A plug throttling stop valve

Abstract

The present invention relates to the field of valve technology, and specifically to a plug throttling stop valve. The present invention includes a valve body, a bracket, a valve stem, and a rotary power mechanism. The left and right sides of the valve body are respectively provided with a left channel and a right channel. The top of the valve stem is equipped with a rotary power mechanism. The bracket is composed of an upper bracket, a lower bracket, and a bracket support column. The lower bracket is installed on the upper part of the valve body. A second sealing gasket is installed between the lower bracket and the upper part of the valve body. The bracket support column is located between the upper bracket and the lower bracket, and the bracket support column is fixed to the upper bracket and the lower bracket as a whole. The beneficial effect of the present invention is that by transferring the force load of the first external thread on the valve stem to the flow channel hole of the valve body, the first external thread at the valve stem does not bear a large load when it can withstand the thrust of the ultra-high pressure working medium, thereby avoiding the breakage of the valve stem and the bracket support column.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to a plug throttling stop valve. Background Art

[0002] The stop valve is also called the gate valve. It is a forced sealing valve. Therefore, when the valve is closed, the valve stem must apply pressure to the valve disc to force the sealing surface to prevent leakage. There are three types of connection methods: flange connection, threaded connection, and welding connection. When the medium enters the valve from below the valve disc, the medium will apply an upward thrust to the valve disc. In order to achieve the sealing effect, the valve stem needs to apply a large downward thrust to the valve disc. While overcoming the upward thrust of the medium, the valve stem also applies additional thrust to the seal to achieve the sealing effect. The valve stem of the stop valve is relatively long, and the two ends of the valve stem bear relatively large forces, which makes it easy to bend and break.

[0003] The stop valve pressure range is: Class150LB-2500LB, PN1.0MPa-42.0MPa, JIS10K-40K. There are even stop valves with a pressure range of 100MPa. For stop valves with a working pressure range of 1.0MPa-1.6MPa, the life of the valve stem can be increased by thickening the diameter of the valve stem. However, for stop valves with water hammer impact and high working pressure in the pipeline, the fatigue life of the valve stem cannot be increased by infinitely thickening the diameter. The valve stem often bends and breaks, and even the valve cannot pass the first pressure test seal after installation. Calculate the upward thrust of the medium on the valve disc with a 42.0MPa, DN50 stop valve. The valve disc diameter of the DN50 stop valve is basically around 50mm. The calculation is as follows:

[0004]

[0005] 82.425KN is equivalent to a gravity of more than 8 tons, which does not include the thrust required for sealing on the sealing surface, the safety pressure test margin required for valve pressure testing, and the water hammer impact force of the pipeline.

[0006] In order to solve this problem, my country's valve "three-in-one" series, generalization, and standardization have stipulated that the flow direction of the stop valve should be from top to bottom, so that the medium enters the valve from above the valve disc, and the medium exerts downward pressure on the valve disc to achieve the sealing effect. However, the flow direction of the stop valve from top to bottom is inconsistent with the mainstream flow direction of the international stop valve. It is only a helpless move because China cannot produce high-pressure stop valves. At the same time, when the flow direction of the stop valve is from top to bottom, another technical problem will arise, that is, when the stop valve is opened, the valve disc needs to overcome the downward thrust exerted by the medium on the valve disc. At this time, the valve stem will bear a large load, and the valve stem often bends and breaks. The stop valve adopts the top-down method to only solve the sealing problem, but cannot solve the life of the valve stem.

[0007] At present, there are only a handful of domestic manufacturers that can produce high-pressure stop valves, and their lifespan is short, which belongs to a blank area. There are even no 100MPa pressure stop valves at home and abroad. For 100MPa pressure conditions, basically only needle valves can be used for installation, but needle valves are only available in small specifications, and the flow diameter of needle valves is very small, which cannot adapt to large flows. Summary of the invention

[0008] In order to overcome the shortcomings of the background technology, a first embodiment of the present invention provides a plug throttling stop valve.

[0009] The technical solution of the first embodiment of the present invention is: comprising a valve body, a bracket, a valve stem, and a rotary power mechanism, wherein the left and right sides of the valve body are respectively provided with a left channel and a right channel, a rotary power mechanism is installed on the top of the valve stem, the bracket is composed of an upper bracket, a lower bracket, and a bracket support column, the lower bracket is installed on the upper part of the valve body through a thread, a second sealing gasket is installed between the lower bracket and the upper part of the valve body, the bracket support column is located between the upper bracket and the lower bracket, and the bracket support column is fixed to the upper bracket and the lower bracket as a whole, a first internal thread is provided on the inner hole of the upper bracket, a first external thread is provided on the upper part of the valve stem, the valve stem is installed on the upper bracket through the first external thread and the first internal thread cooperating with each other, a packing is installed at the middle position of the lower bracket, a packing gland is installed above the lower bracket, and the inner hole of the packing is tightly matched and sealed with the outer diameter of the valve stem under the pressing action of the packing gland;

[0010] The valve body is provided with a flow channel hole between the left channel and the right channel, the flow channel hole is a circular through hole, and the central axis of the flow channel hole is concentric with the central axis of the valve stem, a sealing boss protruding upward is provided above the flow channel hole, a T-shaped valve disc is provided below the valve stem, a second internal thread is provided on the inner hole of the flow channel hole, a second external thread is provided at the outer circle of the small step below the valve disc, the second external thread and the second internal thread are installed in cooperation with each other, and the lead of the second external thread is the same as the lead of the first external thread;

[0011] A first sealing gasket is installed at the small step below the valve disc, a third external thread is provided at the outer circle of the large step of the valve disc, a cap is threadedly installed on the third external thread, the inner hole of the cap is smaller than the outer circle of the first sealing gasket, and the inner hole of the cap is larger than the outer diameter of the sealing boss.

