CN113738921A - Safety valve structure and method for avoiding valve clack impact during opening and closing - Google Patents

Safety valve structure and method for avoiding valve clack impact during opening and closing Download PDF

Info

Publication number
CN113738921A
CN113738921A CN202110979613.4A CN202110979613A CN113738921A CN 113738921 A CN113738921 A CN 113738921A CN 202110979613 A CN202110979613 A CN 202110979613A CN 113738921 A CN113738921 A CN 113738921A
Authority
CN
China
Prior art keywords
valve
piston
oil
buffer
clack
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110979613.4A
Other languages
Chinese (zh)
Inventor
钱锦远
徐毅翔
刘步展
高志新
金志江
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN202110979613.4A priority Critical patent/CN113738921A/en
Publication of CN113738921A publication Critical patent/CN113738921A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
    • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
    • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
    • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
    • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
    • F16K17/0433—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded with vibration preventing means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K47/00—Means in valves for absorbing fluid energy
    • F16K47/02—Means in valves for absorbing fluid energy for preventing water-hammer or noise
    • F16K47/023—Means in valves for absorbing fluid energy for preventing water-hammer or noise for preventing water-hammer, e.g. damping of the valve movement

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)

Abstract

The invention discloses a safety valve structure and a method thereof for avoiding valve clack impact during opening and closing, wherein an upper buffer of the safety valve structure is fixed above a valve rod, a first piston is arranged at the bottom of the safety valve structure, and an inner cavity above the first piston is used as a first oil cavity; a first oil transfer hole at the upper part of the side wall; the lower buffer group comprises at least two lower buffers with the same structure, and all the lower buffers are positioned in the valve seat and are uniformly distributed; the top of the lower buffer is provided with a second piston, and an inner cavity positioned below the second piston is used as a second oil cavity; a second oil conveying hole is formed below the outer side wall, the first oil cavity, the oil conveying pipe and the second oil cavity jointly form a communicated and always-closed buffer passage, and a buffer medium is filled in the buffer passage. The invention can reduce the impact of the valve clack on the guide sleeve in the initial stage and the impact of the valve clack on the valve seat in the closing stage on the basis of ensuring that the safety valve is opened and closed in a short enough time, prolongs the service life of the internal part of the safety valve and avoids the impact damage in the opening and closing process of the safety valve.

