CN105484784A - Overflow safety valve - Google Patents

Abstract

The invention discloses an overflow safety valve comprising a valve casing, a liquid inlet joint with a liquid inlet and a valve element assembly, wherein the valve element assembly is movably arranged in the valve casing and used for controlling opening and closing of the liquid inlet, a liquid drain hole is formed in the valve casing, the valve element assembly comprises a nut and a valve pad arranged in the nut, the valve pad comprises a sealing surface matched with the liquid inlet joint, and the sealing surface is a spherical surface. According to the overflow safety valve, the movable valve element assembly is arranged in the valve casing and can be used for controlling connection and disconnection of an oil path from the liquid inlet to the liquid drain hole, large-flow overflow can be realized after the valve element assembly is far away from the liquid inlet joint, the flow of the safety valve is greatly increased, quick overflow in a short time can reduce axial displacement of the valve element assembly, reduction of the axial displacement of the valve element assembly can decrease axial deformation of a reset spring, and the pressure fluctuation can be reduced finally.

Description

Overflow relief 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 overflow relief 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 overflow relief valve, object reduces pressure oscillation.

To achieve these goals, the technical scheme that the present invention takes is: overflow relief valve, comprise valve casing and the liquid inlet joint with inlet opening, also comprise for being movably arranged in described valve casing and core assembly for controlling described inlet opening opening and closing, valve casing has outage, core assembly comprises nut and is arranged at the valve pad in nut, and valve pad has the sealing surface for matching with liquid inlet joint, and sealing surface is sphere.

Described liquid inlet joint comprises the joint body that is connected with valve casing and is fixedly connected with joint body and the sealing matched with described core assembly, and described outage is distributed in around sealing.

Described joint body to insert in described valve casing and with described valve casing for being threaded.

Described core assembly comprises nut and to be arranged in nut and the valve pad realizing sealing that matches with described sealing.

Described core assembly also comprises screw plug, described nut having the first accommodating cavity for holding described sealing, holding the second accommodating cavity of described valve pad and the 3rd accommodating cavity for holding screw plug, first accommodating cavity, the second accommodating cavity and the 3rd accommodating cavity are for setting gradually, and screw plug is used for closing the second accommodating cavity.

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

Described oil duct and described outage are positioned in the same radial line of described valve casing.

Described sealing is in first accommodating cavity that can embed described 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 external diameter the first shaft part, the second shaft part and the 3rd shaft part that increase gradually, 3rd shaft part is fixedly connected with described joint body, first shaft part matches with described valve pad, and the external diameter of the second shaft part is not more than the diameter of a described accommodating cavity.

The length of described second shaft part is not less than the degree of depth of described first accommodating cavity.

Overflow relief valve of the present invention, by arranging moveable core assembly in valve casing inside, core assembly 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 safety valve of the present invention;

Fig. 2 is the sectional view of arranged at safety valve of the present invention when opening;

Fig. 3 is the sectional view of core assembly;

Fig. 4 is the sectional view of liquid inlet joint;

Fig. 5 is I place enlarged drawing in Fig. 4;

Fig. 6 is the sectional view of nut;

Fig. 7 is the sectional view of spring base;

Fig. 8 is that the valve pad of the first structure coordinates schematic diagram with sealing;

Fig. 9 is that when being in opening, the first structure valve pad coordinates schematic diagram with sealing;

Figure 10 is the sectional view of the valve pad of the second structure;

Figure 11 is the stressed schematic diagram of the second structure valve pad when being in closed condition;

Figure 12 is that when being in closed condition, the second structure valve pad coordinates schematic diagram with sealing;

Figure 13 is that when being in opening, the second structure valve pad coordinates schematic diagram with sealing;

Be labeled as in figure:

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

3, valve casing; 31, outage; 32, spring cavity;

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

5, nut; 51, large chamber, footpath; 52, the second accommodating cavity; 53, the 3rd accommodating cavity; 54, path chamber; 55, oil duct; 6, screw plug; 61, locating hole; 62, hexagon ring;

7, valve pad; 71, sealing surface; 72, anchor ring; 8, liquid inlet joint; 81, joint body; 82, the first shaft part; 83, the second shaft part; 84, the 3rd shaft part; 9, the first sealing ring; 10, 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 7, the invention provides a kind of overflow relief valve, comprise the valve casing 3 with outage 31, the liquid inlet joint 8 with inlet opening and resetting-mechanism, inlet opening to be communicated with outage 31 by the unloading cavity of valve casing 3 inside and three forms the overflow ducts of safety valve.Overflow relief valve of the present invention also comprises for be movably arranged in valve casing 3 and for the core assembly of 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, namely core assembly realizes the control of overflow ducts break-make by the mobile opening and closing controlling inlet opening.

