Air pressure ratio valve switch

Abstract

The utility model belongs to the technical field of aviation oxygen supply, and particularly relates to an air pressure ratio valve switch integrated in an oxygen regulator pipeline. An electromagnetic valve is used for switching a gas circuit, the weight is large, the size is large, and the reliability is poor. A cavity A is arranged on the outer side of a large-diameter stepped hole, a cavity B is arranged on the outer side of a small-diameter stepped hole, and an air inlet channel D is respectively communicated with the cavity A and the cavity B; a rubber gasket, a valve seat of a cup body structure and a check ring of an annular structure are sequentially installed in the small-diameter stepped hole, the check ring is tightly pressed at the position of the large-diameter stepped hole through a rubber diaphragm, a valve of a rotating body structure is provided with an annular boss, and a spring is installed between the annular boss and the bottom face of the valve seat in a pre-compression mode. One end of the valve is provided with a sealing gasket, and the other end of the valve is further provided with a hard core of a disc-shaped structure; and the air outlet channel C is communicated with the cavity of the area where the spring is located. The size is small, weight is light and reliability is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of aviation oxygen supply, and particularly relates to a pneumatic ratio valve switch integrated in the pipeline of an oxygen regulator. Background Art

[0002] There are multiple gas paths inside an aviation oxygen regulator, and almost all gas path channels are in an open state. Currently, there are some working conditions: when the air source pressure is low, a specified gas path channel inside the oxygen regulator needs to be opened, and when the air source pressure is high, this gas path channel needs to be closed.

[0003] The traditional method is to use a solenoid valve for control. When the air source pressure is low, the solenoid valve opens to enable the specified gas path channel to be opened; when the air source pressure is high, the solenoid valve closes to enable the specified gas path channel to be closed. Switching the gas path through a solenoid valve requires adding a solenoid valve, a pressure sensor to collect the change in air source pressure, and a control module to drive the solenoid valve according to the air pressure change. Adding too many links brings disadvantages such as large weight, large volume, and poor reliability. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a pneumatic ratio valve switch for switching the on-off of the gas path in the gas path channel.

[0005] A pneumatic ratio valve switch allows the air source to pass through when the air source pressure is low and blocks the air source when the air source pressure is high. A transverse stepped hole, an air inlet channel D, an air outlet channel C, a cavity A, and a cavity B are machined inside the housing of the pneumatic ratio valve switch. The cavity A is outside the large-diameter stepped hole, and the cavity B is outside the small-diameter stepped hole. The air inlet channel D is respectively communicated with the cavity A and the cavity B; a rubber gasket, a valve seat in a cup shape structure, and a retaining ring in an annular structure are sequentially installed in the small-diameter stepped hole, and the retaining ring is pressed by a rubber diaphragm at the large-diameter stepped hole. The valve in a rotating body structure has an annular boss, and a spring is pre-compressed and installed between the annular boss and the bottom surface of the valve seat. The other end face of the annular boss is limited by the retaining ring. A sealing gasket is provided at one end of the valve, and its size covers the valve through hole at the bottom of the valve seat. A hard core in a disc shape structure is further provided between the other end of the valve and the rubber diaphragm; the air outlet channel C is communicated with the cavity where the spring is located; the valve is sealed with the retaining ring, and the retaining ring is sealed with the small-diameter stepped hole.

[0006] Advantageously, the retaining ring has an inner annular groove, and a second O-ring is installed therein to achieve the seal between the valve 4 and the retaining ring.

[0007] Advantageously, the small-diameter stepped hole has an inner annular groove, and a first O-ring is installed therein to achieve the seal between the retaining ring and the small-diameter stepped hole.

[0008] Advantageously, the retaining ring has an annular boss at the end, which is stuck on the step surface of the large-diameter stepped hole.

[0009] Advantageously, the valve has an axial boss at the end face, and the hard core has a groove at the end face that cooperates with the axial boss.

[0010] Advantageously, by using hard cores with different diameters, the air pressure ratio of the opening and closing pressure values of the valve switch can be adjusted.

