Sedimentation discharging valve of aircraft fuel system

Abstract

The invention provides a sediment discharge valve of an aircraft fuel system, which belongs to the field of aircraft fuel systems and is characterized in that an oil passing hole is formed in the middle of a shell, and a stop part mounting groove is formed in the lower part; the arch-bridge-shaped elastic steel sheet and the stop part form a stop assembly which is mounted in the stop part mounting groove; the piston rod is of a multi-section variable-diameter cylindrical structure and is arranged in the shell, the middle of the piston rod is in sealing fit, the piston rod is limited in the shell through an end cover, the upper portion of the piston rod is sleeved with a spring and always compressed, the lower portion of the piston rod is matched with a stop circular bead to achieve upward movement of the piston rod to the opening position to be locked, and fuel flows out of the fuel tank through a fuel hole. The self-locking oil drainage device can realize self-locking and unlocking at an opening position, can be mounted in a narrow space blocked by a multi-layer structure in an airplane, and can realize a self-locking oil drainage function under the condition that the self-locking oil drainage device is invisible to an operator.

Description

Technical Field

[0001] The invention belongs to the field of aircraft fuel systems and relates to a sedimentation relief valve of an aircraft fuel system. Background Art

[0002] The sedimentation valve is a commonly used device in civil aviation fuel systems. It is used to release the fuel and deposited impurities at the bottom of the fuel tank when the aircraft is docked. Commonly used sedimentation valves can be divided into two types: those with self-locking in the open position and those without self-locking in the open position. Generally, a sedimentation valve with a self-locking function requires the valve core to be pushed and rotated to achieve self-locking. However, some aircraft fuel tanks are arranged inside the aircraft, and the installation of the sedimentation valve cannot be exposed on the surface of the aircraft. Ground maintenance personnel cannot directly push and rotate the sedimentation valve, that is, the sedimentation valve is installed in a small space inside the aircraft, and is a long distance away from the oil drain port on the surface of the aircraft. There may be a multi-layer structure between the sedimentation valve and the aircraft oil drain port. The oil drain path of the sedimentation valve is composed of an oil drain hose and a connector assembly, and the oil drain path is a non-linear oil drain path. At this time, when a metal long-rod oil drain tool is used, it is difficult to reach the sedimentation valve in the non-linear path; when a non-metallic (flexible rod, bendable) long-rod oil drain tool is used, it can be reached, but the torque cannot be transmitted. In summary, the self-locking oil drain of the sedimentation valve (under the conditions of non-visible and non-linear oil drain path) cannot be achieved. Summary of the invention

[0003] The present invention provides a sediment discharge valve for an aircraft fuel system. The sediment discharge valve can realize self-locking and unlocking of an open position by applying vertical operation to a piston. The valve can be installed in a multi-layer structural barrier or a narrow space in an aircraft, and can realize a self-locking oil discharge function without being visible to an operator.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A sedimentation valve for an aircraft fuel system, comprising a housing 1, a piston rod 2, an end cover 3, a spring 4, a sealing ring 5, an elastic retaining ring 6, an elastic steel sheet 7, and a stopper part 8.

[0006] The shell 1 is a cylindrical structure, with a plurality of "L"-shaped slots evenly distributed along the circumference on the top, and a plurality of oil holes formed along the circumference in the middle of the outer wall of the cylinder. The oil passing area of ​​the oil hole is not less than the inner diameter of the bottom of the shell 1, thereby ensuring the oil discharge flow rate; a thread is formed on the outer wall of the cylinder below the oil hole for installation with the aircraft equipment interface, and an elongated circular groove structure is provided in the threaded area for bonding rubber parts. After the sedimentation valve is installed on the aircraft body, the rubber parts are squeezed to prevent loosening; a hexagonal boss is formed on the outer wall of the cylinder below the threaded area for convenient twisting with tools; an elastic retaining ring mounting groove is formed near the port on the top of the inner wall of the cylinder of the shell 1, and a positioning boss is set along the circumference in the middle of the inner wall of the cylinder corresponding to the threaded area of ​​the outer wall of the cylinder, a plurality of stop part mounting grooves are evenly distributed along the circumference on the lower part of the inner wall of the cylinder, and a through hole is formed on the cylinder wall at the bottom of the groove, and a plurality of guide bosses are evenly distributed along the circumference on the bottom of the inner wall of the cylinder for guiding maintenance tools to the correct acting position.

