A sediment drain valve for an aircraft fuel system

Abstract

The application provides a kind of sediment valve of aircraft fuel system, belongs to the field of aircraft fuel system, the middle part of its shell is made of oil hole, the lower part is made of stop moving parts installation groove;The elastic steel sheet of arch bridge shape and stop moving parts constitute stop moving assembly and are installed in stop moving parts installation groove;Piston rod position multi-section variable diameter cylindrical structure, is placed in the shell and is sealed cooperation in the middle part, and is limited in the shell by end cover, spring is sleeved on the upper part of piston rod and is always pressed, the lower part of stop moving shoulder is cooperated with stop moving assembly to realize the locking of piston rod upward movement to open position, fuel flows out of fuel tank through oil hole.The application can realize the self-locking and unlocking of open position, can be installed in the multi-layer structure barrier in the aircraft, narrow space, and can realize the self-locking fuel discharge function under the condition that the operator cannot be seen.

Description

Technical Field

[0001] This invention belongs to the field of aircraft fuel systems and relates to a settling valve for an aircraft fuel system. Background Technology

[0002] The flare release valve is a commonly used device in civil aviation fuel systems. It is used to release fuel and deposited impurities from the bottom of the fuel tank when the aircraft is parked. Commonly used flare release valves can be divided into two categories: those with self-locking function in the open position and those without. Generally, flare release valves with self-locking function require pushing and rotating the valve core to achieve self-locking. However, in some aircraft where fuel tanks are located inside the aircraft and the drain valve cannot be exposed on the aircraft surface, ground maintenance personnel cannot directly push or rotate the drain valve. This is because the drain valve is installed in a confined space inside the aircraft, a considerable distance from the drain port on the aircraft surface. There may be multiple layers between the drain valve and the drain port, and the drain path consists of a drain hose and connector assembly, which is a non-linear path. In this case, using a long metal drain tool makes it difficult to reach the drain valve along this non-linear path. Using a non-metallic (flexible, bendable) long drain tool allows for reach, but torque cannot be transmitted. Therefore, self-locking draining of the drain valve (under the condition of a non-visible, non-linear drain path) cannot be achieved. Summary of the Invention

[0003] This invention provides a settling valve for an aircraft fuel system. By applying vertical operation to the piston, the settling valve can be self-locked and unlocked in its open position. It can be installed in confined spaces with multiple layers of structure inside the aircraft and can achieve self-locking fuel release function without being visible to the operator.

[0004] The technical solution adopted in this invention is as follows:

[0005] A settling valve for an aircraft fuel system, the settling valve comprising a housing 1, a piston rod 2, an end cap 3, a spring 4, a sealing ring 5, an elastic retaining ring 6, an elastic steel sheet 7, and a stop component 8.

[0006] The outer casing 1 is a cylindrical structure with multiple "L"-shaped grooves evenly distributed around the top circumference. Multiple oil passage holes are formed around the middle of the outer wall of the cylinder, with the oil passage area of ​​each hole not less than the inner diameter of the bottom of the outer casing 1, thus ensuring oil flow. Below the oil passage holes, threads are formed on the outer wall of the cylinder for interface installation with aircraft equipment. An elongated groove structure is provided in the threaded area for bonding rubber parts. After the sediment discharge valve is installed on the aircraft fuselage, the rubber parts are compressed, preventing loosening. Below the threaded area, a hexagonal boss is formed around the outer wall of the cylinder for easy turning with tools. An elastic retaining ring mounting groove is formed at the top of the inner wall of the outer casing 1 near the port. A positioning boss is set around the middle of the inner wall of the cylinder corresponding to the threaded area of ​​the outer wall. Multiple stop part mounting grooves are evenly distributed around the lower part of the inner wall of the cylinder, with through holes formed at the bottom of the grooves. Multiple guide bosses are evenly distributed around the bottom of the inner wall of the cylinder to guide maintenance tools to the correct operating position.

