CN105484785A - Valve core assembly of safety valve - Google Patents

Abstract

The invention discloses a valve core assembly of a safety valve. The valve core assembly comprises a sliding seat, a thread sleeve arranged in the sliding seat and a valve pad which is arranged in the thread sleeve and matched with a liquid inlet connector of the safety valve, wherein the valve part is provided with a spherical groove. The valve core assembly is applied to the safety valve and can be used for controlling on-off of an oil line from a liquid inlet hole to a liquid discharge hole, high-flow overflowing can be realized when the valve core assembly is far away from the liquid inlet connector, the flow of the safety valve is greatly increased, axial displacement of the valve core assembly can be reduced through short-term fast overflowing, axial deformation of a reset spring can be reduced through reduction of the axial displacement of the valve core assembly, and pressure fluctuation can be reduced finally.

Description

The core assembly of safety valve

Technical field

The invention belongs to and relate to coal mine fully-mechanized mining hydraulic support, specifically, the present invention relates to a kind of core assembly of safety valve.

Background technology

Along with large-scale enforcement and the development of coal mine fully-mechanized mining hydraulic support; the requirement of working face to hydraulic support is also more and more stricter; so just there is further requirement to the safety valve of protective cradle hydraulic jack; especially to application life of safety valve and reliability having had further requirement; when the pressure from hydraulic support top causes by power; can safety valve when bearing high pressure, and short time fully stable in time off-load directly affects application life and the supporting safety of support.It not only can damage seal, pipeline and Hydraulic Elements, but also can cause vibrations and noise; Sometimes some pressure controlled Hydraulic Elements is made to produce error.

The safety valve of current use, mainly comprises valve casing, liquid inlet joint, spool, valve pocket, back-moving spring, spring base and voltage regulation screw.In valve casing contained spring chamber, it is that on the voltage regulation screw that is threaded, the other end is against on moveable spring base that back-moving spring one end is against with valve casing.Valve body inserts the valve casing other end and with valve casing for being threaded, valve inner is provided with the cavity for holding valve pocket, and spool is positioned at valve pocket, and the end of spool contacts with spring base, moves for promoting spring base the unlatching realizing safety valve.

The overflow ducts of existing safety valve adopts around the liquid pass hole be arranged on spool sidewall, liquid pass hole aperture is little, cause that draining flow is little, flow loss is large, and match with spring base due to spool, spring base bears the axial force that back-moving spring applies, cause spool force-bearing situation bad, in the course of work, pressure oscillation is larger, and then cause the closing presure of safety valve general all undesirable, the Hydraulic Elements be connected with safety valve finally can be caused to cause waste as the fluid of high-voltage oil cylinder too much runs off.Sealing effectiveness between spool and valve pocket is undesirable, and it is wayward for the groove processing precision of installing seal that spool face is arranged.In addition, the spring cavity of valve casing inside is in open state, dust-proof, waterproof and rust-proof effect poor, reduce the application life of safety valve.

Summary of the invention

The present invention is intended at least to solve one of technical problem existed in prior art.For this reason, the invention provides a kind of core assembly of safety valve, object reduces pressure oscillation.

To achieve these goals, the technical scheme that the present invention takes is: the core assembly of safety valve, and comprise sliding seat, be arranged at the swivel nut in sliding seat and be arranged in swivel nut and valve pad for matching with the liquid inlet joint of safety valve, valve pad has ball recess.

Described liquid inlet joint comprises the joint body that is connected with the valve body of safety valve and is fixedly connected with joint body and the sealing matched with described nut and valve pad, and liquid inlet joint has inlet opening, and valve body has outage.

Described valve pad is fixedly clamped by described sliding seat and described swivel nut.

Described swivel nut has the first accommodating cavity for holding described sealing with the described valve pad of accommodation and the second accommodating cavity is communicated with the first accommodating cavity, and described sliding seat has the 3rd accommodating cavity of accommodation swivel nut.

The end face of described sliding seat is provided with the first oil duct for fluid being guided to outage, the end face of described swivel nut is provided with the second oil duct for fluid being guided to the first oil duct, when described valve pad and described hermetic unit from after, the fluid in described inlet opening flow to described outage place through the second oil duct, the first oil duct successively.

Described first oil duct, the second oil duct and described outage are positioned in the same radial line of described valve body.