[0012] Preferably, a copper nut is fixedly installed in the upper bracket, the first internal thread is arranged on the inner hole of the copper nut, the valve stem is made of steel, and the copper nut is made of copper alloy; the valve disc is composed of an upper limit sleeve and a lower locking sleeve, the valve stem is provided with a limit cone larger than the outer diameter of the valve stem at the bottom, the upper limit sleeve is installed on the valve stem above the limit cone through a first flat key, the lower locking sleeve is fixedly installed on the upper limit sleeve, the third external thread is arranged on the large outer circle of the lower locking sleeve, the cap is installed on the third external thread, and the second external thread is arranged on the small outer circle of the lower locking sleeve, the valve stem slides in the space between the upper limit sleeve and the lower locking sleeve, and the cooperation between the limit cone and the upper limit sleeve limits the highest point of the valve stem sliding upward, and the lower locking sleeve is made of copper alloy.

[0013] Preferably, the copper nut can be installed on the upper bracket by threaded connection or brazing molding process. If threaded connection is adopted, a fixing pin needs to be installed on the thread to prevent the copper nuts from rotating when the valve stem 8 rotates.

[0014] Preferably, the upper limit sleeve and the valve stem are provided with mating threads, the upper limit sleeve is provided with a first keyway milled through, the valve stem is processed with a second keyway at a position corresponding to the first keyway, and the first flat key is installed in the first keyway and the second keyway.

[0015] Preferably, a first spring is installed in the space, a guiding bevel is provided at the bottom of the lower locking sleeve, and a guiding bevel is provided on the second internal thread.

[0016] Preferably, the rotary power mechanism adopts a hand wheel.

[0017] Preferably, the rotary power mechanism adopts a pneumatic actuator, and the inner hole of the output end of the pneumatic actuator is provided with an inner cylinder thread that cooperates with the first outer thread.

[0018] Embodiment 2 of the present invention provides a plug throttling stop valve. The technical solution of embodiment 2 of the present invention is:

[0019] It includes a valve body, a bracket, a valve stem, and a rotary power mechanism. The left and right sides of the valve body are respectively provided with a left channel 10a and a right channel. The top of the valve stem is equipped with a rotary power mechanism. The bracket consists of an upper bracket, a lower bracket, and a bracket support column. The lower bracket is installed on the upper part of the valve body through a thread. A second sealing gasket is installed between the lower bracket and the upper part of the valve body. The bracket support column is located between the upper bracket and the lower bracket, and the bracket support column is fixed to the upper bracket and the lower bracket as a whole. The inner hole of the upper bracket is a step hole. A copper slider is installed in the step hole. A second flat key is fixed on the outer circle of the copper slider. A flat key groove is provided at a position corresponding to the second flat key of the step hole. The length of the copper slider is less than the large hole depth of the step hole to form a sliding space. The second flat key and the flat key groove on the copper slider cooperate with each other to limit the rotation of the copper slider. The copper slider makes an up and down linear motion in the step hole. A limit plate is installed on the top of the step hole. The step hole and the limit plate cooperate with each other to limit the highest position of the copper slider sliding upward.

[0020] A third internal thread is provided at the inner hole position of the copper slider, a first external thread is provided at the upper part of the valve stem, the valve stem is mounted on the upper bracket through the cooperation of the first external thread and the third internal thread, a packing is installed at the middle position of the lower bracket, a packing gland is installed above the lower bracket, and the inner hole of the packing is tightly matched and sealed with the outer diameter of the valve stem under the pressing action of the packing gland;

[0021] The valve body is provided with a flow channel hole between the left channel and the right channel, the flow channel hole is a circular through hole, and the central axis of the flow channel hole is concentric with the central axis of the valve stem, a sealing boss protruding upward is provided above the flow channel hole, and a multi-head internal thread is provided on the inner hole of the flow channel hole, and a limiting round table larger than the outer diameter of the valve stem is provided below the valve stem, an upper limit sleeve is installed above the limiting round table of the valve stem through a first flat key, a lower locking sleeve is fixedly installed below the upper limit sleeve, and a first flat key is provided on the large outer circle of the lower locking sleeve Three external threads, a cap is installed on the third external thread, a multi-start external thread is provided on the small outer circle of the lower locking sleeve, the valve stem slides in the space between the upper limit sleeve and the lower locking sleeve, and the cooperation between the limit cone and the upper limit sleeve limits the highest point of the valve stem sliding upward, the multi-start external threads and the multi-start internal threads are matched and tightened with each other, the thread lead of the multi-start external threads is 3 times to 8 times the thread lead of the first external threads, and the thread tooth depth of the multi-start external threads is 3 times to 8 times the thread tooth depth of the first external threads.