[0007] The elastic steel sheet 7 is an "arch bridge" type with a central through hole. The tail of the stop part 8 is a sliding rod, and the head is a trapezoidal stop block. The sliding rod passes through the central through hole from the arched side of the elastic steel sheet 7 to form a stop assembly. Multiple stop assemblies are provided and are installed in the stop part mounting groove on the inner wall of the outer shell 1. The stop part 8 is inclined downward and its sliding rod passes through the through hole at the bottom of the stop part mounting groove. The elastic steel sheet 7 acts on the trapezoidal stop block of the stop part 8, continuously providing an inward force.

[0008] The piston rod 2 is a four-section variable-diameter cylindrical structure. The second section has the largest outer diameter, which matches the inner diameter of the positioning boss on the inner wall of the outer shell 1. A spring mounting limiting boss is formed along the circumference of the middle of this section. The spring 4 passes through the piston rod 2 from the top and is limited at the bottom on the spring mounting limiting boss. The outer diameter of the spring mounting limiting boss matches the inner diameter of the outer shell 1. The piston rod 2 is inserted into the outer shell 1 from the top. The spring mounting limiting boss matches the positioning boss on the inner wall of the outer shell 1 to achieve limitation. The upper end of the piston rod 2 is not lower than the elastic retaining ring mounting groove at the top of the outer shell 1, and the lower end is flush with the bottom port of the outer shell 1. A sealing ring mounting groove is formed in the contact area between the second section of the piston rod 2 and the positioning boss of the outer shell 1 for installing the sealing ring 5 to ensure that the sediment discharge valve is closed. The piston rod 2 is sealed at the top; the shoulder between the first and second sections of the piston rod 2 serves as a limiting shoulder for the upward sliding of the piston rod 2; the third section of the piston rod 2 cooperates with the stop assembly, which presses against the third section of the piston rod 2; the outer diameter of the fourth section of the piston rod 2 is smaller than that of the third section, and the shoulder between the two sections serves as a stopping shoulder for the upward sliding of the piston rod 2, cooperating with the stop assembly to achieve self-locking of the release valve in the open position; the positions of the limiting shoulder and the stopping shoulder, i.e. the lengths of the first and fourth sections of the piston rod 2, are set according to the distance between the positioning boss on the inner wall of the outer casing 1 and the upper end of the oil passage hole, so that after the piston rod 2 slides up to the open position, its spring-mounted limiting boss is located above the oil passage hole, allowing fuel to flow into the inner casing 1 and out of the fuel tank.

[0009] The end cap 3 has a through hole in the center, the inner diameter of which matches the outer diameter of the first section of the piston rod 2. The outer edge of the end cap 3 is evenly distributed with multiple mounting bosses. It is installed on the outer shell 1 through the "L"-shaped slot on the top of the outer shell 1, which restricts the piston rod 2 inside the outer shell 1. The spring 4 is pressed between the end cap 3 and the spring mounting limiting boss of the piston rod 2. The spring 4 always applies a downward spring force to the piston rod 2. The limiting shoulder between the first and second sections of the piston rod 2 matches the lower end face of the end cap 3, which restricts the upward sliding height of the piston rod 2. The upper end face of the end cap 3 is provided with a tool mounting groove for mounting with tools.

[0010] The elastic retaining ring 6 is an annular retaining ring, which is installed in the elastic retaining ring mounting groove on the top of the outer shell 1 to prevent the end cover 3 from moving.

[0011] The maintenance tool used in conjunction with the settling valve needs to be equipped with two types of ends: one is a solid cylindrical end, which is used to push against the lower end of the piston rod 2 and push upward to open the settling valve; the other is a hollow cylindrical end, with the inner diameter of the cylinder being larger than the outer diameter of the third section of the piston rod 2, which is used to push open the stop assembly to unlock and close the settling valve.