Described sealing is in first accommodating cavity that can embed described swivel nut and the ledge structure contacted with described valve pad, and the diameter of described second accommodating cavity is greater than the diameter of the first accommodating cavity.

Described sealing has and sets gradually and the first shaft part of increasing gradually of external diameter and the second shaft part, second shaft part is fixedly connected with described joint body, first shaft part matches with described valve pad, and the external diameter of the first shaft part is not more than the diameter of described first accommodating cavity.

Core assembly of the present invention, be applied to safety valve, can be used for controlling the break-make of inlet opening to the oil circuit of outage, large discharge overflow can be realized after core assembly is away from liquid inlet joint, safety valve flow improves greatly, the quick overflow of short time can reduce the axial displacement of core assembly, and core assembly axial displacement is reduced and the axial deformation of back-moving spring can be made to reduce, and finally can reduce pressure oscillation.

Accompanying drawing explanation

This manual comprises the following drawings, shown content respectively:

Fig. 1 is the sectional view of the safety valve with core assembly of the present invention;

Fig. 2 is the sectional view of core assembly of the present invention;

Fig. 3 is the sectional view of liquid inlet joint;

Fig. 4 is the sectional view of sliding seat;

Fig. 5 is the lateral view of sliding seat;

Fig. 6 is the sectional view of swivel nut;

Fig. 7 is the lateral view of swivel nut;

Fig. 8 is the sectional view of valve body;

Fig. 9 is the sectional view of valve pad;

Figure 10 is the sectional view of spring base;

Figure 11 is that the valve pad of the first structure coordinates schematic diagram with sealing;

Figure 12 is that when being in opening, the first structure valve pad coordinates schematic diagram with sealing;

Figure 13 is the sectional view of the valve pad of the second structure;

Figure 14 is the stressed schematic diagram of the second structure valve pad when being in closed condition;

Figure 15 is that when being in opening, the second structure valve pad coordinates schematic diagram with sealing;

Figure 16 is the sectional view of the valve pad of the third structure;

Figure 17 is the stressed schematic diagram of the third structure valve pad when being in closed condition;

Figure 18 is that when being in opening, the third structure valve pad coordinates schematic diagram with sealing;

Be labeled as in figure:

1, voltage regulation screw; 2, back-moving spring;

3, valve body; 31, outage; 32, unloading cavity;

4, spring base; 41, the first boss; 42, guide section; 43, the first locating hole;

5, swivel nut; 51, large chamber, footpath; 52, path chamber; 53, the second accommodating cavity; 54, the second oil duct; 6, sliding seat; 61, the second locating hole; 62, the 3rd accommodating cavity; 63, the first oil duct;

7, valve pad; 71, inner bottom surface; 72, anchor ring; 73, sunk structure; 74, male cone (strobilus masculinus); 75, baseplane; 8, liquid inlet joint; 81, joint body; 82, the first shaft part; 83, the second shaft part; 84, inlet opening; 9, valve casing; 10, spheroid; 11, the first sealing ring; 12, the second sealing ring.

Detailed description of the invention

Contrast accompanying drawing below, by the description to embodiment, be described in further detail the specific embodiment of the present invention, object helps those skilled in the art to have more complete, accurate and deep understanding to design of the present invention, technical scheme, and contribute to its enforcement.

As shown in Figures 1 to 10, for adopting a kind of safety valve of core assembly of the present invention, this safety valve comprises the valve body 3 with outage 31, the liquid inlet joint 8 with inlet opening 84, the valve casing 9 be connected with valve body 3 and the resetting-mechanism being arranged at valve casing 9 inside, and inlet opening 84 to be communicated with outage 31 by the unloading cavity 32 of valve body 3 inside and three forms the overflow ducts of safety valve.In order to solve problem existing in prior art, this safety valve also comprises core assembly of the present invention, core assembly of the present invention is for be movably arranged in valve body 3 and for controlling water kick passage break-make, core assembly is between liquid inlet joint 8 and resetting-mechanism, core assembly and opening and closing for controlling inlet opening 84, namely core assembly realizes the control of overflow ducts break-make by the mobile opening and closing controlling inlet opening 84.

