CN210637509U - Valve rod connecting structure suitable for pressure self-balancing stop throttle valve - Google Patents

Abstract

The utility model belongs to the technical field of stop valve structures, and discloses a valve rod connecting structure suitable for a pressure self-balancing stop throttle valve, wherein a valve cover with a valve rod channel is detachably arranged on a valve body of the throttle valve, a valve cover used for installing a power unit is also detachably buckled on the valve cover, and a sealing ring structure is arranged at the joint of the valve cover and the valve cover; a cavity for the up-and-down movement of the coupler is formed between the valve cover and the valve cover, the top of the valve rod penetrates through the valve cover through the valve rod channel and is connected with the power unit in the cavity through the coupler in a transmission manner, and a discharge valve communicated with the cavity is arranged on the valve cover; a gap is reserved between the coupler and the inner wall of the cavity, and the neutral line of the power unit is parallel to or coincided with the neutral line of the valve rod.

Description

Valve rod connecting structure suitable for pressure self-balancing stop throttle valve

Technical Field

The utility model belongs to the technical field of the stop valve structure, concretely relates to valve rod connection structure suitable for pressure self-balancing stop throttle valve.

Background

Huge pressure energy is contained in the natural gas conveying pipeline network. In a west-east gas transmission pipeline with the length of 3856 kilometers, the annual gas transmission amount reaches 1200 hundred million cubic meters, the pressure is up to 10MPa, and the pressure to a user end only needs 0.4 MPa; the valve core of the throttle valve is required to realize frequent opening and closing actions for realizing the opening and closing control of a channel by the throttle valve serving as an on-off switch due to the huge pressure of pipeline conveying, and the valve core of the throttle valve is required to resist the extremely large pressure difference in the cavity in the opening and closing process.

As in the prior art, the prior application of the applicant has the publication number CN207246426U, the publication number is 2018, 4 and 17, and the name "manual-automatic dual-purpose high-pressure balance stop throttle valve" is a utility model patent document, which discloses a full-balance emptying valve and relates to the technical field of valves. The utility model discloses design into the area the same with the horizontal cross section of disk seat hole with the horizontal cross section area of the cavity that forms between case, case cover and the valve gap for the case receives cavity internal pressure and disk seat hole inlet pressure the same, and when opening and close the valve, the valve rod just need not overcome the pressure differential that the case received, only need overcome the frictional force between filler and valve rod, valve rod and the valve stem nut, opens and close moment and will significantly reduce. The valve in this technical solution is a low inlet and high outlet, and its balance structure principle, the balance hole is always through, as mentioned above, the open and close working condition will receive the area pressure from the bottom, when closing, it needs extra propelling force to counteract the pressure, and when closing, it also needs to continuously apply this counteracting force.

In a natural gas transmission pipeline, each pressure-resistant container is required to be provided with a regulating valve for controlling gas and water to enter and exit, the regulating valve is required to be opened and closed twice per minute, if the service life of the regulating valve is one year, the service life of a sealing element of the regulating valve is millions of times, and the regulating valve is required to be designed to be convenient to open and close and have longer service life.

For a valve rod structure which needs high frequency and can realize reciprocating motion for many times, the problems of direct abrasion or blocking and the like of a valve rod and a power unit caused by the interference of problems such as environmental factors, mechanical errors and the like can be frequently encountered, so that a valve rod and power unit connecting structure suitable for the environment is needed, the connection is ensured, and the adjustment in a small range can be considered.

Disclosure of Invention

An object of the utility model is to prior art not enough, thereby provide one kind and be suitable for the operating mode condition that the case was opened and close millions of times, utilize the inside piston structure of case to realize automatic pressure balance adaptation high frequency, long life switch's valve rod connection structure by the choke valve.

