Electrically driven hydraulic hold servo cylinder

Abstract

The utility model provides electric drive hydraulic retention servo oil cylinder belongs to hydraulic equipment technical field, includes, oil cylinder and piston rod, piston rod is slidingly embedded in the inner wall department of oil cylinder, the space formed with piston rod of oil cylinder is provided with pressure retention cavity, maintains subassembly, is located at the outside department of oil cylinder, wherein: the maintenance subassembly includes mounting panel, shunt pipe, pressure tank, pressurizing pipe, check valve, overflow valve, electromagnetic reversing valve, screw rod, limit rod and transmission assembly. Utilize pressure tank compressed air to form hydraulic pressure main lock, firmly lock piston rod in target position, effectively resist external force, simultaneously, clutch quick cut off power, make screw rod and load isolation, constitute mechanical auxiliary retention, when overload, overflow valve automatic pressure relief protection system, and because power cut off, pressure relief process does not damage transmission mechanism, whole collaborative work, has guaranteed the accurate positioning of system, reliable retention and safe operation.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic equipment technology, specifically relating to an electric-driven hydraulic holding servo cylinder. Background Technology

[0002] In industrial applications requiring precise position control and strong holding force (such as heavy equipment positioning and precision mold clamping), electrically or hydraulically driven cylinder systems are widely used. However, existing technologies often face the following key challenges: insufficient holding force and poor stability: Traditional hydraulic locking systems (such as those relying solely on the neutral position locking of the directional valve) are prone to slow piston rod position drift (creeping) under continuous or impactful external forces due to valve core leakage or oil compressibility, failing to provide long-term, reliable rigid holding force and affecting positioning accuracy. Purely mechanical locking (such as brakes) can provide rigid holding, but their structure is complex, response is slow, and they wear out quickly in high-frequency extension and retraction applications. Furthermore, their overload protection mechanisms are inadequate: when the piston rod is subjected to intentional... When subjected to a large external force impact, existing systems lack effective pressure relief paths or have unreasonable relief mechanisms. Excessive pressure may directly damage the cylinder, seals, or pipelines. More importantly, the piston rod retraction force generated during the pressure relief process may reverse-drive the transmission mechanism (such as lead screw, gear, motor), causing overload, deformation, or even damage to the transmission components. The switching efficiency between drive and hold is low and the impact is large: when switching between the drive (extend / retract) state and the hold state, the transmission system often does not move smoothly enough and there is an impact. In particular, when switching from the hold state to the retract state, it is necessary to first release the hydraulic lock (pressure relief) and then start the mechanical retraction. The process is cumbersome and may cause the retraction action to jam or generate hydraulic shock due to insufficient pressure relief. Utility Model Content

[0003] The purpose of this invention is to provide an electrically driven hydraulically held servo cylinder, which aims to solve the problems mentioned in the background art.

[0004] Electric-driven hydraulic holding servo cylinder, including,

[0005] The cylinder and piston rod, wherein the piston rod is slidably embedded in the inner wall of the cylinder;

[0006] The space formed by the oil cylinder and the piston rod is provided with a pressure holding chamber;

[0007] A maintaining assembly, located outside the hydraulic cylinder, includes: a mounting plate, a flow divider, a pressure tank, a pressurizing pipe, a check valve, a relief valve, a solenoid directional valve, a lead screw, a limit rod, and a transmission assembly. The mounting plate is fixed to the outer wall of one end of the piston rod by a nut. The flow divider is fixed to the center of the outer wall of the hydraulic cylinder and communicates with the pressure holding chamber. The pressurizing pipe communicates with the pressure tank. The check valve, relief valve, and solenoid directional valve are respectively communicated with the pressure tank. The check valve, relief valve, and solenoid directional valve communicate with the pressure holding chamber through the flow divider. The lead screw is threaded to an opening on one side of the outer wall of the mounting plate. The limit rod is rotatably embedded in an opening on one side of the outer wall of the mounting plate. The transmission assembly is located on one side of the outer wall of the lead screw.

[0008] Furthermore, the transmission assembly includes a protective housing, a servo motor, a gearbox, a clutch, a driving bevel gear, and a driven bevel gear.