[0012] Furthermore, the number of stop components consisting of the elastic steel sheet 7 and the stop part 8 is determined according to the internal load size of the sediment discharge valve.

[0013] The assembly process of the sediment discharge valve is as follows: After assembling the elastic steel sheet 7 and the stop part 8, install them in the stop part mounting groove at the bottom of the outer shell 1; install the sealing ring 5 in the sealing ring mounting groove of the piston rod 2, sleeve the spring 4 on the piston rod 2, sleeve the end cap 3 on the upper end of the piston rod 2, and place the spring 4 between the spring limiting boss of the piston rod 2 and the end cap 3; insert the piston rod 2, with the spring 4, end cap 3 and sealing ring 5 assembled, into the outer shell 1 from above, and assemble and limit the boss of the end cap 3 with the "L"-shaped groove at the top of the outer shell 1; finally, install the elastic retaining ring 6 into the elastic retaining ring mounting groove at the top of the outer shell 1.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. This invention, while fulfilling the oil discharge function of a traditional sedimentation valve, adds a self-locking function in the open position, freeing up ground maintenance personnel and making it more practical;

[0016] 2. This invention has a simple structure, is easy to implement and practical, and has high economic benefits;

[0017] 3. This product has good versatility and outstanding comprehensive advantages in terms of functionality and reliability. It can be used in aircraft fuel systems and auxiliary fuel systems, and has a wide range of applications.

[0018] 4. It can achieve oil drain self-locking when the sedimentation valve is placed in a non-visible, long-distance environment, and has extremely high promotion value. Attached Figure Description

[0019] Figure 1 This is an overall view of the invention;

[0020] Figure 2 This is a diagram showing the components of the present invention;

[0021] Figure 3 This is a schematic diagram of the outer casing;

[0022] Figure 4 This is a schematic diagram of the outer shell cross-section;

[0023] Figure 5 This is a schematic diagram of the piston rod;

[0024] Figure 6 This is a schematic diagram of the end cap;

[0025] Figure 7 This is a schematic cross-sectional view of the present invention;

[0026] Figure 8 A cross-sectional view of the end of a maintenance tool during the opening of the sedimentation valve;

[0027] Figure 9 This is a cross-sectional view of the end of a maintenance tool during the closing process of the sedimentation valve;

[0028] In the diagram: 1. Housing; 2. Piston rod; 3. End cap; 4. Spring; 5. Sealing ring; 6. Elastic retaining ring; 7. Elastic steel sheet; 8. Stopping parts. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments derived by those skilled in the art based on the embodiments of the present invention through modifications or adjustments are within the protection scope of the present invention.

[0030] This embodiment provides a settling valve for an aircraft fuel system. The settling valve includes a housing 1, a piston rod 2, an end cap 3, a spring 4, a sealing ring 5, an elastic retaining ring 6, an elastic steel sheet 7, and a stop component 8. Figure 1 , Figure 2 and Figure 7 As shown.

[0031] like Figure 3 and Figure 4As shown, the outer casing 1 is a cylindrical structure with three "L"-shaped slots evenly distributed around the circumference at the top. Four oil passage holes are formed around the circumference in the middle of the outer wall of the cylinder. The oil passage area of ​​the oil passage holes is not less than the inner diameter of the bottom of the outer casing 1, thereby ensuring the oil flow rate. Threads are formed on the outer wall of the cylinder below the oil passage holes for installation with the bottom interface of the aircraft fuel tank. An elongated groove structure is set in the threaded area for bonding rubber parts. After the sediment release valve is installed on the aircraft fuselage, the rubber parts are compressed, which plays a role in preventing loosening. A hexagonal boss is formed around the circumference of the outer wall of the cylinder below the threaded area for easy turning with tools. An elastic retaining ring mounting groove is formed at the top of the inner wall of the outer casing 1 near the port. A positioning boss is set around the circumference in the middle of the inner wall corresponding to the threaded area of ​​the outer wall. Two stop part mounting grooves are evenly distributed around the circumference at the bottom of the inner wall, and through holes are formed in the cylinder wall at the bottom of the grooves. Three guide bosses are evenly distributed around the circumference at the bottom of the inner wall to guide maintenance tools to the correct operating position.

