Hard sealing leakage-proof needle valve

Abstract

The invention relates to the technical field of valves, in particular to a hard sealing leakage-proof needle valve which comprises a valve seat and a valve element, a mounting cavity is formed in the valve seat, a first sealing face is arranged on the inner wall of the mounting cavity and is in a conical surface shape, a liquid inlet and a liquid outlet are formed in the two sides of the valve seat and communicate with the mounting cavity, and the liquid inlet and the liquid outlet communicate with the valve element. The valve element is slidably arranged in the mounting cavity. The first sealing part, the second sealing part, the middle connecting part and the valve seat are arranged, the first cavity is located between the liquid inlet and the liquid outlet, and the pressure in the first cavity is smaller than the fluid pressure at the liquid inlet and larger than the fluid pressure at the liquid outlet, so that fluid at the liquid inlet is more difficult to flow into the liquid outlet through the first cavity, and the sealing effect is better. In addition, the first cavity is formed, so that the pressure difference borne by the sealing face of the valve element is reduced, the radial or axial stress in the valve element is correspondingly reduced, the problem of plastic deformation of the valve element can be effectively solved, and the sealing effect of the needle valve is improved.

Description

Technical Field

[0001] The invention relates to the technical field of valves, in particular to a hard-sealed leak-proof needle valve. Background Art

[0002] A needle valve is a fine-tuning valve used to accurately control fluid flow. It is mainly used in high-pressure fluid delivery. It is named a needle valve because its valve stem head is needle-shaped. Its working principle is to drive the valve core up and down by rotating the operating mechanism, changing the distance between the needle valve core and the valve seat, thereby changing the channel area through which the fluid passes and achieving precise control of the flow rate.

[0003] The sealing of the needle valve is achieved by the conical sealing surface of the valve seat and the conical sealing surface of the valve core fitting each other. When the needle valve is in a sealed state, the pressure of the fluid on the inlet side on the needle valve sealing surface is much greater than the pressure of the fluid on the outlet side on the needle valve sealing surface. Due to the large pressure difference on both sides of the needle valve sealing surface, a large radial or axial stress will be generated inside the valve core, which can easily cause plastic deformation of the valve core and greatly reduce the sealing effect of the needle valve. Summary of the invention

[0004] Based on this, it is necessary to provide a hard-sealed leak-proof needle valve to address the problems existing in the current needle valve, which is used to solve the problem that when the needle valve is in a sealed state, the pressure difference on both sides of the valve core is too large, and the valve core is prone to plastic deformation.

[0005] The above purpose is achieved through the following technical solutions: A hard-sealed leak-proof needle valve comprises: A valve seat, wherein a mounting cavity is formed in the valve seat, a first sealing surface is formed on the inner wall of the mounting cavity, and a liquid inlet and a liquid outlet are formed on both sides of the valve seat, wherein the liquid inlet and the liquid outlet are connected to the mounting cavity; A valve core is slidably disposed in the installation cavity, and the valve core can move along the first axis so that the valve core and the first sealing surface can fit together or move away from each other; The valve core comprises a first sealing portion, a second sealing portion and an intermediate connecting portion, wherein the first sealing portion and the second sealing portion are spaced apart along the first axis, and the intermediate connecting portion is connected between the first sealing portion and the second sealing portion; When the valve core and the first sealing surface are in contact with each other, the first sealing portion, the second sealing portion, the intermediate connecting portion and the first sealing surface circumferentially enclose a closed first cavity, and the pressure in the first cavity is less than the fluid pressure at the liquid inlet and greater than the fluid pressure at the liquid outlet.

[0006] Preferably, the intermediate connecting part is a rubber ring, both ends of the rubber ring are fixedly connected to the first sealing part and the second sealing part respectively, and the rubber ring, the first sealing part and the second sealing part enclose a closed second cavity, and the preset pressure in the second cavity is less than the fluid pressure at the liquid inlet and greater than the fluid pressure at the liquid outlet.

