Negative pressure relief valve guide structure

Abstract

The utility model relates to the field of aviation cockpit pressure control, in particular to a negative pressure relief valve guide structure. Comprising a shell, a valve, a rotating shaft, a guide rod, a spring and a nut, the valve is hinged to the shell through a rotating shaft, two symmetrical guide rods are arranged on the side, close to the free end of the valve, of the shell, kidney-shaped holes are symmetrically distributed in one side of the free end of the valve, the guide rods penetrate through the kidney-shaped holes and springs, and the guide rods are screwed and tightened through nuts. When the difference between the pressure outside the shell and the pressure inside the shell reaches a threshold value, the pressure acts on the valve, and the free end of the valve upwards overcomes the elastic force of the spring with the rotating shaft as the rotating center to be opened. When the difference between the pressure outside the shell and the pressure inside the shell is lower than a threshold value, the elastic force of the spring pushes the free end of the valve to the initial position. The inclined guide structure is higher in stability, the phenomenon of clamping stagnation of the guide rod and the valve is avoided, and the purpose of reducing the pressure difference inside and outside the cabin is achieved.

Description

Technical Field

[0001] This utility model relates to the field of aircraft cabin pressure control, and specifically to a negative pressure relief valve guide structure. Background Technology

[0002] The negative pressure relief valve is one of the actuators of the cabin pressure control system. When an aircraft is making a high-altitude dive or emergency descent, the descent rate is high and the external environmental pressure increases rapidly. The cabin pressure increases at a relatively slow rate due to limitations, while the external atmospheric static pressure increases more rapidly. This results in the external atmospheric pressure being higher than the cabin pressure, creating a negative pressure differential in the cabin. When the aircraft generates a large negative pressure differential, if it exceeds the aircraft's structural limits, it will lead to structural damage to the aircraft, or even the aircraft breaking apart, resulting in the destruction of the aircraft and loss of life.

[0003] The cabin pressure control system is equipped with a negative pressure relief valve to ensure that the positive and negative pressure difference in the aircraft cabin does not exceed the limit value, i.e., the safety pressure relief function. The cabin negative pressure difference safety pressure relief function test is to simulate the possible failure state of the pressure relief valve when the air conditioning loses its air supply, and to verify that during the emergency descent or high-speed climb of the aircraft, the negative pressure relief valve is sufficient to ensure that the negative pressure difference in the cabin does not exceed the limit value, thus ensuring flight safety.

[0004] Currently, the structures used in the industry for negative pressure relief valves have disadvantages such as small flow area, large external dimensions, heavy weight, large degree of freedom, low reliability, and poor stability, which cannot better introduce external airflow into the cabin to complete the negative pressure relief function. Utility Model Content

[0005] Utility Model Purpose

[0006] A negative pressure relief valve guide structure suitable for large-cabin aircraft is proposed. During normal flight, the negative pressure relief valve is in the closed state. When the aircraft descends rapidly and the pressure difference between the external atmospheric pressure and the cabin pressure reaches a critical value, the pressure acting on the shell will overcome the spring force, causing the valve to open. Atmosphere enters the cabin through the valve, reducing the pressure difference and ensuring the structural safety of the aircraft.

[0007] Compared to guide structures with vertical rods, the inclined guide structure of this invention has higher stability, avoids the phenomenon of guide rods and valves getting stuck, and achieves the purpose of reducing the pressure difference between the inside and outside of the cabin.

[0008] Technical solution

[0009] A negative pressure relief valve guide structure includes a housing, a valve, a pivot, guide rods, a spring, and a nut. The valve is hinged to the housing via the pivot. Two symmetrical guide rods are arranged on the housing near the free end of the valve. A waist-shaped hole is symmetrically distributed on the free end of the valve. The guide rods pass through the waist-shaped hole and the spring, and are tightened by screwing the nut. When the pressure difference between the external air pressure and the internal pressure of the housing reaches a threshold, the air pressure acts on the valve, and the free end of the valve opens upwards against the spring force, rotating around the pivot. When the pressure difference between the external air pressure and the internal pressure of the housing is lower than the threshold, the spring force pushes the free end of the valve to its initial position.

[0010] Furthermore, it also includes a sealing gasket, which is disposed on the housing and located in the contact area between the housing and the valve to achieve a seal on the valve.

[0011] Furthermore, it also includes a guide sleeve, which is disposed on the guide rod and located inside the spring, and is used to constrain the spring and prevent the spring from swinging left and right.

[0012] Furthermore, it also includes a pivot bushing, which is installed at the pivot connection between the valve and the housing to ensure that the valve rotates flexibly.

[0013] Furthermore, it also includes a spring bushing, which is disposed on the valve, through which the guide rod passes and on which the spring presses.

[0014] Furthermore, the tilt angle of the guide rod on the housing and the length of the oblong hole should meet the opening requirements of the valve and prevent jamming.

[0015] The beneficial effects of this application are as follows:

[0016] Under certain operating conditions, when the pressure difference between the external atmospheric pressure and the cabin pressure reaches a critical value, the pressure acting on the valve will overcome the spring force, causing the valve to move along the inclined guide rod, opening the valve, and allowing air to enter the cabin through the valve, reducing the pressure difference and ensuring the structural safety of the aircraft. The aforementioned utility model uses an inclined guide structure to achieve smooth valve opening, ensuring the introduction of fresh outside air into the cabin while avoiding the risk of jamming. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an embodiment of a negative pressure relief valve guide structure of this utility model;

[0018] Figure 2 This is a diagram showing the opening of the trapdoor;

[0019] Figure 3 This is a schematic diagram of a waist-shaped hole. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be described in more detail below with reference to the embodiments of this utility model. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model. The embodiments described below with reference to the embodiments are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to their specific implementation.