The utility model discloses a valve rod connection structure suitable for pressure self-balancing stop throttle valve, its characterized in that: the valve body of the throttle valve is detachably provided with a valve cover with a valve rod channel, the valve cover is also detachably buckled with a valve cover for installing a power unit, the detachable structure is convenient to adjust and maintain, a cavity for a coupler to move up and down is formed between the valve cover and the valve cover, the shaft coupler is guaranteed to have sufficient space on a motion track and can be protected, the top of the valve rod penetrates through the valve cover through the valve rod channel to be in transmission connection with the power unit in the cavity through the coupler, the shaft coupler is connected to guarantee tightness, and meanwhile adjustment during installation and replacement of the valve rod or the power unit according to use specifications and requirements are facilitated; leave the space between shaft coupling and the cavity inner wall, the valve rod is the up-and-down motion in principle, and its shaft coupling as connecting device that corresponds also is the motion in-process vertical direction, but because mechanical structure's error, actual service environment's influence factor etc. have about being difficult to avoid rocking of direction, especially detachable assembled structure, just parallel or coincidence between the neutral line of power pack and the neutral line of valve rod probably has the deviation with the neutral line of valve rod when satisfying the adjustment requirement.

The shaft coupling includes flange and lower flange, pass through between the top of power pack and valve rod upper flange links to each other with the transmission of lower flange, be connected through supporting screw rod and nut between upper flange and the lower flange, the dismouting of being convenient for and stable, just the body of rod of screw with leave the space between the screw inner wall of upper flange and/or lower flange, this also be convenient for can independently adjust when meetting the deviation in reciprocating motion and leave the allowance.

The valve cover is connected with the valve cover through a matched screw rod and a nut, a gap is reserved between the rod body of the screw rod and the inner wall of the screw hole in the upper valve cover and/or the inner wall of the screw hole in the valve cover, and a transverse adjusting allowance is reserved to be beneficial to avoiding mechanical collision and blocking.

Preferably, the junction of valve bonnet and valve gap is provided with the sealing washer structure, avoids leaking gas decompression to influence the valve body performance.

The valve cover is provided with a discharge valve communicated with the cavity, and due to the valve body cover structure and moving parts such as a valve rod, a valve core and the like, partial pressure gas can be leaked into the cavity inevitably, and manual or automatic pressure relief can be performed through the discharge valve in order to avoid overlarge pressure accumulation.

The power unit is a hydraulic telescopic rod or an electric telescopic device and aims to provide power for movement of the valve rod.

Further, be provided with the stuffing box structure that corresponds above-mentioned valve rod body of rod on the valve rod passageway inner wall, it is corresponding, valve rod passageway top detachable is provided with the valve rod guide cover that the internal diameter corresponds with the valve rod passageway, can take out or put into at the valve rod passageway through dismantling the valve rod guide cover the stuffing box structure.

Compared with the scheme in the prior art, the scheme is provided.

The valve cover is positioned by a valve core sleeve arranged on the valve body, the valve cover is made into an I-shaped flange, the upper and lower positioning spigot and the inner hole of the packing box are basically concentric by machining, the coaxiality of the valve cover and the valve rod can be adjusted by utilizing the gap between the valve cover and a flange bolt hole in the valve body during installation, and the friction between the valve rod and packing during high-speed movement is reduced.

The valve cover can be made into an I-shaped flange, the upper and lower positioning spigots and the inner hole of the shaft lever of the actuator are arranged to ensure basic concentricity by machining, meanwhile, the clearance of the flange bolt hole on the valve cover of the valve cover is utilized to adjust the coaxiality of the shaft lever of the power unit, and the concentricity of the shaft lever of the power unit and the valve lever is basically ensured, namely the same heart rate in the motion direction is kept at any time.

On the basis, in order to meet the working condition that the regulating valve is frequently opened and closed and the valve rod moves up and down at a high speed, a coupling is specially designed, the coupling is divided into an upper connecting sleeve and a lower connecting sleeve which are respectively arranged on a shaft lever of the power unit and the valve rod, and the influence on the service life of the whole regulating valve caused by the non-concentricity of the shaft lever of the power unit and the valve rod is further reduced by utilizing the clearance between a screw hole and a screw rod on the upper connecting sleeve and the lower connecting sleeve during assembly.