[0007] Preferably, a support assembly is provided in the first sealing portion, and the support assembly has an extended state and a retracted state; When in the extended state, the middle connecting portion is surrounded by the supporting assembly to the inside thereof; When in the retracted state, the intermediate connecting portion is exposed from the supporting assembly.

[0008] Preferably, the support assembly comprises a sleeve and a power unit, the sleeve is slidably disposed in the first sealing portion, the sleeve axis coincides with the first axis, the power unit is disposed inside the first sealing portion, and the power unit is used to drive the sleeve to move along the first axis; When the support assembly is in the extended state, the middle connecting portion is surrounded by the sleeve to the inside thereof; When the support assembly is in a contracted state, the sleeve is retracted into the first sealing portion, and the middle connecting portion is exposed from the sleeve.

[0009] Preferably, the power unit comprises a first elastic member, a first liquid inlet hole, a first liquid outlet hole, a second liquid inlet hole and a second liquid outlet hole, the first elastic member is connected between the sleeve and the first sealing portion, the first liquid inlet hole is provided on one circumferential side of the sleeve, and the first liquid outlet hole is provided on the other circumferential side of the sleeve; The second liquid inlet hole is opened on one side of the installation cavity, and the second liquid inlet hole is connected with the liquid inlet port; The second liquid outlet hole is opened on the other side of the installation cavity, and the second liquid outlet hole is connected with the liquid outlet port; When the first liquid inlet hole and the second liquid inlet hole are connected, the fluid flows into the sleeve through the first liquid inlet hole and the second liquid inlet hole to drive the sleeve to move along the first axis in a direction away from the second sealing portion; When the first liquid outlet hole and the second liquid outlet hole are connected, the fluid flows out from the inside of the sleeve through the first liquid outlet hole and the second liquid outlet hole, and under the action of the first elastic member, the sleeve moves along the first axis toward the second sealing portion.

[0010] Preferably, a one-way valve is provided in the first liquid outlet hole, and the one-way valve restricts the fluid in the second liquid outlet hole from flowing into the first liquid outlet hole.

[0011] Preferably, a hard-sealed leak-proof needle valve further includes a driving assembly, and the driving assembly is used to drive the first sealing part to move along the first axis.

[0012] Preferably, the drive assembly includes a valve stem, a second elastic member and an intermediate cylinder, the valve stem is coaxially fixedly connected to the upper end of the first sealing portion, the intermediate cylinder is threadedly connected to the valve seat, the axis of the intermediate cylinder coincides with the first axis, the intermediate cylinder and the valve stem are mutually sleeved, and the intermediate cylinder and the valve stem can move synchronously along the first axis and rotate relative to each other around the first axis, the second elastic member is sleeved on the outside of the valve stem and the two ends of the second elastic member are respectively fixedly connected to the intermediate cylinder and the first sealing portion.

[0013] Preferably, a hard-sealed leak-proof needle valve further includes a water inlet connector, which is threadedly connected to the liquid inlet.

[0014] Preferably, a hard-sealed leak-proof needle valve further includes a water outlet connector, which is threadedly connected to the liquid outlet.

[0015] The beneficial effects of the present invention are: The present invention is provided with a first sealing part, a second sealing part, an intermediate connecting part and a valve seat. The first sealing part, the second sealing part, the intermediate connecting part and the first sealing surface circumferentially surround a closed first cavity. Since the first cavity is between the liquid inlet and the liquid outlet, and the pressure in the first cavity is less than the fluid pressure at the liquid inlet and greater than the fluid pressure at the liquid outlet, the fluid at the liquid inlet is less likely to flow into the liquid outlet through the first cavity, and the leakage prevention effect is better. In addition, the provision of the first cavity also reduces the pressure difference on the sealing surface of the valve core, and the radial or axial stress inside the valve core is correspondingly reduced. Therefore, the problem of plastic deformation of the valve core can be effectively improved, which is beneficial to improving the sealing effect of the needle valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an overall schematic diagram of the present invention; Figure 2 It is a front view of the present invention; Figure 3 is a side view of the present invention; Figure 4 for Figure 3 Middle AA section view; Figure 5 This is a schematic diagram of the valve closed state in the present invention; Figure 6 It is a schematic diagram of the state where the first sealing surface is blocked by foreign matter in the present invention; Figure 7 This is a schematic diagram of the valve opening state in the present invention; Figure 8 It is an exploded view of the valve core in the present invention; Fig. 9 for Figure 4 Schematic diagram of the enlarged structure at B in the middle; Fig.10 for Figure 5 Schematic diagram of the enlarged structure at C in the middle; Fig.11 for Figure 6 Schematic diagram of the enlarged structure at D in the middle; Fig.12 for Figure 7 Schematic diagram of the enlarged structure at E in the middle.