[0022] Preferably, a guiding bevel is provided at the bottom of the lower locking sleeve, a guiding bevel is provided on the multi-start internal thread, a second spring is installed in the sliding space, and a first spring is installed in the space.

[0023] Preferably, a guiding bevel is provided at the bottom of the lower locking sleeve, a guiding bevel is provided on the multi-start internal thread, a second spring is installed in the sliding space, and a third spring is installed between the upper limit sleeve and the lower bracket.

[0024] Preferably, the upper limit sleeve and the valve stem are provided with mating threads, the upper limit sleeve is provided with a first keyway milled through, the valve stem is processed with a second keyway at a position corresponding to the first keyway, and the first flat key is installed in the first keyway and the second keyway.

[0025] Preferably, the lower locking sleeve is welded with stainless steel and hard alloy. The specific method is to first use stainless steel material, such as stainless steel 304 or 316L, to process the preliminary shape, and then weld hard alloy at the place where the multiple external threads need to be processed, and then use a lathe or milling machine to process the multiple external threads. Since the valve body 1 is usually made of stainless steel or carbon steel and other materials, the material of the multiple external threads and the material of the multiple internal threads will be significantly different, avoiding the problem of multiple external threads and multiple internal threads biting each other in the case of long-term acceptance. Of course, the welded hard alloy can also be made of Stellite alloy, which has the advantages of wear resistance, corrosion resistance, and high temperature resistance.

[0026] The beneficial effect of the present invention is that by transferring the stress load of the first external thread on the valve stem to the flow channel hole of the valve body, the first external thread at the valve stem does not bear a large load while being able to withstand the thrust of the ultra-high pressure working medium, thereby avoiding the breakage of the valve stem and the bracket support column. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a common stop valve on the market.

[0028] Figure 2 A schematic structural diagram of embodiment 1 of the present invention.

[0029] Figure 3 A schematic structural diagram of embodiment 2 of the present invention.

[0030] Figure 4 A schematic structural diagram of embodiment 3 of the present invention.

[0031] Figure 5 A perspective view of the present invention.

[0032] Figure 6 Exploded view of the third embodiment of the present invention.

[0033] Figure 7 An exploded view of the valve stem, upper limit sleeve, lower locking sleeve, first flat key, and first spring in Embodiment 3 of the present invention.

[0034] Figure 1-Figure 7In the figure, valve body 1, left channel 10a, right channel 10b, flow channel hole 101, second internal thread 1011, guide bevel 1012, multi-head internal thread 1013, sealing boss 102, bracket 2, upper bracket 21, first internal thread 211, step hole 212, flat keyway 213, sliding space 214, lower bracket 22, bracket support column 23, packing 3, copper nut 4, handwheel 5, fixing pin 6, packing gland 7, valve stem 8, first external thread 81, valve disc 82, small step 821, large step 822, second external thread 823, third external thread 824, limiting cone 83, first flat key 84, second keyway 85, upper limit sleeve 91, first keyway 911, lower locking sleeve 92, guide slope 921, multi-head external thread 922, cap 93, space 94, first sealing gasket 10, second sealing gasket 11, first spring 12, copper slider 13, third internal thread 131, second flat key 14, limiting plate 15, second spring 16, third spring 17. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are further described below with reference to the accompanying drawings:

[0036] like Figure 1-Figure 7As shown, the present embodiment 1 provides a plug throttling stop valve, including a valve body 1, a bracket 2, a valve stem 8, and a rotary power mechanism. The left and right sides of the valve body 1 are respectively provided with a left channel 10a and a right channel 10b. The top of the valve stem 8 is provided with a rotary power mechanism, and the rotary power mechanism is used to drive the valve stem 8 to rotate forward or reversely. The bracket 2 is composed of an upper bracket 21, a lower bracket 22, and a bracket support column 23. The lower bracket 22 is installed on the upper part of the valve body 1 through threads. The lower bracket 22 can be connected by bolts or by directly providing threads on the lower bracket 22 when installed on the valve body 1. However, the best method is to fix the lower bracket 22 on the valve body 1 with bolts, which is convenient for disassembling and installing the lower bracket 22. A second sealing gasket 11 is installed between the lower bracket 22 and the upper part of the valve body 1. The sealing effect between the lower bracket 22 and the valve body 1 is achieved by pressing the second sealing gasket 11 against the valve body 1. The bracket support column 2 3 is located between the upper bracket 21 and the lower bracket 22, and the bracket support column 23 is fixed to the upper bracket 21 and the lower bracket 22 as a whole. The bracket support column 23 can be in the shape of [ or arc. The arc shape is conducive to the deformation of the bracket support column 23 and increases the bearing capacity limit of the bracket support column 23. The inner hole of the upper bracket 21 is provided with a first internal thread 211, and the upper part of the valve stem 8 is provided with a first external thread 81. The valve stem 8 is installed on the upper bracket 21 through the first external thread 81 and the first internal thread 211. The middle position of the lower bracket 22 is equipped with a packing 3, and the upper part of the lower bracket 22 is equipped with a packing gland 7. The inner hole of the packing 3 is tightly matched and sealed with the outer diameter of the valve stem 8 under the pressing action of the packing gland 7. The first external thread 81 and the first internal thread 211 are preferably trapezoidal threads. The trapezoidal thread has the advantages of large transmission torque and can withstand several times the load than ordinary triangular threads. At the same time, the trapezoidal thread rotates more smoothly.