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 depicted in figs. 1 and 2, valve casing 3 is the cylindrical member of both ends open, inner hollow, and valve casing 3 inside has the spring cavity 32 holding resetting-mechanism.Resetting-mechanism is the axial force of closing for applying to make it to move to realize inlet opening 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 screws in spring cavity 32 in one end of valve casing 3 to be threaded with valve casing 3, back-moving spring 2 is clipped between voltage regulation screw 1 and spring base 4, spring base 4 can moving axially along valve casing 3 by the promotion of back-moving spring 2 and core assembly in valve casing 3, 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 depicted in figs. 1 and 2, liquid inlet joint 8 is as hydraulic cylinder socket connection for the Hydraulic Elements with coal mine fully-mechanized mining hydraulic support, the voltage regulation screw 1 of resetting-mechanism is threaded with valve casing 3 in one end of valve casing 3, and liquid inlet joint 8 to screw in valve casing 3 and with valve casing 3 for being threaded at the other end of valve casing 3.As shown in Figure 4, liquid inlet joint 8 to comprise with valve casing 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 inner surface at valve casing 3 is provided with internal thread.Inlet opening 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 casing 3 inner and for matching with core assembly, with the break-make of controlling water kick passage.

As depicted in figs. 1 and 2, the part cavity between joint body 81 and core assembly of valve casing 3 inside as unloading cavity, because the relative liquid inlet joint 8 of core assembly is moveable, then the adjustable volume of unloading cavity.Sealing is by realizing the closedown of inlet opening with contacting of core assembly, and now unloading cavity volume is minimum, and inlet opening 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 increases gradually, and inlet opening is communicated with outage 31 by unloading cavity, overflow ducts conducting, and safety valve realizes opening.Therefore, overflow relief valve of the present invention moving axially by core assembly, realize the control of overflow ducts break-make, and be communicated with inlet opening and outage 31 by unloading cavity, unloading cavity volume is large, large discharge overflow can be realized when overflow ducts conducting, it is little that fluid in inlet opening 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 s vertically in valve casing 3 can complete breakdown action.And the axial displacement of core assembly is reduced, when overflow relief valve of the present invention adopts the back-moving spring with identical coefficient of elasticity with the safety valve of prior art, the stroke of the back-moving spring 2 in overflow relief valve 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 depicted in figs. 1 and 2, outage 31 is arranged on the sidewall of valve casing 3, outage 31 and through hole for radially running through setting.Outage 31 is also circumferentially uniform multiple on the sidewall of valve casing 3, and all outages 31 are distributed in around the sealing of unloading cavity and liquid inlet joint 8, like this when safety valve is opened, the fluid in inlet opening 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 shown in Figure 1 to Figure 3, core assembly comprise nut 5, be arranged at nut 5 in and the valve pad 7 that realizes sealing and be arranged at the interior and screw plug 6 matched with nut 5 for carrying out axial limiting to valve pad 7 of nut 5 of matching with sealing.Nut 5 is the cylindrical structural of both ends open and inner hollow, the cavity at nut 5 inside center place is the first accommodating cavity, accommodation the second accommodating cavity 52 of valve pad 7 and the 3rd accommodating cavity 53 for holding screw plug 6 for holding sealing, first accommodating cavity, the second accommodating cavity 52 and the 3rd accommodating cavity 53 are for axially setting gradually along 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 plane with the axis perpendicular of liquid inlet joint 8, and valve pad 7 is by carrying out with sealing the control that plane contact realizes closing inlet opening, adopting flat seal form, good sealing effect.

As depicted in figs. 1 and 2, the periphery of nut 5 contacts with the inner headed face of valve casing 3, and nut 5 is between spring base 4 and liquid inlet joint 8.As shown in Figure 3 and Figure 6, the first accommodating cavity, the second accommodating cavity 52 and the 3rd accommodating cavity 53 three are coaxial and be communicated with, and the first accommodating cavity is formed and allows the sealing of liquid inlet joint 8 insert opening in the first accommodating cavity on the end face of 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 52, diameter due to the first accommodating cavity is less than the diameter of the second accommodating cavity 52, a limited step is formed in first accommodating cavity and the second accommodating cavity 52, valve pad 7 is filled in after being through the 3rd accommodating cavity 53 when installing in the second accommodating cavity 52, valve pad 7 and with nut 5 interference fit, and in the second accommodating cavity 52, load screw plug 6, screw plug 6 is for closing the open-ended of the second accommodating cavity 52, screw plug 6 also matches with limited step and clamps valve pad 7, realize the axial restraint of valve pad 7.