[0017] in: 100, valve seat; 110, installation cavity; 111, first sealing surface; 120, liquid inlet; 130, liquid outlet; 200, valve core; 210, first sealing portion; 220, second sealing portion; 230, intermediate connecting portion; 310, first cavity; 320, second cavity; 400, support assembly; 410, sleeve; 420, power unit; 421, first elastic member; 422, first liquid inlet hole; 423, first liquid outlet hole; 424, second liquid inlet hole; 425, second liquid outlet hole; 430, one-way valve; 500, valve stem; 510, second elastic member; 600, intermediate cylinder; 610, screw; 620, hand wheel; 630, third liquid inlet hole; 640, third liquid outlet hole; 710, water inlet connector; 720, water outlet connector. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0020] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] like Figures 1 to 12 As shown, a hard-sealed leak-proof needle valve includes a valve seat 100 and a valve core 200. An installation cavity 110 is provided in the valve seat 100. A first sealing surface 111 is provided on the inner wall of the installation cavity 110. The first sealing surface 111 is conical. A liquid inlet 120 and a liquid outlet 130 are provided on both sides of the valve seat 100. The liquid inlet 120 and the liquid outlet 130 are connected to the installation cavity 110. The valve core 200 is slidably arranged in the installation cavity 110. The valve core 200 is needle-shaped, and the valve core 200 can move along a first axis so that the valve core 200 and the first sealing surface 111 can fit together or move away from each other. Specifically, the first axis is the axis of the valve core 200. The valve core 200 includes a first sealing portion 210, a second sealing portion 220 and an intermediate connecting portion 230. The first The sealing portion 210 and the second sealing portion 220 are spaced apart along the first axis, and both the first sealing portion 210 and the second sealing portion 220 are conical, and both the first sealing portion 210 and the second sealing portion 220 are made of hard material, and the small end diameter of the first sealing portion 210 is larger than the large end diameter of the second sealing portion 220, and the intermediate connecting portion 230 is connected between the first sealing portion 210 and the second sealing portion 220. When the valve core 200 and the first sealing surface 111 are in contact with each other, the first sealing portion 210, the second sealing portion 220, the intermediate connecting portion 230 and the first sealing surface 111 circumferentially enclose a closed first cavity 310, and the pressure in the first cavity 310 is less than the fluid pressure at the liquid inlet 120 and greater than the fluid pressure at the liquid outlet 130.

[0022] In the valve open state, the fluid enters the mounting cavity 110 of the needle valve from the liquid inlet 120 , then flows out from the mounting cavity 110 to the liquid outlet 130 , and finally flows out of the needle valve.

[0023] In the valve closing state, the fluid stops directional flow from the liquid inlet 120 to the liquid outlet 130. At this time, the valve core 200 and the first sealing surface 111 are in contact with each other. Specifically, the first sealing portion 210, the second sealing portion 220, the intermediate connecting portion 230 and the first sealing surface 111 circumferentially enclose a closed first cavity 310. Since the first cavity 310 is between the liquid inlet 120 and the liquid outlet 130, and the pressure in the first cavity 310 is less than the fluid pressure at the liquid inlet 120 and greater than the fluid pressure at the liquid outlet 130, the fluid at the liquid inlet 120 is less likely to flow into the liquid outlet 130 through the first cavity 310, and the leakage prevention effect is better. In addition, the provision of the first cavity 310 also reduces the pressure difference on the sealing surface of the valve core 200, and the radial or axial stress inside the valve core 200 is correspondingly reduced. Therefore, the problem of plastic deformation of the valve core 200 can be effectively improved, which is beneficial to improving the sealing effect of the needle valve.