[0007] The elastic steel sheet 7 is of an "arch bridge" type with a through hole in the center. The tail of the stop part 8 is a slide rod, and the head is a trapezoidal stop block. The slide rod passes through the through hole in the center of the arched side of the elastic steel sheet 7 to form a stop assembly. The stop assembly is provided with multiple groups, which are correspondingly installed in the stop part installation groove on the inner wall of the outer shell 1. The stop part 8 is inclined downward and its slide rod passes through the through hole at the bottom of the stop part installation groove. The elastic steel sheet 7 acts on the trapezoidal stop block of the stop part 8 to continuously provide an inward force.

[0008] The piston rod 2 is a four-stage 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 shell 1. A spring installation limit boss is formed along the circumference in the middle of this section. The spring 4 penetrates the piston rod 2 from the upper end, and its bottom is limited on the spring installation limit boss. The outer diameter of the spring installation limit boss matches the inner diameter of the shell 1; the piston rod 2 is inserted into the shell 1 from the upper end, and the spring installation limit boss cooperates with the positioning boss on the inner wall of the shell 1 to achieve limitation. The upper end of the piston rod 2 is not lower than the elastic retaining ring installation groove at the top of the shell 1, and the lower end is flush with the bottom port of the shell 1; a sealing ring installation groove is formed in the contact area between the second section of the piston rod 2 and the positioning boss of the shell 1, which is used to install the sealing ring 5 to ensure that the sedimentation valve is closed. When sealed; the shoulder between the first section and the second section of the piston rod 2 at the top serves as a limit 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 tightly 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 stop shoulder for the piston rod 2 to slide upward, and cooperates with the stop assembly to achieve self-locking of the sedimentation valve in the open position; the position of the limit shoulder and the stop shoulder, that is, the length of the first section and the fourth section of the piston rod 2 is set according to the distance between the positioning boss on the inner wall of the shell 1 and the upper end of the oil hole, so that after the piston rod 2 slides up to the open position, its spring-mounted limit boss is located above the oil hole, so that the fuel can flow into the inside of the shell 1 and out of the fuel tank.

[0009] The end cover 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 cover 3 is evenly distributed with multiple mounting bosses. It is installed on the shell 1 through the "L"-shaped slot on the top of the shell 1, so that the piston rod 2 is restricted in the shell 1, and the spring 4 is pressed between the end cover 3 and the spring mounting limit boss of the piston rod 2. The spring 4 always applies a downward spring force to the piston rod 2. The limit shoulder between the first section and the second section of the piston rod 2 matches with the lower end face of the end cover 3 to limit the upward sliding height of the piston rod 2; the upper end face of the end cover 3 is formed with a tool mounting groove for matching with the tool to achieve installation.

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

[0011] The maintenance tool used in conjunction with the sedimentation release valve needs to be provided with two types of end heads, one is a solid cylindrical end head, which is used to press against the lower end of the piston rod 2 and push upward to open the sedimentation release valve, and the other is a hollow cylindrical end head, the inner diameter of the cylinder is 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 sedimentation release valve.

[0012] Furthermore, the number of the stopper components composed of the elastic steel sheet 7 and the stopper part 8 is determined according to the internal load size of the sedimentation valve.

[0013] The assembly process of the sedimentation valve is as follows: after assembling the elastic steel sheet 7 and the stop part 8, install them in the stop part installation groove at the bottom of the shell 1; install the sealing ring 5 in the sealing ring installation groove of the piston rod 2, the spring 4 is sleeved on the piston rod 2, the end cover 3 is sleeved on the upper end of the piston rod 2, and the spring 4 is between the spring limiting boss of the piston rod 2 and the end cover 3; the piston rod 2 assembled with the spring 4, the end cover 3 and the sealing ring 5 is installed into the shell 1 from above, and the boss of the end cover 3 is assembled and limited with the "L"-shaped groove at the top of the shell 1; finally, the elastic retaining ring 6 is installed in the elastic retaining ring installation groove at the top of the shell 1.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention not only meets the oil discharge function of the traditional sedimentation discharge valve, but also adds a self-locking function in the open position, freeing up ground maintenance personnel and making it more practical;