The safety valve of prior art to be generally connected on coal mine fully-mechanized mining hydraulic support and the Hydraulic Elements that pressure medium is housed as on hydraulic cylinder, when in the work set pressure that hydraulic cylinder internal liquid is in safety valve, overflow relief valve, under initial tension of spring effect, is in closed condition; When hydraulic cylinder is subject to External Force Acting internal pressure higher than minimum setting pressure of relief valve, hydraulic medium pressure exceedes initial tension of spring and opens spool overflow, and the moment of unlatching is called as the work opening pressure of safety valve; Make medium flow out release pressure to hydraulic cylinder internal pressure and spring pre-tightening dynamic balance by the overflow of a period of time of safety valve, now safety valve cuts out, and the steady pressure that safety valve keeps after stopping overflow being called as closing presure,

Specifically, as illustrated in figures 1 and 8, liquid inlet joint 8, valve body 3 and valve casing 9 are the cylindrical member of both ends open, inner hollow, in the end that liquid inlet joint 8 inserts valve body 3 and with valve body 3 for being threaded, in the end that the other end of valve body 3 inserts valve casing 9 and with valve casing 9 for being threaded.Valve casing 9 inside has the spring cavity holding resetting-mechanism, resetting-mechanism is the axial force of closing for applying to make it to move to realize inlet opening 84 towards liquid inlet joint 8 place to core assembly, resetting-mechanism comprises spring base 4, back-moving spring 2 and voltage regulation screw 1, voltage regulation screw 1 is in the other end screw-in spring cavity of valve casing 9 and is threaded with valve casing 9, back-moving spring 2 is clipped between voltage regulation screw 1 and spring base 4, spring base 4 can moving axially along valve casing 9 by the promotion of back-moving spring 2 and core assembly in valve casing 9, core assembly promotion spring base 4 moves towards voltage regulation screw 1 place and safety valve can be made to open, back-moving spring 2 promotes spring base 4 and core assembly and moves safety valve can be made to close.

As shown in figures 1 and 3, liquid inlet joint 8 is as hydraulic cylinder socket connection for the Hydraulic Elements with coal mine fully-mechanized mining hydraulic support, as shown in figures 1 and 3, liquid inlet joint 8 to comprise with valve body 3 for the joint body 81 that is threaded and is the sealing being coaxially fixedly connected with and matching with core assembly with joint body 81, the external surface of joint body 81 is provided with external screw thread, and the corresponding terminal interior surface at valve body 3 is provided with internal thread.Inlet opening 84 is from the end face center of joint body 81 and the through hole be through to vertically on the end face of sealing, and sealing is that to be positioned at valve body 3 inner and for matching with core assembly, with the break-make of controlling water kick passage.

As illustrated in figures 1 and 8, valve body 3 inside be positioned at part cavity inside joint body 81 as the unloading cavity 32 allowing fluid pass through, outage 31 is communicated with unloading cavity 32, because the relative liquid inlet joint 8 of core assembly is moveable, then and the adjustable volume of unloading cavity 32.Sealing is by realizing the closedown of inlet opening 84 with contacting of core assembly, and now unloading cavity 32 volume is minimum, and inlet opening 84 is not communicated with outage 31, and then overflow ducts is disconnected, and safety valve realizes cutting out.When core assembly is vertically towards when moving away from liquid inlet joint 8 direction, the volume of unloading cavity 32 increases gradually, and inlet opening 84 is communicated with outage 31 by unloading cavity 32, overflow ducts conducting, and safety valve realizes opening.Therefore, safety valve moving axially by core assembly, realize the control of overflow ducts break-make, and be communicated with inlet opening 84 and outage 31 by unloading cavity 32, unloading cavity 32 volume is large, large discharge overflow can be realized when overflow ducts conducting, it is little that fluid in inlet opening 84 flow to drag losses in outage 31 process, thus quick relief in the short time can be realized, corresponding, the quick overflow of short time can reduce the axial displacement of core assembly, and core assembly moves very little distance vertically in valve body 3 can complete breakdown action.And the axial displacement of core assembly is reduced, when the safety valve of the safety valve with prior art with core assembly of the present invention adopts the back-moving spring 2 with identical coefficient of elasticity, the stroke with the back-moving spring 2 in the safety valve of core assembly of the present invention is short, the axial deformation of back-moving spring 2 is little, finally makes the pressure oscillation of overflow relief valve little.

As illustrated in figures 1 and 8, outage 31 is arranged on the sidewall of valve body 3, outage 31 and through hole for radially running through setting.Outage 31 is also circumferentially uniform multiple on the sidewall of valve body 3, and all outages 31 are distributed in around the sealing of unloading cavity 32 and liquid inlet joint 8, like this when safety valve is opened, the fluid in inlet opening 84 can from passing through between sealing and core assembly and flowing to outage 31.This unloading way liquid flow area is large, and flow is larger more direct, and drag losses is little.

