Plug-in mounting type high-pressure large-flow speed-limiting stop valve for stall protection of actuator cylinder

Abstract

An upper valve sleeve and a lower valve sleeve are installed in a valve body through hole, the two ends of the upper valve sleeve and the two ends of the lower valve sleeve are fixedly connected in a sealed mode through a cover plate, a valve element is connected into the upper valve sleeve and the lower valve sleeve in a matched mode, a spring cavity is formed in the upper valve sleeve and between the bottom of the cover plate and the top of the valve element, and a spring is arranged in the spring cavity. Two ends of the spring are respectively connected with the bottom of the cover plate and the top of the valve core; the lower valve sleeve is provided with two peripheral holes, the peripheral holes are main channel oil ports, and the main channel oil ports are communicated with a rodless cavity of the actuator cylinder. The speed-limiting stop valve is suitable for safety protection measures of the plunger type actuating cylinder under the working conditions of high pressure and large flow. And due to the plug-in mounting structure, the requirement on the mounting space is not high, and the reliability is not influenced by the external working environment. When the plunger type actuator cylinder operates abnormally, the plug-in type speed-limiting stop valve can automatically monitor the pressure difference between the inlet end and the outlet end of the valve and reliably, rapidly and automatically stop the valve element, and electrical control is not needed.

Description

Technical Field

[0001] The invention relates to a safety protection device for an actuator cylinder, in particular to a plug-in type high pressure large flow rate limiting cut-off valve. Background Art

[0002] The actuator installed on ships and marine equipment can realize the wave compensation function by its linear reciprocating motion. When the load of the actuator drops sharply or the connecting parts such as wire rope, safety pin, connecting rod suddenly break, the load of the actuator will be zero. At this time, high-pressure air or high-pressure hydraulic oil acts on the actuator to cause its moving parts to stall along the axial direction of the actuator and quickly hit the cylinder body, causing the cylinder body of the actuator to be damaged or the moving parts to pop out of the cylinder body, causing safety accidents. Therefore, the actuator must be equipped with a safety protection device, which can quickly cut off the power source of the actuator when the actuator is stalled, so that its moving parts can stop running quickly to prevent damage to equipment and personnel. The speed limit cut-off valve is installed on the oil side of the actuator. When the actuator is stalled, the oil flow of the speed limit cut-off valve increases sharply, and the valve core will overcome the spring force to quickly close the main valve and cut off the oil circuit. The operating state of the actuator changes from stall to stop, realizing the function of safety protection of the operating state of the actuator.

[0003] The actuator is divided into two types according to its structural type: piston type and plunger type, and the speed limiting cut-off valve is installed in the actuator.

[0004] The speed limiting shut-off valve for piston actuators is generally installed externally, and is installed at the oil port of the rod chamber (oil side) of the actuator. This technology has an invention patent, and the name of the invention patent is "A large flow control valve with two-way flow and automatic over-flow shut-off function."

[0005] At present, the plunger-type actuator adopts electromagnetically controlled speed-limiting cut-off valve in China. By setting a force sensor or a cylinder motion detection controller to monitor the load or operation change of the actuator, when the load of the actuator drops sharply or the operation stalls, the detection device sends an alarm signal, and the control program controls the speed-limiting cut-off valve electromagnet to attract the valve core to switch the hydraulic oil circuit to shut off, so as to realize the emergency stop function of the actuator. This technology has an invention patent, and the name of the invention patent is "A speed-limiting cut-off valve for improving the safety of large-scale offshore wave compensation devices". However, the plunger-type actuator is installed on the deck of a ship or an offshore platform. The force sensor, controller and 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 are significantly reduced. If any link in the force sensor, controller, or electromagnet fails or the control system itself fails, and the plunger-type actuator stalls at this time, the speed-limiting cut-off valve cannot cut off the high-pressure hydraulic oil in time, and the plunger rod is directly hit by the high-pressure hydraulic oil and hits the cylinder body, resulting in a safety accident.

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

[0007] (1) The piston-type actuator speed limiting cut-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 cut-off valve is 31.5MPa, the working pressure of the actuator is low and it is only suitable for medium and low pressure occasions.

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

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

[0010] (1) The electromagnetic speed limit cut-off valve is greatly affected by the "three highs" environment of the ocean, resulting in low reliability and safety of the speed limit cut-off function of the speed limit cut-off valve.

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

[0012] In view of the above problems, it is urgent to invent a speed limiting cut-off valve which has a simple structure, is suitable for high pressure and large flow conditions, and can work reliably in the marine "three highs" environment. Summary of the invention

[0013] In order to solve the above technical problems, the present invention proposes a plug-in high-pressure and high-flow speed-limiting cut-off valve for stall protection of the actuator. The plug-in speed-limiting cut-off valve is suitable for safety protection measures of plunger-type actuators under high-pressure and high-flow conditions. Due to its plug-in structure, its installation space requirement is not high, and its reliability is not affected by the external working environment. When the plunger-type actuator is working normally, the plug-in speed-limiting cut-off valve does not affect its operation. When the plunger-type actuator is operating abnormally, the plug-in speed-limiting cut-off valve can automatically monitor the pressure difference between the inlet and outlet of the valve, and reliably and quickly automatically cut off the valve core without the need for electrical control.

