A type of oil and gas recovery refueling nozzle

Abstract

This utility model discloses an oil and gas recovery refueling nozzle. An oil outlet pipe is located at the front end of the nozzle body, and an internal coaxial air passage pipe forms a ring-shaped oil passage. A valve assembly is located at the front end of the air passage: a fixed plate, a movable plate, and a return spring. The fixed plate and the movable plate each have a staggered perforation array. When the negative pressure pump is working, the movable plate retracts under the pressure difference, connecting the perforation array; when the pump stops, it closes and seals under the action of the spring. An air bladder is connected in parallel between the air passage and the negative pressure pump to buffer pulsations, and the return spring is covered with an oil-proof film. This structure maintains the refueling function while achieving rapid closure of the front end upon nozzle removal, suppressing the escape of residual oil and gas, and reducing droplet entrainment and product loss through perforation array throttling, thereby improving recovery stability and sealing reliability.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas recovery technology, specifically to an oil and gas recovery refueling nozzle. Background Technology

[0002] Gasoline and other light petroleum products are prone to volatility during refueling and storage, and the resulting volatile organic compounds can adversely affect the environment and human health. Most existing gas stations employ secondary vapor recovery systems, which use a return gas channel within the fuel nozzle connected to a recovery unit to draw the vapors expelled from the vehicle's fuel tank back to a storage tank or treatment device. Current fuel nozzles are typically coaxial, with the fuel line handling refueling and the gas line handling vapor recovery. Their operation largely depends on check valves, throttling devices, or negative pressure-driven valves located inside or upstream of the nozzle. However, the following problems still exist in actual use: when refueling is completed or the negative pressure pump stops and the refueling nozzle is pulled out of the fuel tank, a small amount of oil and gas often remains at the front end of the nozzle and in the front section of the air path cavity. Due to the lack of an immediate closing structure at the very front of the nozzle, the gas diffuses into the environment the moment the nozzle is pulled out. Based on the above problems, there is an urgent need for an end valve mechanism with a simple structure that can be passively opened when negative pressure is present and can automatically close at the front end of the nozzle the moment the negative pressure pump is turned off or the nozzle is pulled out, so as to achieve immediate sealing and stable recovery of residual oil and gas, in order to meet the more stringent emission control requirements for volatile organic compounds. Utility Model Content

[0003] This invention aims to solve the problem of residual oil and gas at the nozzle tip of traditional oil and gas recovery refueling nozzles escaping and polluting the environment when the nozzle is pulled out immediately after oil and gas recovery is completed.

[0004] The technical solution of this utility model is as follows: An oil and gas recovery refueling gun includes: a gun body with an oil chamber inside, the oil chamber being connected to an oil delivery pipe; a trigger on the gun body; an oil outlet pipe fixedly connected to the front end of the gun body and connected to the oil chamber; an air passage pipe located inside the oil outlet pipe and coaxially arranged with the oil outlet pipe, forming an annular oil passage between the air passage pipe and the oil outlet pipe, the front end of the air passage pipe extending to the oil outlet, and the other end connected to a negative pressure pump via a hose; and a valve assembly located at the front end of the air passage pipe for controlling the closing and opening of the air passage pipe.

[0005] Furthermore, according to the aforementioned oil and gas recovery refueling nozzle, the valve assembly includes a fixed plate, a movable plate, and a return spring; the fixed plate is fixedly mounted on the front end of the gas pipeline, and a plurality of sliding grooves are provided on the inner wall of the gas pipeline near the fixed plate; a plurality of protrusions are provided on the movable plate, and the protrusions cooperate with the sliding grooves; one end of the return spring abuts against the movable plate, and the other end abuts against the spring seat, which is fixedly mounted inside the gas pipeline to support the return spring and guide it.

[0006] Preferably, according to the aforementioned oil and gas recovery refueling gun, a plurality of first vent holes are provided on the fixed plate, and a plurality of second vent holes are provided on the movable plate; the first vent holes and the second vent holes are staggered with each other, and the air passage is closed when the movable plate and the fixed plate are in the contact position, and the air passage is opened when the movable plate and the fixed plate are separated.

[0007] Preferably, in some embodiments, the return spring sleeve of the aforementioned oil and gas recovery refueling nozzle is protected with an oil-proof film.

[0008] Preferably, according to the aforementioned oil and gas recovery refueling nozzle, an air bladder is provided between the gas pipeline and the negative pressure pump.