[0021] The negative pressure relief valve guide structure includes a housing 1, a valve 2, a rotating shaft 3, guide rods 7, a spring 8, and a nut 10. The valve 2 is hinged to the housing 1 via the rotating shaft 3. Two symmetrical guide rods 7 are arranged on the housing 1 near the free end of the valve 2. A waist-shaped hole is symmetrically distributed on the free end of the valve 2. The guide rods 7 pass through the waist-shaped hole and the spring 8, and are screwed together with the nut 10. When the pressure difference between the external air pressure and the internal pressure of the housing 1 reaches a threshold value, the air pressure acts on the valve 2, and the free end of the valve 2 opens upwards against the elastic force of the spring 8, with the rotating shaft 3 as the rotation center. When the pressure difference between the external air pressure and the internal pressure of the housing 1 is lower than the threshold value, the elastic force of the spring 8 pushes the free end of the valve 2 to its initial position.

[0022] In one embodiment of this utility model, a sealing gasket 5 is also included. The sealing gasket 5 is disposed on the housing 1 and located in the contact area between the housing 1 and the valve 2, thereby achieving a seal on the valve 2.

[0023] In one embodiment of this utility model, a guide sleeve 9 is also included. The guide sleeve 9 is disposed on the guide rod 7 and located inside the spring 8, and is used to constrain the spring 8 to prevent the spring 8 from swinging left and right.

[0024] In one embodiment of this utility model, a rotating shaft bushing 4 is also included. The rotating shaft bushing 4 is disposed at the connection between the valve 2 and the rotating shaft 3 of the housing 1 to ensure that the valve 2 rotates flexibly.

[0025] In one embodiment of this utility model, a spring bushing 6 is also included. The spring bushing 6 is disposed on the valve 2, the guide rod 7 passes through the spring bushing 6, and the spring 8 presses on the spring bushing 6.

[0026] In one embodiment of this utility model, the tilt angle of the guide rod 7 on the housing 1 and the length of the waist-shaped hole should meet the opening requirements of the valve 2 and should not cause jamming.

[0027] Under normal circumstances, the valve is closed. Under certain operating conditions, when the pressure difference between the outside atmospheric pressure and the cabin pressure reaches a critical value, the pressure acting on the valve will overcome the spring force, causing the valve to move along the inclined guide rod.

[0028] A negative pressure relief valve guide structure suitable for large-cabin aircraft is characterized by: nut, guide sleeve, spring, guide rod, bushing, pivot bushing, valve, housing, pivot, and sealing gasket.

[0029] Nuts and guide sleeves are installed on the guide rod to guide the direction of spring force transmission. Springs are installed on the guide rod to transmit force on the valve. Bushings are installed on the valve to reduce friction between the guide rod and the valve. A rotating shaft connects the valve and the valve housing to fix the valve.

[0030] This invention does not affect the normal ventilation function of the negative pressure relief valve. Under normal circumstances, the negative pressure relief valve is used to control the cabin air intake, with an opening range of 0° to 17°. At this range, there is an appropriate margin between the valve and the guide rod to avoid friction. When the negative pressure difference exceeds 4.83 kPa, outside air flows into the cabin to balance the pressure difference between the inside and outside of the cabin.

[0031] The advantage of this invention is that when the negative pressure relief valve is opened under uneven force, the inclined guide rod can better avoid the risk of jamming, ensuring that the air flowing into the cabin is not affected, and thus has higher reliability.

[0032] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this invention. It should be understood that the above descriptions are merely specific embodiments of this invention and are not intended to limit this invention. Within the spirit and principles of this invention, any person skilled in the art may modify or alter the disclosed technical content to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, alterations, modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solution of this invention should be included within the protection scope of this invention.

Claims

1. A negative pressure relief valve guide structure, characterized in that, The device includes a housing, a valve, a pivot, guide rods, a spring, and a nut. The valve is hinged to the housing via the pivot. Two symmetrical guide rods are arranged on the housing near the free end of the valve. A waist-shaped hole is symmetrically distributed on the free end of the valve. The guide rods pass through the waist-shaped hole and the spring, and are tightened with nuts. When the pressure difference between the outside and inside of the housing reaches a threshold, the pressure acts on the valve, causing the free end of the valve to open upwards against the spring force, rotating around the pivot. When the pressure difference is below the threshold, the spring force pushes the free end of the valve to its initial position.

2. The structure as described in claim 1, characterized in that, It also includes a sealing gasket, which is disposed on the housing and located in the contact area between the housing and the valve to achieve a seal on the valve.

3. The structure as described in claim 2, characterized in that, It also includes a guide sleeve, which is disposed on the guide rod and located inside the spring, and is used to constrain the spring and prevent the spring from swinging left and right.

4. The structure as described in claim 3, characterized in that, It also includes a pivot bushing, which is installed at the pivot connection between the valve and the housing to ensure that the valve rotates flexibly.

5. The structure as described in claim 4, characterized in that, It also includes a spring bushing, which is disposed on the valve, through which a guide rod passes and on which a spring presses against the spring bushing.

6. The structure as described in claim 5, characterized in that, The tilt angle of the guide rod on the housing and the length of the oblong hole should meet the opening requirements of the valve and prevent jamming.

Images