[0037] The valve body 1 is provided with a flow channel hole 101 between the left channel 10a and the right channel 10b. The flow channel hole 101 is a circular through hole, and the central axis of the flow channel hole 101 is concentric with the central axis of the valve stem 8. A sealing boss 102 protruding upward is provided above the flow channel hole 101. For a high-pressure stop valve, the sealing width of the sealing boss 102 can be narrower. By reducing the sealing width of the sealing boss 102, the contact area of ​​the sealing surface is reduced, thereby increasing the sealing specific pressure. A T-shaped valve flap 82 is provided below the valve stem 8. A second internal thread 1011 is provided on the inner hole of the flow channel hole 101, and a second external thread 823 is provided on the outer circle of the small step 821 below the valve disc 82. The second external thread 823 and the second internal thread 1011 are installed in cooperation with each other. The lead of the second external thread 823 is the same as the lead of the first external thread 81. The second external thread 823 can be a trapezoidal thread like the first external thread 81. For a DN50 stop valve, the lead of the second external thread 823 and the lead of the first external thread 81 are both 6mm, which is a better effect.

[0038] A first sealing gasket 10 is installed at the small step 821 below the valve disc 82, and a third external thread 824 is provided at the outer circumference of the large step 822 of the valve disc 82. A cap 93 is threadedly installed on the third external thread 824. The inner hole of the cap 93 is smaller than the outer circumference of the first sealing gasket 10, and the inner hole of the cap 93 is larger than the outer diameter of the sealing boss 102. In addition, a groove can be provided at the bottom of the second external thread 823, so that the first sealing gasket 10 is stuck in the groove at the bottom of the second external thread 823, and the cap 93 presses the first sealing gasket 10 to prevent the first sealing gasket 10 from falling off during use.

[0039] When in use, the valve stem 8 is rotated clockwise downward by the rotary power mechanism, so that the second external thread 823 is screwed into the second internal thread 1011. Since the second external thread 823 has the same lead as the first external thread 81, and the second internal thread 1011 and the first internal thread 211 are processed at the same time, it is ensured that when the valve stem 8 is rotated clockwise downward, the second external thread 823 can be aligned with the second internal thread 1011. Of course, a certain gap can be made between the second internal thread 1011 and the second external thread 823, reducing the precision requirements for processing. When the valve stem 8 is rotated clockwise downward and fully tightened, the first sealing gasket 10 will be completely pressed on the sealing boss 102 to make it sealed. When the left channel 10a of the valve is passed with a pressurized medium, the medium will give the valve flap 82 an upward thrust. Since the second external thread 823 on the valve flap 82 has been completely tightened with the second internal thread 1011 on the valve body 1, most of the thrust of the medium will be borne by the second external thread 823 and the second internal thread 1011, and the first external thread 81 and the first internal thread 211 only bear a small amount of thrust, ensuring that the valve stem 8 will not bear a large pressure. In this way, the valve stem 8 of the ordinary stop valve on the market can be effectively solved. The risk of the valve stem 8 becoming crooked or broken due to the overload thrust. In addition, since there is little force between the first external thread 81 and the first internal thread 211, the support column 23 on the support 2 does not need to bear a relatively large tensile force, and the breakage of the support column 23 is also avoided. For high-pressure stop valves, the diameter of the valve stem 8 and the cross-sectional area of ​​the support column 23 can also be effectively reduced. Since the valve body 1 needs to withstand high-pressure working pressure, the wall thickness of the valve body 1 can be designed to be very thick, so the second internal thread 1011 on the valve body 1 can be very thick, and most of the load is distributed to the valve body 1 through the second internal thread 1011.

[0040] Since it is difficult and costly to process the second internal thread 1011 and the first internal thread 211 at the same time, and since threads of the same material are prone to seizure when bearing loads, especially for stainless steel, in order to solve the above problems. Preferably, a copper nut 4 is fixedly installed in the upper bracket 21, the first internal thread 211 is arranged on the inner hole of the copper nut 4, the valve stem 8 is made of steel, and the copper nut 4 is made of copper alloy; the valve disc 82 is composed of an upper limit sleeve 91 and a lower locking sleeve 92, the valve stem 8 is provided with a limiting round table 83 larger than the outer diameter of the valve stem 8 at the bottom, the upper limit sleeve 91 is installed on the valve stem 8 above the limiting round table 83 through a first flat key 84, the lower locking sleeve 92 is fixedly installed on the upper limit sleeve 91, the third external thread 824 is arranged on the large outer circle of the lower locking sleeve 92, the cap 93 is installed on the third external thread 824, the second external thread 823 is arranged on the small outer circle of the lower locking sleeve 92, the valve stem 8 slides in the space 94 between the upper limit sleeve 91 and the lower locking sleeve 92, and the cooperation of the limiting round table 83 and the upper limit sleeve 91 limits the highest point of the valve stem 8 sliding upward, and the lower locking sleeve 92 is made of copper alloy.

[0041] In this way, the first internal thread 211 becomes a copper alloy, while the first external thread 81 is still made of stainless steel, which can prevent the first external thread 81 and the first internal thread 211 from biting each other. At the same time, the copper alloy has the advantage of wear resistance. The copper alloy can be made of brass such as H52, H58, and H62. The H52, H58, and H62 brass have the advantages of low price and sufficient raw materials on the market. Of course, copper alloys with higher grades, higher wear resistance, and higher strength are also possible. Even cemented carbide can be used, but cemented carbide is difficult to process and the raw material cost of cemented carbide is several times that of copper alloy. Even 1 kg of raw materials of some cemented carbides can reach several thousand yuan.