Description

Safety valve structure and method for avoiding valve clack impact during opening and closing
Technical Field
The invention belongs to the field of valve structure design, and particularly relates to a safety valve structure and a method for avoiding valve clack impact during opening and closing.
Background
The safety valve is a special valve, wherein the opening and closing part is in a normally closed state under the action of external force, and when the pressure of a medium in equipment or a pipeline rises to exceed a specified value, the medium is discharged to the outside of the system to prevent the pressure of the medium in the pipeline or the equipment from exceeding the specified value. Safety valve structures mainly fall into two categories: spring type and lever type. The spring type is that the valve clack and the valve seat are sealed by the acting force of the spring, and is the most widely used safety valve at present. The spring type safety valve can be opened rapidly after the pressure exceeds the set pressure, so that the overpressure medium can be discharged rapidly. Although the rapid discharge of overpressure media has important safety significance for pipeline systems or pressure vessels, in most cases, due to the fact that the opening speed of the safety valve is too high, the valve clack generates severe impact on other parts in the safety valve, the service life of the safety valve is shortened, even the deformation and damage of valve internals are caused, and serious safety accidents are caused.
Therefore, it is urgently needed to provide a safety valve structure and a method thereof for avoiding the impact of the valve clack during opening and closing, which not only can ensure the short enough opening and closing time of the safety valve, but also can avoid the violent impact of the valve clack on the valve internals during the opening and closing process, prolong the service life of the safety valve, and avoid the sudden failure of the valve internals, and have important significance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a safety valve structure and a method thereof for avoiding the impact of a valve clack during opening and closing. The invention avoids the violent impact on other valve internals generated in the opening and closing process of the safety valve clack, and can ensure the short enough opening and closing time of the safety valve to a certain extent.
The invention adopts the following specific technical scheme:
in a first aspect, the invention provides a safety valve structure for avoiding the impact of a valve clack during opening and closing, which comprises a valve cover, a valve rod, a guide sleeve, the valve clack, a valve seat, a valve body, an upper buffer and a lower buffer group, wherein the valve cover is arranged on the valve rod;
the upper buffer is fixed above the valve rod and is of a closed tubular structure, the bottom of the upper buffer is provided with a first piston capable of moving in the upper buffer along the axial direction, the joint of the first piston and the inner wall of the upper buffer is always closed, and an inner cavity above the first piston is used as a first oil cavity; the side wall of the upper buffer positioned at the first oil cavity is uniformly provided with at least two first oil transmission holes along the circumferential direction; the bottom of the first piston extends out of the upper buffer and coaxially suspends above the valve rod in an initial state; the distance between the first piston and the valve rod in the initial state is smaller than the moving distance of the valve rod, so that the valve rod can transfer the force to the first piston through contact;
the lower buffer group comprises at least two lower buffers with the same structure, and all the lower buffers are positioned in the valve seat and are uniformly distributed; the lower buffer is of a closed tubular structure, the top of the lower buffer is provided with a second piston capable of axially moving inside, the joint of the second piston and the inner wall of the lower buffer is always closed, and an inner cavity below the second piston is used as a second oil cavity; the top of the second piston is always positioned above the valve seat and can be contacted with the bottom of the valve clack; the outer side wall of the lower buffer positioned at the second oil cavity is provided with second oil conveying holes, and all the first oil conveying holes are respectively communicated with the second oil conveying holes of different lower buffers through corresponding oil conveying pipes; the first oil cavity, the oil delivery pipe and the second oil cavity jointly form a communicated and always-closed buffer passage, and the buffer passage is filled with buffer media.
Preferably, the top of the valve body is fixed with a guide sleeve of which the part extends into the inner cavity of the valve body, and a valve cover is detachably arranged above the valve body; the valve rod is coaxially sleeved in the guide sleeve, can slide up and down under the limiting action of the guide sleeve, and is sealed at the connecting part of the guide sleeve and the valve rod; the upper end of the valve rod extends into the valve cover, the lower end of the valve rod extends into the inner cavity of the valve body, and a valve clack capable of forming closed connection with the valve seat is fixed at the bottom of the valve body; the travel of the valve clack in the inner cavity of the valve body is limited by the bottom of the guide sleeve and the top of the valve seat, and the axes of the valve rod, the valve clack and the valve seat are the same.
Furthermore, a recoil disc is circumferentially arranged at the bottom of the valve clack, and can be in closed connection with the valve seat through the recoil disc.
Furthermore, the top of the valve body is provided with a heat insulation disc, and the guide sleeve is clamped and fixed by the valve body and the heat insulation disc together.
Further, a spring is sleeved on the periphery of the valve rod inside the valve cover.