[0024] In this embodiment, if Figure 9-10As shown, the middle connecting part 230 is a rubber ring, and the two ends of the rubber ring are fixedly connected to the first sealing part 210 and the second sealing part 220 respectively, and the rubber ring, the first sealing part 210 and the second sealing part 220 enclose a sealed second cavity 320, and the preset pressure in the second cavity 320 is less than the fluid pressure at the liquid inlet 120 and greater than the fluid pressure at the liquid outlet 130.

[0025] In the valve closing state, the first sealing portion 210 and the second sealing portion 220 are both in contact with the first sealing surface 111. At the same time, the first sealing portion 210, the second sealing portion 220, the intermediate connecting portion 230 and the mounting cavity 110 circumferentially enclose the first cavity 310. At the same time, the first sealing portion 210, the second sealing portion 220 and the intermediate connecting portion 230 circumferentially enclose the closed second cavity 320, and the pressure value in the second cavity 320 is between the fluid pressure at the liquid inlet 120 and the fluid pressure at the mounting cavity 110. At this time, if the pressure value in the first cavity 310 is less than the pressure value in the second cavity 320, the intermediate connecting portion 230 expands and arches outward, thereby increasing the fluid pressure in the first cavity 310 to a value greater than the fluid pressure at the liquid inlet 120 and less than the fluid pressure at the liquid outlet 130.

[0026] In this embodiment, if Figure 7 As shown, a support assembly 400 is provided in the first sealing portion 210, and the support assembly 400 has an extended state and a retracted state. When the support assembly 400 is in the extended state, the intermediate connecting portion 230 is surrounded by the support assembly 400 to the inside thereof, and when the support assembly 400 is in the retracted state, the intermediate connecting portion 230 is exposed from the support assembly 400.

[0027] In the valve open state, the valve core 200 is not in contact with the first sealing surface 111. At this time, the support assembly 400 is in an extended state, and the intermediate connection part 230 is surrounded by the support assembly 400. Therefore, the intermediate connection part 230 is protected by the support assembly 400 inside, and will not be damaged due to direct contact between the intermediate connection part 230 and the fluid.

[0028] In the valve closing state, the support assembly 400 is in a contracted state, and the intermediate connection portion 230 is exposed from the inside of the support assembly 400. At this time, the intermediate connection portion 230 expands outward so that the fluid pressure value in the first cavity 310 increases to a value between the fluid pressure at the liquid inlet 120 and the fluid pressure at the liquid outlet 130.

[0029] It can be understood that in the valve closing state, if foreign matter or impurities remain at the position corresponding to the first sealing surface 111 and the second sealing portion 220, the second sealing portion 220 will not be able to continue to move downward before moving to the preset position, and the first sealing portion 210 and the second sealing portion 220 are flexibly connected by the intermediate connecting portion 230, so the first sealing portion 210 will still move downward, so the distance between the first sealing portion 210 and the second sealing portion 220 will gradually decrease. At this time, the intermediate connecting portion 230 is compressed by force, and the intermediate connecting portion 230 expands outward so that the outer peripheral surface of the intermediate connecting portion 230 fits with the first sealing surface 111, thereby forming a temporary sealing portion that can replace the second sealing portion 220, so that the connection between the first sealing surface 111 can still maintain two seals to prevent leakage at the sealing portion of the needle valve.

[0030] In this embodiment, if Figure 7-10 As shown, the support assembly 400 includes a sleeve 410 and a power unit 420. The sleeve 410 is slidably disposed inside the first sealing portion 210. The axis of the sleeve 410 coincides with the first axis. The power unit 420 is also disposed inside the first sealing portion 210. The power unit 420 is used to drive the sleeve 410 to move along the first axis. When the support assembly 400 is in an extended state, the intermediate connecting portion 230 is surrounded by the sleeve 410 to the inside. When the support assembly 400 is in a retracted state, the sleeve 410 is retracted to the inside of the first sealing portion 210, and the intermediate connecting portion 230 is exposed from the sleeve 410.