As depicted in figs. 1 and 2, core assembly comprises the sliding seat 6 be movably arranged in valve body 3 inner chamber, be arranged at the swivel nut 5 in sliding seat 6 and be arranged in swivel nut 5 and the valve pad 7 realizing sealing that matches with sealing, valve pad 7 and being fixedly clamped by sliding seat 6 and swivel nut 5.

As shown in Figure 2 and Figure 6, swivel nut 5 is the cylindrical structural of both ends open and inner hollow, the cavity at swivel nut 5 inside center place is that the first accommodating cavity for holding sealing is with accommodation valve pad 7 and the second accommodating cavity 53 be communicated with the first accommodating cavity, first accommodating cavity and the second accommodating cavity 53 are for axially setting gradually along swivel nut 5, and diameter is for increase gradually.One end of valve pad 7 is towards sealing, and this end end face of valve pad 7 is the circular flat with the axis perpendicular of liquid inlet joint 8, as shown in Figure 9, valve pad 7 is by carrying out with sealing the control that plane contact realizes closing inlet opening 84, adopt flat seal form, good sealing effect.

As shown in Figure 2 and Figure 6, the first accommodating cavity and both the second accommodating cavities 53 are coaxial and be communicated with, and the first accommodating cavity forms the opening allowing the sealing of liquid inlet joint 8 insert on the end face of swivel nut 5.Valve pad 7 is the circular block shape structure adopting polyurethane to make, the diameter of valve pad 7 is not less than the diameter of the second accommodating cavity 53, diameter due to the first accommodating cavity is less than the diameter of the second accommodating cavity 53, a limited step is formed in first accommodating cavity and the second accommodating cavity 53, valve pad 7 is fill in the second accommodating cavity 53 when installing, valve pad 7 and with swivel nut 5 interference fit, clamp valve pad 7 finally by sliding seat 6, realize the axial restraint of valve pad 7.

As shown in Figure 2 and Figure 4, sliding seat 6 is and valve body 3 and the coaxial cylindrical structural of swivel nut 5, the periphery of sliding seat 6 contacts with the inner headed face of valve body 3, and sliding seat 6 is between spring base 4 and liquid inlet joint 8, and sliding seat 6 can move axially along valve body 3 and can insert valve casing 9 inside.It is arrange and the circular cavity extended to form towards sliding seat 6 inside in the end face center facing liquid inlet joint 8 of sliding seat 6 that sliding seat 6 has the 3rd accommodating cavity the 62, three accommodating cavity 62 holding swivel nut 5.Installing valve pad 7 and being filled in after in the second accommodating cavity 53 of swivel nut 5, the swivel nut 5 with valve pad 7 is filled in the 3rd accommodating cavity 62 of sliding seat 6, the diapire of the 3rd accommodating cavity 62 until valve pad 7 is conflicted, clamping valve pad 7.

As shown in Figure 2, as preferably, swivel nut 5 to insert in the 3rd accommodating cavity 62 and with sliding seat 6 for being threaded, and is correspondingly provided with external screw thread at swivel nut 5 external surface, and the inner surface in the 3rd accommodating cavity 62 is provided with internal thread.Swivel nut 5 is arranged to be threaded with sliding seat 6, easy disassembly swivel nut 5, so that change valve pad 7.

As shown in Figure 4 and Figure 5, as preferably, the end face facing liquid inlet joint 8 of sliding seat 6 be provided with allow fluid by and fluid is guided to the first oil duct 63 of outage 31, this first oil duct 63 is the groove extended to along the radial direction of sliding seat 6 from the 3rd accommodating cavity 62 place on the periphery of sliding seat 6.As shown in Figure 6 and Figure 7, the end face facing liquid inlet joint 8 of swivel nut 5 be provided with allow fluid by and fluid is guided to the second oil duct 54 of the first oil duct 63, this second oil duct 54 is the groove extended to along the radial direction of swivel nut 5 from the first accommodating cavity place on the periphery of swivel nut 5, first oil duct 63 is communicated with the second oil duct 54, and diametrically, the first oil duct 63 is between outage 31 and the second oil duct 54.By arranging oil duct on the end face of swivel nut 5 and sliding seat 6, when valve pad 7 and hermetic unit from after, these oil ducts guide to outage 31 by from inlet opening 84 fluid flow in unloading cavity 32, are conducive to the quick overflow that safety valve realizes the short time.

