Integrated differential pressure annunciator

Abstract

The invention discloses an integrated differential pressure annunciator, belongs to the technical field of differential pressure annunciators, and solves the problems that an existing differential pressure annunciator is large in size, ablated in contact and single in signal. The device comprises a shell, a push rod is vertically and slidably arranged in the shell, a microswitch and a socket which are located in the shell are arranged on the two sides of the push rod respectively, a piston is slidably arranged at the position, located at the bottom of the push rod, in the shell, a movable magnet is arranged in the top end of the piston, and a static magnetic ring is arranged on the movable magnet. According to the invention, the instantaneous characteristic between the moving magnet and the static magnetic ring and the small-volume pressure sensitive element formed by the spring are utilized, and a bouncing system formed by the moving magnet and the static magnetic ring has the characteristics of rapid action and sudden displacement change, and is high in pressure signal sensitivity, simple in structure, small in size, high in reliability and high in reliability. The requirements of small size and light weight of engine accessories can be better met, and meanwhile, the combination of the push rod, the microswitch and the socket is adopted, so that synchronous alarm of electric signals and mechanical signals is realized.

Description

Technical Field

[0001] The invention relates to the technical field of differential pressure signal devices, and in particular to an integrated differential pressure signal device. Background Art

[0002] The fuel system of aircraft engines has high requirements for fuel cleanliness. To ensure system reliability, it is usually necessary to measure the pressure difference at both ends of the oil filter to detect the blockage status of the oil filter. When the oil filter flow resistance reaches the limit value, the pressure difference signal device sends an electrical signal or a mechanical signal to indicate an early warning. At the same time, a bypass device is set for the oil filter. When the oil filter flow resistance reaches the bypass pressure, the bypass valve opens to bypass the fuel to ensure normal fuel supply to the engine. The pressure difference signal device currently used in the fuel system has three main shortcomings:

[0003] 1. It is difficult to miniaturize the differential pressure signal device with small pressure difference. When elastic elements are used as sensitive elements, when the working pressure point is low, in order to produce the required displacement, when the thickness of the diaphragm cannot be further reduced, it is generally necessary to increase the effective working area of ​​the diaphragm or the diaphragm box, which makes it difficult to achieve miniaturization. Aviation and aerospace have strict requirements on product volume and weight. When the reed switch is used as a sensitive element, it is very easy to be interfered by the surrounding electromagnetic devices and cause false alarms. At the same time, when the reed switch is used under high temperature conditions, its glass is very easy to be damaged by temperature stress; when the Hall element is used as a sensitive element, the cost is high and a special processing circuit is required. The following two principles are not suitable for aircraft engine fuel systems.

[0004] 2. Contact erosion. The contacts of the differential pressure signal device with the existing structure close and open slowly, which is easy to generate sparks and arcs, causing contact erosion of the pressure switch. It is more obvious in a vibrating environment, seriously affecting the reliability and life of the pressure switch. Moreover, when the pressure value changes near the rated starting pressure value, the contacts will close and open repeatedly, and the pressure switch will send out a false alarm signal. If the back end of the pressure switch is connected to an inductive load, there will be an induced electromotive force at the moment the contacts are disconnected, which will accelerate the erosion of the contact points.

[0005] 3. The existing differential pressure signal device can only provide one of the electrical signal or mechanical signal. Usually, the oil filter blockage signal has a low alarm level, and the alarm electrical signal needs to be specifically read in the flight parameters or controller, which can easily lead to untimely maintenance. Summary of the invention

[0006] In view of the above problems in the prior art, the present invention provides an integrated differential pressure signal device, which solves the problems of large volume, contact ablation and single signal of the prior differential pressure signal device.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] Provided is an integrated differential pressure signal device, comprising a shell with a T-shaped cross section, a push rod is vertically slidably arranged in the shell, a micro switch and a socket located in the shell are respectively arranged on both sides of the push rod, a knob spring sheet is arranged at the bottom of the micro switch, the free end of the knob spring sheet is placed on the step circle in the middle of the push rod, and the push rod will drive the knob spring sheet to trigger the micro switch during the upward movement of the push rod, and the micro switch transmits the changed electrical signal to the socket; a piston is slidably arranged at the bottom of the push rod in the shell, the bottom end of the piston is arranged in a nozzle tube, the nozzle tube is fixedly connected to the bottom of the piston through a spring, and liquid inlets are opened on both sides of the nozzle tube at the piston sealing connection; the top end of the piston enters the shell and is provided with a moving magnet inside, and a static magnetic ring located on the push rod is arranged at the outer ring of the moving magnet; when the piston is in the initial position, there is an attractive force between the static magnetic ring and the moving magnet, and when the piston moves, there is a repulsive force between the static magnetic ring and the moving magnet.