[0009] Furthermore, the protective shell is fitted onto the outer wall of one end of the lead screw, and the driven bevel gear is fixedly disposed at the center of the outer wall of one end of the lead screw.

[0010] Furthermore, the output end of the servo motor is fixedly disposed at the input end of the transmission, the output end of the transmission is fixedly disposed at the center of the outer wall of the input end of the clutch, and the outer wall of the output end of the clutch is fixedly disposed at the center of the outer wall of the driving bevel gear.

[0011] Furthermore, the driving bevel gear and the driven bevel gear are meshed and connected in a transmission manner.

[0012] Furthermore, a pressure gauge is connected to the outer wall of the pressure tank.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] The system maintains the position using a hydraulic main lock and position holding mechanism. When the piston rod reaches the designated position, the hydraulic system utilizes the continuous pressure generated by compressed air in the pressure tank to convert the hydraulic oil filling the pressure holding chamber into strong passive resistance, firmly locking the piston rod in the target position. This effectively resists external thrust and ensures position stability. Mechanical isolation and auxiliary holding are also provided. Simultaneously with hydraulic locking, the clutch quickly disengages, completely cutting off the power transmission path from the servo motor to the lead screw. This completely isolates the lead screw system from the power source and load, eliminating any possible reverse drive or small displacement transmission, effectively complementing the hydraulic locking and jointly ensuring position accuracy. Overload protection and safe pressure relief are also included. If the external thrust abnormally increases, causing the hydraulic pressure to exceed the limit... If the safety limit is exceeded, the relief valve will automatically open to release pressure, allowing some hydraulic oil to flow back to the pressure tank, thereby protecting the cylinder, pipeline and related components from high pressure damage. At this time, because the clutch has been disengaged, the slight retraction (pressure relief) that the piston rod may generate during the pressure relief process will not drive the lead screw in the reverse direction, protecting the transmission mechanism. The flow of hydraulic fluid can be controlled and efficiently recovered. By opening and closing the solenoid directional valve, the flow direction of hydraulic oil can be precisely controlled. When the piston rod extends, the hydraulic oil in the pressure tank is pushed open by compressed air to automatically replenish the increased pressure holding chamber by opening the check valve. When the piston rod retracts, the solenoid directional valve opens to provide a return flow path, allowing the hydraulic oil to flow smoothly back to the pressure tank under the action of piston rod retraction and / or gas pressure, realizing the recycling of hydraulic fluid. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0016] Figure 1 This is a perspective view of the present utility model;

[0017] Figure 2 This is an enlarged schematic diagram of A of this utility model;

[0018] Figure 3 This is a perspective view of the hydraulic cylinder of this utility model;

[0019] Figure 4 This is a schematic diagram of the pressure holding chamber of this utility model.

[0020] In the diagram: 1. Hydraulic cylinder; 2. Piston rod; 3. Diverter pipe; 4. Pressure tank; 5. Pressurization pipe; 6. Pressure gauge; 7. Protective housing; 8. Lead screw; 9. Limit rod; 10. Servo motor; 11. Gearbox; 12. Clutch; 13. Driving bevel gear; 14. Driven bevel gear; 15. Pressure holding chamber; 201. Mounting plate; 401. Check valve; 402. Relief valve; 403. Solenoid directional valve. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] Please see Figure 1-4 The technical solution provided in this embodiment is as follows:

[0025] Electric-driven hydraulic holding servo cylinder, including,

[0026] The hydraulic cylinder 1 and the piston rod 2 are slidably embedded in the inner wall of the hydraulic cylinder 1;

[0027] The space formed by the hydraulic cylinder 1 and the piston rod 2 is provided with a pressure holding chamber 15;

[0028] The maintaining assembly is located outside the cylinder 1. The maintaining assembly includes a mounting plate 201, a diversion pipe 3, a pressure tank 4, a pressurizing pipe 5, a one-way valve 401, an overflow valve 402, a solenoid directional valve 403, a lead screw 8, a limit rod 9, and a transmission assembly. The mounting plate 201 is fixed to the outer wall of one end of the piston rod 2 by a nut. The diversion pipe 3 is fixed to the center of the outer wall of the cylinder 1 and is connected to the pressure holding chamber 15. The pressurizing pipe 5 is connected to the pressure tank 4. The one-way valve 401, overflow valve 402, and solenoid directional valve 403 are respectively connected to the pressure tank 4. The one-way valve 401, overflow valve 402, and solenoid directional valve 403 are connected to the pressure holding chamber 15 through the diversion pipe 3. The lead screw 8 is threaded to an opening on one side of the outer wall of the mounting plate 201. The limit rod 9 is rotatably embedded in an opening on one side of the outer wall of the mounting plate 201. The transmission assembly is located on one side of the outer wall of the lead screw 8.