The closed valve cover is provided with the relief valve, one of the functions of the relief valve is that once the filler fails, a gas medium enters the valve cover, and whether the regulating valve leaks outwards can be observed through a small hole in the relief valve; the second function is to discharge the space pressure in the valve cover once the adjusting valve leaks and needs to be overhauled.

Drawings

The foregoing and following detailed description of the invention will be apparent when read in conjunction with the following drawings, in which:

FIG. 1 is a schematic view of the internal structure of a throttle valve suitable for use in the present invention;

FIG. 2 is a schematic structural diagram of a throttle valve cartridge suitable for use in the present invention;

FIG. 3 is a schematic structural diagram of a secondary valve core of a throttle valve applicable to the present invention;

fig. 4 is a schematic structural diagram applicable to the present invention;

FIG. 5 is a schematic diagram of a stuffing box structure of a throttle valve suitable for use in the present invention;

in the figure:

1. a valve body; 2. a valve core; 3. a valve core sleeve; 4. a valve stem; 5. a valve bore; 6. a balance hole; 7. a pressure inlet hole; 8. a channel cavity; 9. an auxiliary valve sleeve cavity; 10. a pressure relief cavity; 11. an auxiliary valve core; 12. a valve cover; 13. a valve housing; 14. a power unit; 15. a coupling; 15.1, an upper flange; 15.2, lower flange; 16. a bleed valve; 17. a piston rod; 18. a plug head; 19. a sealing pair; 20. a screw and a nut; 21. a V-shaped packing structure; 22. a seal ring; 23. an oil groove.

Detailed Description

The technical solution for achieving the objectives of the present invention will be further described by using several specific examples, and it should be noted that the technical solution claimed in the present invention includes, but is not limited to, the following examples.

Example 1

As a most basic embodiment of the present embodiment, as shown in fig. 4, the present embodiment discloses a valve rod connecting structure suitable for a pressure self-balancing stop throttle valve, a valve cover 12 with a passage of the valve rod 4 is detachably arranged on the valve body 1 of the throttle valve, a valve cover 13 for installing a power unit 14 is also detachably buckled on the valve cover 12, the detachable structure is convenient for adjustment and maintenance, a cavity for the shaft coupling 15 to move up and down is formed between the valve cover 13 and the valve cover 12, the shaft coupling is ensured to have sufficient space on the motion track and can be protected at the same time, the top of the valve rod 4 penetrates through the valve cover 12 through the passage of the valve rod 4 and is connected with the power unit 14 in a transmission way in the cavity through the shaft coupling 15, the tightness is ensured by the connection of the shaft coupling, meanwhile, the valve rod 4 or the power unit 14 is convenient to adjust during installation and replace according to the use specification and requirements; leave the space between shaft coupling 15 and the cavity inner wall, valve rod 4 is the up-and-down motion in principle, and its shaft coupling 15 as connecting device that corresponds also is the motion in-process vertical direction, but because mechanical structure's error, actual service environment's influence factor etc. have about difficult to avoid the rocking of direction, especially detachable assembled structure, just parallel or coincidence between power pack 14's neutral conductor and valve rod 4's neutral conductor, perhaps there is the deviation in power pack 14 neutral conductor and valve rod 4's neutral conductor when satisfying the adjustment requirement.