[0009] In this solution, when the two ends of the piston overcome the force of the spring due to the pressure difference, they will move up or down in the nozzle tube to a preset point, so that the static magnetic ring will instantly switch the suction stress of the moving magnet to repulsion, causing the push rod to bounce upward, and the outer shell will emerge from the top of the push rod to form a mechanical alarm signal, and during the displacement process, the knob spring sheet is pushed to trigger the micro switch, and the micro switch transmits the switch signal to the socket through the wire to output an electrical alarm signal. This solution uses the instantaneous characteristics between the moving magnet and the static magnetic ring and the small-volume pressure sensitive element composed of the spring. It has a simple structure, small size, and high reliability. It can better meet the requirements of small size and light weight of engine accessories. At the same time, the combination of the push rod, the micro switch and the socket is used to realize the synchronous alarm of electrical and mechanical signals, solving the problems of large volume, contact ablation and single signal of the existing differential pressure signal device.

[0010] Furthermore, the nozzle pipe is welded to the bottom of the shell, the bottom liquid inlet of the nozzle pipe is internally threadedly connected with an adjusting nut, a retaining ring is arranged on the adjusting nut, and a spring is arranged between the retaining ring and the bottom of the piston. The adjusting nut can adjust the position of the retaining ring, thereby adjusting the elastic force of the spring, so as to facilitate the adjustment of the pre-pressure of the piston.

[0011] Furthermore, the bottom of the piston is a stepped cylindrical structure with a hollow interior and an opening at the bottom end, and an O-ring is provided on the outer wall of the large diameter end of the bottom of the piston. The O-ring, as a pressure difference isolation element, can achieve a small damping dynamic seal, which is conducive to small pressure measurement and product miniaturization.

[0012] Furthermore, the liquid inlet at the bottom of the nozzle tube is the first liquid inlet, the liquid inlet on the nozzle tube close to the small diameter end of the piston is the second liquid inlet, and the diameter of the first liquid inlet is larger than that of the second liquid inlet.

[0013] Furthermore, the bottom of the push rod is a stepped cylindrical structure with a hollow interior and an opening at the bottom end, the top sliding seal of the piston is arranged in the opening at the bottom of the push rod, and the static magnetic ring is arranged inside the outer wall of the bottom end of the push rod. When the push rod is reset, the moving magnet of the bottom of the push rod that pushes the piston is located in the middle of the static magnetic ring.

[0014] Furthermore, the middle bottom of the shell is provided with a channel slidably connected to the push rod, and a stopper sleeved on the push rod is threadedly connected in the channel. The stopper can be adjusted up and down to limit the bounce depth of the push rod.

[0015] Furthermore, a transparent cover is arranged on the middle top of the shell, and a red warning mark is attached to the top of the push rod; when the push rod is in an upward state, the red warning mark is exposed in the transparent cover.

[0016] Furthermore, a self-reset button for triggering the knob spring piece is arranged on the bottom of the micro switch. The arrangement of the self-reset button facilitates resetting the electrical signal of the micro switch without the squeezing of the knob spring piece.

[0017] Furthermore, one end of the knob spring sheet is hinged in the housing, and the other end of the knob spring sheet extends to the step circle in the middle of the push rod.

[0018] Furthermore, a torsion spring is provided at the hinged connection between the knob spring piece and the housing, and the provision of the torsion spring facilitates the knob spring piece to reset.

[0019] The present invention discloses an integrated differential pressure signal device, which has the following beneficial effects:

[0020] The present invention utilizes the instantaneous characteristics between the moving magnet and the static magnetic ring and a small-volume pressure sensitive element composed of a spring. The bouncing system composed of the moving magnet and the static magnetic ring has the characteristics of rapid action and sudden displacement change, and the pressure signal has high sensitivity. It can avoid the phenomenon of contact ablation caused by repeated connection and disconnection in a vibration environment due to the small contact gap of the pressure switch. It has a simple structure, small size, and high reliability, and can better meet the requirements of small volume and light weight of engine accessories. At the same time, a combination of a push rod, a micro switch and a socket is adopted to realize the synchronous alarm of electrical signals and mechanical signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of an integrated pressure difference signal device;

[0022] Among them: 1. Take-over nozzle; 2. O-ring; 3. Adjusting nut; 4. Retaining ring; 5. Spring; 6. Piston; 7. Moving magnet; 8. Static magnetic ring; 9. Push rod; 10. Stopper; 11. Housing; 12. Knob spring sheet; 13. Micro switch; 14. Socket; 15. Transparent cover. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0024] refer to Figure 1 This embodiment provides an integrated differential pressure signal device, including a housing 11, a nozzle 1, a push rod 9, a micro switch 13, a socket 14 and a piston 6.