[0031] In the valve open state, the power unit 420 drives the sleeve 410 to move along the first axis in the direction away from the second sealing part 220, so that the sleeve 410 contracts to the inside of the first sealing part 210. At this time, the intermediate connecting part 230 is exposed from the sleeve 410, so that when the first sealing part 210 and the second sealing part 220 are in contact with the first sealing surface 111, the intermediate connecting part 230 can expand outward, so that the pressure value in the first cavity 310 increases to between the fluid pressure at the liquid inlet 120 and the fluid pressure at the liquid outlet 130.

[0032] In the valve closing state, the power unit 420 drives the sleeve 410 to move along the first axis toward the second sealing part 220, so that the sleeve 410 extends from the inside of the first sealing part 210. At this time, the intermediate connecting part 230 is surrounded by the sleeve 410 to the inside, thereby preventing the intermediate connecting part 230 from contacting with the fluid during the fluid transportation process and being damaged.

[0033] In this embodiment, if Figure 9-12As shown, the power unit 420 includes a first elastic member 421, a first liquid inlet hole 422, a first liquid outlet hole 423, a second liquid inlet hole 424 and a second liquid outlet hole 425. The first elastic member 421 is connected between the sleeve 410 and the first sealing portion 210. Specifically, the first elastic member 421 is a compression spring. The first liquid inlet hole 422 is provided on one circumferential side of the sleeve 410. The first liquid outlet hole 423 is provided on the other circumferential side of the sleeve 410. The second liquid inlet hole 424 is provided on one side of the installation cavity 110. The second liquid inlet hole 424 is connected to the liquid inlet port 120. The second liquid outlet hole 425 is provided on the installation cavity 110. On the other side, the second liquid outlet hole 425 is connected with the liquid outlet port 130. When the first liquid inlet hole 422 and the second liquid inlet hole 424 are connected, the fluid flows into the sleeve 410 through the first liquid inlet hole 422 and the second liquid inlet hole 424 to drive the sleeve 410 to move along the first axis in a direction away from the second sealing portion 220. When the first liquid outlet hole 423 and the second liquid outlet hole 425 are connected, the fluid flows out from the sleeve 410 through the first liquid outlet hole 423 and the second liquid outlet hole 425. Under the action of the first elastic member 421, the sleeve 410 moves along the first axis in a direction close to the second sealing portion 220.

[0034] In the initial valve open state, the first liquid inlet hole 422 and the second liquid inlet hole 424 are in a disconnected state. At this time, the fluid will not enter the interior of the sleeve 410. Under the action of the first elastic member 421, the sleeve 410 is exposed from the interior of the first sealing portion 210. At this time, the intermediate connecting portion 230 is surrounded by the sleeve 410 to its interior. The intermediate connecting portion 230 will not directly contact the fluid, thereby preventing the intermediate connecting portion 230 from being damaged by contact with the fluid during the fluid transportation process.

[0035] When the valve needs to be closed, the valve core 200 moves downward along the first axis. When the valve core 200 moves to the point where the first liquid inlet hole 422 is connected to the second liquid inlet hole 424, the fluid enters the cavity between the sleeve 410 and the first sealing portion 210 through the first liquid inlet hole 422 and the second liquid inlet hole 424. At this time, the fluid pushes the sleeve 410 to move upward along the first axis, and the first elastic member 421 is gradually compressed. At this time, the sleeve 410 shrinks to the inside of the first sealing portion 210, and the middle connecting portion 230 is exposed from the enclosure of the sleeve 410.