Example 2

As a preferable embodiment of this embodiment, on the basis of the above embodiment 1, further, the coupling 15 includes an upper flange 15.1 and a lower flange 15.2, the power unit 14 and the top of the valve rod 4 are in transmission connection through the upper flange 15.1 and the lower flange 15.2, the upper flange 15.1 and the lower flange 15.2 are connected with the nut 20 through a matching screw rod, so as to be convenient for disassembly and assembly and stable, and a gap is left between the rod body of the screw rod and the inner wall of the screw hole of the upper flange 15.1 and/or the lower flange 15.2, which is also convenient for self-adjustment when encountering deviation in reciprocating motion. Similarly, the valve bonnet 13 and the valve bonnet 12 are connected with the nut 20 through a matched screw rod, a gap is reserved between the rod body of the screw rod and the inner wall of the screw hole on the upper valve bonnet 13 and/or the valve bonnet 12, and similarly, a transverse adjusting allowance is reserved, so that mechanical collision and blocking are avoided. The valve cover 12 is positioned by using the valve core sleeve 3 arranged on the valve body 1, the valve cover 12 can be made into an I-shaped flange, the upper and lower positioning spigots and the inner hole of the packing box are basically concentric by using machining, the coaxiality of the valve cover 12 and the valve rod 4 can be adjusted by using the gap between the valve cover 12 and the flange bolt hole in the valve body 1 during installation, and the friction between the valve rod 4 and packing during high-speed movement is reduced; the valve cover 13 can be made into an I-shaped flange, the upper and lower positioning spigots and the inner hole of the shaft lever for installing the actuator are machined to ensure that the shaft lever is basically concentric, and meanwhile, the coaxiality of the shaft lever of the power unit 14 and the shaft lever of the power unit 14 is adjusted by utilizing the gap of the flange bolt hole of the valve cover 12 of the valve cover 13, so that the heart rate of the shaft lever of the power unit 14 and the heart rate of the valve lever 4 are basically ensured, namely the heart rate in the motion direction is kept.

Preferably, a sealing ring structure is arranged at the joint of the valve cover 13 and the valve cover 12, so that the performance of the valve body 1 is prevented from being influenced by air leakage and pressure loss; the valve cover 13 is provided with a discharge valve 16 communicated with the cavity, and due to the cover structure of the valve body 1 and the moving parts such as the valve rod 4 and the valve core 2, partial pressure gas can be leaked into the cavity inevitably, in order to avoid overlarge pressure accumulation, manual or automatic pressure relief can be carried out through the discharge valve 16, the discharge valve is installed on the closed valve cover 13, one of the functions of the discharge valve is that once the filler fails, a gas medium enters the valve cover 13, and whether the regulating valve leaks outwards or not can be observed through a small hole on the discharge valve; the second function is to discharge the space pressure in the valve cover 13 once the adjusting valve leaks and needs to be repaired.

The power unit 14 is a hydraulic telescopic rod or an electric telescopic device, the purpose of the power unit 14 is to provide power for the movement of the valve rod 4, and further, a stuffing box structure corresponding to the rod body of the valve rod 4 is arranged on the inner wall of the channel of the valve rod 4, correspondingly, a valve rod 4 guide cover with the inner diameter corresponding to the channel of the valve rod 4 is detachably arranged at the top of the channel of the valve rod 4, and the stuffing box structure can be taken out or put into the channel of the valve rod 4 by detaching the valve rod 4 guide cover.

In order to meet the working condition that the regulating valve is frequently opened and closed and the valve rod 4 moves up and down at a high speed, a coupling is specially designed, the coupling is divided into an upper connecting sleeve and a lower connecting sleeve which are respectively arranged on a shaft rod of the power unit 14 and the valve rod 4, and the influence on the service life of the whole regulating valve caused by the non-concentricity of the shaft rod of the power unit 14 and the valve rod 4 is further reduced by utilizing the clearance between a screw hole and a screw rod on the upper connecting sleeve and the lower connecting sleeve during assembly.