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

[0017] 3. This fuel pump has good versatility and outstanding comprehensive advantages in functions 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 realize the oil release self-locking of the sedimentation valve arranged in a non-visual and long-distance environment, which has a very high promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 2 It is a component diagram of the present invention;

[0021] Figure 3 is a schematic diagram of the housing;

[0022] Figure 4 is a schematic diagram of the shell section;

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

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

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

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

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

[0028] In the figure: 1 housing; 2 piston rod; 3 end cover; 4 spring; 5 sealing ring; 6 elastic retaining ring; 7 elastic steel sheet; 8 stop part. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments improved or adjusted by ordinary technicians in this field based on the embodiments of the present invention belong to the protection scope of the present invention.

[0030] This embodiment provides a sedimentation valve for an aircraft fuel system, the sedimentation valve comprising a housing 1, a piston rod 2, an end cover 3, a spring 4, a sealing ring 5, an elastic retaining ring 6, an elastic steel sheet 7, and a stopper 8. Figure 1 , Figure 2 and Figure 7 shown.

[0031] like Figure 3 and Figure 4As shown, the shell 1 is a cylindrical structure, with three "L"-shaped slots evenly distributed along the circumference on the top, and four oil holes formed along the circumference in the middle of the outer wall of the cylinder. The oil passing area of ​​the oil hole is not less than the inner diameter of the bottom of the shell 1, thereby ensuring the oil discharge flow rate; the outer wall of the cylinder below the oil hole is threaded for installation with the bottom interface of the aircraft fuel tank, and an oblong groove structure is provided in the threaded area for bonding rubber parts. After the sedimentation valve is installed on the aircraft body, the rubber parts are squeezed to prevent loosening; the outer wall of the cylinder below the threaded area is formed with a hexagonal boss along the circumference for convenient twisting with tools; an elastic retaining ring mounting groove is formed near the port on the top of the inner wall of the shell 1, and a positioning boss is set along the circumference in the middle of the inner wall of the cylinder corresponding to the threaded area of ​​the outer wall of the cylinder, and two stop part mounting grooves are evenly distributed along the circumference on the lower part of the inner wall of the cylinder, and a through hole is formed on the cylinder wall at the bottom of the groove, and three guide bosses are evenly distributed along the circumference on the bottom of the inner wall of the cylinder for guiding the maintenance tool to the correct action position.

[0032] The elastic steel sheet 7 is of an "arch bridge" type with a through hole in the center. The tail of the stop part 8 is a slide rod, and the head is a trapezoidal stop block. The slide rod passes through the through hole in the center of the arched side of the elastic steel sheet 7 to form a stop assembly. The stop assembly is provided with two groups, which are correspondingly installed in the stop part installation groove on the inner wall of the outer shell 1. The stop part 8 is inclined downward and its slide rod passes through the through hole at the bottom of the stop part installation groove. The elastic steel sheet 7 acts on the trapezoidal stop block of the stop part 8 to continuously provide an inward force.

[0033] like Figure 5 As shown, the piston rod 2 is a four-stage 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 shell 1 tube. A spring installation limit boss is formed along the circumference in the middle of this section. The spring 4 penetrates the piston rod 2 from the upper end, and its bottom is pressed against the spring installation limit boss. The outer diameter of the spring installation limit boss matches the inner diameter of the shell 1; the piston rod 2 is inserted into the shell 1 from the upper end, and the spring installation limit boss cooperates with the positioning boss on the inner wall of the shell 1 tube to achieve limitation. The upper end of the piston rod 2 is flush with the elastic retaining ring installation groove at the top of the shell 1, and the lower end is flush with the bottom port of the shell 1; two sealing ring installation grooves are formed in the contact area between the second section of the piston rod 2 and the positioning boss of the shell 1 for installing the sealing ring 5. Ensure that the sedimentation valve is sealed when closed; the shoulder between the first and second sections of the piston rod 2 at the top serves as a limit 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 tightly 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 stop shoulder for the piston rod 2 to slide upward, and cooperates with the stop assembly to achieve self-locking of the sedimentation valve in the open position; the positions of the limit shoulder and the stop 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 hole, so that after the piston rod 2 slides up to the open position, its spring-mounted limit boss is located above the oil hole, so that the fuel can flow into the inside of the outer shell 1 and out of the fuel tank.