As shown in Figure 3, as preferably, screw plug 6 and nut 5, for being threaded, are correspondingly provided with external screw thread at screw plug 6 external surface, and the inner surface in the 3rd accommodating cavity 53 of nut 5 is provided with internal thread.Screw plug 6 is arranged to be threaded with nut 5, easy disassembly screw plug 6, so that change valve pad 7.

As shown in Figure 3 and Figure 6, as preferably, the end face facing liquid inlet joint 8 of nut 5 be provided with allow fluid by and fluid is guided to the oil duct 55 of outage 31, this oil duct 55 is the groove extended to along the radial direction of nut 5 from the first accommodating cavity place on the periphery of nut 5.By arranging oil duct 55 on the end face of nut 5, when valve pad 7 and hermetic unit from after, oil duct 55, by the fluid flow in unloading cavity guides to outage 31 from inlet opening, is conducive to the quick overflow that safety valve realizes the short time.

As depicted in figs. 1 and 2, as preferably, oil duct 55 and aligned in position equal with the quantity of outage 31, oil duct 55 on the end face of nut 5 for being uniformly distributed circumferentially.At valve casing 3 axially, outage 31 is between spring base 4 and joint body 81, and each oil duct 55 is positioned in the same radial line of valve casing 3 with outage 31 aligned in position in outside respectively.

As preferably, sealing is in first accommodating cavity that can embed 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 Figure 4 and Figure 5, in the present embodiment, sealing is three grades of step-like structures, sealing have set gradually and the first shaft part 82, second shaft part 83 of increasing gradually of external diameter and the 3rd shaft part 84, first shaft part 82, second shaft part 83 and the 3rd shaft part 84 three coaxial.The end of the 3rd shaft part 84 and joint body 81 is for be coaxially fixedly connected with, and the external diameter of the 3rd shaft part 84 is less than the external diameter of joint body 81.First shaft part 82 and the second shaft part 83 are for embedding in the first accommodating cavity of 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 second shaft part 83 is not more than the diameter of an accommodating cavity.

As shown in Figure 4 and Figure 5, the length of the second shaft part 83 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 forms the opening allowing fluid flow 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 all contacts with valve pad 7 with the end face of the second shaft part 83, the end face of the 3rd shaft part 84 and the end contact of nut 5, the end face of the second shaft part 83 and the 3rd shaft part 84 is the plane paralleled with the end face of the first shaft part 82, 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 nut 5 is divided into columniform path chamber 54 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 54, and the miner diameter end in large chamber, footpath 51 is connected with path chamber 54.Chamber, large footpath 51 is coaxial with path chamber 54, path chamber 54 between chamber, large footpath 51 and the second accommodating cavity 52, the diameter of the bigger diameter end in chamber, large footpath 51 is greater than the external diameter of the second shaft part 83, and oil duct 55 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 nut 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 depicted in figs. 1 and 2, core assembly also comprises the second sealing ring 10 be sheathed on nut 5, second sealing ring 10 is clipped between valve casing 3 and nut 5, second sealing ring 10 and between spring base 4 and outage 31, for realizing the sealing between unloading cavity and spring cavity 32, avoid fluid to flow in spring cavity 32 from the gap between nut 5 and valve casing 3, thus can avoid corroding back-moving spring 2.