[0032] The elastic steel sheet 7 is an "arch bridge" type with a central through hole. The tail of the stop part 8 is a sliding rod, and the head is a trapezoidal stop block. The sliding rod passes through the central through hole from the arched side of the elastic steel sheet 7 to form a stop assembly. There are two sets of stop assemblies, which are installed in the stop part mounting grooves on the inner wall of the outer shell 1. The stop part 8 is inclined downward and its sliding rod passes through the through hole at the bottom of the stop part mounting groove. The elastic steel sheet 7 acts on the trapezoidal stop block of the stop part 8, continuously providing an inward force.

[0033] like Figure 5 As shown, the piston rod 2 is a four-section variable-diameter cylindrical structure. The second section has the largest outer diameter, which matches the inner diameter of the positioning boss on the inner wall of the outer shell 1. A spring mounting limiting boss is formed along the circumference of the middle part of this section. The spring 4 passes through the piston rod 2 from the top, and its bottom is pressed against the spring mounting limiting boss. The outer diameter of the spring mounting limiting boss matches the inner diameter of the outer shell 1. The piston rod 2 is inserted into the outer shell 1 from the top. The spring mounting limiting boss and the positioning boss on the inner wall of the outer shell 1 cooperate to achieve limiting. The upper end of the piston rod 2 is flush with the elastic retaining ring mounting groove at the top of the outer shell 1, and the lower end is flush with the bottom port of the outer shell 1. Two sealing ring mounting grooves are formed in the contact area between the second section of the piston rod 2 and the positioning boss of the outer shell 1 for installing sealing rings. 5. Ensure the settling valve is sealed when closed; the shoulder between the first and second sections of piston rod 2 at the top serves as a limiting shoulder for the upward sliding of piston rod 2; the third section of piston rod 2 cooperates with the stop assembly, which presses against the third section of piston rod 2; the outer diameter of the fourth section of piston rod 2 is smaller than that of the third section, and the shoulder between the two sections serves as a stopping shoulder for the upward sliding of piston rod 2, cooperating with the stop assembly to achieve self-locking of the settling valve in the open position; the positions of the limiting shoulder and the stopping shoulder are set according to the distance between the positioning boss on the inner wall of the outer shell 1 and the upper end of the oil passage hole, so that after piston rod 2 slides up to the open position, its spring-mounted limiting boss is located above the oil passage hole, allowing fuel to flow into the inner shell 1 and out of the fuel tank.

[0034] like Figure 6 As shown, the end cap 3 has a through hole in the center, the inner diameter of which matches the outer diameter of the first section of the piston rod 2. The outer edge of the end cap 3 has three mounting bosses evenly distributed. It is installed on the outer shell 1 through the "L"-shaped slot on the top of the outer shell 1, which restricts the piston rod 2 inside the outer shell 1. The spring 4 is pressed between the end cap 3 and the spring mounting limiting boss of the piston rod 2. The spring 4 always applies a downward spring force to the piston rod 2. The limiting shoulder between the first and second sections of the piston rod 2 matches the lower end face of the end cap 3, which restricts the upward sliding height of the piston rod 2. The upper end face of the end cap 3 has a tool mounting groove for mounting with tools.

[0035] The elastic retaining ring 6 is an annular retaining ring, which is installed in the elastic retaining ring mounting groove on the top of the outer shell 1 to prevent the end cover 3 from moving.