As depicted in figs. 1 and 2, as preferably, the first oil duct 63, second oil duct 54 and aligned in position equal with the quantity of outage 31, the first oil duct 63 and the second oil duct 54 respectively on the end face of sliding seat 6 and swivel nut 5 for being uniformly distributed circumferentially.At valve body 3 axially, outage 31 is between spring base 4 and joint body 81, each oil duct is positioned in the same radial line of valve body 3 with outage 31 aligned in position in outside respectively, when valve pad 7 and hermetic unit from after, the fluid in inlet opening 84 flow to outage 31 place through the second oil duct 54, first oil duct 63 successively.

As preferably, sealing is in first accommodating cavity that can embed swivel nut 5 and the multi-stage stairs shape structure contacted with valve pad 7, and such sealing can have multiple plane contact with core assembly, improves the reliability of sealing.

As shown in figures 1 and 3, in the present embodiment, sealing is two-stage step-like structure, and sealing has and to set gradually and both the first shaft part 82 of increasing gradually of external diameter and the second shaft part 83, first shaft part 82 and the second shaft part 83 are coaxial.The end of the second shaft part 83 and joint body 81 is for be coaxially fixedly connected with, and the external diameter of the second shaft part 83 is less than the external diameter of joint body 81.First shaft part 82 is for embedding in the first accommodating cavity of swivel nut 5, and the first shaft part 82 matches with valve pad 7 and can carry out plane contact, and the external diameter of the first shaft part 82 is not more than the diameter of an accommodating cavity.

As shown in figures 1 and 3, the length of the first shaft part 82 is not less than the degree of depth of the first accommodating cavity, with guarantee the first shaft part 82 end face can with the end contact of valve pad 7, realize sealing.Inlet opening 84 forms the opening allowing fluid flow out on the end face of the first shaft part 82, and this end face of the first shaft part 82 is also the end face of the insertion end of liquid inlet joint 8.The external diameter of the first shaft part 82 is less than the end face diameter of valve pad 7, thus guarantees that the opening on the end face of the first shaft part 82 can seal by the end face of valve pad 7 completely.And, when sealing contacts with core assembly, safety valve cuts out, now the end face of the first shaft part 82 contacts with valve pad 7, the end face of the second shaft part 83 and the end contact of swivel nut 5 and sliding seat 6, the end face of the first shaft part 82 and the second shaft part 83 is the plane paralleled with the end face of swivel nut 5, sliding seat 6 and valve pad 7, and namely sealing has multiple plane to contact with core assembly to realize sealing, good sealing effect, reliability is high.In addition, owing to adopting face structure to cross liquid mode, valve pad 7 is by the end contact effect of liquid inlet joint 8, and the impact that valve pad 7 bears is little, long service life.

As preferably, as shown in Figure 6, the first accommodating cavity in swivel nut 5 is divided into columniform path chamber 52 and chamber, conical large footpath 51, chamber, large footpath 51 has bigger diameter end and miner diameter end, the diameter of the miner diameter end in chamber, large footpath 51 is equal with the diameter in path chamber 52, and the miner diameter end in large chamber, footpath 51 is connected with path chamber 52.Chamber, large footpath 51 is coaxial with path chamber 52, path chamber 52 between chamber, large footpath 51 and the second accommodating cavity 53, the diameter of the bigger diameter end in chamber, large footpath 51 is greater than the external diameter of the first shaft part 82, and the second oil duct 54 to arrange from the place of chamber 51, large footpath and inner surface in chamber, large footpath 51 forms opening.It is uncovered that the swivel nut 5 of this structure has towards sealing, be convenient to sealing and embed, and conical inner surface has good water conservancy diversion effect to fluid.

As preferably, as shown in Figure 1, core assembly also comprises the second sealing ring be sheathed on sliding seat 6, second sealing ring is clipped between valve body 3 and sliding seat 6, second sealing ring and between spring base 4 and outage 31, for realizing the sealing between unloading cavity 32 and spring cavity, avoid fluid to flow in spring cavity from the gap between sliding seat 6 and valve body 3, thus can avoid corroding back-moving spring 2.