[0034] like Figure 6 As shown, the end cover 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. Three mounting bosses are evenly distributed on the outer edge of the end cover 3, which is installed on the shell 1 through the "L"-shaped slot on the top of the shell 1, so that the piston rod 2 is restricted in the shell 1, and the spring 4 is pressed between the end cover 3 and the spring mounting limit boss of the piston rod 2. The spring 4 always applies a downward spring force to the piston rod 2, and the limit shoulder between the first section and the second section of the piston rod 2 matches with the lower end face of the end cover 3 to limit the upward sliding height of the piston rod 2; the upper end face of the end cover 3 is provided with a tool mounting groove for matching with the tool to achieve installation.

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

[0036] The assembly process of the sedimentation release valve is as follows: after assembling the elastic steel sheet 7 and the stopper part 8, install them in the stopper part installation groove at the bottom of the shell 1; install the sealing ring 5 in the sealing ring installation groove of the piston rod 2, the spring 4 is sleeved on the piston rod 2, the end cover 3 is sleeved on the upper end of the piston rod 2, and the spring 4 is between the spring limiting boss of the piston rod 2 and the end cover 3; the piston rod 2 assembled with the spring 4, the end cover 3 and the sealing ring 5 is installed into the shell 1 from above, and the boss of the end cover 3 is assembled and limited with the "L"-shaped groove at the top of the shell 1; finally, the elastic retaining ring 6 is installed in the elastic retaining ring installation groove at the top of the shell 1; the upper end of the assembled sedimentation release valve is inserted into the interface at the bottom of the fuel tank, and is screwed and installed on the interface.

[0037] After the sedimentation valve is installed inside the aircraft, an oil drain collection box should be arranged below the sedimentation valve, and a corresponding hose assembly should be set. The hose can pass through the multi-layer body structure, and an oil drain interface should be set on the lower surface of the aircraft, that is, an oil drain passage should be arranged inside the aircraft for the sedimentation valve. The maintenance tools used to open and close the sedimentation valve are flexible strut maintenance tools, the strut diameter should be slightly smaller than the inner diameter of the hose to ensure that the maintenance tool can be inserted without excessive bending. At the same time, the maintenance tool needs to have two types of ends, one is a solid cylindrical end, which is used to press against the lower end of the piston rod 2 and push upward to open the sedimentation valve, and the other is a hollow cylindrical end, the inner diameter of the cylinder is larger than the outer diameter of the third section of the piston rod 2, and is used to push open the stop assembly to unlock and close the sedimentation valve. Figure 8 and Fig. 9 shown.

[0038] The opening process of the sedimentation valve is as follows: the maintenance tool is installed with a solid cylindrical end head, which is extended from the aircraft oil discharge interface along the hose assembly. After being adjusted by the guide boss at the bottom of the sedimentation valve housing 1, the end head is aligned with the bottom of the piston rod 2, and the piston rod 2 is lifted to move upward. When the stop boss at the bottom of the piston rod 2 is pushed to the top of the stop part 8, the stop part 8 pops out under the action of the elastic steel sheet 7, and the stop part 8 jams the stop boss to lock the sedimentation valve in the open position.

[0039] The closing process of the sedimentation valve is as follows: the maintenance tool is installed with a hollow cylindrical end head, which is extended from the aircraft oil discharge interface along the hose assembly. After adjustment by the guide boss at the bottom of the sedimentation valve housing 1, the inner hole of the end head is aligned with the piston rod 2, and the piston rod 2 falls into the inner hole of the end head. The end head continues to move upward along the piston rod 2 until it contacts the inclined surface of the stop part 8 and pushes the stop part 8 to move outward. During this process, the elastic steel sheet 7 is continuously compressed. When the stop part 8 is separated from the stop boss at the bottom of the piston rod 2, the sedimentation valve is released, and the piston rod 2 slides along the inner hole of the end head to the closed position under the action of the spring 4.