[0029] In a specific embodiment of this utility model, initially, pressure tank 4 stores hydraulic oil and compressed air. Electromagnetic directional valve 403 is closed, preventing hydraulic oil from flowing back from pressure holding chamber 15 to pressure tank 4. Check valve 401 allows hydraulic oil to flow from pressure tank 4 to pressure holding chamber 15, but prevents reverse flow. Overflow valve 402 is closed, set to the maximum pressure allowed by the system. Clutch 12 is in the disengaged state, cutting off the power connection between servo motor 10 and lead screw 8. Servo motor 10 stops, piston rod 2 is stationary, piston rod 2 extends (driving and oil injection), the control system issues a command for piston rod 2 to extend, servo motor 10 starts, and the power of servo motor 10 is adjusted in speed and torque via transmission 11. Clutch 12... The power output from the transmission 11 is transmitted through the clutch 12, which drives the driving bevel gear 13 to rotate. The driving bevel gear 13 meshes and drives the driven bevel gear 14 to rotate. The driven bevel gear 14 drives the lead screw 8 to rotate. The rotating lead screw 8 is threadedly connected to the mounting plate 201, pushing the mounting plate 201 and the piston rod 2 fixed on it to extend outward (away from the cylinder body of the hydraulic cylinder 1). At the same time, the compressed air in the pressure tank 4 pushes the hydraulic oil, which opens the one-way valve 401. The hydraulic oil flows through the diverter pipe 3 into the pressure holding chamber 15, which has increased in volume due to the extension of the piston rod 2. The hydraulic oil reaches the position and is hydraulically held (power cut-off and hydraulic lock). When the piston rod 2 moves to the designated target position, the servo motor... When the machine 10 stops rotating, the clutch 12 immediately disengages, completely cutting off the power transmission path from the servo motor 10 to the lead screw 8. At this time, the hydraulic oil filled in the pressure holding chamber 15, under the continuous pressure of compressed air, forms a passive pressure that resists external thrust, firmly locking the piston rod 2 in the target position. This is the main source of holding force. The lead screw 8 is isolated from the power source and load due to the disengagement of the clutch 12, providing overload protection. If the external thrust on the piston rod 2 is too large, causing the pressure in the pressure holding chamber 15 to rise above the set pressure of the relief valve 402, the relief valve 402 automatically opens, and part of the hydraulic oil in the pressure holding chamber 15 flows back to the pressure tank 4 through the relief valve 402 to release pressure. This process protects the pressure holding chamber 15. The hydraulic cylinder 1 and related pipelines are protected from overload impact damage. Simultaneously, because the clutch 12 is disengaged, the slight retraction (pressure relief) of the piston rod 2 during the pressure relief process will not reverse the drive of the lead screw 8, thus protecting the lead screw 8 and transmission components from damage. The piston rod 2 retracts (oil relief and drive retraction), and the control system issues a command for the piston rod 2 to retract. The solenoid directional valve 403 opens, providing a path for the hydraulic oil in the pressure holding chamber 15 to flow back to the pressure tank 4. Under the action of the piston rod 2 retraction and / or the gas pressure in the pressure tank 4, the hydraulic oil in the pressure holding chamber 15 flows back to the pressure tank 4 through the diverter pipe 3 and the opened solenoid directional valve 403. The clutch 12 engages, reconnecting the power transmission path, and the servo motor 10 starts and reverses.The reverse power of the servo motor 10 passes sequentially through the gearbox 11, clutch 12, driving bevel gear 13, and driven bevel gear 14, driving the lead screw 8 to rotate in the opposite direction. The rotating lead screw 8, through a threaded connection with the mounting plate 201, pulls the mounting plate 201 and the piston rod 2 fixed thereon back into the cylinder of the hydraulic cylinder 1, retracting it and resetting it. When the piston rod 2 is fully retracted to its initial position (or designated retraction position), the servo motor 10 stops rotating, the clutch 12 disengages, the solenoid directional valve 403 closes, cutting off the hydraulic oil return channel, and the system returns to its initial state, ready for the next work cycle.