The valve rod connecting structure suitable for the pressure self-balancing stop throttle valve comprises a valve body 1 provided with an inlet and an outlet, as shown in figure 1, a valve core 2 and a valve core sleeve 3 are arranged at a valve hole 5 in the valve body 1, and the valve core 2 is driven by a valve rod 4 to move up and down in the valve core sleeve 3 to realize the opening and closing of the valve hole 5; as shown in fig. 2, the top of the valve core 2 is connected with the valve rod 4 and is provided with a balance hole 6, the bottom of the valve core 2 is provided with a pressure inlet hole 7 corresponding to the position of the valve hole 5, a sectional hollow cavity is arranged inside the valve core 2, and the balance hole 6 and the pressure inlet hole 7 are communicated with the hollow cavity; the hollow cavity comprises a pressure relief cavity 10, an auxiliary valve sleeve cavity 9 and a channel cavity 8 from top to bottom, the opening diameter of the channel cavity 8 is smaller than that of the auxiliary valve sleeve cavity 9 and the pressure relief cavity 10, the opening diameter of the auxiliary valve sleeve cavity 9 is smaller than or equal to that of the pressure relief cavity 10, an auxiliary valve core 11 which can move up and down in the auxiliary valve sleeve cavity 9 to open and close the channel cavity 8 is arranged in the auxiliary valve sleeve cavity 9 through a piston rod 17, namely an auxiliary valve core 2 structure is arranged in the valve core 2, the auxiliary valve sleeve cavity 9 serving as a moving track of the auxiliary valve core 2 is a section of the valve core hollow cavity, so that the opening and closing of the channel cavity 8 can be realized along with the up and down movement of the auxiliary valve core 2 in the auxiliary valve sleeve cavity 9, and as the pressure relief cavity 10, the auxiliary valve sleeve cavity 9 and the channel cavity 8 are arranged from top to bottom in the hollow cavity, and a balance hole 6 and a pressure inlet hole 7 are respectively arranged at the top and the bottom of the valve core 2, after, pressure gas enters the channel cavity 8 from the pressure inlet hole 7, an upward pressure is formed at the bottom, when the pressure is greater than the weight of the auxiliary valve core 2, the auxiliary valve core 2 moves upwards after receiving the pressure to open the channel cavity 8, the pressure is filled into the pressure relief cavity 10 and enters a cavity formed between the top of the valve core 2 and the upper part of the valve sleeve and the bottom of the valve cover 12 from the balance hole 6, and a pressure enough to balance the pressure from the bottom is applied to the upper part of the valve core 2, so that the pressure balance or relative balance of the space in the valve body 1 is realized, the defect that the valve core 2 needs larger force to maintain the closing after being closed due to the large pressure at the valve hole 5 in the prior art is overcome, the power consumption is saved, meanwhile, the stress of a valve core 2 device is more uniform due to the balanced pressure, the external force is less applied, the high-frequency opening and closing action is convenient to realize lower, the characteristics of long service life and good effect are presented.

Further, as shown in fig. 3, the top end of the piston rod 17 is connected with the top of the hollow cavity, the auxiliary valve element 11 is movably sleeved at the bottom end of the piston rod 17 up and down, that is, the piston rod 17 is used as the motion track guide of the auxiliary valve element 2, the auxiliary valve element 2 moves to realize opening and closing completely according to the gas pressure at the upper end and the lower end until the pressure reaches balance, and the automatic adjustment effect is achieved automatically in real time. Further, as shown in fig. 3, a plug 18 with a size corresponding to the size of the opening of the passage chamber 8 is disposed at a position corresponding to the passage chamber 8 at the bottom of the secondary valve element 11, and the plug 18 is completely or partially plugged into the passage chamber 8, so as to facilitate better sealing; the plug head 18 is an inverted conical cylinder, the cross-sectional area of the position where the plug head 18 contacts the bottom of the auxiliary valve core 11 is larger than the cross-sectional area of the opening of the channel cavity 8, the cross-sectional area of the bottom end of the plug head 18 is smaller than the cross-sectional area of the opening of the channel cavity 8, the plug type structure with the wide top and the narrow bottom is the most classical structure, the self-regulation function of the auxiliary valve core 2 is realized based on the pressure difference in the cavity, the pressure acts on a contact surface, pressure gas is applied to the plug head 18 of the auxiliary valve core 2 from the bottom, the pressure in the valve sleeve cavity where the valve core 2 is located acts on the top of the valve core 2, when the pressure difference exists up and down, the quick reaction is convenient, the concentrated stress with a small area can be beneficial to realizing the quick opening and closing action of the auxiliary valve core 2; preferably, the contact position between the plug 18 and the channel cavity 8 is a sealing pair 19 made of hard alloy, and the sealing pair 19 made of hard alloy material is arranged at the contact surface of the reciprocating motion, so that the sealing and the durability can be both considered.