[0040] The above-described embodiments merely express the implementation methods of the present invention, but they should not be understood as limiting the scope of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A sedimentation valve for an aircraft fuel system, characterized in that: It comprises a housing (1), a piston rod (2), an end cover (3), a spring (4), an elastic steel sheet (7), and a stopper (8); The housing (1) is a cylindrical structure, with a plurality of "L"-shaped slots evenly distributed along the circumference at the top, and a plurality of oil holes formed along the circumference in the middle of the outer wall of the cylinder; threads are formed on the outer wall of the cylinder below the oil holes for installation with the aircraft equipment interface; a positioning boss is formed along the circumference in the middle of the inner wall of the cylinder corresponding to the threaded area of ​​the outer wall of the cylinder, and a plurality of stopper component installation grooves are evenly distributed along the circumference at the lower part of the inner wall of the cylinder; The elastic steel sheet (7) is of an "arch bridge" type with a through hole in the center. The tail of the stop part (8) is a slide rod, and the head is a trapezoidal stop block. The slide rod passes through the through hole in the center of the arched side of the elastic steel sheet (7) to form a stop assembly. The stop assembly is provided with multiple groups, which are correspondingly installed in the stop part installation groove on the inner wall of the shell (1). The stop part (8) is inclined downward and its slide rod passes through the through hole at the bottom of the stop part installation 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-stage variable diameter cylindrical structure, the second stage having the largest outer diameter, which matches the inner diameter of the positioning boss on the inner wall of the shell (1). A spring installation limiting boss is formed along the circumference of the middle part of the stage. The spring (4) penetrates the piston rod (2) from the upper end, and its bottom is limited on the spring installation limiting boss. The outer diameter of the spring installation limiting boss matches the inner diameter of the shell (1); the piston rod (2) is inserted into the shell (1) from the upper end, and the spring installation limiting boss cooperates with the positioning boss on the inner wall of the shell (1) to achieve limiting; the piston rod (2) is located in the first stage at the upper part. The shoulder between the second section serves as a limit shoulder for the piston rod (2) to slide upward; the third section of the piston rod (2) cooperates with a stop assembly, and the stop assembly is pressed tightly 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 stop shoulder for the piston rod (2) to slide upward, and cooperates with the stop assembly to achieve self-locking of the sedimentation valve in the open position; after the piston rod (2) slides up to the open position, its spring-mounted limit boss is located above the oil hole of the housing (1), so that the fuel can flow into the housing (1) and out of the fuel tank; The end cover (3) has a through hole at its center, the inner diameter of the through hole matches the outer diameter of the first section of the piston rod (2), and the outer edge of the end cover (3) is evenly distributed with a plurality of mounting bosses, which are mounted on the outer shell (1) through an "L"-shaped slot at the top of the outer shell (1) to restrict the piston rod (2) within the outer shell (1), and the spring (4) is pressed between the end cover (3) and the spring mounting limiting boss of the piston rod (2), and the limiting shoulder between the first section and the second section of the piston rod (2) matches the lower end surface of the end cover (3) to limit the upward sliding height of the piston rod (2).

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

3. The sedimentation relief valve of an aircraft fuel system according to claim 1, characterized in that: The threaded area of ​​the housing (1) is provided with an oblong groove structure for bonding the rubber part, so as to prevent the sedimentation valve from loosening after installation.

4. The sedimentation relief valve of an aircraft fuel system according to claim 1, characterized in that: The bottom of the inner wall of the shell (1) is evenly distributed along the circumference with a plurality of guide bosses for guiding the maintenance tool to the correct action position.

5. The sedimentation valve of an aircraft fuel system according to claim 1, characterized in that: The number of the stopper components composed of the elastic steel sheet (7) and the stopper parts (8) is determined according to the internal load size of the sedimentation valve.

6. The sedimentation relief valve of an aircraft fuel system according to claim 1, characterized in that: The sedimentation release valve further comprises an elastic retaining ring (6). An elastic retaining ring installation groove is formed at 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 installation groove to prevent the end cover (3) from moving.

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

8. A sedimentation relief valve for an aircraft fuel system according to any one of claims 1 to 7, characterized in that: The maintenance tool used in conjunction with the sediment release valve needs to be provided with two end heads, one is a solid cylindrical end head for opening the sediment release valve, and the other is a hollow cylindrical end head, the inner diameter of the cylinder is larger than the outer diameter of the third section of the piston rod (2), and is used to close the sediment release valve.

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