Antifouling and anti-overload valve

Abstract

The antifouling and anti-overload valve comprises an inlet shell and an outlet shell which are connected with each other, a head supporting frame, a filter screen supporting frame and a corrugated filter screen are installed in an inner cavity of the antifouling and anti-overload valve, the head of a valve rod penetrates out of the head supporting frame, a spring is arranged on an optical axis section in the middle of the valve rod in a sleeved mode, and a boss at the tail of the valve rod serves as a spring seat. The two ends of the spring abut against the spring seat and the inner wall of the head supporting frame, a boss at the tail of the valve rod and the filter screen supporting frame form cylindrical pair sliding fit, a sleeve type sealing ring is installed between the head of the valve rod and the head supporting frame, and the corrugated filter screen is welded to the outer circumference of the filter screen supporting frame. The head supporting frame is provided with an oil through hole communicated with the sleeve type sealing ring cavity and the spring cavity, and the front cavity and the rear cavity of the valve tail boss are also communicated. Clamping stagnation caused by the influence of redundant substances in fuel can be prevented, the control function of the valve on oil flowing when the aircraft is in different postures can be achieved, and meanwhile the influence of the redundant substances generated by unclean oil on the function of the valve is eradicated through the structure of the valve.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft fuel control, and in particular to an anti-fouling and anti-overload valve. Background Art

[0002] In the fuel supply pipeline of aerospace or aviation power systems, multiple fuel tanks are often connected in series to output oil. In order to prevent a certain end of the fuel tank wall from being subjected to a large fuel overload pressure when the flight attitude changes or the acceleration is overloaded, it is necessary to connect gravity valves in series between the fuel tanks to cut off the fuel liquid column under specified working conditions.

[0003] At present, there are two main types of commonly used gravity valves. The first type is the traditional flap-type gravity valve, which relies on the system angle to control the rotation of the flap. When the system is flying horizontally, the flap opens to pass oil. When the system reaches a certain acceleration or stands upright, the flap falls to seal the pipeline. The advantage of the flap type is that it is not easy to get stuck, but the biggest drawback is that it can only complete the erection and closing tasks when the system rotates in a fixed direction, which cannot meet the increasingly complex flight system working conditions.

[0004] The second type is a piston-type gravity valve, which uses a spring and sliding valve core structure similar to a one-way valve, and uses the inertial force caused by acceleration or gravity to overcome the spring force to close the pipeline. The advantage is that it has a universal function and can meet the flight attitude changes in any direction; the disadvantage is that the sliding valve core is at risk of being stuck by excess matter, and the valve function is difficult to self-repair after the jam, which seriously affects the flight function of the system. The fuel in the fuel tank is generally not clean and is prone to produce excess matter. The normal fuel supply system is only connected to the filter after the last tank. If a filter is connected in series in front of each valve in order to ensure the reliability of valve opening and closing, it will increase the system weight and flow resistance while complicating the system.

[0005] In the patent application "A two-way oil-passing valve and its design method" with application number 2019101866945, a piston-type gravity valve is disclosed. On the basis of the traditional piston-type valve, a two-way anti-overload function is added, which can further consider the protection of the fuel tank when the aircraft reverses and accelerates overload. However, the sliding part of the valve sleeve is easily stuck by excess matter in the oil. When using this valve, it is often necessary to ensure that the upstream oil has a certain degree of cleanliness. Summary of the invention

[0006] The technical problem solved by the present invention is to provide an anti-fouling and anti-overload valve, which can prevent excess objects from getting stuck and prevent overload, and can pass oil in the horizontal cruising state of the flight system. Under the action of gravity during erection or the overload during horizontal acceleration, the fuel pipeline is cut off to solve the problem of excessive fuel pressure in the fuel tank.