Preferably, the buffer medium is hydraulic oil.
Preferably, the top of the valve cap is detachably provided with a valve cap, and a fixing nut is radially fixed in the valve cap; go up the top periphery of buffer and be equipped with the screw thread, through the threaded connection with fixation nut, realize going up the fixed connection of buffer in the valve rod top.
Preferably, the first piston and the second piston are both in an I-shaped piston structure with straight upper and lower ends, and the tops of all the second pistons are always flush.
Preferably, the lower buffer group comprises two lower buffers with the same structure, and the two lower buffers are symmetrically arranged around the axis of the valve seat respectively; the first oil conveying holes of the upper buffer are two and are respectively arranged at the same side of the two lower buffers.
In a second aspect, the present invention provides a method for avoiding the impact of the valve flap when opening and closing by using any one of the safety valve structures of the first aspect, specifically as follows:
s1: the safety valve is in a closed state in an initial state, and the valve clacks are tightly attached to the tops of all the second pistons; all the second pistons are positioned at the lower limit position under the action of the gravity of the valve clack and the valve rod, only a small amount of buffer medium exists in the second oil cavity, and the rest of the buffer medium exists in the oil pipeline and the first oil cavity; the first piston is positioned at a lower limit position under the action of gravity and oil pressure;
s2: when the pressure at the inlet of the safety valve exceeds the setting pressure, the safety valve is quickly opened, and the valve clack and the valve rod move upwards under the action of the inlet pressure and are gradually separated from the second piston; all the second pistons move upwards due to the reduction of the top pressure, and the buffer medium gradually flows into the second oil cavity;
s3: when the valve rod moves upwards to contact the bottom of the first piston, the upward force is transferred to the first piston to drive the first piston to move upwards; the first piston presses the buffer medium in the first oil chamber in the process of moving upwards, so that the buffer medium flows out of the first oil chamber; however, the slow flow rate of the buffer medium can hinder the ascending trend of the first piston, and the oil pressure acting on the top of the first piston generates resistance to the movement of the valve rod, so that the first piston, the valve rod and the valve clack start to decelerate at the same time;
s4: the first piston, the valve rod and the valve clack are continuously decelerated under the action of oil pressure generated by the first oil cavity and move to the maximum opening position of the safety valve at a lower speed, so that severe collision between the valve clack and the guide sleeve is avoided; at the moment, the second oil cavity is filled with a buffer medium, and the first piston and the second piston are both positioned at the upper limit position;
s5: when the pressure at the inlet of the safety valve is lower than the set recoil pressure, the valve clack and the valve rod move downwards, the valve rod is gradually separated from the first piston, and the first piston moves downwards under the action of the oil pressure and the gravity of the first oil cavity;
s6: when the valve rod moves downwards to contact the top of the second piston, the valve rod transmits the downward force to the second piston to drive the second piston to move downwards; the second piston presses the buffer medium in the second oil chamber in the process of moving downwards so as to enable the buffer medium to flow out of the second oil chamber; however, the slow flow rate of the buffer medium can hinder the descending trend of the second piston, and the oil pressure acting on the bottom of the second piston generates resistance to the movement of the valve rod, so that the second piston, the valve rod and the valve clack start to decelerate at the same time;
s7: the second piston, the valve rod and the valve clack are continuously decelerated under the action of oil pressure generated by the second oil chamber and move to the closing position of the safety valve at a lower speed, so that severe collision between the valve clack and the valve seat is avoided, and the safety valve returns to the initial state in S1.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, through the arrangement of the upper buffer and the lower buffer group, the safety valve can be ensured to have short enough opening and closing time, severe impact on the valve internals caused by the valve clack in the opening and closing process can be avoided, the service life of the safety valve can be effectively prolonged, sudden failure of the valve internals can be avoided, and a new thought is provided for the optimization design of the safety valve structure.
Drawings
FIG. 1 is a front sectional view of a relief valve construction;
FIG. 2 is a right side sectional view of the relief valve arrangement of FIG. 1;
FIG. 3 is a front and right side view of the upper bumper;
FIG. 4 is a schematic view of a mating arrangement of the lower damper group and the valve seat;
the reference numbers in the figures are: the valve comprises a valve cover 1, a spring 2, a valve rod 3, a heat insulation disc 4, a guide sleeve 5, a valve clack 6, a recoil disc 7, a valve seat 8, a valve body 9, a fixing nut 10, an upper buffer 11, threads 11-1, a first oil transmission hole 11-2, a first oil cavity 11-3, a first piston 11-4, an oil transmission pipe 12, a lower buffer 13, a second oil transmission hole 13-1, a second oil cavity 13-2 and a second piston 13-3.
Detailed Description
The invention will be further elucidated and described with reference to the drawings and the detailed description. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.