[0014] To achieve the above-mentioned purpose, the complete technical solution provided by the present invention is: a plug-in high-pressure and large-flow speed-limiting cut-off valve for stall protection of an actuator, comprising 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 the two ends are fixedly sealed and connected by the cover plate, the valve core is matched and connected inside the upper valve sleeve and the lower valve sleeve, a spring chamber 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 chamber, the two ends of the spring are respectively connected to the bottom of the cover plate and the top of the valve core, when in use, the spring chamber is connected to the accumulator; the lower valve sleeve is provided with two peripheral holes, the peripheral holes are main channel oil ports, when in use, the main channel oil port is connected to the rodless chamber of the actuator.

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

[0016] Furthermore, the main channel oil port in the lower valve sleeve has an aperture determined by calculating the hydraulic oil flow rate according to the operating speed of the actuator, and a throttling pressure drop will occur at the lower valve sleeve port.

[0017] Furthermore, the diameters of the upper and lower ends of the valve core are different, and a damping long hole is provided in the middle. The upper end senses the pressure in the spring chamber, and the lower end senses the secondary pressure of the inlet pressure passing through the damping long hole. Through the movement of the valve core, the spring is compressed and the pressure difference at the valve port is changed.

[0018] Furthermore, the spring has a certain preload force, and the spring adopts a spring that is resistant to plastic failure and fatigue failure, which can slow down the attenuation speed of the spring elastic modulus and increase the life of the spring.

[0019] Furthermore, the plug-in high-pressure and high-flow rate-limiting cut-off valve realizes automatic cut-off of different flow rates by adopting springs with different spring forces.

[0020] Furthermore, a plug-in high-pressure, high-flow speed-limiting cut-off valve is installed between the rodless chamber of the actuator and the accumulator. When the plunger-type actuator works normally, the speed-limiting cut-off valve realizes free two-way flow. When the load of the actuator drops sharply or the wire rope, safety pin, or connecting rod suddenly breaks, causing the load of the actuator to be zero, the instantaneous high-pressure, high-flow oil under the action of the accumulator flows to the rodless chamber of the actuator through the speed-limiting cut-off valve, causing the flow through the speed-limiting cut-off valve to increase rapidly, and at the same time causing the pressure difference at the inlet and outlet of the speed-limiting cut-off valve to increase rapidly. When the pressure difference at the inlet and outlet of the speed-limiting cut-off valve exceeds the preset 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 quickly close the main valve port, and then the hydraulic oil will flow through the small channel to control the actuator plunger rod to run at a low speed to the top limit, thereby preventing the plunger rod from hitting the cylinder body and protecting the safety of equipment and personnel.

[0021] The beneficial effects brought about by the technical solution adopted by the present invention are:

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

[0023] 2. The built-in installation effectively improves the working environment of the speed limit cut-off valve, avoiding the impact of the high temperature, high humidity and high salt environment of the ocean on the reliability and life of the speed limit 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, which can be applied to various large flow cut-off conditions, and the sensitivity of the speed limiting cut-off valve can be adjusted by calculating the spring force, which has a wide range of applications.

[0025] 4. When the pressure difference between the inlet and outlet ends reaches the set pressure difference value, the valve core can be automatically switched to cut off the oil source and then realize small flow circulation, so that when the actuator plunger rod 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 improve the safety of the operation of the plunger actuator and ensure the personal safety of on-site workers. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 2 It is a schematic diagram of the speed limiting cut-off valve;

[0030] Figure 3 1 is a schematic diagram of the structure of the upper valve sleeve;

[0031] Figure 4 1 is a schematic diagram of the structure of the lower valve sleeve;

[0032] Figure 5 It is a schematic diagram of the valve core structure. DETAILED DESCRIPTION

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

[0034] like Figure 1 As shown, the plug-in high-pressure and high-flow speed-limiting cut-off valve for stall protection of the actuator of the present invention is installed between the rodless chamber of the actuator and the accumulator. When the plunger-type actuator works normally, the speed-limiting cut-off valve can realize two-way free flow. When the load of the actuator drops sharply or the connecting parts such as the wire rope, safety pin, and connecting rod suddenly break, causing the load of the actuator to be zero, the instantaneous high-pressure and high-flow oil under the action of the accumulator flows to the rodless chamber of the actuator through the speed-limiting cut-off valve. This causes the flow through the speed-limiting cut-off valve to increase rapidly, and at the same time, the pressure difference at both ends of the inlet and outlet of the speed-limiting cut-off valve also increases rapidly. When the pressure difference at both ends of the inlet and outlet of the speed-limiting cut-off valve exceeds the preset 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 quickly close the main valve port. Then the hydraulic oil flows through the small channel to control the plunger rod of the actuator to run at a low speed to the top limit. Prevent the plunger rod from hitting the cylinder body and protecting the safety of equipment and personnel.