[0007] The technical solution adopted by the present invention is an anti-fouling and anti-overload valve, comprising an inlet shell and an outlet shell connected to each other, a head support frame and a filter support frame are arranged in the shell, a valve rod is inserted into the internal cavity of the head support frame and the filter support frame, the head of the valve rod passes through the head support frame, the optical axis section in the middle of the valve rod is sleeved with a spring, the two ends of the spring touch the tail boss of the valve rod and the inner wall of the head support frame, the tail boss of the valve rod and the filter support frame form a cylindrical pair sliding fit, a sleeve sealing ring is installed between the head of the valve rod and the head support frame, the head of the valve rod is provided with an external thread, and a valve pressure plate and a valve head are screwed on the thread, and the threaded connection part is spot welded to prevent loosening. The upper and lower end surfaces of the valve pressure plate and the valve head clamp the head of the sleeve sealing ring, the tail of the sleeve sealing ring is sleeved on the outer circumference of the valve pressure plate and fixed and sealed, the corrugated filter is welded on the outer circumference of the filter support frame, and an oil hole is provided on the head support frame, the oil hole connects the sleeve sealing ring cavity and the spring cavity, and an oil passage is processed on the boss at the tail of the valve, and the oil passage connects the front and rear cavities at the tail of the valve.

[0008] The thickness of the head of the sleeve seal ring is at least 3 times the thickness of the ring wall. The head of the sleeve seal ring contacts the inlet shell in the valve state to form a seal, and the contact surface is a surface seal or a line seal.

[0009] The tail of the sleeve-type sealing ring is fixed on the outer circumference of the head support frame through a clamp.

[0010] The boss at the tail of the valve is circular, and the oil passage is formed by trimming the four corners of the cylinder.

[0011] The beneficial effects of the present invention are that the sleeve-type rubber structure and the filter structure are used to wrap and protect the valve sleeve sliding section that is easily stuck by excess matter, thereby avoiding the influence of excess matter in the fuel on the sliding clearance, and the filter structure and multiple oil holes are used to realize oil exchange between the inside and outside of the sliding cavity or between various cavities inside the sliding cavity, thereby avoiding the formation of a dead cavity in a certain internal variable volume space to cause the moving parts to get stuck;

[0012] To solve the fuel tank pressure protection problem of the flight system, when the flight system is vertical or in the acceleration overload stage, the valve is closed to cut off the fuel; when the flight system is horizontal or cruising, the valve is opened to pass the fuel. It can resist the influence of excess fuel on the movement function of the valve and ensure its own operation reliability in harsh environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the present invention.

[0014] Figure 2 This is a structural diagram of the valve open state when the flight system is cruising horizontally.

[0015] Figure 3 This is a schematic diagram of the structure of the valve in the closed state when the flight system is erected.

[0016] Markings in the figure are: 1-shell, 2-head support frame, 21-oil hole, 3-corrugated filter, 4-filter support frame, 5-outlet shell, 6-spring, 7-valve rod, 71-cutting edge, 8-clamp, 9-valve pressure plate, 10-sleeve sealing ring, 11-valve head. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] The present invention discloses an anti-fouling and anti-overload valve capable of resisting the influence of superfluous materials, comprising an inlet shell 1 and an outlet shell 4 connected to each other, wherein a head support frame 2, a filter screen support frame 4, a ripple filter screen 3, a spring 6, a valve rod 7, a clamp 8, a valve pressure plate 9, a sleeve seal ring 10, and a valve head 11 are installed in the inner cavity thereof. The valve rod head passes through the head support frame, the light axis section in the middle of the valve rod is sleeved with a spring, the valve rod tail boss serves as a spring seat, the two ends of the spring touch the spring seat and the inner wall of the head support frame, the valve rod tail boss and the filter screen support frame form a cylindrical pair sliding fit, a sleeve seal ring is installed between the valve rod head and the head support frame, the ripple filter screen is welded on the outer circumference of the filter screen support frame, an oil through hole 21 communicating with the sleeve seal ring cavity and the spring cavity is provided on the head support frame, and the front and rear cavities of the valve tail boss are also connected.