As shown in fig. 1 and 2, the safety valve structure for avoiding the impact of the valve flap during opening and closing provided by the invention comprises a valve cover 1, a valve rod 3, a guide sleeve 5, a valve flap 6, a valve seat 8 and a valve body 9 which are arranged conventionally, wherein the guide sleeve 5 partially extending into an inner cavity of the valve body 9 is fixed at the top of the valve body 9, and the valve cover 1 is detachably arranged above the valve body 9. The valve rod 6 is coaxially sleeved in the guide sleeve 5, the valve rod 6 can slide up and down under the limiting effect of the guide sleeve 5, and the joint between the valve rod and the guide sleeve is closed. The upper end of the valve rod 6 extends into the valve cover 1, the lower end extends into the inner cavity of the valve body, and the bottom of the valve rod is fixed with a valve clack 4 which can form closed connection with the valve seat 12. The travel of the valve clack 4 in the inner cavity of the valve body 9 is limited by the bottom of the guide sleeve 5 and the top of the valve seat 12, and the axes of the valve rod 6, the valve clack 4 and the valve seat 12 are the same.
In practical application, the recoil disc 7 can be arranged at the bottom of the valve clack 6 in the circumferential direction as required, and a closed connection can be formed between the recoil disc 7 and the valve seat 8. The heat insulation disc 4 can be arranged on the top of the valve body 9 according to requirements, and the guide sleeve 5 is clamped and fixed by the valve body 1 and the heat insulation disc 4 together. The spring 2 can be sleeved on the periphery of the valve rod 3 positioned in the valve cover 1 according to requirements.
In addition, the safety valve structure of the present invention is further provided with an upper buffer 11 and a lower buffer group. The upper buffer is used for preventing the valve clack from violently colliding with the guide sleeve in the opening process of the safety valve, and the lower buffer group is used for preventing the valve clack from violently colliding with the valve seat in the closing process of the safety valve. The upper damper 11 and the lower damper group generate resistance to the valve flap in rapid movement through hydraulic damping, so that the valve flap is forced to decelerate, and finally collision is avoided. The structure and connection of the respective components will be specifically described below.
As shown in FIG. 3, the upper buffer 11 is fixed above the valve rod 6, and is a closed cylindrical structure, the bottom of the upper buffer is provided with a first piston 11-4 capable of moving axially along the upper buffer 11 in the upper buffer 11, the joint of the first piston 11-4 and the inner wall of the upper buffer 11 is always closed, an inner cavity above the first piston 11-4 is used as a first oil cavity 11-3, and the first oil cavity 11-3 is used for storing a buffer medium. The side wall of the upper buffer 11 at the first oil chamber 11-3 is uniformly provided with at least two first oil transmission holes 11-2 along the circumferential direction for communicating with the lower buffer group. The bottom of the first piston 11-4 protrudes beyond the upper bumper 11 and is located below the upper bumper 11. The first piston 11-4 is positioned at the lower limit position in the initial state, is coaxial with the valve rod 6 and is suspended right above the valve rod, and a certain distance is reserved between the first piston and the valve rod, so that the valve clack can be ensured to start to decelerate after reaching a certain opening height, and the phenomenon that the discharge of overpressure media is influenced due to overlong opening time of the safety valve is prevented. However, it is required to ensure that the distance between the first piston 11-4 and the valve rod 6 in the initial state is smaller than the moving distance of the valve rod 6, so that when the safety valve works, the first piston 11-4 and the valve rod 6 can contact with each other during the up-and-down movement of the valve rod 6, and the valve rod 6 can transmit the force to the first piston 11-4 through the contact.
In practical application, the buffer medium can be hydraulic oil, because hydraulic oil not only has higher pressure-bearing capacity, but also can play a certain lubricating role. In order to fix the upper buffer 11 above the valve rod 6 and form an integral with the safety valve structure, a bonnet may be detachably provided on the top of the bonnet 1, and a fixing nut 10 is radially fixed in the bonnet. The periphery of the top of the upper buffer 11 is provided with a thread 11-1, and the upper buffer 11 is fixedly connected above the valve rod 6 through the thread connection with the fixing nut 10. The first piston 11-4 may be configured as an i-shaped piston structure with straight and parallel upper and lower ends, so that the upper and lower ends of the first piston 11-4 are uniformly stressed. The top of the first piston 11-4 is located in the upper buffer 11, and needs to be closely attached to the inner wall of the upper buffer 11 to form a closed state, thereby preventing the buffer medium from leaking down from the junction.
As shown in fig. 4, the lower buffer group includes at least two lower buffers 13 having the same structure, and all the lower buffers 13 are located in the valve seat 8 and are uniformly distributed. The lower buffer 13 is a closed cylindrical structure, the top of the lower buffer is provided with a second piston 13-3 capable of axially moving inside, the joint of the second piston 13-3 and the inner wall of the lower buffer 13 is always closed, and an inner cavity below the second piston 13-3 is used as a second oil cavity 13-2. The top of the second piston 13-3 is always above the valve seat 8 and can be in contact with the bottom of the flap 4. In the initial state, the second piston 13-3 is in contact with the valve flap 4, and the second piston 13-3 is at the lower limit. The outer side wall of the lower buffer 13 positioned at the second oil chamber 13-2 is provided with a second oil transmission hole 13-1, and all the first oil transmission holes 11-2 are respectively communicated with the second oil transmission holes 13-1 of different lower buffers 13 through different oil transmission pipes 12. The first oil cavity 11-3, all the oil delivery pipes 12 and all the second oil cavities 13-2 jointly form a communicated and always closed buffer passage, and the buffer passage is filled with buffer media.