[0009] Preferably, according to the aforementioned oil and gas recovery refueling gun, when the negative pressure pump is working, the movable plate overcomes the reset spring to separate and connect the vent holes; the first vent hole and the second vent hole together constitute a throttling structure to limit the flow rate entering the gas path during negative pressure recovery.

[0010] The beneficial effects of this utility model are as follows: by setting a fixed plate and a movable plate with staggered holes at the front end of the air circuit and pre-tightening it with a return spring, it achieves passive opening when negative pressure exists and immediate closing when the pump stops. This directly isolates the residual cavity at the front end of the nozzle at the moment of refueling or nozzle removal, significantly suppressing oil and gas escape and reducing VOC emissions. The throttling and flow-limiting structure formed by the first and second vent holes and the air circuit port, combined with the stroke limit, makes the opening process gentle and reduces product loss. The air bladder connected in parallel on the air circuit between the hose and the negative pressure pump buffers and stabilizes the negative pressure pulsation, reduces valve vibration and noise, and improves opening and closing stability and sealing reliability. The guide groove and spring seat ensure axial guidance of the movable plate, reduce friction and jamming risks, and maintain surface sealing and repeatability accuracy. The anti-oil film on the outside of the return spring isolates the spring from the corrosion and adhesion of oil vapor and sludge, maintains long-term stability of the return force, and extends service life. The coaxial arrangement of the air circuit inside the oil outlet pipe makes the structure compact and easy to be compatible with and assembled with existing refueling nozzle platforms. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of an oil and gas recovery refueling nozzle provided in an embodiment of this application; Figure 2 A side view of an oil and gas recovery refueling nozzle provided in an embodiment of this application; Figure 3 for Figure 2 A cross-sectional schematic diagram of an oil and gas recovery refueling nozzle valve assembly structure provided in the embodiments of this application; Attached icon numbers:1. Gun body; 11. Trigger; 12. Oil supply pipe; 13. Oil outlet pipe; 14. Gas pipe; 2. Valve assembly; 21. Fixing plate; 211. First vent hole; 22. Movable plate; 221. Second vent hole; 23. Return spring; 24. Protrusion; 25. Slide groove; 26. Spring seat; 3. Negative pressure pump; 31. Airbag; 32. Hose. Detailed Implementation

[0012] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application.

[0013] An oil and gas recovery refueling nozzle includes: a nozzle body 1 with an oil chamber inside, the oil chamber being connected to an oil delivery pipe 12; a trigger 11 mounted on the nozzle body 1; an oil outlet pipe 13 fixedly connected to the front end of the nozzle body 1 and connected to the oil chamber; an air passage pipe 14 located inside the oil outlet pipe 13, coaxially arranged with the oil outlet pipe 13, forming an annular oil passage between the air passage pipe 14 and the oil outlet pipe 13, the front end of the air passage pipe 14 extending to the oil outlet, and the other end connected to a negative pressure pump 3 via a hose 32; and a valve assembly 2 located at the front end of the air passage pipe 14 for controlling the opening and closing of the air passage pipe 14.

[0014] This invention aims to solve the problem that when a traditional oil and gas recovery refueling nozzle is pulled out after oil and gas recovery is completed, the residual oil and gas at the front end of the nozzle cannot be sealed off in time, thus escaping and polluting the environment.

[0015] The beneficial effects of this utility model are as follows: A valve assembly 2 with staggered holes, consisting of a fixed plate 21 and a movable plate 22, is installed at the front end of the air path and pre-tightened by a return spring 23. It passively opens when negative pressure is present and closes immediately upon pump stoppage, thus directly isolating the residual cavity at the nozzle tip at the moment of refueling or nozzle removal, suppressing oil and gas escape and reducing VOC emissions; the throttling and flow-limiting structure formed by the first vent 211, the second vent 221, and the air path opening, combined with stroke limitation, ensures a gentle opening process and reduces product loss; the air path between the hose 32 and the negative pressure pump 3... The upper parallel airbag 31 buffers and stabilizes negative pressure pulsation, reduces valve vibration and noise, and improves opening and closing stability and sealing reliability; the slide groove 25 and the protrusion 24 ensure the axial guidance of the movable plate 22, reduce friction and jamming risks, and maintain surface sealing and repeatability accuracy; the oil-proof film on the outside of the return spring 23 isolates the spring from the corrosion and adhesion of oil vapor and sludge, maintains long-term stability of the return force and extends service life; the air pipeline 14 is coaxially arranged inside the oil outlet pipeline 13 to make the structure compact and easy to be compatible with and assembled with existing refueling gun platforms.