[0042] Preferably, the copper nut 4 can be installed on the upper bracket 21 by threaded connection or brazing forming process. If threaded connection is adopted, a fixing pin 6 needs to be installed on the thread to prevent the copper nut 4 from rotating when the valve stem 8 rotates. The copper nut 4 installed on the bracket 21 by threaded connection is easy to replace, which is convenient for the problem of quick replacement of the copper nut 4 after wear.

[0043] In order to solve the problem that the lower lock sleeve 92 is easy to slide up and down on the valve stem 8 when the stop valve is in the open state. Figure 3Preferably, the upper limit sleeve 91 and the valve stem 8 are provided with mutually matching threads, the upper limit sleeve 91 is provided with a first key groove 911 milled through, the valve stem 8 is processed with a second key groove 85 at a position corresponding to the first key groove 911, and the first flat key 84 is installed in the first key groove 911 and the second key groove 85. In this way, after the stop valve is opened, the lower lock sleeve 92 and the upper limit sleeve 91 cannot easily slide up and down on the valve stem 8. In addition, the mutually matching threads between the upper limit sleeve 91 and the valve stem 8 can be processed looser. In the case of the looseness of the first flat key 84, the first key groove 911 and the second key groove 85, the lower lock sleeve 92 and the upper limit sleeve 91 as a whole can be offset at a small angle along the center line of the valve stem 8, thereby greatly reducing the assembly concentricity requirements of the second external thread 823 and the second internal thread 1011.

[0044] Preferably, a first spring 12 is installed in the space 94, a guiding bevel 921 is provided at the bottom of the lower lock sleeve 92, and a guiding bevel 1012 is provided on the second internal thread 1011. The guiding bevel 1012 cooperates with the guiding bevel 921, so that the second external thread 823 has a self-centering effect when it is screwed into the second internal thread 1011, which facilitates the opening and closing of the stop valve and reduces the possibility of getting stuck. At the same time, the guiding bevel 921 makes the bottom of the lower lock sleeve 92 into a cone, so that the stop valve has the function of throttling and regulating flow.

[0045] Preferably, the rotary power mechanism adopts a hand wheel 5.

[0046] Preferably, the rotary power mechanism adopts a pneumatic actuator, and the inner hole of the output end of the pneumatic actuator is provided with a cylinder inner thread that cooperates with the first outer thread 81. Of course, the rotary power mechanism can also adopt an angular stroke device such as an electric actuator and a worm gear.

[0047] For an ultra-high pressure stop valve, the medium thrust of its working pressure is huge, which will make the second outer thread 823 and the second inner thread 1011 of the ordinary trapezoidal thread unable to withstand the problem of thread breakage in the end. Embodiment 2 of the present invention provides a plug throttling stop valve, and the technical solution of Embodiment 2 of the present invention is:

[0048] like Figure 3As shown, embodiment three includes a valve body 1, a bracket 2, a valve stem 8, and a rotating power mechanism, wherein the rotating power mechanism is used to drive the valve stem 8 to rotate forward or reversely, and the left and right sides of the valve body 1 are respectively provided with a left channel 10a and a right channel 10b, and the top of the valve stem 8 is equipped with a rotating power mechanism, and the bracket 2 is composed of an upper bracket 21, a lower bracket 22, and a bracket support column 23, and the lower bracket 22 is installed on the upper part of the valve body 1 through threads, and the lower bracket 22 can be connected by bolts or by directly providing threads on the lower bracket 22 when installed on the valve body 1, but the best method is to fix the lower bracket 22 to the valve body 1 with bolts, so as to facilitate the disassembly and installation of the lower bracket 22, and a second sealing gasket 11 is installed between the lower bracket 22 and the upper part of the valve body 1, and the bracket support column 23 is located between the upper bracket 21 and the lower bracket 22, and the bracket support column 23 is fixed to the upper bracket 21 and the lower bracket 22 as a whole, and the bracket The support column 23 can be in the shape of [ or arc. The arc shape is conducive to the deformation of the bracket support column 23 and increases the bearing capacity limit of the bracket support column 23. The inner hole of the upper bracket 21 is a step hole 212. A copper slider 13 is installed in the step hole 212. A second flat key 14 is fixed on the outer circle of the copper slider 13. The step hole 212 is provided with a flat key groove 213 at the corresponding position of the second flat key 14. The length of the copper slider 13 is less than the large hole depth of the step hole 212 to form a sliding space 214. The second flat key 14 and the flat key groove 213 on the copper slider 13 cooperate with each other to limit the rotation of the copper slider 13. The copper slider 13 makes an up and down linear motion in the step hole 212. A limiting plate 15 is installed on the top of the step hole 212. The limiting plate 15 can be welded or threaded on the top of the step hole 212. The step hole 212 and the limiting plate 15 cooperate with each other to limit the highest position of the copper slider 13 sliding upward. The inner hole of the copper slider 13 is provided with a third internal thread 131, the upper part of the valve stem 8 is provided with a first external thread 81, the valve stem 8 is mounted on the upper bracket 21 through the first external thread 81 and the third internal thread 131, the packing 3 is installed in the middle of the lower bracket 22, and the packing gland 7 is installed above the lower bracket 22. The inner hole of the packing 3 is tightly matched and sealed with the outer diameter of the valve stem 8 under the pressing action of the packing gland 7. Of course, the sliding space 214 can be above the copper slider 13 or below the copper slider 13.