In practical application, the second piston 13-3 can be set to be an I-shaped piston structure with straight and parallel upper and lower ends, so that the upper and lower ends of the second piston 13-3 are uniformly stressed; meanwhile, the tops of all the second pistons 13-3 are always flush and are positioned on the same horizontal plane, so that the movement and the stress condition of each second piston 13-3 are kept the same.
The number of the lower damper groups may be selected and set according to actual conditions, and for example, the lower damper groups may be set to include two lower dampers 13 having the same structure, each being symmetrically arranged with respect to the axis of the valve seat 8. Correspondingly, the number of the first oil delivery holes 11-2 of the upper buffer 11 is two, and the two oil delivery holes are respectively arranged on the same side as the two lower buffers 13.
The method for avoiding the impact of the valve clack when the safety valve structure is opened and closed specifically comprises the following steps:
s1: in the initial state, the safety valve is in a closed state, and the valve clacks 6 are closely attached to the tops of all the second pistons 13-3. Due to the gravity action of the valve clack 6 and the valve rod 3, all the second pistons 13-3 are positioned at the lower limit position, only a small amount of buffer medium exists at the bottom in the second oil cavity 13-2, and the rest of the buffer medium exists in the oil pipeline 12 and the first oil cavity 11-3. The first piston 11-4 is at a lower limit under the action of gravity and oil pressure.
S2: when the pressure at the inlet of the safety valve exceeds the setting pressure, the safety valve can be quickly opened, the valve clack 6 and the valve rod 3 can quickly move upwards for a certain distance under the action of the inlet pressure, and are gradually separated from the second piston 13-3 in the upward movement process. All the second pistons 13-3 move upward due to the reduction in the top pressure, and the damping medium gradually flows into the second oil chambers 13-2.
S3: when the valve rod 3 moves upwards to contact the bottom of the first piston 11-4, the upward force is transmitted to the first piston 11-4, and the first piston 11-4 is driven to move upwards together. The first piston 11-4 presses the buffer medium in the first oil chamber 11-3 during the upward movement, so that the buffer medium flows out of the first oil chamber 11-3, and the buffer medium enters the second oil chamber through the oil pipeline. However, since the slow flow rate of the buffer medium in the buffer passage may hinder the ascending trend of the first piston 11-4, so that the first piston 11-4 cannot ascend quickly, the oil pressure acting on the top of the first piston 11-4 may generate resistance to the movement of the valve rod 3, and force the first piston 11-4, the valve rod 3 and the valve flap 6 to start decelerating simultaneously.
S4: the first piston 11-4, the valve rod 3 and the valve clack 6 are continuously decelerated under the action of oil pressure generated by the first oil cavity 11-3 and move to the maximum opening height position of the safety valve at a lower speed, so that severe collision between the valve clack 6 and the guide sleeve 5 is avoided. At this time, the second oil chamber 13-2 is filled with the buffer medium, and both the first piston 11-4 and the second piston 13-3 are at the upper limit.
S5: when the pressure at the inlet of the safety valve is lower than the set recoil pressure, the valve clack 6 and the valve rod 3 rapidly move downwards under the action of the pressure, the valve rod 3 is gradually separated from the first piston 11-4, and the first piston 11-4 moves downwards under the action of the oil pressure and the gravity of the first oil chamber 11-3.
S6: when the valve clack and the valve rod move for a certain distance quickly, the valve clack contacts the top of the second piston 13-3, and at the moment, the valve clack transmits the downward force to the second piston 13-3 to drive the second piston 13-3 to move downward together. The second piston 13-3 presses the buffer medium in the second oil chamber 13-2 during the downward movement, so that the buffer medium flows out of the second oil chamber 13-2, and the buffer medium enters the first oil chamber through the oil pipeline. However, since the flow rate of the damping medium is slow, the downward trend of the second piston 13-3 is hindered, and therefore, the oil pressure acting on the bottom of the second piston 13-3 generates resistance to the movement of the valve rod 3, so that the second piston 13-3, the valve rod 3 and the valve flap 6 start to decelerate at the same time.
S7: the second piston 13-3, the valve rod 3 and the valve flap 6 are continuously decelerated under the oil pressure generated by the second oil chamber 13-2 and move to the closed position of the safety valve at a low speed, so that the severe collision of the valve flap 6 with the valve seat 8 is avoided, and at the moment, the whole safety valve returns to the initial state in S1.
The safety valve structure reduces the impact of the valve clack on the guide sleeve in the initial stage and the impact of the valve clack on the valve seat in the closing stage on the basis of ensuring the opening and closing in a short enough time, prolongs the service life of the internal part of the safety valve and avoids the impact damage in the opening and closing process of the safety valve.
The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.