[0016] This invention features an oil chamber located inside the gun body 1, which is connected to the fuel delivery pipe 12. A trigger 11 is mounted on the gun body 1 and used to drive the main valve, allowing the oil chamber to be connected to or closed by the front flow path. The fuel outlet pipe 13 is fixedly connected to the front end of the gun body 1 and connected to the oil chamber. An air passage pipe 14 is arranged inside the fuel outlet pipe 13 and is coaxially aligned with it, forming an annular oil passage. The front end of the air passage pipe 14 extends to the fuel outlet, and the rear end is connected to an external negative pressure pump 3 via a hose 32. A valve assembly 2 is provided at the front end of the air passage pipe 14 for selectively closing or opening the air passage during use. "Coaxial alignment" means that the air passage pipe 14 and the fuel outlet pipe 13 share a geometric central axis; "annular oil passage" means that the annular fluid passage between them is used to transport fuel; "fuel outlet" refers to the front end of the fuel outlet pipe 13 located within the vehicle's fuel tank inlet; "connected" means that a continuous fluid flow can be achieved; "closed" and "open" refer to the fluid blocking or releasing states formed by the valve assembly 2 at the front end of the air passage.

[0017] Specifically, the opening and closing of valve assembly 2 is closely related to the opening and closing of negative pressure pump 3. When the fuel outlet is inserted into the vehicle's fuel tank inlet, the operator pulls trigger 11, the main valve opens, and fuel enters the annular fuel passage through the fuel chamber and is output to the fuel tank through the fuel outlet. During this stage, if no negative pressure is applied or the opening threshold is not reached, valve assembly 2 remains closed, and the front end of the air passage is blocked. After refueling, the negative pressure pump 3 is started, and a negative pressure is formed at the rear end of the air passage. Valve assembly 2 opens as the negative pressure is formed to recover fuel vapors. When the nozzle is removed, valve assembly 2 closes as the negative pressure pump 3 closes, and the remaining cavity at the front end of the nozzle is directly isolated, making it difficult for fuel vapors to escape.

[0018] In some embodiments, the valve assembly 2 includes a fixed plate 21, a movable plate 22, and a return spring 23; the fixed plate 21 is fixedly disposed at the front end of the air passage 14, and a plurality of sliding grooves 25 are provided on the inner wall of the air passage 14 near the fixed plate 21; a plurality of protrusions 24 are provided on the movable plate 22, and the protrusions 24 cooperate with the sliding grooves 25; one end of the return spring 23 abuts against the movable plate 22, and the other end abuts against the spring seat 26, which is fixedly disposed in the air passage 14 and is used to support the return spring 23 and guide it.

[0019] Furthermore, the fixed plate 21 is fixed to the front end of the gas pipeline 14, with its end face perpendicular to the gas pipeline axis and forming a rigid reference with the pipe end, so that the movable plate 22 can achieve surface sealing and repeated positioning on this reference. The slide groove 25 extends along the gas pipeline axis to provide linear guidance for the movable plate 22; the protrusion 24 of the movable plate 22 mates with the slide groove 25, which can be a slight interference fit or clearance fit, so that the movable plate 22 can reciprocate axially but is restricted in the radial and circumferential directions, avoiding wobble and rotation, and ensuring parallelism and sealing surface contact stability during contact. One end of the return spring 23 abuts against the back of the movable plate 22, and the other end abuts against the spring seat 26. The spring seat 26 carries and guides the return spring 23, keeping its axis aligned and preventing buckling during compression, while applying a preload force to the movable plate 22. The groove 25 is a linear guide groove formed on the inner wall of the gas pipeline 14, the protrusion 24 is a matching guide protrusion formed on the outer periphery or back of the movable plate 22, and the spring seat 26 is a bearing and positioning component used to house and limit the return spring 23.

