinder head (2). A throttle rod (7) is fitted in the fitting hole (22). The throttle rod (7) has a through hole (71) along its own axis. Throttling screw one (8) and throttle screw two (9) are installed in the through hole (71) from the inside to the outside. A through hole (75) is opened radially on the through hole (71) at the outer end of throttle screw two (9). Throttling screw one (8) passes through to open throttle hole one (81), and throttle screw two (9) passes through to open throttle hole two (91). The size of the end opening of throttle hole one (81) facing the cavity (21) is larger than the size of the end opening of throttle hole two (91) facing the cavity (21).

2. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: The number of mounting holes (22) corresponds to the number of cavities (21), and the mounting holes (22) and cavities (21) are evenly spaced along the circumference of the cylinder head (2).

3. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: A pressure measuring hole (25) is provided in the cylinder head (2) and connected to the cavity (21) radially from the outside to the inside. A pressure gauge (3) is installed in the pressure measuring hole (25); multiple pressure gauges (3) are arranged at intervals along the circumference of the cylinder head (2).

4. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: A plug (5) is fitted at the outer opening of the fitting hole (22), and an circumferential groove (23) is provided on the end face of the cylinder head (2) facing the cylinder body (4). An extension hole (221) is provided in the circumferential groove (23) and connected to each fitting hole (22). The extension hole (221) is connected to the internal through hole (71) of the throttle rod (7) through the fitting hole (22) and the through hole (75).

5. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 4, characterized in that: The outer wall of the throttle rod (7) is provided with a circumferential groove (72), and the middle part of the circumferential groove (72) extends outward in the circumferential direction to form a convex ring (73). A gap is provided between the outer wall of the convex ring (73) and the inner wall of the fitting hole (22). The circumferential groove (72) located inside the convex ring (73) is directly connected to the extension hole (221), and the circumferential groove (72) located outside the convex ring (73) is directly connected to the through hole (75).

6. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 4, characterized in that: A sealing ring 1 (10) is press-fitted between the end face of the cylinder head (2) located outside the circumferential groove (23) and the end face of the cylinder body (4), and a sealing ring 2 (11) is press-fitted between the end face of the cylinder head (2) located inside the circumferential groove (23) and the end face of the cylinder body (4).

7. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: Along the axial direction of the central hole (20), the inner wall surfaces of the cylinder head (2) on both sides of the cavity (21) are respectively provided with oil return grooves (26) in the circumferential direction. The cylinder head (2) is radially connected to the oil return grooves (26) and provided with oil return holes (24). The oil return holes (24) of the two oil return grooves (26) are connected through the connecting hole (27) and led to the outside of the cylinder head (2). A plug is installed at the outer opening of the oil return hole (24).

8. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: The fitting hole (22) is a stepped hole structure with a large end and a small inner end. The inner end of the throttle rod (7) installed in the fitting hole (22) is limited by the step, and the outer end of the throttle rod (7) is limited by the clamping member (6) installed in the fitting hole (22).

9. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: The throttling rod (7) extends inward from the inner end of the through hole (71) to form a flange (74), and the end face of the throttling screw (9) is fitted and limited by the flange (74).

10. The two-stage throttling structure for static pressure balance between the cylinder head and piston rod as described in claim 1, characterized in that: A sealing groove (28) is provided circumferentially at the end of the center hole (20) away from the cylinder body (4), and a sealing ring (12) is installed in the sealing groove (28).

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