[0035] like Figure 2As shown, the plug-in high-pressure, large-flow, speed-limiting cut-off valve for the stall protection of the actuator of the present invention 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 fixedly sealed and connected by the cover plate 4. The valve core 3 is matched and connected inside the upper valve sleeve 1 and the lower valve sleeve 2. In the upper valve sleeve 1, a spring cavity is provided between the bottom of the cover plate 4 and the top of the valve core 3, and a spring 5 is provided in the spring cavity. The two ends of the spring 5 are respectively connected to the bottom of the cover plate 4 and the top of the valve core 3. When in use, the spring cavity is connected to the accumulator; the lower valve sleeve 2 is provided with two peripheral holes, which are the main channel oil ports (see Figure 4 ), when in use, the main channel oil port is connected to the rodless chamber of the actuator.

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

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

[0038] like Figure 5 As shown, the diameters of the upper and lower ends of the valve core are different, a damping long hole is provided in the middle, a spring is installed at the upper end, and it senses the pressure in the spring cavity, and the lower end senses the secondary pressure of the inlet pressure passing through the damping long hole. Through the movement of the valve core, the spring is compressed and the pressure difference at the valve port is changed.

[0039] Key technical points of the present invention:

[0040] (1) Realize compact installation of plug-in speed limiting cut-off valve.

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

[0042] (3) The spring preload force of the plug-in speed limiting cut-off valve is large, and the spring is designed to prevent plastic failure and fatigue failure, which slows down the attenuation rate of the spring elastic modulus to increase the spring life.

Claims

1. A plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection, characterized in that: It 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 the two ends are fixedly sealed and connected by the cover plate. The upper valve sleeve and the lower valve sleeve are matched to connect the valve core. In the upper valve sleeve, a spring chamber is provided between the bottom of the cover plate and the top of the valve core, and a spring is provided in the spring chamber. The two ends of the spring are respectively connected to the bottom of the cover plate and the top of the valve core. When in use, the spring chamber is connected to the accumulator; the lower valve sleeve is provided with two peripheral holes, which are the main channel oil ports. When in use, the main channel oil port is connected to the rodless chamber of the actuator.

2. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1 is characterized in that: The upper valve sleeve is provided with two small holes for sensing the load pressure to the spring chamber, and when switching to the low speed state, the accumulator oil is introduced into the load chamber from the holes.

3. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1 is characterized in that: The main channel oil port in the lower valve sleeve has an aperture determined by calculating the hydraulic oil flow rate according to the operating speed of the actuator, and a throttling pressure drop will occur at the lower valve sleeve port.

4. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1 is characterized in that: The diameters of the upper and lower ends of the valve core are different, and a damping long hole is provided in the middle. The upper end senses the pressure in the spring chamber, and the lower end senses the secondary pressure of the inlet pressure passing through the damping long hole. Through the movement of the valve core, the spring is compressed and the pressure difference at the valve port is changed.

5. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1 is characterized in that: The spring has a certain preload force. The spring adopts a spring that is resistant to plastic failure and fatigue failure, which can slow down the attenuation rate of the spring elastic modulus and increase the life of the spring.

6. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1, characterized in that: The plug-in high-pressure, high-flow, speed-limiting cut-off valve uses springs with different spring forces to achieve automatic cut-off at different flow rates.

7. The plug-in high-pressure, high-flow, speed-limiting cut-off valve for actuator stall protection according to claim 1, characterized in that: The plug-in high-pressure, high-flow speed-limiting cut-off valve is installed between the rodless chamber of the actuator and the accumulator. When the plunger-type actuator works normally, the speed-limiting cut-off valve realizes two-way free flow; when the load of the actuator drops sharply or the wire rope, safety pin, or connecting rod suddenly breaks, causing the load of the actuator to be zero, the instantaneous high-pressure, high-flow oil under the action of the accumulator flows to the rodless chamber of the actuator through the speed-limiting cut-off valve, causing the flow through the speed-limiting cut-off valve to increase rapidly, and at the same time, the pressure difference at the inlet and outlet of the speed-limiting cut-off valve also increases rapidly. When the pressure difference at the inlet and outlet of the speed-limiting cut-off valve exceeds the preset 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 quickly close the main valve port, and then the hydraulic oil will flow through the small channel to control the actuator plunger rod to run at a low speed to the top limit, preventing the plunger rod from hitting the cylinder body and protecting the safety of equipment and personnel.

Images