[0020] During operation, when the air path does not generate negative pressure or the pressure difference does not reach the opening threshold, the return spring 23 pushes the movable plate 22 towards the fixed plate 21. The movable plate 22 is guided along the slide groove 25 to its end position and fits against the end face of the fixed plate 21. The valve assembly 2 is in a closed state, blocking the connection between the front end of the air path and the outside. When the negative pressure pump 3 operates and generates a pressure difference at the rear end of the air path, the aerodynamic force acting on the pressure-facing surface of the movable plate 22 overcomes the elastic force of the return spring 23 axially. The movable plate 22 moves backward in a short stroke under the guidance of the slide groove 25, and the valve assembly 2 enters the open state, allowing gas to enter the air path pipe 14. When the negative pressure pump 3 stops, the pressure difference disappears, or decreases below the threshold, the return spring 23 releases its elastic potential energy, pushing the movable plate 22 back to its original position along the slide groove 25 and fitting against the end face of the fixed plate 21 again. The front end of the air path is immediately restored to closed. The entire reciprocating motion is constrained by the slide groove 25 and the protrusion 24 to be an axial linear motion, avoiding jamming caused by lateral clearance or torsion.

[0021] With the above structure, valve assembly 2 forms a surface-fit seal directly near the front end of the air passage, making it difficult for residual oil and gas to escape when the gun is pulled out; the cooperation between the slide groove 25 and the protrusion 24 provides stable linear guidance, reduces friction and uneven wear, and ensures the repeatability and response speed of opening and closing; the spring seat 26 supports and guides the return spring 23, suppresses spring buckling and deviation, and improves the stability and lifespan of the long-term return force; the preload of the return spring 23 ensures that valve assembly 2 remains reliably closed when the pump is stopped, and opens quickly when there is negative pressure, realizing passive opening and closing without additional control, improving the sealing reliability of the air passage end and reducing the escape of oil and gas during the gun pulling process.

[0022] In some embodiments, the fixed plate 21 has a plurality of first vent holes 211, and the movable plate 22 has a plurality of second vent holes 221. The first vent holes 211 and the second vent holes 221 are staggered. When the movable plate 22 and the fixed plate 21 are in the contact position, the air passage is closed. When the movable plate 22 and the fixed plate 21 are separated, the air passage is opened. The staggered arrangement of the first vent holes 211 and the second vent holes 221 means that in the closed state, the area directly opposite any first vent hole 211 is the solid sealing surface of the opposite side plate, not the opening of the second vent hole 221. Under negative pressure recovery conditions, the movable plate 22 separates axially by a short distance under the action of pressure difference, forming an inter-plate cavity. The first vent holes 211 and the second vent holes 221 are connected through the inter-plate cavity, and the air passage is thus opened. When the pump stops, the movable plate 22 returns to its position under the action of the return spring 23, the inter-plate cavity disappears, and the air passage is immediately closed. This combination has no direct leakage path when closed, and achieves controlled conduction through the inter-plate cavity when open. It can directly cut off the residual cavity at the front end of the nozzle and reduce leakage at the moment of nozzle removal. It can also obtain a relatively uniform suction flow field through the number and distribution of the aperture array, suppress droplet entrainment and reduce product loss.

[0023] In some embodiments, an oil-proof film is fitted around the outside of the return spring 23 to isolate it from direct erosion and deposition by gasoline vapor and oil mist, reducing rust, gumming, and adhesion, and maintaining long-term stability of elasticity and return performance. The film has low friction characteristics, reducing interference wear with guide components or cavity walls, and suppressing jamming caused by media adhesion. During assembly, the film moves with the return spring 23 throughout its entire stroke without changing the guiding relationship and sealing state of the valve assembly 2. During assembly, the return spring 23 and the oil-proof film are pre-assembled, and then the assembly, along with the movable plate 22 and the fixed plate 21, are sequentially assembled at the front end of the gas pipeline 14. The guide protrusion 24 is aligned with the slide groove 25 and pushed into place. The fixed plate 21 is fixed by a pressure ring or screw connection. Subsequently, the valve assembly 2 is positioned and connected to the oil outlet pipeline 13 and the gun body 1, and then the rear hose 32 is connected to the parallel branch of the negative pressure pump 3 and the airbag 31. After assembly, the airtightness and opening / closing response are checked to verify that there is no leakage, no jamming, and the opening and closing stroke is smooth.

