A plug-in high-pressure and large-flow speed-limiting cut-off valve for actuating cylinder stall protection

Abstract

The application relates to a plug-in type high-pressure and large-flow speed-limiting cut-off valve for actuating cylinder stall protection. An upper valve sleeve and a lower valve sleeve are installed in a through hole of a valve body and are fixedly and sealingly connected through cover plates. The upper valve sleeve and the lower valve sleeve are connected with a valve core in a matched mode. A spring cavity is arranged between the bottom of the cover plate and the top of the valve core in the upper valve sleeve, a spring is arranged in the spring cavity, the two ends of the spring are connected with the bottom of the cover plate and the top of the valve core respectively, and the spring cavity is communicated with an energy accumulator. The lower valve sleeve is provided with two peripheral holes which are main channel oil ports and are communicated with a rodless cavity of an actuating cylinder. The speed-limiting cut-off valve is suitable for the safety protection of a plunger type actuating cylinder under high-pressure and large-flow working conditions. The plug-in type structure of the speed-limiting cut-off valve has low requirements on the installation space, and the reliability is not affected by external working environments. When the plunger type actuating cylinder operates abnormally, the plug-in type speed-limiting cut-off valve can automatically monitor the pressure difference between the two ends of the valve inlet and outlet, and reliably and rapidly automatically cut off the valve core without the participation of electrical control.

Description

TECHNICAL FIELD

[0001] The present application relates to a safety protection device of a cylinder, in particular to a plug-in type high-pressure and large-flow speed-limiting cut-off valve. BACKGROUND

[0002] The ship, ocean equipment installation cylinder can realize wave compensation function by using its linear reciprocating motion, when the load of the cylinder sharply drops or the connecting member such as steel wire rope, safety pin, connecting rod suddenly breaks, the load of the cylinder is zero. At this time, high-pressure air or high-pressure hydraulic oil acts on the cylinder to make the moving part of the cylinder stall along the axial direction of the cylinder, and quickly impact the cylinder body, causing the cylinder body to be damaged or the moving part to pop out of the cylinder, causing a safety accident. Therefore, the cylinder must be installed with a safety protection device, which can quickly cut off the power source of the cylinder when the cylinder stalls, so that the moving part of the cylinder can quickly stop running, preventing the equipment and personnel from being injured. The speed-limiting cut-off valve is installed on the oil side of the cylinder, when the cylinder stalls, the flow of the oil passage of the speed-limiting cut-off valve increases sharply, the valve core quickly closes the main valve to cut off the oil passage by overcoming the spring force, the running state of the cylinder changes from stall to stop, realizing the safety protection function of the running state of the cylinder.

[0003] The cylinder is divided into piston type and plunger type according to its structure type, and the speed-limiting cut-off valve is installed in the cylinder.

[0004] The piston type cylinder is generally installed with an external speed-limiting cut-off valve, which is installed at the oil port of the rod cavity (oil side) of the cylinder. This technology has an invention patent, the invention patent name is "Large flow control valve with bidirectional flow and automatic cut-off function".

[0005] The plunger type cylinder currently uses an electromagnetic control speed-limiting cut-off valve, which monitors the load or running change of the cylinder by setting a force sensor or a cylinder motion detection controller. When the load of the cylinder sharply drops or the cylinder stalls, the detection device sends an alarm signal, and the control program controls the electromagnetic iron of the speed-limiting cut-off valve to attract and switch the valve core to cut off the hydraulic oil passage, so as to realize the emergency stop function of the cylinder. This technology has an invention patent, the invention patent name is "Speed-limiting cut-off valve for improving the safety of large-scale marine wave compensation device". However, the plunger type cylinder is installed on the deck of the ship or the ocean platform, and the force sensor, the controller and the speed-limiting cut-off valve are in a high temperature, high humidity and high salt environment for a long time, and the reliability, stability and safety of the electrical components decrease obviously. If any link of the force sensor, the controller and the electromagnetic iron fails or the control system itself has a fault, and at this time the plunger type cylinder stalls, the speed-limiting cut-off valve cannot cut off the high-pressure hydraulic oil in time, and the plunger rod is directly impacted by the high-pressure hydraulic oil, which causes a safety accident.

[0006] In summary, the existing speed-limiting cut-off valve for the piston type cylinder has the following problems:

[0007] (1) The piston-type actuator speed limiting shut-off valve is installed in the rod chamber of the actuator. Due to the area ratio between the piston rod and the piston, and the maximum design pressure of the speed limiting shut-off valve is 31.5MPa, the working pressure of the actuator is low, and it is only suitable for medium and low pressure applications.