Claims (10)

1. A safety valve structure for avoiding valve clack impact during opening and closing comprises a valve cover (1), a valve rod (3), a guide sleeve (5), a valve clack (6), a valve seat (8) and a valve body (9), and is characterized by further comprising an upper buffer (11) and a lower buffer group;
the upper buffer (11) is fixed above the valve rod (6) and is of a closed tubular structure, the bottom of the upper buffer is provided with a first piston (11-4) capable of moving in the upper buffer along the axial direction, the joint of the first piston (11-4) and the inner wall of the upper buffer (11) is always closed, and an inner cavity above the first piston (11-4) is used as a first oil cavity (11-3); the side wall of the upper buffer (11) positioned at the first oil cavity (11-3) is uniformly provided with at least two first oil transmission holes (11-2) along the circumferential direction; the bottom of the first piston (11-4) extends out of the upper buffer (11) and is coaxially suspended above the valve rod (6) in an initial state; the distance between the first piston (11-4) and the valve rod (6) in the initial state is smaller than the moving distance of the valve rod (6), so that the valve rod (6) can transmit the force to the first piston (11-4) through contact;
the lower buffer group comprises at least two lower buffers (13) with the same structure, and all the lower buffers (13) are positioned in the valve seat (8) and are uniformly distributed; the lower buffer (13) is of a closed cylindrical structure, the top of the lower buffer is provided with a second piston (13-3) capable of axially moving in the lower buffer, the joint of the second piston (13-3) and the inner wall of the lower buffer (13) is always closed, and an inner cavity positioned below the second piston (13-3) is used as a second oil cavity (13-2); the top of the second piston (13-3) is always positioned above the valve seat (8) and can be contacted with the bottom of the valve clack (4); the outer side wall of the lower buffer (13) positioned at the second oil cavity (13-2) is provided with second oil conveying holes (13-1), and all the first oil conveying holes (11-2) are respectively communicated with the second oil conveying holes (13-1) of different lower buffers (13) through corresponding oil conveying pipes (12); the first oil cavity (11-3), the oil delivery pipe (12) and the second oil cavity (13-2) jointly form a communicated and always-closed buffer passage, and buffer media are filled in the buffer passage.
2. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 1, characterized in that a guide sleeve (5) partially extending into an inner cavity of the valve body (9) is fixed at the top of the valve body (9), and a valve cover (1) is detachably arranged above the valve body (9); the valve rod (6) is coaxially sleeved in the guide sleeve (5), the valve rod (6) can slide up and down under the limiting action of the guide sleeve (5), and the joint between the valve rod and the guide sleeve is closed; the upper end of the valve rod (6) extends into the valve cover (1), the lower end extends into the inner cavity of the valve body, and a valve clack (4) which can form closed connection with the valve seat (12) is fixed at the bottom of the valve body; the stroke of the valve clack (4) in the inner cavity of the valve body (9) is limited by the bottom of the guide sleeve (5) and the top of the valve seat (12), and the axes of the valve rod (6), the valve clack (4) and the valve seat (12) are the same.
3. A safety valve structure for preventing the impact of the valve clack during opening and closing according to claim 2, characterized in that the bottom of the valve clack (6) is provided with a recoil disc (7) in the circumferential direction, and a closed connection can be formed between the recoil disc (7) and the valve seat (8).
4. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 2, characterized in that the top of the valve body (9) is provided with a heat insulation disc (4), and the guide sleeve (5) is clamped and fixed by the valve body (1) and the heat insulation disc (4) together.
5. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 2, characterized in that a spring (2) is sleeved on the periphery of the valve rod (3) positioned inside the valve cover (1).
6. The safety valve structure for preventing the valve clack from impacting during opening and closing of claim 1, wherein the buffering medium is hydraulic oil.
7. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 1, characterized in that a bonnet is detachably arranged on the top of the valve cover (1), and a fixing nut (10) is radially fixed in the bonnet; the periphery of the top of the upper buffer (11) is provided with threads (11-1), and the upper buffer (11) is fixedly connected above the valve rod (6) through threaded connection with the fixing nut (10).
8. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 1, characterized in that the first piston (11-4) and the second piston (13-3) are both in an I-shaped piston structure with straight upper and lower ends, and the tops of all the second pistons (13-3) are always flush.
9. The safety valve structure for avoiding the impact of the valve clack during opening and closing according to claim 1, characterized in that the lower buffer group comprises two lower buffers (13) with the same structure, which are respectively arranged symmetrically about the axis of the valve seat (8); the number of the first oil transmission holes (11-2) of the upper buffer (11) is two, and the two oil transmission holes are respectively arranged on the same side of the two lower buffers (13).
10. A method for avoiding the impact of a valve clack when opening and closing by using the safety valve structure of any one of claims 1 to 9, which is characterized by comprising the following steps:
s1: the safety valve is in a closed state in an initial state, and the valve clacks (6) are tightly attached to the tops of all the second pistons (13-3); due to the gravity action of the valve clack (6) and the valve rod (3), all the second pistons (13-3) are positioned at the lower limit position, only a small amount of buffer medium exists in the second oil cavity (13-2), and the rest of the buffer medium exists in the oil pipeline (12) and the first oil cavity (11-3); the first piston (11-4) is positioned at a lower limit position under the action of gravity and oil pressure;
s2: when the pressure at the inlet of the safety valve exceeds the setting pressure, the safety valve is opened, and the valve clack (6) and the valve rod (3) move upwards under the action of the inlet pressure; all the second pistons (13-3) move upwards due to the reduction of the top pressure, and the buffer medium gradually flows into the second oil chambers (13-2);
s3: when the valve rod (3) moves upwards to contact the bottom of the first piston (11-4), the upward force is transmitted to the first piston (11-4) to drive the first piston (11-4) to move upwards together; the first piston (11-4) presses the buffer medium in the first oil chamber (11-3) during upward movement, so that the buffer medium flows out of the first oil chamber (11-3); but the flow rate of the buffer medium is slow, so that the ascending trend of the first piston (11-4) can be hindered, the oil pressure acting on the top of the first piston (11-4) generates resistance to the movement of the valve rod (3), and the first piston (11-4), the valve rod (3) and the valve clack (6) are forced to start to decelerate at the same time;
s4: the first piston (11-4), the valve rod (3) and the valve clack (6) are continuously decelerated under the action of oil pressure generated by the first oil cavity (11-3) and move to the maximum opening position of the safety valve at a low speed, so that severe collision between the valve clack (6) and the guide sleeve (5) is avoided; at the moment, the second oil cavity (13-2) is filled with a buffer medium, and the first piston (11-4) and the second piston (13-3) are both positioned at an upper limit position;
s5: when the pressure at the inlet of the safety valve is lower than the set recoil pressure, the valve clack (6) and the valve rod (3) move downwards, and the first piston (11-4) moves downwards under the action of the oil pressure and the gravity of the first oil chamber (11-3);
s6: when the valve clack (6) moves downwards to contact the top of the second piston (13-3), the downward force is transmitted to the second piston (13-3) to drive the second piston (13-3) to move downwards together; the second piston (13-3) presses the buffer medium in the second oil chamber (13-2) during the downward movement, so that the buffer medium flows out of the second oil chamber (13-2); but the flow rate of the buffer medium is slow, the descending trend of the second piston (13-3) can be hindered, the oil pressure acting on the bottom of the second piston (13-3) generates resistance to the movement of the valve rod (3), and the second piston (13-3), the valve rod (3) and the valve clack (6) are forced to start to decelerate at the same time;
s7: the second piston (13-3), the valve rod (3) and the valve clack (6) are continuously decelerated under the action of oil pressure generated by the second oil chamber (13-2) and move to the closing position of the safety valve at a low speed, so that severe collision between the valve clack (6) and the valve seat (8) is avoided, and the safety valve returns to the initial state in S1.
CN202110979613.4A 2021-08-25 2021-08-25 Safety valve structure and method for avoiding valve clack impact during opening and closing Pending CN113738921A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110979613.4A CN113738921A (en) 2021-08-25 2021-08-25 Safety valve structure and method for avoiding valve clack impact during opening and closing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110979613.4A CN113738921A (en) 2021-08-25 2021-08-25 Safety valve structure and method for avoiding valve clack impact during opening and closing