[0049] The valve body 1 is provided with a flow channel hole 101 between the left channel 10a and the right channel 10b. The flow channel hole 101 is a circular through hole, and the central axis of the flow channel hole 101 is concentric with the central axis of the valve stem 8. A sealing boss 102 protruding upward is provided above the flow channel hole 101. The sealing width of the sealing boss 102 can be narrower. The contact area of ​​the sealing surface is reduced by reducing the sealing width of the sealing boss 102, thereby improving the sealing specific pressure. A multi-head internal thread 1013 is provided on the inner hole of the flow channel hole 101. The valve stem 8 is provided with a limiting cone 83 larger than the outer diameter of the valve stem 8 at the bottom. The valve stem 8 is installed with an upper limit sleeve 91 above the limiting cone 83 through a first flat key 84. The upper limit sleeve 91 is provided with a first flat key 84. A lower locking sleeve 92 is fixedly installed below the sleeve 91, and a third external thread 824 is provided on the large outer circle of the lower locking sleeve 92, and a cap 93 is installed on the third external thread 824. A multi-start external thread 922 is provided on the small outer circle of the lower locking sleeve 92, and the valve stem 8 slides in the space 94 between the upper limit sleeve 91 and the lower locking sleeve 92, and the cooperation between the limiting truncated cone 83 and the upper limit sleeve 91 limits the highest point of the valve stem 8 sliding upward, and the multi-start external thread 922 and the multi-start internal thread 1013 are matched and tightened with each other, and the thread lead of the multi-start external thread 922 is 3 to 8 times the thread lead of the first external thread 81, and the thread depth of the multi-start external thread 922 is 3 to 8 times the thread depth of the first external thread 81. The multi-start internal thread 1013 and the multi-start external thread 922 can adopt 3-start threads or 5-start threads. The effect is better when the thread lead of the multi-start external thread 922 is 5 times the thread lead of the first external thread 81. The structural shape of the multi-start external thread 922 is similar to the shape of a propeller. The multi-start external thread 922 uses a non-standard thread structure to facilitate lathe processing. In addition, the multi-start external thread 922 can also use a helical gear like a worm.

[0050] Preferably, a guiding bevel 921 is provided at the bottom of the lower locking sleeve 92 , a guiding bevel 1012 is provided on the multi-start internal thread 1013 , a second spring 16 is installed in the sliding space 214 , and a first spring 12 is installed in the space 94 .

[0051] like Figure 4 , Figure 6 , Figure 7 As shown, embodiment three of the present invention provides a plug throttling stop valve. The technical solution of embodiment three of the present invention is to add technical features on the basis of embodiment two. Preferably, a guide bevel 921 is provided at the bottom of the lower locking sleeve 92, and a guide bevel 1012 is provided on the multi-start internal thread 1013. A second spring 16 is installed in the sliding space 214, and a third spring 17 is installed between the upper limit sleeve 91 and the lower bracket 22.

[0052] The guide bevel 1012 cooperates with the guide bevel 921, so that the second external thread 823 has a self-centering effect when it is screwed into the second internal thread 1011, which facilitates the opening and closing of the stop valve and reduces the possibility of getting stuck. The schemes of the first spring 12 and the third spring 17 can both reduce the shaking of the lower lock sleeve 92. The specific method to be used can be selected according to the characteristics of the medium. After all, the spring cannot contact a small part of the medium. At the same time, the guide bevel 921 makes the bottom of the lower lock sleeve 92 into a cone, so that the stop valve has the function of throttling and regulating flow.

[0053] In order to solve the problem that the lower lock sleeve 92 is easy to slide up and down on the valve stem 8 when the stop valve is in the open state. Preferably, the upper limit sleeve 91 and the valve stem 8 are also provided with mutually matching threads, the upper limit sleeve 91 is provided with a milled first keyway 911, the valve stem 8 is processed with a second keyway 85 at a position corresponding to the first keyway 911, and the first flat key 84 is installed in the first keyway 911 and the second keyway 85. In addition, the mutually matching threads between the upper limit sleeve 91 and the valve stem 8 can be processed looser. In the case of the loose fitting of the first flat key 84, the first keyway 911 and the second keyway 85, the lower lock sleeve 92 and the upper limit sleeve 91 as a whole can be offset at a small angle along the center line of the valve stem 8, thereby greatly reducing the assembly concentricity requirements of the second external thread 823 and the second internal thread 1011.

[0054] Preferably, the lower lock sleeve 92 is welded with stainless steel and hard alloy. The specific method is to first use stainless steel, such as stainless steel 304 or 316L, to process the initial shape, then weld hard alloy at the place where the multi-head external thread 922 needs to be processed, and then use a lathe or milling machine to process the multi-head external thread 922. Since the valve body 1 is usually made of stainless steel or carbon steel, the material of the multi-head external thread 922 and the material of the multi-head internal thread 1013 will be significantly different, avoiding the problem of the multi-head external thread 922 and the multi-head internal thread 1013 being stuck in the case of long-term acceptance. Of course, the hard alloy for surfacing welding can also be Stellite alloy, which has the advantages of wear resistance, corrosion resistance, high temperature resistance, etc. It can solve the problem that copper alloy cannot be used in a small number of media working conditions.