[0036] When the valve needs to be opened, the valve core 200 moves upward along the first axis. When the valve core 200 moves to the point where the first liquid outlet 423 is connected to the second liquid outlet 425, the fluid in the cavity between the sleeve 410 and the first sealing portion 210 flows out through the first liquid outlet 423 and the second liquid outlet 425. At this time, the pressure of the fluid on the sleeve 410 gradually decreases, and the compression amount of the first elastic member 421 gradually decreases. The first elastic member 421 pushes the sleeve 410 to gradually emerge from the inside of the first sealing portion 210. At this time, the intermediate connecting portion 230 is surrounded by the sleeve 410 to its interior.

[0037] It is understandable that when closing the valve, if there are foreign objects or impurities at the position corresponding to the liquid inlet 120 and the second sealing part 220, the second sealing part 220 will stop moving downward before moving to the preset position, while the first sealing part 210 is still moving downward, so the distance between the first sealing part 210 and the second sealing part 220 will gradually decrease, so that the middle connecting part 230 is compressed by force, and the middle connecting part 230 expands outward so that the outer peripheral surface of the middle connecting part 230 fits with the liquid inlet 120, thereby forming a temporary seal that can replace the second sealing part 220, so that two seals can still be maintained at the connection of the liquid inlet 120 to prevent leakage at the valve seal.

[0038] In this embodiment, if Figure 9-12 As shown, a one-way valve 430 is provided in the first liquid outlet hole 423 , and the one-way valve 430 restricts the fluid in the second liquid outlet hole 425 from flowing into the first liquid outlet hole 423 .

[0039] The one-way valve 430 is provided to limit the backflow of the fluid in the second liquid outlet 425 into the first liquid outlet 423 in the closed state, thereby limiting the backflow of the fluid through the first liquid outlet 423 into the area between the sleeve 410 and the first sealing portion 210, so as to limit the upward movement of the sleeve 410 in the open state.

[0040] In this embodiment, if Fig. 9 As shown, a hard-sealed anti-leakage needle valve further includes a driving assembly, which is used to drive the first sealing part 210 to move along the first axis.

[0041] When the valve core 200 needs to move along the first axis, the driving assembly is started, and the driving assembly drives the valve core 200 to move along the first axis, so that the valve can be opened or closed.

[0042] In this embodiment, if Figure 9-12As shown, the drive assembly includes a valve stem 500, a second elastic member 510, an intermediate cylinder 600 and a screw 610. The valve stem 500 is coaxially fixedly connected to the upper end of the first sealing portion 210. The screw 610 is threadedly connected to the valve seat 100. The screw 610 and the intermediate cylinder 600 are mutually sleeved, and the screw 610 and the intermediate cylinder 600 can move synchronously along the first axis and rotate relative to each other. The axis of the intermediate cylinder 600 coincides with the first axis. The lower part of the intermediate cylinder 600 is mutually sleeved with the valve stem 500, and the intermediate cylinder 600 and the valve stem 500 can move synchronously along the first axis and rotate relative to each other around the first axis. The second elastic member 510 is a compression spring. The second elastic member 510 is sleeved on the outside of the valve stem 500, and the two ends of the second elastic member 510 are respectively fixedly connected to the intermediate cylinder 600 and the first sealing portion 210.

[0043] When closing the valve, the staff rotates the screw 610, and the screw 610 drives the intermediate cylinder 600 to move downward along the first axis through threaded cooperation. The intermediate cylinder 600 pushes the first sealing part 210 to move downward through the second elastic part 510, and the first sealing part 210 drives the second sealing part 220 to move downward through the intermediate connecting part 230. When the first sealing part 210 fits with the first sealing surface 111, as the intermediate cylinder 600 continues to move downward, the second elastic part 510 is gradually compressed. At this time, the valve core 200 is tightly attached to the first sealing surface 111. In this way, it is easy to adjust the sealing force between the first sealing surface 111 and the valve core 200 without worrying about the sealing force between the valve core 200 and the first sealing surface 111 being too large or the valve core 200 and the first sealing surface 111 not being able to fit tightly and seal.