[0024] In some embodiments, an air bladder 31 is provided between the gas pipeline 14 and the negative pressure pump 3. The air bladder 31 is preferably connected in parallel to the main gas pipeline via a T-junction to form a sealed compressible cavity. When the negative pressure pump 3 starts, it introduces a pressure difference and periodic pulsation in the gas pipeline. The air bladder 31 expands to absorb excess suction during the peak phase of the pulsation and contracts to return gas during the trough phase, so that the instantaneous pressure of the main pipeline tends to be smooth, thereby stabilizing the opening and closing of the valve assembly 2, reducing over-suction and droplet entrainment, and reducing noise and vibration. When the pump stops or the pressure difference disappears, the air bladder 31 is in constant pressure equilibrium and does not affect the front-end seal.

[0025] In some embodiments, when the negative pressure pump 3 is working, the movable plate 22 overcomes the reset spring 23 to separate and connect the vent holes 211 and 221; the first vent hole 211 and the second vent hole 221 together constitute a throttling structure to limit the flow rate into the air path when the negative pressure is recovered. Specifically, after the negative pressure is formed, it acts on the pressure-facing surface of the movable plate 22. The movable plate 22 moves axially, and an inter-plate cavity is formed between the fixed plate 21 and the movable plate 22. The first vent 211 and the second vent 221 are connected through the inter-plate cavity. The aperture and the inter-plate gap together form an equivalent throttling impedance, thereby limiting and smoothing the instantaneous flow rate and apparent flow velocity, avoiding suction concentration, suppressing droplet entrainment, and improving opening and closing stability. After the pump stops, the movable plate 22 returns to its original position under the action of the return spring 23. The aperture array is misaligned and the inter-plate cavity disappears, and the front end is immediately closed, realizing passive opening and closing based on pressure difference drive and elastic reset. The flow rate can be predictably limited and evenly distributed by setting the aperture, matching the load of the negative pressure pump 3 and the elasticity of the return spring 23, and meeting the requirements of stable recovery and loss reduction.

[0026] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An oil and gas recovery refueling nozzle, characterized in that, include: The gun body (1) has an oil chamber inside, which is connected to the oil supply pipe (12); A trigger (11) is mounted on the gun body (1); An oil outlet pipe (13) is fixedly connected to the front end of the gun body (1) and communicates with the oil chamber; The gas pipeline (14) is located inside the oil outlet pipeline (13) and is coaxially arranged with the oil outlet pipeline (13). The gas pipeline (14) and the oil outlet pipeline (13) form an annular oil passage. The front end of the gas pipeline (14) extends to the oil outlet, and the other end is connected to the negative pressure pump (3) through the hose (32). A valve assembly (2) is located at the front end of the gas pipeline (14) and is used to control the closing and opening of the gas pipeline (14).

2. The oil and gas recovery refueling nozzle according to claim 1, characterized in that, The valve assembly (2) includes a fixed plate (21), a movable plate (22), and a return spring (23). The fixed plate (21) is fixed to the front end of the gas pipeline (14), and a plurality of sliding grooves (25) are provided on the inner wall of the gas pipeline (14) near the fixed plate (21). A plurality of protrusions (24) are provided on the movable plate (22), and the protrusions (24) cooperate with the sliding grooves (25). One end of the return spring (23) abuts against the movable plate (22), and the other end abuts against the spring seat (26). The spring seat (26) is fixed inside the gas pipeline (14) and is used to support the return spring (23) and guide it.

3. The oil and gas recovery refueling nozzle according to claim 2, characterized in that, The fixed plate (21) is provided with a plurality of first vent holes (211), and the movable plate (22) is provided with a plurality of second vent holes (221); the first vent holes (211) and the second vent holes (221) are staggered with each other. When the movable plate (22) and the fixed plate (21) are in the contact position, the air passage is closed. When the movable plate (22) and the fixed plate (21) are separated, the air passage is opened.

4. The oil and gas recovery refueling nozzle according to claim 2, characterized in that, An oil-proof film is fitted on the outside of the return spring (23).

5. The oil and gas recovery refueling nozzle according to claim 1, characterized in that, An air bladder (31) is provided between the air passage (14) and the negative pressure pump (3).

6. The oil and gas recovery refueling nozzle according to claim 3, characterized in that, When the negative pressure pump (3) is working, the movable plate (22) overcomes the reset spring (23) and separates to make the first vent (211) and the second vent (221) connected; the first vent (211) and the second vent (221) together form a throttling structure to limit the flow rate entering the air passage (14) when the negative pressure is recovered.

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