Furthermore, as shown in fig. 3, the auxiliary valve element 11 is further provided with a plurality of through holes which are vertically through, that is, when the auxiliary valve element 2 moves upwards to open the channel cavity 8, the pressure gas can enter the pressure relief cavity 10 from the through holes of the auxiliary valve element 2 and then enter the upper cavity after entering the pressure relief cavity, so that the pressure balance can be rapidly realized, and the pressure of the upper cavity can be easily released when the valve element 2 rises to open the valve port.

In order to better provide a mechanical motion environment to adapt to high-frequency opening and closing actions, as shown in fig. 4, a valve cover 12 with a valve rod 4 channel is further detachably arranged on the valve body 1, a valve cover 13 for installing a power unit 14 is also detachably buckled on the valve cover 12, the detachable structure is convenient to adjust and maintain, a cavity for the coupling 15 to move up and down is formed between the valve cover 13 and the valve cover 12, the shaft coupling is guaranteed to have a sufficient space on a motion track and can be protected, the top of the valve rod 4 penetrates through the valve cover 12 through the valve rod 4 channel and is in transmission connection with the power unit 14 through the coupling 15 in the cavity, the tightness is guaranteed through the connection of the shaft coupling, and adjustment during installation and replacement of the valve rod 4 or the power unit 14 according to use specifications and requirements are facilitated; leave the space between shaft coupling 15 and the cavity inner wall, valve rod 4 is the up-and-down motion in principle, and its shaft coupling 15 as connecting device that corresponds also is the motion in-process vertical direction, but because mechanical structure's error, actual service environment's influence factor etc. have about difficult to avoid the rocking of direction, especially detachable assembled structure, just parallel or coincidence between power pack 14's neutral conductor and valve rod 4's neutral conductor, perhaps there is the deviation in power pack 14 neutral conductor and valve rod 4's neutral conductor when satisfying the adjustment requirement.

The coupling 15 comprises an upper flange 15.1 and a lower flange 15.2, the power unit 14 is in transmission connection with the top of the valve rod 4 through the upper flange 15.1 and the lower flange 15.2, the upper flange 15.1 and the lower flange 15.2 are connected with a nut 20 through a matched screw rod, so that the coupling is convenient to disassemble, assemble and stabilize, a gap is reserved between a rod body of the screw rod and the inner wall of a screw hole of the upper flange 15.1 and/or the lower flange 15.2, and a margin can be reserved for self-adjustment when deviation occurs in reciprocating motion; the valve cover 13 and the valve cover 12 are connected with a nut 20 through a matched screw rod, a gap is reserved between the rod body of the screw rod and the inner wall of a screw hole on the upper valve cover 13 and/or the valve cover 12, and a transverse adjusting allowance is reserved to avoid mechanical collision and clamping; and preferably, a sealing ring structure is arranged at the joint of the valve cover 13 and the valve cover 12, so that the performance of the valve body 1 is prevented from being influenced by air leakage and pressure loss.

For safety reasons, as shown in fig. 4, a relief valve 16 communicating with the cavity is provided on the valve housing 13, and due to the cover structure of the valve body 1 and the moving parts such as the valve rod 4 and the valve core 2, it is inevitable that part of the pressure gas leaks into the cavity, and in order to avoid excessive pressure accumulation, manual or automatic pressure relief can be performed through the relief valve 16.

As for the choice of the power unit 14, the power unit 14 may be a hydraulic telescopic rod or an electric telescopic device, the purpose of the power unit 14 being to power the movement of the valve stem 4.