[0055] The technical idea of ​​the present invention to solve the problem is to transfer the force load of the first external thread 81 on the valve stem 8 to the flow channel hole 101 of the valve body 1. Under the condition of being able to withstand the thrust of the ultra-high pressure working medium, the first external thread 81 at the valve stem 8 does not bear a large load, thereby avoiding the breakage of the valve stem 8 and the bracket support column 23.

[0056] When the medium of the stop valve flows into the right channel 10b, when the stop valve is opened, the first external thread 81 at the valve stem 8 only bears the torque load, and the downward thrust of the medium mainly acts on the multi-start external thread 922. The breakage of the valve stem 8 and the bracket support column 23 is effectively avoided.

[0057] This embodiment should not be regarded as a limitation of the invention, but any improvement based on the spirit of the invention should be within the protection scope of the invention.

Claims

1. A plug throttling stop valve, comprising a valve body (1), a bracket (2), a valve stem (8), and a rotary power mechanism, wherein the valve body (1) is provided with a left channel (10a) and a right channel (10b) on the left and right sides respectively, and the top of the valve stem (8) is provided with a rotary power mechanism, characterized in that: The bracket (2) is composed of an upper bracket (21), a lower bracket (22), and a bracket support column (23); the lower bracket (22) is mounted on the upper portion of the valve body (1) by means of threads; a second sealing gasket (11) is mounted between the lower bracket (22) and the upper portion of the valve body (1); the bracket support column (23) is located between the upper bracket (21) and the lower bracket (22); the bracket support column (23) is fixed to the upper bracket (21) and the lower bracket (22) as a whole; the upper bracket (21) is A first internal thread (211) is provided on the inner hole, a first external thread (81) is provided on the upper portion of the valve stem (8), the valve stem (8) is mounted on the upper bracket (21) by means of the first external thread (81) and the first internal thread (211) cooperating with each other, a packing (3) is mounted in the middle of the lower bracket (22), a packing gland (7) is mounted above the lower bracket (22), and the inner hole of the packing (3) is tightly matched and sealed with the outer diameter of the valve stem (8) under the pressing action of the packing gland (7); The valve body (1) is provided with a flow channel hole (101) between the left channel (10a) and the right channel (10b); the flow channel hole (101) is a circular through hole, and the central axis of the flow channel hole (101) is concentric with the central axis of the valve stem (8); a sealing boss (102) protruding upward is provided above the flow channel hole (101); a T-shaped valve flap (82) is provided below the valve stem (8); a second internal thread (1011) is provided on the inner hole of the flow channel hole (101); a second external thread (823) is provided at the outer circle of the small step (821) below the valve flap (82); the second external thread (823) and the second internal thread (1011) are mounted in cooperation with each other; the lead of the second external thread (823) is the same as the lead of the first external thread (81); A first sealing gasket (10) is installed at the small step (821) below the valve disc (82), and a third external thread (824) is provided at the outer circumference of the large step (822) of the valve disc (82). A cap (93) is threadedly installed on the third external thread (824), and the inner hole of the cap (93) is smaller than the outer circumference of the first sealing gasket (10), and the inner hole of the cap (93) is larger than the outer diameter of the sealing boss (102).

2. A plug throttling stop valve according to claim 1, characterized in that: A copper nut (4) is fixedly installed in the upper bracket (21); the first internal thread (211) is arranged on the inner hole of the copper nut (4); the valve stem (8) is made of steel; the copper nut (4) is made of copper alloy; the valve flap (82) is composed of an upper limit sleeve (91) and a lower locking sleeve (92); the valve stem (8) is provided with a limit truncated cone (83) having a larger outer diameter than the valve stem (8) at the bottom; the upper limit sleeve (91) is installed on the valve stem (8) above the limit truncated cone (83) via a first flat key (84); the lower locking sleeve (92) is provided with a first flat key (84) and a second flat key (85) at the bottom of the valve stem (8); the second limit sleeve (91) is installed on the valve stem (8) above the limit truncated cone (83) via a first flat key (84); the second limit sleeve (92) is provided with a first flat key (85) and a second flat key (85) at the bottom of the valve stem (8); the second limit sleeve (91) is provided with a first flat key (84 ... ) is fixedly mounted on the upper limit sleeve (91), the third external thread (824) is arranged on the large outer circle of the lower locking sleeve (92), the cap (93) is mounted on the third external thread (824), the second external thread (823) is arranged on the small outer circle of the lower locking sleeve (92), the valve stem (8) slides in the space (94) between the upper limit sleeve (91) and the lower locking sleeve (92), and the cooperation between the limiting cone (83) and the upper limit sleeve (91) limits the highest point of the upward sliding of the valve stem (8), and the lower locking sleeve (92) is made of copper alloy.

3. A plug throttling stop valve according to claim 2, characterized in that: The upper limit sleeve (91) and the valve stem (8) are provided with mutually matching threads, the upper limit sleeve (91) is provided with a first keyway (911) milled through, the valve stem (8) is provided with a second keyway (85) at a position corresponding to the first keyway (911), and the first flat key (84) is fitted in the first keyway (911) and the second keyway (85).