As shown in Figure 10, the spring base 4 of resetting-mechanism is made up of guide section 42 and the first boss 41, guide section 42 is circular block shape structure, and be connected to form one in the center, side of guide section 42 and guide section 42 spring base 4, first boss 41 of structure of the first boss 41 protrudes towards voltage regulation screw 1.First boss 41 is coaxial with guide section 42, and the first boss 41 is cylindrical, and the diameter of guide section 42 is greater than the diameter of the first boss 41.Back-moving spring 2 is helical spring, and the first boss 41 positions one end of back-moving spring 2 for inserting in back-moving spring 2, and voltage regulation screw 1 has for inserting in back-moving spring 2 boss that the other end of back-moving spring 2 positions.

As shown in Fig. 1 and Figure 10, resetting-mechanism also comprises the spheroid 10 be clipped between spring base 4 and sliding seat 6, spheroid 10 is complete ball, and the effect of spheroid 10 makes spring base 4 and sliding seat 6 in moving process, have good adaptivity, spring base 4 is had good in disposition.The end face center facing sliding seat 6 of spring base 4 has allows spheroid 10 embed and for conical first locating hole 43, the end face center facing spring base 4 of sliding seat 6 has allows spheroid 10 embed and the locating surface of fitting as the sphere with spheroid 10 for the conical inner surface in conical second locating hole 61, the first locating hole 43 and the second locating hole 61.Spring base 4 is owing to being clipped between back-moving spring 2 and core assembly, and spring base 4 diametrically and leave gap (namely spring base 4 radial direction lacking support) between valve casing 9 inwall, core assembly and back-moving spring 2 are all to the active force that spring base 4 applies vertically, match with spheroid 10 by arranging conical locating hole in spring base 4 and sliding seat 6, form sphere-contact, spring base 4 uniform force can be guaranteed, make spring base 4 by axial force, not by diametral interference, prevent from causing the stuck or flexural deformation of back-moving spring 2 by radial load, improve reliability.

As is illustrated by figs. 11 and 12, two ends end face is to the valve pad 7 of plane, one end of valve pad 7 is towards sealing, and this end end face of valve pad 7 is the plane with the axis perpendicular of liquid inlet joint 8, when overflow opened by safety valve, produce shear flow when liquid flows out during overflow, the center position of valve pad 7 can form negative pressure of vacuum pulling force, valve pad 7 can be caused to pull out lost efficacy, affect the reliability of safety valve.

Therefore, as variant embodiment, as shown in FIG. 13 to 15, valve pad 7 is the circular block shape structure adopting polyurethane to make, one end of valve pad 7 is towards sealing, and this end end face of valve pad 7 is made up of an inner bottom surface 71 and a sealing surface 72, this end end face of valve pad 7 is formed towards the sunk structure 73 of valve pad 7 internal recess.Sealing surface 72 is for having the annular plane of centre bore, and sealing surface 72 for contacting with the internal face of the second accommodating cavity 53, and keeps in touch for the end face of the first shaft part 82 with liquid inlet joint, is closed by inlet opening.Inner bottom surface 71 is arranged in the centre bore of sealing surface 72, and both are coaxial, and the inner edge of the outer rim of inner bottom surface and sealing surface 72 is connected to form complete end face.As preferably, inner bottom surface 71 is sphere, forms an inwardly recessed ball recess, namely form sunk structure 73 in the center, end of valve pad 7.Sealing surface 72 realizes sealing for matching with liquid inlet joint, the external diameter of sealing surface 72 is not less than the diameter of the second accommodating cavity 53, the external diameter of sealing surface 72 is greater than the external diameter of the first shaft part 82, the interior diameter of sealing surface 72 is not more than the external diameter of the first shaft part 82, guarantee that sealing surface 72 can keep in touch with the end face of the first shaft part 82 like this when safety valve cuts out, inlet opening is closed.

For the valve pad 7 with sunk structure, as shown in figure 14, because valve pad 7 has inner concave arc surface effect, highly pressurised liquid from liquid inlet joint can be divided into axial thrust load Fn and radial component Fr on curved surface, component Fr is with under the acting in conjunction of the directed force F a produced by support member at cylindrical and the back side and Fb, butt joint sealing position produces extruding force, and increase with fluid pressure and increase, and plane valve pad just can not produce such effect, therefore to compare the valve pad (Fig. 9 shown in) not having sunk structure, higher pressure can be born.As shown in figure 15, when also large discharge overflow opened by safety valve, valve pad is because of the reflex of inner concave arc surface, the highly pressurised liquid of flowing produces unordered disorder flowing in the central area of valve pad, the pressure fluid of this unordered disorder flowing forms lasting pressure effect to valve pad contact surface, on the supporting surface being pressed in behind making valve pad stable; If when valve pad surface is plane, during overflow, liquid can directly radially flow out, and forming negative pressure of vacuum region in valve pad center, the liquid of this negative pressure region can produce pulling force effect to valve pad and cause valve pad to leave supporting surface behind until be drawn out damage and cause seal failure.