Further, be provided with the stuffing box structure that corresponds the above-mentioned 4 body of rod of valve rod on the 4 passageway inner walls of valve rod, it is corresponding, 4 passageway tops of valve rod detachable are provided with the valve rod 4 guide cover that the internal diameter corresponds with the 4 passageways of valve rod, can take out or put into at the 4 passageways of valve rod through dismantling the valve rod 4 guide cover the stuffing box structure.

As shown in fig. 5, the stuffing box structure includes a sealing grease structure from the upper part and a V-shaped stuffing structure 21 from the lower part; the sealing grease structure comprises at least one upper sealing ring 22 and at least one lower sealing ring 22, the inner diameter of each sealing ring 22 is smaller than that of the stuffing box structure, a plurality of groups of oil grooves 23 are arranged between the sealing rings 22, lubricating oil is contained in the middle of each oil groove 23, electrochemical corrosion is easily generated under friction generated by frequent movement of the valve rod 4 to cause the valve rod 4 to fail in advance, and therefore the lubricating oil of the sealing grease structure enables the outer surface of the valve rod 4 to generate a long-term oil film, the valve rod 4 is prevented from failing in advance, and the long-term service life of the regulating; the V-shaped packing structure 21 includes several layers of stacked V-shaped packing.

The V-shaped packing structure 21 comprises an upper packing pad, a middle packing pad and a lower packing pad, the middle packing pad is formed by stacking a plurality of layers of V-shaped packing, and the service life of the V-shaped packing is long; spring washers are arranged in the upper packing pad and the lower packing pad, rubber washers are arranged at the upper end of the outer ring of the upper packing pad and the lower end of the outer ring of the lower packing pad, the lower end of the upper packing pad and the upper end of the lower packing pad are both V-shaped structures corresponding to the V-shaped packing, and a clearance groove is arranged at the vertex angle of each V-shaped structure; the included angle of the V-shaped structure is larger than that of the V-shaped filler; middle spring washers are arranged among the V-shaped fillers which are stacked and arranged as the middle filler pads; the thicknesses of the upper packing pad and the lower packing pad are both larger than that of the V-shaped packing.

Compared with the scheme in the prior art, the medium (pressure gas) of the throttle valve in the scheme is high in inlet and low in outlet, enters the matching gap between the valve core sleeve 3 and the valve core 2 through the window on the valve core sleeve 3 and reaches the upper space of the valve core 2, at the moment, the valve rod 4 tightly attaches the valve core 2 to the valve port under the downward force action of the power unit 14, the balance hole 6 on the valve core 2 is closed, and the medium pressure entering the space cavity of the valve core 2, the valve sleeve and the valve cover 12 and the downward force of the power unit 14 jointly ensure that the valve core 2 is tightly closed.

When the regulating valve is opened, the valve rod 4 moves upwards for a short distance under the action of the power unit 14, the needle-shaped conical surface at the lower part of the valve rod 4 leaves the auxiliary valve core 2, the auxiliary valve core 2 is opened, a medium flows to the lower end surface of the valve core 2 from the balance hole 6, the medium pressure on the upper space of the valve core 2 is rapidly reduced because the area of the fit clearance between the valve core sleeve 3 and the valve core 2 is smaller than the area of the balance hole 6 on the valve core 2, at the moment, the valve rod 4 drives the valve core 2 to easily leave a valve port, the inlet and the outlet of the regulating valve are communicated, the area of the upper space of the valve core 2 is smaller than the area of the lower part of the valve core 2 by one diameter area of the valve rod 4, the valve core 2 generates an upward force, and the regulating valve can be rapidly.