[0044] It is understandable that if there is foreign matter remaining on the first sealing surface 111, then when the valve core 200 is closed, the second sealing portion 220 cannot fit tightly with the first sealing surface 111. At this time, the fluid will pass through the gap between the second sealing portion 220 and the first sealing surface 111 at an extremely fast flow rate and flush the foreign matter remaining on the first sealing surface 111. As the amount of foreign matter remaining on the first sealing surface 111 gradually decreases, under the elastic action of the second elastic member 510, the first sealing portion 210 will gradually move downward, so that after the foreign matter is flushed away, the first sealing portion 210 can drive the second sealing portion 220 to gradually move downward through the intermediate connecting portion 230, so that the second sealing portion 220 fits with the first sealing surface 111 again.

[0045] It should be further explained that a third liquid inlet hole 630 is provided on one side of the lower portion of the intermediate tube 600, and a third liquid outlet hole 640 is provided on the other side of the lower portion of the intermediate tube 600. In the valve open state, the first liquid inlet hole 422 and the third liquid inlet hole 630 are vertically offset, and similarly, the first liquid outlet hole 423 and the third liquid outlet hole 640 are vertically offset, and at the same time, the second liquid inlet hole 424 and the third liquid inlet hole 630 are mutually offset, and the third liquid outlet hole 640 and the second liquid outlet hole 425 are mutually offset, so that the fluid will not enter the space area between the first sealing portion 210 and the sleeve 410. When the intermediate cylinder 600 drives the first sealing part 210 to move downward through the second elastic part 510 until the first sealing part 210 and the second sealing part 220 are both in contact with the first sealing surface 111, the second liquid inlet hole 424, the third liquid inlet hole 630 and the first liquid inlet hole 422 are connected. At this time, the fluid can enter the space area between the first sealing part 210 and the sleeve 410, and push the sleeve 410 upward.

[0046] When the valve switches from a closed state to an open state, the intermediate cylinder 600 drives the first sealing portion 210 to move upward through the first elastic member 421. When the first liquid outlet hole 423, the second liquid outlet hole 425 and the third liquid outlet hole 640 are connected, the fluid in the space between the first sealing portion 210 and the sleeve 410 is discharged outward through the first liquid outlet hole 423, the second liquid outlet hole 425 and the third liquid outlet hole 640. At this time, under the action of the elastic force of the first elastic member 421, the sleeve 410 moves downward along the first axis until the sleeve 410 is exposed from the lower part of the first sealing portion 210.

[0047] It should also be noted that, in order to rotate the screw rod 610 , a hand wheel 620 is fixedly connected to the upper end of the screw rod 610 , so that the staff can rotate the screw rod 610 through the hand wheel 620 .

[0048] In this embodiment, if Figure 4 As shown, a hard-sealed leak-proof needle valve also includes a water inlet connector 710, which is threadedly connected to the liquid inlet 120. The water inlet connector 710 is provided to facilitate the connection of a water inlet pipe.

[0049] In this embodiment, if Figure 4 As shown, a hard-sealed leak-proof needle valve also includes a water outlet connector 720, which is threadedly connected to the liquid outlet 130. The water outlet connector 720 is provided to facilitate connection to a water outlet pipe.

[0050] In this embodiment, in order to improve the corrosion resistance of the needle valve, specifically, the cavity wall of the installation cavity 110 is plated with an anti-corrosion material, such as nickel alloy, to improve the corrosion resistance of the needle valve.

[0051] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A hard-sealed leak-proof needle valve, characterized in that: include: A valve seat, wherein a mounting cavity is formed in the valve seat, a first sealing surface is formed on the inner wall of the mounting cavity, and a liquid inlet and a liquid outlet are formed on both sides of the valve seat, wherein the liquid inlet and the liquid outlet are connected to the mounting cavity; A valve core is slidably disposed in the installation cavity, and the valve core can move along the first axis so that the valve core and the first sealing surface can fit together or move away from each other; The valve core comprises a first sealing portion, a second sealing portion and an intermediate connecting portion, wherein the first sealing portion and the second sealing portion are spaced apart along the first axis, and the intermediate connecting portion is connected between the first sealing portion and the second sealing portion; When the valve core and the first sealing surface are in contact with each other, the first sealing portion, the second sealing portion, the intermediate connecting portion and the first sealing surface circumferentially enclose a closed first cavity, and the pressure in the first cavity is less than the fluid pressure at the liquid inlet and greater than the fluid pressure at the liquid outlet.