[0025] The cross section of the shell 11 is T-shaped, and a push rod 9 is vertically slidably arranged inside the shell 11. A transparent cover 15 is arranged on the middle top of the shell 11, and a red warning mark is attached to the top of the push rod 9; when the push rod 9 is in the upward state, the red warning mark is exposed in the transparent cover 15.

[0026] A micro switch 13 and a socket 14 are respectively arranged on both sides of the push rod 9, and a knob spring sheet 12 is arranged at the bottom of the micro switch 13. One end of the knob spring sheet 12 is hinged in the shell 11, and a torsion spring is arranged at the hinged connection between the knob spring sheet 12 and the shell 11. The other end of the knob spring sheet 12 extends to the step circle in the middle of the push rod 9. A self-reset button for triggering the knob spring sheet 12 is arranged at the bottom of the micro switch 13. When the push rod 9 moves upward, it will drive the knob spring sheet 12 to trigger the self-reset button of the micro switch 13, and the micro switch 13 will transmit the changed electrical signal to the socket 14.

[0027] A piston 6 is slidably disposed at the bottom of the push rod 9 in the housing 11, and the bottom end of the piston 6 is disposed in the nozzle 1. Liquid inlets are provided on both sides of the sealing connection of the piston 6 on the nozzle 1. The liquid inlet at the bottom of the nozzle 1 is the first liquid inlet, and the liquid inlet on the nozzle 1 near the small diameter end of the piston 6 is the second liquid inlet. The diameter of the first liquid inlet is larger than that of the second liquid inlet.

[0028] The nozzle 1 is welded to the bottom of the housing 11, and the bottom liquid inlet of the nozzle 1 is internally threadedly connected with an adjusting nut 3, a retaining ring 4 is arranged on the adjusting nut 3, and a spring 5 is arranged between the retaining ring 4 and the bottom of the piston 6. The adjusting nut 3 can adjust the position of the retaining ring 4, thereby adjusting the elastic force of the spring 5, so as to adjust the pre-pressure of the piston 6. At the same time, since the force-bearing areas of the first liquid inlet and the second liquid inlet and the piston 6 are different, the force of the first liquid inlet pushing the piston 6 upward is greater than the force of the second liquid inlet pushing the piston 6 downward, so that the setting of the spring 5 can not only adjust the pre-pressure that needs to be overcome when the piston 6 moves, but also the additional pulling force provided by the spring 5 can facilitate the piston 6 to be in the initial balanced position.

[0029] The top end of the piston 6 enters into the outer shell 11 and a moving magnet 7 is arranged inside. A static magnetic ring 8 located on the push rod 9 is arranged on the outer ring of the moving magnet 7. When the piston 6 is in the initial position, there is an attractive force between the static magnetic ring 8 and the moving magnet 7. When the piston 6 moves, there is a repulsive force between the static magnetic ring 8 and the moving magnet 7.

[0030] As a further solution of this embodiment, the middle bottom of the housing 11 is provided with a channel slidably connected to the push rod 9, and the inner thread of the channel is connected with a stopper 10 sleeved on the push rod 9. The stopper 10 can be adjusted up and down to limit the bounce depth of the push rod 9.

[0031] Specifically, as a specific structure of the piston 6, the bottom of the piston 6 is a stepped cylindrical structure with a hollow interior and an opening at the bottom end, and an O-ring 2 is provided on the outer wall of the large diameter end of the bottom of the piston 6. The O-ring 2 serves as a pressure difference isolation element and can realize a small damping dynamic seal, which is beneficial to small pressure measurement and product miniaturization.

[0032] Specifically, as a specific structure of the push rod 9, the bottom of the push rod 9 is a stepped cylindrical structure with a hollow interior and an opening at the bottom end, the top sliding seal of the piston 6 is arranged in the opening at the bottom of the push rod 9, and the static magnetic ring 8 is arranged inside the outer wall of the bottom end of the push rod 9. When the push rod 9 is reset, the bottom of the push rod 9 pushes the moving magnet 7 of the piston 6 to be located in the middle of the static magnetic ring 8.