When the regulating valve needs to be closed, the valve rod 4 moves downwards for a short distance under the action of the power unit 14, and the secondary valve core 2 is closed; the medium is prevented from flowing to the lower end face of the valve core 2 from the balance hole 6, the medium pressure on the upper space of the valve core 2 is rapidly increased, and the valve core 2 is only subjected to upward small force of the cross section area of the valve rod 4 before the auxiliary valve core 2 is closed, so that the power unit 14 is only required to overcome the force again, and the valve core 2 can be ensured to be rapidly closed.

The regulating valve needs millions of opening and closing service lives, so that the regulating valve stuffing box adopts the V-shaped stuffing with long service life, the V-shaped stuffing is a non-metal stuffing, electrochemical corrosion is easy to generate under the friction generated by frequent movement of the valve rod 4, and the valve rod 4 is easy to fail in advance; therefore, the special sealing grease mechanism is arranged at the upper part of the stuffing box, the O-shaped sealing rings are arranged above and below the sealing grease mechanism, sealing grease is guaranteed not to flow out of the sealing grease mechanism when the valve rod 4 moves up and down, and therefore a long-term oil film is generated on the outer surface of the valve rod 4, the possibility that the valve rod 4 fails in advance is avoided, and the long-term service life of the regulating valve is guaranteed.

Claims (7)

1. Valve rod connection structure suitable for pressure self-balancing stop throttle valve, its characterized in that: a valve cover (12) with a valve rod (4) channel is detachably arranged on a valve body (1) of the throttle valve, a valve cover (13) used for installing a power unit (14) is also detachably buckled on the valve cover (12), and a sealing ring structure is arranged at the joint of the valve cover (13) and the valve cover (12); a cavity for a coupler (15) to move up and down is formed between the valve cover (13) and the valve cover (12), the top of the valve rod (4) penetrates through the valve cover (12) through a channel of the valve rod (4) and is in transmission connection with the power unit (14) through the coupler (15) in the cavity, and a discharge valve (16) communicated with the cavity is arranged on the valve cover (13); a gap is reserved between the coupler (15) and the inner wall of the cavity, and the neutral line of the power unit (14) is parallel to or coincided with the neutral line of the valve rod (4).

2. The valve stem connecting structure suitable for the pressure self-balancing stop throttle valve according to claim 1, wherein: the shaft coupling (15) includes upper flange (15.1) and lower flange (15.2), pass through between the top of power pack (14) and valve rod (4) upper flange (15.1) and lower flange (15.2) transmission link to each other, be connected with nut (20) through supporting screw rod between upper flange (15.1) and lower flange (15.2), just the body of rod of screw rod with leave the space between the screw inner wall of upper flange (15.1) and/or lower flange (15.2).

3. The valve stem connecting structure suitable for the pressure self-balancing stop throttle valve according to claim 1, wherein: the valve cover (13) is connected with the valve cover (12) through a matched screw rod and a nut (20), and a gap is reserved between the rod body of the screw rod and the inner wall of a screw hole in the valve cover (13) and/or the valve cover (12).

4. The valve stem connecting structure for a pressure self-balancing stop throttle valve according to claim 1 or 3, wherein: and a sealing ring structure is arranged at the joint of the valve cover (13) and the valve cover (12).

5. The valve stem connecting structure for a pressure self-balancing stop throttle valve according to claim 1 or 3, wherein: and a discharge valve (16) communicated with the cavity is arranged on the valve cover (13).

6. The valve stem connecting structure suitable for the pressure self-balancing stop throttle valve according to claim 1, wherein: the power unit (14) is a hydraulic telescopic rod or an electric telescopic device, and the power unit (14) aims to provide power for the movement of the valve rod (4).

7. The valve stem connecting structure suitable for the pressure self-balancing stop throttle valve according to claim 1, wherein: be provided with the stuffing box structure that corresponds above-mentioned valve rod (4) body of rod on valve rod (4) passageway inner wall, corresponding, valve rod (4) passageway top detachable is provided with valve rod (4) guide cover that internal diameter and valve rod (4) passageway correspond, can take out or put into at valve rod (4) passageway through dismantling valve rod (4) guide cover the stuffing box structure.

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