4. A plug throttling stop valve according to claim 3, characterized in that: A first spring (12) is installed in the space (94), a guiding inclined surface (921) is provided at the bottom of the lower locking sleeve (92), and a guiding bevel (1012) is provided on the second internal thread (1011).

5. A plug throttling stop valve according to any one of claims 1 to 4, characterized in that: The rotary power mechanism adopts a hand wheel (5).

6. A plug throttling stop valve according to any one of claims 1 to 4, characterized in that: The rotary power mechanism adopts a pneumatic actuator, and the inner hole of the output end of the pneumatic actuator is provided with a first outer thread (81) and a cylinder inner thread that cooperate with each other.

7. A plug throttling stop valve, comprising a valve body (1), a bracket (2), a valve stem (8), and a rotary power mechanism, wherein the valve body (1) is provided with a left channel (10a) and a right channel (10b) on the left and right sides respectively, and the top of the valve stem (8) is provided with a rotary power mechanism, characterized in that: The bracket (2) is composed of an upper bracket (21), a lower bracket (22), and a bracket support column (23); the lower bracket (22) is mounted on the upper part of the valve body (1) by means of threads; a second sealing gasket (11) is mounted between the lower bracket (22) and the upper part of the valve body (1); the bracket support column (23) is located between the upper bracket (21) and the lower bracket (22); the bracket support column (23) is fixed to the upper bracket (21) and the lower bracket (22) as a whole; the inner hole of the upper bracket (21) is a stepped hole (212); a copper slider (13) is mounted in the stepped hole (212); a first two flat keys (14), the step hole (212) is provided with a flat key groove (213) at a position corresponding to the second flat key (14), the length of the copper slider (13) is less than the large hole depth of the step hole (212) to form a sliding space (214), the second flat key (14) and the flat key groove (213) on the copper slider (13) cooperate with each other to limit the rotation of the copper slider (13), the copper slider (13) performs up and down linear motion in the step hole (212), a limit plate (15) is installed on the top of the step hole (212), and the step hole (212) and the limit plate (15) cooperate with each other to limit the highest position of the copper slider (13) sliding upward; A third internal thread (131) is provided at the inner hole position of the copper slider (13), a first external thread (81) is provided at the upper part of the valve stem (8), the valve stem (8) is mounted on the upper bracket (21) by means of the first external thread (81) and the third internal thread (131) cooperating with each other, a packing (3) is installed at the middle position of the lower bracket (22), a packing gland (7) is installed above the lower bracket (22), and the inner hole of the packing (3) is tightly matched and sealed with the outer diameter of the valve stem (8) under the pressing action of the packing gland (7); The valve body (1) is provided with a flow channel hole (101) between the left channel (10a) and the right channel (10b); the flow channel hole (101) is a circular through hole, and the central axis of the flow channel hole (101) is concentric with the central axis of the valve stem (8); a sealing boss (102) protruding upward is provided above the flow channel hole (101); the inner hole of the flow channel hole (101) is provided with a multi-head internal thread (1013); a limiting truncated cone (83) having a larger outer diameter than the valve stem (8) is provided below the valve stem (8); an upper limit sleeve (91) is installed above the limiting truncated cone (83) via a first flat key (84) on the valve stem (8); a lower locking sleeve (92) is fixedly installed below the upper limit sleeve (91); the lower locking sleeve (92) has a large diameter. A third external thread (824) is provided on the outer circle, a cap (93) is installed on the third external thread (824), a multi-thread external thread (922) is provided on the small outer circle of the lower locking sleeve (92), the valve stem (8) slides in the space (94) between the upper limit sleeve (91) and the lower locking sleeve (92), and the cooperation between the limiting cone (83) and the upper limit sleeve (91) limits the highest point of the valve stem (8) sliding upward, the multi-thread external thread (922) and the multi-thread internal thread (1013) are matched and tightened with each other, the thread lead of the multi-thread external thread (922) is 3 to 8 times the thread lead of the first external thread (81), and the thread tooth depth of the multi-thread external thread (922) is 3 to 8 times the thread tooth depth of the first external thread (81).

8. The plug throttling stop valve according to claim 7, characterized in that: A guiding bevel (921) is provided at the bottom of the lower locking sleeve (92), a guiding bevel (1012) is provided on the multi-start internal thread (1013), a second spring (16) is installed in the sliding space (214), and a first spring (12) is installed in the space (94).

9. A plug throttling stop valve according to claim 7, characterized in that: A guiding bevel (921) is provided at the bottom of the lower locking sleeve (92), a guiding bevel (1012) is provided on the multi-start internal thread (1013), a second spring (16) is installed in the sliding space (214), and a third spring (17) is installed between the upper limit sleeve (91) and the lower bracket (22).

10. A plug throttling stop valve according to any one of claims 7 to 9, characterized in that: The upper limit sleeve (91) and the valve stem (8) are provided with mutually matching threads, the upper limit sleeve (91) is provided with a first keyway (911) milled through, the valve stem (8) is provided with a second keyway (85) at a position corresponding to the first keyway (911), and the first flat key (84) is fitted in the first keyway (911) and the second keyway (85).

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