As shown in Figure 7, the spring base 4 of resetting-mechanism is made up of guide section 42, first boss 41 and the second boss 43, guide section 42 is circular block shape structure, and the first boss 41 and the second boss 43 are connected to form one in the side of guide section 42 and guide section 42 spring base 4 of structure respectively.First boss 41 and the second boss 43 coaxial with guide section 42, the first boss 41 is cylindrical, and the diameter of guide section 42 is greater than the diameter of the first boss 41 and the second boss 43.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.Second boss 43 is spherical, and as shown in Figure 3, the end face center facing spring base 4 of screw plug 6 has allows the second boss 43 embed and for conical locating hole 61, the locating surface that the conical inner surface in locating hole 61 is fitted as the sphere with the second boss 43.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 3 inwall, core assembly and back-moving spring 2 are all to the active force that spring base 4 applies vertically, match with the second boss 43 of spring base 4 by arranging conical locating hole 61 in screw plug 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 shown in Figure 8 and Figure 9, 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 Figure 10 to Figure 13, valve pad 7 is the circular block shape structure adopting polyurethane to make, and one end of valve pad 7 is towards sealing, and this end end face of valve pad 7 is made up of a sealing surface 71 and an anchor ring 72.Anchor ring 72 is for having the annular plane of centre bore, and anchor ring 72 is for contacting with the internal face of the second accommodating cavity 52.Sealing surface 71 is arranged in the centre bore of anchor ring 72, and both are coaxial, and the inner edge of the outer rim of sealing surface 71 and anchor ring 72 is connected to form complete end face.As preferably, sealing surface 71 is sphere, forms an inwardly recessed ball recess in the center, end of valve pad 7.Sealing surface 71 realizes sealing for matching with liquid inlet joint, the external diameter of anchor ring 72 is not less than the diameter of the second accommodating cavity 52, the interior diameter of anchor ring 72 is greater than the external diameter of the second shaft part 83, guarantee that the area of sealing surface 71 is enough large, guarantee when safety valve cuts out to keep in touch with the end face of the first shaft part 82, inlet opening is closed.

For the valve pad 7 of sealing surface 71 with indent, as shown in figure 11, because valve pad 7 has inner concave arc surface effect, highly pressurised liquid from liquid inlet joint can be divided into axial force Fr and radial load Fn on curved surface, to compare the valve pad (Fig. 8 shown in) not having inner concave arc surface, higher pressure can be born.As shown in figure 12, because valve pad 7 has inner concave arc surface effect, leave gap after the end face of liquid inlet joint contacts with sealing surface 71, at this gap place, highly pressurised liquid flows into acting in opposition in liquid inlet joint by large cambered surface, can alleviate the pressure of liquid inlet joint end face.As shown in figure 13, when overflow opened by safety valve, under the sealing surface 71 of indent acts on, the unordered disorder flowing of highly pressurised liquid, liquid contact surface formed active force produce continuous, make valve pad stable be pressed on screw plug, avoid valve pad occur pull-out lost efficacy situation.

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 (9)

1. overflow relief valve, comprise valve casing and the liquid inlet joint with inlet opening, it is characterized in that: also comprise for being movably arranged in described valve casing and core assembly for controlling described inlet opening opening and closing, valve casing has outage, core assembly comprises nut and is arranged at the valve pad in nut, valve pad has the sealing surface for matching with liquid inlet joint, and sealing surface is sphere.

2. overflow relief valve according to claim 1, it is characterized in that: described liquid inlet joint comprises the joint body that is connected with valve casing and is fixedly connected with joint body and the sealing matched with described core assembly, and described outage is distributed in around sealing.

3. overflow relief valve according to claim 2, is characterized in that: described joint body to insert in described valve casing and with described valve casing for being threaded.

4. overflow relief valve according to claim 2, it is characterized in that: described core assembly also comprises screw plug, described nut having the first accommodating cavity for holding described sealing, holding the second accommodating cavity of described valve pad and the 3rd accommodating cavity for holding screw plug, first accommodating cavity, the second accommodating cavity and the 3rd accommodating cavity are for setting gradually, and screw plug is used for closing the second accommodating cavity.

5. overflow relief valve according to claim 4, it is characterized in that: the end face of described nut is provided with the oil duct for fluid being guided to outage, when described valve pad and described hermetic unit from after, the fluid in described inlet opening flow to described outage place through oil duct.

6. overflow relief valve according to claim 5, is characterized in that: described oil duct and described outage are positioned in the same radial line of described valve casing.

7. overflow relief valve according to claim 4, is characterized in that: described sealing is in first accommodating cavity that can embed described 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. overflow relief valve according to claim 4, it is characterized in that: described sealing has and sets gradually and external diameter the first shaft part, the second shaft part and the 3rd shaft part that increase gradually, 3rd shaft part is fixedly connected with described joint body, first shaft part matches with described valve pad, and the external diameter of the second shaft part is not more than the diameter of a described accommodating cavity.

9. overflow relief valve according to claim 8, is characterized in that: the length of described second shaft part is not less than the degree of depth of described first accommodating cavity.