Publications (1)

Publication Number Publication Date
CN113738921A true CN113738921A (en) 2021-12-03

Family

ID=78732714

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110979613.4A Pending CN113738921A (en) 2021-08-25 2021-08-25 Safety valve structure and method for avoiding valve clack impact during opening and closing

Country Status (1)

Country Link
CN (1) CN113738921A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB836387A (en) * 1957-02-15 1960-06-01 Manning Maxwell & Moore Inc Improvements in or relating to fluid control spring-loaded safety valves
CN101936413A (en) * 2010-08-09 2011-01-05 安徽铜都阀门股份有限公司 Hydraulic self-control bevel-seat type wee-resistance slow-closing non-return valve
CN208123528U (en) * 2018-02-09 2018-11-20 郑州中特阀门有限公司 A kind of swing check valve
US20180356002A1 (en) * 2017-06-08 2018-12-13 Mueller International, Llc Rod-mounted buffer to cushion check valve closure
CN113007403A (en) * 2021-03-05 2021-06-22 浙江大学 Safety valve structure capable of preventing back seat from being locked based on circumferential discharge pressure relief and method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB836387A (en) * 1957-02-15 1960-06-01 Manning Maxwell & Moore Inc Improvements in or relating to fluid control spring-loaded safety valves
CN101936413A (en) * 2010-08-09 2011-01-05 安徽铜都阀门股份有限公司 Hydraulic self-control bevel-seat type wee-resistance slow-closing non-return valve
US20180356002A1 (en) * 2017-06-08 2018-12-13 Mueller International, Llc Rod-mounted buffer to cushion check valve closure
CN208123528U (en) * 2018-02-09 2018-11-20 郑州中特阀门有限公司 A kind of swing check valve
CN113007403A (en) * 2021-03-05 2021-06-22 浙江大学 Safety valve structure capable of preventing back seat from being locked based on circumferential discharge pressure relief and method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
黄凯林: "《城市轨道交通车辆总体及走行部》", 31 August 2016, 中国铁道出版社 *

Similar Documents

Publication Publication Date Title
EP1881227B1 (en) Shock absorber
CN202149175U (en) Buffer
EP2348227B1 (en) Stiff damper
EP0119197B1 (en) A rebound stop member for a telescopic hydraulic shock absorber
US4527674A (en) Shock absorber with a hydro-mechanical stop
CN110439952B (en) Hydraulic damper and design method thereof
CN104613123A (en) Two-stage pressure type hydro-pneumatic spring and working method
CN103527697A (en) Hydro-pneumatic spring suspension cylinder
CN208686865U (en) A kind of hydraulic damper of bidirectional damper
CN202091583U (en) Overflow relief valve
CN113383179B (en) Hydraulic stop with inertial mass for a motor vehicle suspension
CN113738921A (en) Safety valve structure and method for avoiding valve clack impact during opening and closing
CN206569532U (en) Oil-leakage-prevention servicing unit in a kind of oil truck
US20010006269A1 (en) Vehicle suspension apparatus
EP1811198B1 (en) Piston rod of vehicle height adjusting shock absorber and method of machining the same
CN1613741A (en) Small-size hydraulic buffer for elevator
CN202687688U (en) Oil buffer
CN111098881A (en) Gas-liquid buffer with pull-press bidirectional buffering function and buffering device thereof
CN106801629A (en) A kind of steam turbine quick-closing valve servomotor
CN208935248U (en) A kind of high speed and large stroke damper of suitable blasting impact environment
CN202038785U (en) Air pressure buffer of elevator
CN105715736B (en) A kind of damper and damping balance system
CN212954085U (en) Hydraulic device with buffering function
CN106015434A (en) Damping regulating valve for shock absorber
CN203585188U (en) Hydro-pneumatic spring suspension oil cylinder

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20211203

RJ01 Rejection of invention patent application after publication