[0019] The assembly process is as follows: the threaded end at the front of the valve rod passes through the head support frame 2, and the middle optical axis and the circular hole of the head support frame 2 form a cylindrical pair.

[0020] A sleeve-type sealing ring 10 is installed between the valve rod head and the head support frame. The sleeve-type sealing ring 10 is molded from vulcanized fluorosilicone rubber and has good elasticity, tensile strength, heat resistance and compatibility with the fuel medium. During installation, the head of the sleeve-type sealing ring is pressed and fixed by the valve pressure plate 9 and the valve head 11. The valve pressure plate 9 and the valve head 11 are screwed on the external thread of the valve rod head, and the threaded connections are spot welded to prevent loosening. Finally, the sleeve end of the tail of the sleeve-type sealing ring 10 is sleeved on the head support frame 2 and fixed with a clamp 8. The thickness of the sleeve-type sealing ring head is at least three times the thickness of the sleeve wall. The larger thickness not only increases the strength, but also allows a larger compression amount, can withstand a larger clamping force, and prolongs the service life.

[0021] The folded filter 3 is welded to the outer periphery of the frame part of the filter support frame 4, and plays the role of filtering the oil entering the inner cavity of the valve sliding section to prevent the sliding section from being stuck by excess objects. The folded structure can greatly increase the effective filtering area in a limited space and increase the reliability of the valve movement.

[0022] In the above state, the boss at the tail end of the valve rod 7 is installed into the filter support frame 4, and the boss at the tail end of the valve rod also serves as a spring seat, and the spring seat and the filter support frame 4 form a cylindrical pair. At the same time, the head support frame 2 and the filter support frame 4 are plugged in. At this time, the moving part can slide back and forth axially through the two cylindrical pairs.

[0023] The inlet shell 1 and the outlet shell 5 are plugged in and then welded to fix the above components inside.

[0024] The present invention is connected between two fuel tank pipelines by welding or flange. When the flight system is erected or accelerated overloaded, the gravity inertia force of the moving part overcomes the spring force and moves until it is sealed and the fuel is cut off. When the aircraft is cruising or stationary on the ground, the spring force returns the moving part to its position and the pipeline is connected to oil.

[0025] When the flight system is cruising horizontally, the valve opening state is as follows Figure 2 As shown, the oil flows smoothly.

[0026] Figure 3 The figure shows a schematic diagram of the structure of the valve in the closed state when the flight system is erected. The sleeve sealing ring 10 can be extended axially when the valve is closed. The head of the sleeve sealing ring is a sealing surface, and the sealing surface is in contact with the inlet shell 1, and a sealing structure is formed by non-metallic deformation. Here, the design can be selected as a line seal or a surface seal according to the actual working conditions. As shown in the figure, when the sealing surface contacts the edge of the inlet shell, it is a line seal, and the advantages are large opening and large diameter. When the sealing surface contacts the inner conical surface of the inlet shell, it is a surface seal, and the advantages are that it can withstand a large overload force and is more convenient for spring calculation. Of course, the telescopic form and installation method of the sleeve sealing ring are not limited by the form in the invention, as long as it plays a wrapping and protective role on the matching clearance of the cylindrical pair.

[0027] A plurality of oil holes 21 are provided on the head support frame 2, so that oil can be replaced between the sleeve-type sealing ring wrapped part and the spring cavity, thereby preventing the sleeve-type sealing ring wrapped part from forming a dead cavity and being unable to retract.