2. A hard-sealed leak-proof needle valve according to claim 1, characterized in that: The middle connecting part is a rubber ring, and both ends of the rubber ring are fixedly connected to the first sealing part and the second sealing part respectively, and the rubber ring, the first sealing part and the second sealing part enclose a closed second cavity, and the preset pressure in the second cavity is less than the fluid pressure at the liquid inlet and greater than the fluid pressure at the liquid outlet.

3. A hard-sealed leak-proof needle valve according to claim 2, characterized in that: A support assembly is provided in the first sealing portion, and the support assembly has an extended state and a retracted state; When in the extended state, the middle connecting portion is surrounded by the supporting assembly to the inside thereof; When in the retracted state, the intermediate connecting portion is exposed from the supporting assembly.

4. A hard-sealed leak-proof needle valve according to claim 3, characterized in that: The support assembly includes a sleeve and a power unit, the sleeve is slidably arranged in the first sealing part, the sleeve axis coincides with the first axis, the power unit is arranged inside the first sealing part, and the power unit is used to drive the sleeve to move along the first axis; When the support assembly is in the extended state, the middle connecting portion is surrounded by the sleeve to the inside thereof; When the support assembly is in a contracted state, the sleeve is retracted into the first sealing portion, and the middle connecting portion is exposed from the sleeve.

5. A hard-sealed leak-proof needle valve according to claim 4, characterized in that: The power unit comprises a first elastic member, a first liquid inlet hole, a first liquid outlet hole, a second liquid inlet hole and a second liquid outlet hole, the first elastic member is connected between the sleeve and the first sealing portion, the first liquid inlet hole is provided on one circumferential side of the sleeve, and the first liquid outlet hole is provided on the other circumferential side of the sleeve; The second liquid inlet hole is opened on one side of the installation cavity, and the second liquid inlet hole is connected with the liquid inlet port; The second liquid outlet hole is opened on the other side of the installation cavity, and the second liquid outlet hole is connected with the liquid outlet port; When the first liquid inlet hole and the second liquid inlet hole are connected, the fluid flows into the sleeve through the first liquid inlet hole and the second liquid inlet hole to drive the sleeve to move along the first axis in a direction away from the second sealing portion; When the first liquid outlet hole and the second liquid outlet hole are connected, the fluid flows out from the inside of the sleeve through the first liquid outlet hole and the second liquid outlet hole, and under the action of the first elastic member, the sleeve moves along the first axis toward the second sealing portion.

6. A hard-sealed leak-proof needle valve according to claim 5, characterized in that: A one-way valve is arranged in the first liquid outlet hole, and the one-way valve restricts the fluid in the second liquid outlet hole from flowing into the first liquid outlet hole.

7. A hard-sealed leak-proof needle valve according to claim 1, characterized in that: Also included is a driving assembly for driving the first sealing portion to move along the first axis.

8. A hard-sealed leak-proof needle valve according to claim 7, characterized in that: The driving assembly includes a valve stem, a second elastic member and an intermediate cylinder. The valve stem is coaxially fixedly connected to the upper end of the first sealing portion. The intermediate cylinder is threadedly connected to the valve seat. The axis of the intermediate cylinder coincides with the first axis. The intermediate cylinder and the valve stem are sleeved with each other, and the intermediate cylinder and the valve stem can move synchronously along the first axis and rotate relative to each other around the first axis. The second elastic member is sleeved on the outside of the valve stem and the two ends of the second elastic member are respectively fixedly connected to the intermediate cylinder and the first sealing portion.

9. A hard-sealed leak-proof needle valve according to claim 1, characterized in that: It also includes a water inlet joint, which is threadedly connected in the liquid inlet.

10. A hard-sealed leak-proof needle valve according to claim 1, characterized in that: It also includes a water outlet joint, which is threadedly connected in the liquid outlet.

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