[0008] (2) The speed limiting shut-off valve has a large valve body weight and is installed in a pipeline, making maintenance inconvenient.

[0009] 2. The plunger-type actuator electromagnetic speed-limiting shut-off valve has the following problems:

[0010] (1) Electromagnetic speed limiting shut-off valves are greatly affected by the "three highs" marine environment, resulting in low reliability and safety of the speed limiting shut-off function.

[0011] (2) The shut-off response speed of the electromagnetic speed-limiting shut-off valve is limited by the response speed of the force sensor, electromagnet, and electronic control system. Moreover, if any of these components fails, the speed-limiting shut-off valve will fail to shut off, resulting in poor reliability.

[0012] To address the above problems, there is an urgent need to invent a speed-limiting shut-off valve that is simple in structure, suitable for high-pressure and high-flow conditions, and can reliably operate in the "three-high" environment of the ocean. Summary of the Invention

[0013] To address the aforementioned technical problems, this invention proposes a cartridge-type high-pressure, high-flow-rate limiting shut-off valve for actuator stall protection. This cartridge-type limiting shut-off valve is suitable for safety protection measures of plunger-type actuators under high-pressure, high-flow-rate conditions. Due to its cartridge-type structure, it has low installation space requirements, and its reliability is not affected by the external working environment. When the plunger-type actuator is operating normally, the cartridge-type limiting shut-off valve does not affect its operation. When the plunger-type actuator malfunctions, the cartridge-type limiting shut-off valve can automatically monitor the pressure difference between the valve inlet and outlet and reliably and quickly shut off the valve core automatically, without requiring electrical intervention.

[0014] To achieve the above objectives, the complete technical solution provided by this invention is: a cartridge-type high-pressure, high-flow-rate limiting shut-off valve for actuator stall protection, comprising an upper valve sleeve, a valve core, a lower valve sleeve, and a cover plate. The upper and lower valve sleeves are installed in the through hole of the valve body, and their two ends are fixedly and sealed by the cover plate. The valve core is connected to the upper and lower valve sleeves. A spring cavity is provided between the bottom of the cover plate and the top of the valve core in the upper valve sleeve, and a spring is provided in the spring cavity. The two ends of the spring are respectively connected to the bottom of the cover plate and the top of the valve core. In use, the spring cavity is connected to the accumulator. The lower valve sleeve has two peripheral holes, which are the main channel oil ports. In use, the main channel oil ports are connected to the rodless cavity of the actuator.

[0015] Further, the upper valve sleeve is provided with two small holes for sensing the load pressure to the spring cavity, and introducing the accumulator oil into the load cavity from the holes when switching to the low speed state.

[0016] Further, the main passage oil port in the lower valve sleeve determines the hole diameter according to the hydraulic oil flow rate calculated based on the operating speed of the actuator cylinder, and a throttling pressure drop is generated at the lower valve sleeve port.

[0017] Further, the diameters of the upper and lower ends of the valve core are different, and a damping long hole is arranged in the middle, the upper end senses the spring cavity pressure, the lower end senses the secondary pressure of the inlet pressure through the damping long hole, and the spring is compressed and the valve port pressure difference is changed through the movement of the valve core.

[0018] Further, the spring has a certain pre-tightening force, and the spring is made of a spring that can prevent plastic failure and fatigue failure, which can slow down the spring elastic modulus decay rate and improve the spring life.

[0019] Further, the plug-in high-pressure large-flow speed limiting cut-off valve realizes automatic cut-off of different flows by using springs with different spring forces.

[0020] Further, the plug-in high-pressure large-flow speed limiting cut-off valve is installed between the rodless cavity of the actuator cylinder and the accumulator, when the plunger actuator cylinder works normally, the speed limiting cut-off valve realizes bidirectional free flow; when the load of the actuator cylinder suddenly drops or the steel wire rope, safety pin and connecting rod are suddenly broken, causing the load of the actuator cylinder to be zero, under the action of the accumulator, the instantaneous high-pressure and large-flow oil flows to the rodless cavity of the actuator cylinder through the speed limiting cut-off valve, causing the overvalve flow of the speed limiting cut-off valve to rapidly increase, and at the same time causing the pressure difference between the inlet and outlet of the speed limiting cut-off valve to also rapidly increase, when the pressure difference between the inlet and outlet of the speed limiting cut-off valve exceeds the pre-set value of the spring force of the speed limiting cut-off valve, the valve core of the speed limiting cut-off valve will rapidly close the main valve port against the spring force, and then the hydraulic oil flows through the small hole, controlling the low-speed operation of the actuator cylinder plunger rod to the top limit position, preventing the plunger rod from hitting the cylinder body, and protecting the equipment and personnel safety.