[0033] In summary, the working principle of this solution is:

[0034] The filler nozzle 1 is threadedly connected in the aircraft engine fuel system. When there is a pressure difference between the first liquid inlet and the second liquid inlet in the filler nozzle 1, the two ends of the piston 6 overcome the force of the spring 5 due to the pressure difference. When the piston 6 moves up or down to a preset point in the filler nozzle 1, the static magnetic ring 8 will instantly switch the suction stress with the moving magnet 7 to a repulsive force, causing the push rod 9 to bounce upward, and the shell 11 emerges from the top of the push rod 9 to form a mechanical alarm signal, and during the displacement process, the knob spring sheet 12 is pushed to trigger the micro switch 13. The micro switch 13 transmits the switch signal to the socket 14 through a wire, and outputs an electrical alarm signal.

[0035] When the pressure difference balance needs to be reset, remove the transparent cover 15, press the push rod 9 downward, so that the moving magnet 7 enters the static magnetic ring 8, and there is attraction between the two ends of the static magnetic ring 8 and the two ends of the moving magnet 7, completing the reset of the pressure difference signal device.

[0036] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. An integrated differential pressure signal device, characterized in that: The invention comprises a housing (11) with a T-shaped cross section, a push rod (9) being vertically slidably arranged in the housing (11), a micro switch (13) and a socket (14) being arranged on both sides of the push rod (9) and being located in the housing (11), a knob spring sheet (12) being arranged at the bottom of the micro switch (13), a free end of the knob spring sheet (12) being placed on a step circle in the middle of the push rod (9), and the push rod (9) driving the knob spring sheet (12) to trigger the micro switch (13) when moving upward, and the micro switch (13) transmitting a changed electrical signal to the socket (14); A piston (6) is slidably arranged at the bottom of a push rod (9) in a housing (11), the bottom end of the piston (6) is arranged in a nozzle (1), the nozzle (1) is fixedly connected to the bottom of the piston (6) via a spring (5), and liquid inlets are provided on both sides of a sealing connection with the piston (6) on the nozzle (1); the top end of the piston (6) enters the housing (11) and a moving magnet (7) is arranged inside, and a static magnetic ring (8) located on the push rod (9) is arranged at the outer ring of the moving magnet (7); when the piston (6) is in an initial position, there is an attractive force between the static magnetic ring (8) and the moving magnet (7), and when the piston (6) moves, there is a repulsive force between the static magnetic ring (8) and the moving magnet (7).

2. The integrated differential pressure signal device according to claim 1, characterized in that: The filler nozzle (1) is welded to the bottom of the housing (11); an adjusting nut (3) is threadedly connected to the bottom liquid inlet of the filler nozzle (1); a retaining ring (4) is arranged on the adjusting nut (3); and a spring (5) is arranged between the retaining ring (4) and the bottom of the piston (6).

3. The integrated differential pressure signal device according to claim 1, characterized in that: The bottom of the piston (6) is a stepped cylindrical structure with a hollow interior and an opening at the bottom end. An O-type sealing ring (2) is provided on the outer wall of the large diameter end of the bottom of the piston (6).

4. The integrated differential pressure signal device according to claim 3, characterized in that: The liquid inlet at the bottom of the nozzle (1) is the first liquid inlet, and the liquid inlet on the nozzle (1) close to the small diameter end of the piston (6) is the second liquid inlet. The diameter of the first liquid inlet is larger than that of the second liquid inlet.

5. The integrated differential pressure signal device according to claim 1, characterized in that: The bottom of the push rod (9) is a stepped cylindrical structure with a hollow interior and an opening at the bottom end. The top sliding seal of the piston (6) is arranged in the opening at the bottom of the push rod (9), and the static magnetic ring (8) is arranged inside the outer wall of the bottom end of the push rod (9).

6. The integrated differential pressure signal device according to claim 1, characterized in that: The middle bottom of the housing (11) is provided with a channel slidably connected to the push rod (9), and a stopper (10) sleeved on the push rod (9) is threadedly connected to the inner thread of the channel.

7. The integrated differential pressure signal device according to claim 1, characterized in that: A transparent cover (15) is provided on the middle top of the housing (11), and a red warning mark is attached to the top of the push rod (9); when the push rod (9) is in an upward state, the red warning mark is exposed in the transparent cover (15).

8. The integrated differential pressure signal device according to claim 1, characterized in that: A self-reset button for being triggered by the knob spring sheet (12) is arranged on the bottom of the micro switch (13).

9. The integrated differential pressure signal device according to claim 1, characterized in that: One end of the knob spring sheet (12) is hinged in the housing (11), and the other end of the knob spring sheet (12) extends to the middle step circle of the push rod (9).

10. The integrated differential pressure signal device according to claim 9, characterized in that: A torsion spring is provided at the hinged connection between the knob spring sheet (12) and the housing (11).

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