[0030] Specifically, the transmission assembly includes a protective housing 7, a servo motor 10, a gearbox 11, a clutch 12, a driving bevel gear 13, and a driven bevel gear 14.

[0031] In a specific embodiment of this utility model, the transmission component can ensure stable power transmission.

[0032] Specifically, the protective shell 7 is fitted onto the outer wall of one end of the lead screw 8, and the driven bevel gear 14 is fixedly installed at the center of the outer wall of one end of the lead screw 8.

[0033] In a specific embodiment of this utility model, the driven bevel gear 14 is fixedly disposed at the center of the outer wall of one end of the lead screw 8, which can ensure the stability of the transmission.

[0034] Specifically, the output end of the servo motor 10 is fixedly located at the input end of the gearbox 11, the output end of the gearbox 11 is fixedly located at the center of the outer wall of the input end of the clutch 12, and the outer wall of the output end of the clutch 12 is fixedly located at the center of the outer wall of the active bevel gear 13.

[0035] In a specific embodiment of this utility model, the output end of the servo motor 10 is fixedly set at the input end of the gearbox 11, which can ensure stable power input.

[0036] Specifically, the driving bevel gear 13 and the driven bevel gear 14 are meshed and connected for transmission.

[0037] In a specific embodiment of this utility model, the active bevel gear 13 and the driven bevel gear 14 are meshed and connected to ensure transmission accuracy.

[0038] Specifically, a pressure gauge 6 is installed on the outer wall of the pressure tank 4.

[0039] In a specific embodiment of this utility model, a pressure gauge 6 is connected to the outer wall of the pressure tank 4, which can facilitate pressure detection.

[0040] Working principle:

[0041] Initially, pressure tank 4 contains hydraulic oil and compressed air. Solenoid directional valve 403 is closed, preventing hydraulic oil from flowing back from pressure holding chamber 15 to pressure tank 4. Check valve 401 allows hydraulic oil to flow from pressure tank 4 to pressure holding chamber 15 but prevents reverse flow. Relief valve 402 is closed, set to the maximum allowable pressure of the system. Clutch 12 is disengaged, cutting off the power connection between servo motor 10 and lead screw 8. Servo motor 10 stops, piston rod 2 is stationary, and piston rod 2 extends (driven and oiled). The control system issues a command to extend piston rod 2, starting servo motor 10. The power of servo motor 10 is adjusted in speed and torque via transmission 11. Clutch 12 engages, transmitting the power output from transmission 11. The power output drives the active bevel gear 13 to rotate, which in turn drives the driven bevel gear 14 to rotate. The driven bevel gear 14 then drives the lead screw 8 to rotate. The rotating lead screw 8, through a threaded connection with the mounting plate 201, pushes the mounting plate 201 and the piston rod 2 fixed thereon to extend outward (away from the cylinder body of the hydraulic cylinder 1). Simultaneously, the compressed air in the pressure tank 4 pushes the hydraulic oil, which opens the one-way valve 401. The hydraulic oil flows through the diverter pipe 3 into the pressure holding chamber 15, which has increased in volume due to the extension of the piston rod 2. Upon reaching the position, the hydraulic holding chamber is engaged (power cut-off and hydraulic lock-up). When the piston rod 2 moves to the designated target position, the servo motor 10 stops rotating, and the clutch 12 immediately disengages, completely cutting off the power from the servo motor 10 to the lead screw 8. In the transmission path, the hydraulic oil filling the pressure holding chamber 15, under the continuous pressure of compressed air, forms a passive pressure that resists external thrust, firmly locking the piston rod 2 in the target position. This is the main source of holding force. The lead screw 8 is isolated from the power source and load due to the disengagement of the clutch 12. Overload protection: if the external thrust on the piston rod 2 is too large, causing the pressure in the pressure holding chamber 15 to rise above the set pressure of the relief valve 402, the relief valve 402 will automatically open, and part of the hydraulic oil in the pressure holding chamber 15 will flow back to the pressure tank 4 through the relief valve 402 to release pressure. This process protects the pressure holding chamber 15, the cylinder 1, and related pipelines from overload impact damage. At the same time, because the clutch 12 has been disengaged, the slight movement of the piston rod 2 during the pressure release process... The retraction (pressure relief) does not reverse the drive of the lead screw 8, thus protecting the lead screw 8 and transmission components from damage. The piston rod 2 retracts (oil release and drive retraction). The control system issues a command for the piston rod 2 to retract, and the solenoid directional valve 403 opens, providing a path for the hydraulic oil in the pressure holding chamber 15 to flow back to the pressure tank 4. Under the action of the piston rod 2 retraction and / or the gas pressure in the pressure tank 4, the hydraulic oil in the pressure holding chamber 15 flows back to the pressure tank 4 through the diverter pipe 3 and the opened solenoid directional valve 403. The clutch 12 engages, reconnecting the power transmission path. The servo motor 10 starts and reverses. The reverse power of the servo motor 10 passes sequentially through the gearbox 11, clutch 12, driving bevel gear 13, and driven bevel gear 14, driving the lead screw 8 to rotate in the reverse direction.The screw 8, rotating in the opposite direction, is threadedly connected to the mounting plate 201, pulling the mounting plate 201 and the piston rod 2 fixed thereon back into the cylinder of the hydraulic cylinder 1, resetting it. When the piston rod 2 is fully retracted to its initial position (or the designated retraction position), the servo motor 10 stops rotating, the clutch 12 disengages, the solenoid directional valve 403 closes, cutting off the hydraulic oil return channel, and the system returns to its initial state, ready for the next work cycle.