[0021] The technical scheme adopted by the present application has the following beneficial effects:

[0022] 1. The speed limiting cut-off valve is designed in a plug-in structure, which is compact and can be hidden in the bottom of the actuator cylinder, does not occupy installation space and meets the safety protection function requirements of the actuator cylinder.

[0023] 2. The hidden installation effectively improves the working environment of the speed limiting cut-off valve, and avoids the influence of the high temperature, high humidity and high salt environment of the ocean on the reliability and life of the speed limiting cut-off valve.

[0024] 3. The speed limiting cut-off valve can be set to different oil port diameters according to the operating speed of the actuator cylinder, can be applied to various large-flow cut-off working conditions, and the sensitivity of the speed limiting cut-off valve can be adjusted by calculating the spring force, so the application range is wide.

[0025] 4. When the pressure difference between the inlet and outlet reaches the set pressure difference value, the valve core can be automatically switched to cut off the oil source and then achieve a small flow rate. When the piston rod of the actuator cylinder stalls, it can automatically stop and then slowly run to the top limit.

[0026] 5. No electrical components or electronic control systems are required for its control, which greatly simplifies the actuator control strategy.

[0027] 6. Effectively improves the safety of plunger-type actuator operation and ensures the personal safety of on-site personnel. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the working principle of a speed limiting shut-off valve;

[0029] Figure 2 This is a schematic diagram of the components of a speed-limiting shut-off valve;

[0030] Figure 3 This is a schematic diagram of the upper valve sleeve structure;

[0031] Figure 4 This is a schematic diagram of the lower valve sleeve structure;

[0032] Figure 5 This is a schematic diagram of the valve core structure. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] like Figure 1 As shown, the cartridge-type high-pressure, high-flow-rate limiting shut-off valve for actuator stall protection of the present invention is installed between the rodless chamber of the actuator and the accumulator. When the plunger actuator is working normally, the limiting shut-off valve can achieve bidirectional free flow. When the actuator load drops sharply or the connecting parts such as the wire rope, safety pin, and connecting rod suddenly break, causing the actuator load to be zero, the instantaneous high-pressure, high-flow-rate oil under the action of the accumulator flows to the rodless chamber of the actuator through the limiting shut-off valve. This causes the flow rate through the limiting shut-off valve to increase rapidly, and at the same time, it also causes the pressure difference between the inlet and outlet of the limiting shut-off valve to increase rapidly. When the pressure difference between the inlet and outlet of the limiting shut-off valve exceeds the preset value of the spring force of the limiting shut-off valve, the valve core of the limiting shut-off valve will overcome the spring force and quickly close the main valve port. Subsequently, the hydraulic oil flows through the small orifice, controlling the actuator plunger rod to run at a low speed to the top limit position. This prevents the plunger rod from hitting the cylinder body, protecting the equipment and personnel safety.

[0035] like Figure 2As shown, the plug-in high-pressure large-flow speed-limiting cut-off valve for actuator stall protection of the application comprises an upper valve sleeve 1, a valve core 3, a lower valve sleeve 2 and a cover plate 4. The upper valve sleeve 1 and the lower valve sleeve 2 are installed in the through hole of the valve body, and the two ends are fixed and sealed by the cover plate 4. The upper valve sleeve 1 and the lower valve sleeve 2 are connected with the valve core 3 in a matching manner. In the upper valve sleeve 1, a spring cavity is arranged between the bottom of the cover plate 4 and the top of the valve core 3, and a spring 5 is arranged in the spring cavity. The two ends of the spring 5 are connected with the bottom of the cover plate 4 and the top of the valve core 3, respectively. In use, the spring cavity is connected with the accumulator. The lower valve sleeve 2 is provided with two peripheral holes, which are main channel oil ports (see Figure 4 ). In use, the main channel oil ports are connected with the rodless cavity of the actuator.

[0036] As shown in Figure 3 , the upper valve sleeve is provided with two small holes for sensing the load pressure to the spring cavity, and the accumulator oil can be introduced into the load cavity from the hole when switching to the low-speed state.