Sunk structure 73 is except for except spherical, can also be other shapes, as shown in figure 16, as the variant embodiment to valve pad shown in Figure 13, the shape that the structure of the valve pad 7 of this structure is in sunk structure 73 relative to the structure difference of valve pad shown in Figure 13 is different, and remainder is all identical.The sunk structure 73 of the valve pad 7 of this structure is cone-shaped groove, inner bottom surface is made up of male cone (strobilus masculinus) 74 and baseplane 75, and male cone (strobilus masculinus) 74 is taper seat, and male cone (strobilus masculinus) 74 is arranged in the centre bore of sealing surface 72, both are coaxial, and the outer rim of male cone (strobilus masculinus) 74 is connected with the inner edge of sealing surface 72.Male cone (strobilus masculinus) 74 has bigger diameter end and miner diameter end, and the bigger diameter end of male cone (strobilus masculinus) 74 is connected with the inward flange of sealing surface 72, and miner diameter end is connected with the outward flange of baseplane 75.Baseplane 75 is the disk coaxial with sealing surface 72, and baseplane 75 is arranged in the centre bore of male cone (strobilus masculinus) 74, and both are coaxial, and the outer rim of male cone (strobilus masculinus) 74 is connected with the bigger diameter end outer rim of inner conical surface 73, and form complete end face with sealing surface 72.The valve pad of structure shown in Figure 16 has identical effect with the valve pad of structure shown in Figure 13, as shown in Figure 17 and Figure 18, does not repeat them here.

Below by reference to the accompanying drawings to invention has been exemplary description.Obviously, specific implementation of the present invention is not subject to the restrictions described above.As long as have employed the improvement of the various unsubstantialities that method of the present invention is conceived and technical scheme is carried out; Or without improvement, above-mentioned design of the present invention and technical scheme directly applied to other occasion, all within protection scope of the present invention.

Claims (8)

1. the core assembly of safety valve, is characterized in that: comprise sliding seat, be arranged at the swivel nut in sliding seat and be arranged in swivel nut and valve pad for matching with the liquid inlet joint of safety valve, valve pad has ball recess.

2. the core assembly of safety valve according to claim 1, it is characterized in that: described liquid inlet joint comprises the joint body that is connected with the valve body of safety valve and is fixedly connected with joint body and the sealing matched with described nut and valve pad, liquid inlet joint has inlet opening, and valve body has outage.

3. the core assembly of safety valve according to claim 1, is characterized in that: described valve pad is fixedly clamped by described sliding seat and described swivel nut.

4. the core assembly of safety valve according to claim 2, it is characterized in that: described swivel nut has the first accommodating cavity for holding described sealing with the described valve pad of accommodation and the second accommodating cavity is communicated with the first accommodating cavity, and described sliding seat has the 3rd accommodating cavity of accommodation swivel nut.

5. the core assembly of safety valve according to claim 2, it is characterized in that: the end face of described sliding seat is provided with the first oil duct for fluid being guided to outage, the end face of described swivel nut is provided with the second oil duct for fluid being guided to the first oil duct, when described valve pad and described hermetic unit from after, the fluid in described inlet opening flow to described outage place through the second oil duct, the first oil duct successively.

6. the core assembly of safety valve according to claim 5, is characterized in that: described first oil duct, the second oil duct and described outage are positioned in the same radial line of described valve body.

7. the core assembly of safety valve according to claim 5, is characterized in that: described sealing is in first accommodating cavity that can embed described swivel nut and the ledge structure contacted with described valve pad, and the diameter of described second accommodating cavity is greater than the diameter of the first accommodating cavity.

8. the core assembly of safety valve according to claim 5, it is characterized in that: described sealing has and sets gradually and the first shaft part of increasing gradually of external diameter and the second shaft part, second shaft part is fixedly connected with described joint body, first shaft part matches with described valve pad, and the external diameter of the first shaft part is not more than the diameter of described first accommodating cavity.