[0036] The assembly process of the sediment release valve is as follows: After assembling the elastic steel sheet 7 and the stop part 8, install them in the stop part mounting groove at the bottom of the housing 1; install the sealing ring 5 in the sealing ring mounting groove of the piston rod 2, sleeve the spring 4 on the piston rod 2, and sleeve the end cap 3 on the upper end of the piston rod 2, with the spring 4 between the spring limiting boss of the piston rod 2 and the end cap 3; insert the piston rod 2, with the spring 4, end cap 3 and sealing ring 5 assembled, into the housing 1 from above, and assemble and limit the boss of the end cap 3 with the "L"-shaped groove at the top of the housing 1; finally, install the elastic retaining ring 6 into the elastic retaining ring mounting groove at the top of the housing 1; insert the upper end of the assembled sediment release valve into the interface at the bottom of the fuel tank and screw it onto the interface.

[0037] After the drain valve is installed inside the aircraft, an oil drain collection box should be arranged below it, along with a corresponding hose assembly. The hose can pass through multiple layers of the aircraft structure, and an oil drain port should be provided on the lower surface of the aircraft, thus creating an oil drain passage for the drain valve inside the aircraft. The maintenance tool used to open and close the drain valve should be a flexible strut type. The diameter of the strut should be slightly smaller than the inner diameter of the hose to ensure that the tool can be inserted without excessive bending. The tool should have two types of ends: a solid cylindrical end for pressing against the lower end of piston rod 2 and pushing upwards to open the drain valve; and a hollow cylindrical end with an inner diameter larger than the outer diameter of the third section of piston rod 2, used to open the stop assembly to unlock and close the drain valve. Figure 8 and Figure 9 As shown.

[0038] The process of opening the settling valve is as follows: The maintenance tool is fitted with a solid cylindrical end, which is inserted through the aircraft's drain port along the hose assembly. After being adjusted by the guide boss at the bottom of the settling valve housing 1, the end is aligned with the bottom of the piston rod 2, which lifts the piston rod 2 upward. When the stop boss at the bottom of the piston rod 2 is pushed above the stop part 8, the stop part 8 pops out under the action of the elastic steel sheet 7. The stop part 8 locks the stop boss, locking the settling valve in the open position.

[0039] The closing process of the settling valve is as follows: The maintenance tool is installed with a hollow cylindrical end, which extends into the aircraft's drain port along the hose assembly. After being adjusted by the guide boss at the bottom of the settling valve housing 1, the inner hole of the end is aligned with the piston rod 2. The piston rod 2 falls into the inner hole of the end, and the end continues to move upward along the piston rod 2 until it contacts the inclined surface of the stop part 8, pushing the stop part 8 to move outward. During this process, the elastic steel sheet 7 is continuously compressed. When the stop part 8 separates from the stop boss at the bottom of the piston rod 2, the settling valve is released, and the piston rod 2 slides down along the inner hole of the end to the closed position under the action of the spring 4.