[0028] Similarly, the sliding fit between the tail boss of the valve rod 7 and the filter support frame 4 is performed with a square trim 71, so that the left and right chambers divided by it can be replaced with oil. Of course, the oil replacement can also be facilitated by opening a through hole. The square trimming method can reduce the contact area of ​​the cylindrical pair, which can make the sliding smoother and the probability of jamming lower. The number of trimmings can also be adjusted appropriately, and the number can also be two or three. At the same time, a symmetrical distribution should be maintained to ensure uniform force. However, the number of trimmings should not be too many. If there are too many, the effective oil flow area will be reduced, which is not conducive to the smooth flow of the liquid path. The square trimming is the best implementation method, which not only guarantees the effective oil flow area, but also the cylindrical pair contact section is evenly distributed, and the square trimming is easy to process.

[0029] The present invention realizes the function of cutting off the liquid column between the oil tanks and reducing the pressure of the oil tanks when the flight system is in a vertical attitude or horizontal acceleration overload, and opening the oil flow function in other states; the contact area of ​​the sliding section is reduced, and the friction force when the valve is started is reduced.

[0030] The sleeve-type rubber structure and the built-in filter are innovatively combined to provide wrapping protection for the valve sleeve sliding section that is easily stuck by excess matter, thus avoiding the influence of excess matter in the fuel on the sliding clearance. The filter structure is used to achieve oil change inside and outside the sliding cavity, and the oil hole 21 on the head support frame 2 and the cut edge 71 of the valve rod 7 are used to achieve oil change between the wrapped internal cavities, thus avoiding the formation of a dead cavity in a certain internal variable volume space and causing the moving parts to get stuck.

[0031] The technical solution of the present invention can prevent the jamming caused by the excess matter in the fuel, and can realize the control function of the valve on the flow of oil when the aircraft is in different postures. At the same time, it relies on its own structure to eliminate the influence of the excess matter generated by unclean oil on the valve function.

Claims

1. An anti-fouling and anti-overload valve, comprising an inlet housing and an outlet housing connected to each other, characterized in that: A head support frame and a filter support frame are provided in the shell body, the valve rod is inserted into the internal cavities of the head support frame and the filter support frame, the head of the valve rod passes through the head support frame, the optical axis section in the middle of the valve rod is sleeved with a spring, and the two ends of the spring touch the valve rod tail boss and the inner wall of the head support frame, the valve rod tail boss and the filter support frame form a cylindrical pair sliding fit, a sleeve sealing ring is installed between the valve rod head and the head support frame, the valve rod head is provided with an external thread, and a valve pressure plate and a valve head are screwed on the thread, the upper and lower end faces of the valve pressure plate and the valve head clamp the head of the sleeve sealing ring, the tail of the sleeve sealing ring is sleeved on the outer circumference of the valve pressure plate and fixedly sealed, the folded filter is welded on the outer circumference of the filter support frame, an oil hole is provided on the head support frame, the oil hole connects the sleeve sealing ring cavity and the spring cavity, an oil passage is processed on the valve tail boss, and the oil passage connects the front and rear cavities of the valve tail.

2. The anti-fouling and anti-overload valve according to claim 1, characterized in that: The head thickness of the sleeve sealing ring is at least 3 times the thickness of the ring wall.

3. The anti-fouling and anti-overload valve according to claim 1, characterized in that: The threaded connection between the valve pressure plate or the valve head and the valve head is welded to prevent loosening.

4. The anti-fouling and anti-overload valve according to claim 1, characterized in that: The sleeve sealing ring is in contact with the inlet housing in the valve state.

5. The anti-fouling and anti-overload valve according to claim 4, characterized in that: The head of the sleeve sealing ring contacts the inner wall of the inlet shell to form a seal, and the contact surface is a line seal.

6. The anti-fouling and anti-overload valve according to claim 4, characterized in that: The head of the sleeve sealing ring contacts the inner wall of the inlet shell to form a seal, and the contact surface is a surface seal.

7. The anti-fouling and anti-overload valve according to claim 1, characterized in that: The tail of the sleeve-type sealing ring is fixed on the outer circumference of the head support frame through a clamp.

8. The anti-fouling and anti-overload valve according to claim 1, characterized in that: The boss at the tail of the valve is circular and has four corners cut to form an oil passage.

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