[0042] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An electrically driven hydraulically held servo cylinder, characterized in that, include, The cylinder (1) and piston rod (2) are slidably embedded in the inner wall of the cylinder (1); The space formed by the oil cylinder (1) and the piston rod (2) is provided with a pressure holding chamber (15); A maintaining assembly is located outside the hydraulic cylinder (1), comprising: a mounting plate (201), a diverter pipe (3), a pressure tank (4), a pressurizing pipe (5), a check valve (401), an overflow valve (402), a solenoid directional valve (403), a lead screw (8), a limit rod (9), and a transmission assembly. The mounting plate (201) is fixed to the outer wall of one end of the piston rod (2) by a nut. The diverter pipe (3) is fixed to the center of the outer wall of the hydraulic cylinder (1). The diverter pipe (3) is connected to the pressure holding chamber (15). The pressurizing pipe... (5) It is connected to the pressure tank (4). The one-way valve (401), the overflow valve (402), and the solenoid directional valve (403) are respectively connected to the pressure tank (4). The one-way valve (401), the overflow valve (402), and the solenoid directional valve (403) are connected to the pressure holding chamber (15) through the diversion pipe (3). The lead screw (8) is threaded to the opening on one side of the outer wall of the mounting plate (201). The limiting rod (9) is rotatably embedded in the opening on one side of the outer wall of the mounting plate (201). The transmission component is located on one side of the outer wall of the lead screw (8).

2. The electrically driven hydraulically held servo cylinder according to claim 1, characterized in that, The transmission assembly includes a protective shell (7), a servo motor (10), a gearbox (11), a clutch (12), a driving bevel gear (13), and a driven bevel gear (14).

3. The electrically driven hydraulically held servo cylinder according to claim 2, characterized in that, The protective shell (7) is sleeved on the outer wall of one end of the lead screw (8), and the driven bevel gear (14) is fixedly installed at the center of the outer wall of one end of the lead screw (8).

4. The electrically driven hydraulically held servo cylinder according to claim 3, characterized in that, The output end of the servo motor (10) is fixedly disposed at the input end of the gearbox (11), the output end of the gearbox (11) is fixedly disposed at the center of the outer wall of the input end of the clutch (12), and the outer wall of the output end of the clutch (12) is fixedly disposed at the center of the outer wall of the active bevel gear (13).

5. The electrically driven hydraulically held servo cylinder according to claim 4, characterized in that, The driving bevel gear (13) and the driven bevel gear (14) are meshed and connected.

6. The electrically driven hydraulically held servo cylinder according to claim 5, characterized in that, A pressure gauge (6) is connected to the outer wall of the pressure tank (4).

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