[0040] The above embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A settling valve for an aircraft fuel system, characterized in that, Includes outer casing (1), piston rod (2), end cap (3), spring (4), elastic steel sheet (7), and stop part (8); The outer shell (1) is a cylindrical structure with multiple "L"-shaped slots evenly distributed around the top circumference. Multiple oil passage holes are made around the middle of the outer wall of the cylinder. Threads are made on the outer wall of the cylinder below the oil passage holes for interface installation with aircraft equipment. Positioning bosses are set around the middle of the inner wall of the cylinder corresponding to the threaded area of ​​the outer wall of the cylinder. Multiple stop part mounting slots are evenly distributed around the lower part of the inner wall of the cylinder. The elastic steel sheet (7) is an "arch bridge" type with a central through hole. The tail of the stop part (8) is a sliding rod, and the head is a trapezoidal stop block. The sliding rod passes through the central through hole from the arched side of the elastic steel sheet (7) to form a stop assembly. Multiple stop assemblies are provided and are installed in the stop part mounting groove on the inner wall of the outer shell (1). The stop part (8) is inclined downward and its sliding rod passes through the through hole at the bottom of the stop part mounting groove. The elastic steel sheet (7) acts on the trapezoidal stop block of the stop part (8) to continuously provide an inward force. The piston rod (2) is a four-section variable diameter cylindrical structure. The outer diameter of the second section is the largest and matches the inner diameter of the positioning boss on the inner wall of the outer shell (1). A spring mounting limiting boss is made along the circumference in the middle of this section. The spring (4) passes through the piston rod (2) from the top and is limited at the bottom on the spring mounting limiting boss. The outer diameter of the spring mounting limiting boss matches the inner diameter of the outer shell (1). The piston rod (2) is placed inside the outer shell (1) from the top. The spring mounting limiting boss matches the positioning boss on the inner wall of the outer shell (1) to achieve the limiting. The piston rod (2) is located in the first section at the top. The shoulder between the second and third sections serves as a limiting shoulder for the piston rod (2) to slide upward; the third section of the piston rod (2) cooperates with the stop assembly, and the stop assembly is pressed against the third section of the piston rod (2); the outer diameter of the fourth section of the piston rod (2) is smaller than that of the third section, and the shoulder between the two sections serves as a stopping shoulder for the piston rod (2) to slide upward, and cooperates with the stop assembly to realize the self-locking of the sediment release valve in the open position. After the piston rod (2) slides up to the open position, its spring mounting limiting boss is located above the oil passage hole of the outer shell (1), so that fuel can flow into the interior of the outer shell (1) and out of the fuel tank; The end cap (3) has a through hole in the center, and the inner diameter of the through hole matches the outer diameter of the first section of the piston rod (2). The outer edge of the end cap (3) is evenly distributed with multiple mounting bosses. The piston rod (2) is installed on the outer shell (1) through the "L"-shaped slot on the top of the outer shell (1), which restricts the piston rod (2) inside the outer shell (1). The spring (4) is pressed between the end cap (3) and the spring mounting limiting boss of the piston rod (2). The limiting shoulder between the first and second sections of the piston rod (2) matches the lower end face of the end cap (3), which restricts the upward sliding height of the piston rod (2).

2. The settling valve for an aircraft fuel system according to claim 1, characterized in that, The oil passage area of ​​the oil passage hole of the outer shell (1) is not less than the inner diameter of the bottom of the outer shell (1).

3. The settling valve for an aircraft fuel system according to claim 1, characterized in that, The outer shell (1) has a long circular groove structure in the threaded area for bonding rubber parts to prevent loosening after the sedimentation valve is installed.

4. A settling valve for an aircraft fuel system according to claim 1, characterized in that, The inner wall of the outer shell (1) has multiple guide protrusions evenly distributed around the circumference at the bottom, which are used to guide the maintenance tool to the correct working position.

5. A settling valve for an aircraft fuel system according to claim 1, characterized in that, The number of stop components consisting of the elastic steel sheet (7) and the stop part (8) is determined according to the internal load of the sedimentation valve.

6. A settling valve for an aircraft fuel system according to claim 1, characterized in that, The settling valve also includes an elastic retaining ring (6). An elastic retaining ring mounting groove is made on the top of the inner wall of the outer shell (1) near the port. The elastic retaining ring (6) is installed in the elastic retaining ring mounting groove to prevent the end cap (3) from moving.

7. A settling valve for an aircraft fuel system according to claim 1, characterized in that, The piston rod (2) has a sealing ring mounting groove in the contact area between the second section and the positioning boss of the outer shell (1). A sealing ring (5) is installed in the groove for sealing when the sedimentation valve is closed.

8. A settling valve for an aircraft fuel system according to any one of claims 1-7, characterized in that, The maintenance tool used in conjunction with the settling valve needs to be equipped with two types of ends: one is a solid cylindrical end for opening the settling valve, and the other is a hollow cylindrical end with an inner diameter larger than the outer diameter of the third section of the piston rod (2) for closing the settling valve.

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