[0037] As shown in Figure 4 , the lower valve sleeve is provided with two peripheral holes, which are main channel oil ports. The hole diameter is determined according to the hydraulic oil flow rate calculated according to the running speed of the actuator, and a throttling pressure drop is generated at the port of the lower valve sleeve.

[0038] As shown in Figure 5 , the upper and lower ends of the valve core are different in diameter, and a damping long hole is arranged in the middle. The upper end is provided with a spring and senses the pressure of the spring cavity. The lower end senses the secondary pressure of the inlet pressure through the damping long hole. The spring is compressed by the movement of the valve core, and the pressure difference of the valve port is changed.

[0039] The technical key points of the application are as follows:

[0040] (1) The plug-in speed-limiting cut-off valve is compactly installed.

[0041] (2) The plug-in speed-limiting cut-off valve can reliably realize different flow automatic cut-off technology by calculating the spring force.

[0042] (3) The spring pre-tightening force of the plug-in speed-limiting cut-off valve is large, and the spring is designed to prevent plastic failure and fatigue failure, slow down the attenuation speed of the spring elastic modulus, and improve the service life of the spring.

Claims

1. A plug-in high pressure and large flow rate speed limiting cut-off valve for actuator stall protection, characterized in that: The valve includes an upper valve sleeve, a valve core, a lower valve sleeve and a cover plate. The upper valve sleeve and the lower valve sleeve are installed in the through hole of the valve body and are fixed and sealed at both ends by the cover plate. The valve core is connected in the upper valve sleeve and the lower valve sleeve. A spring cavity is arranged between the bottom of the cover plate and the top of the valve core in the upper valve sleeve, and a spring is arranged in the spring cavity. The two ends of the spring are connected with the bottom of the cover plate and the top of the valve core respectively. In use, the spring cavity is communicated with the accumulator. The lower valve sleeve is provided with two peripheral holes which are main passage oil ports. In use, the main passage oil ports are communicated with the rodless cavity of the actuator cylinder. The upper valve sleeve is provided with two small holes for sensing the load pressure to the spring cavity and introducing the accumulator oil into the load cavity from the holes when switching to the low speed state. The main passage oil ports in the lower valve sleeve determine the hole diameter according to the hydraulic oil flow rate calculated according to the running speed of the actuator cylinder, and a throttling pressure drop is generated at the ports of the lower valve sleeve.

2. The plug-in high pressure and high flow rate speed limiting cut-off valve for stall protection of a ram according to claim 1, characterized in that: The diameters of the upper end and the lower end of the valve core are different, and a damping long hole is arranged in the middle. The upper end senses the pressure of the spring cavity, and the lower end senses the secondary pressure of the inlet pressure through the damping long hole. The spring is compressed and the pressure difference of the valve port is changed through the movement of the valve core.

3. The plug-in high pressure and high flow rate speed limiting cut-off valve for stall protection of a ram according to claim 1, characterized in that: The spring has a certain pre-tightening force. The spring adopts a spring with anti-plastic failure and anti-fatigue failure, which can slow down the elastic modulus decay rate of the spring and improve the service life of the spring.

4. The plug-in high pressure and high flow rate speed limiting cut-off valve for stall protection of a ram according to claim 1, characterized in that: The plug-in high-pressure large-flow speed limiting cut-off valve realizes automatic cut-off of different flow rates by using springs with different spring forces.

5. The plug-in high pressure and high flow rate speed limiting cut-off valve for stall protection of a ram according to claim 1, characterized in that: The plug-in high-pressure large-flow speed limiting cut-off valve is installed between the rodless cavity of the actuator cylinder and the accumulator. When the plunger actuator works normally, the speed limiting cut-off valve realizes bidirectional free flow. When the load of the actuator suddenly drops or the steel wire rope, safety pin and connecting rod are suddenly broken, causing the load of the actuator to be zero, the instantaneous high-pressure and large-flow oil liquid under the action of the accumulator flows to the rodless cavity of the actuator through the speed limiting cut-off valve, causing the over valve flow of the speed limiting cut-off valve to rapidly increase, and causing the pressure difference between the inlet and outlet of the speed limiting cut-off valve to also rapidly increase. When the pressure difference between the inlet and outlet of the speed limiting cut-off valve exceeds the pre-set value of the spring force of the speed limiting cut-off valve, the valve core of the speed limiting cut-off valve will overcome the spring force and rapidly close the main valve port. Subsequently, the hydraulic oil flows through the small hole, controls the low-speed operation of the actuator plunger rod to the top limit position, prevents the plunger rod from hitting the cylinder body, and protects the equipment and personnel safety.

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