[0011] Advantageously, the diameter of the hard core is φM, the diameter of the end face of the valve where the sealing gasket is located is φN, and the diameter of the through hole of the valve is φP, where M > N > P.

[0012] Advantageously, by setting the ratio of M and N and the spring stiffness, the closing air pressure of the valve is determined.

[0013] After the air source enters the air pressure ratio valve switch, when the air source pressure is low, the pressure difference formed at both ends of the air pressure ratio valve switch is not sufficient to close the valve, and the air source can enter the specified channel; as the air source pressure increases, the pressure difference formed at both ends of the air pressure ratio valve switch also increases accordingly until the valve is closed and the air source cannot enter the specified channel.

[0014] Beneficial effects: The utility model adopts a pure mechanical design, is embedded in the air circuit, and has the advantages of small volume, light weight, and high reliability. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the air pressure ratio valve switch of the utility model;

[0016] Figure 2 is a schematic diagram of the state of the air pressure ratio valve switch when it is open;

[0017] Figure 3 is a schematic diagram of the state of the air pressure ratio valve switch when it is closed.

[0018] 1 - housing, 2 - rubber gasket, 3 - valve seat, 4 - valve, 5 - spring, 6 - first O-ring, 7 - second O-ring, 8 - retaining ring, 9 - hard core, 10 - rubber diaphragm Detailed Embodiment

[0019] Referring to Figure 1 the embodiment of the air pressure ratio valve switch shown, it mainly consists of a housing 1, a rubber gasket 2, a valve seat 3, a valve 4, a spring 5, a first O-ring 6, a second O-ring 7, a retaining ring 8, a hard core 9, and a rubber diaphragm 10.

[0020] Inside the lateral stepped hole of the housing 1, a rubber washer 2, a valve seat 3, a valve 4 sleeved with a spring 5 and a retaining ring 8, a hard core 9, and a rubber diaphragm 10 are installed in sequence. The spring 5 and the retaining ring 8 are located on both sides of the valve boss. The retaining ring 8 is limited by the outer step of the lateral stepped hole. The pre-compressed spring 5 presses the valve 4 against the retaining ring 8. The first O-ring 7 is installed in the inner annular groove of the retaining ring 8 to maintain the seal between the retaining ring 8 and the valve 4. The second O-ring 6 is installed in the annular groove of the lateral stepped hole to maintain the seal between the retaining ring 8 and the housing 1. The gland of the housing 1 presses the edge of the rubber diaphragm 10 against the outer end face of the retaining ring 8, and at the same time presses the retaining ring 8, the valve seat 3, and the rubber washer 2 in the lateral stepped hole. A gasket is also provided at the end of the valve 4. The air source leads to the A chamber and the B chamber on both sides of the lateral stepped hole through the intake passage D. The housing 1 also has an outlet passage C communicating with the lateral stepped hole within the range where the spring 5 is located. After the rubber diaphragm 10 is pressed, it deforms and applies an inward pressure to the hard core 9, and the hard core 9 drives the valve 4 to overcome the elastic force of the spring 5.

[0021] After the installation is completed, the A chamber, the B chamber, and the outlet passage C in the housing 1 are in communication. The spring 5 presses the valve 4 against the valve boss, and the valve 4 is not in contact with the valve seat 3. The rubber washer 2 is in a compressed state after installation. One end of the rubber washer 2 contacts the inner wall of the housing 1, and the other end contacts the end face of the valve seat 3, ensuring airtightness.

[0022] In this embodiment, the valve seat 3 is a cup-shaped structure. The bottom of the valve seat 3 has a valve through-hole with a diameter of φP. The valve seat 3 is provided with 4 evenly distributed radial through-holes around the circumference on the cup body, connecting the inner cavity of the valve seat 3 with the outlet passage C. The radial through-holes are round holes, and the diameter of the round holes should ensure that there is no throttling at this place.

[0023] The valve 4 is a rotating body structure. A gasket is provided on the end face of the valve 4 close to the valve seat 3; the other end has an axial boss, which is connected with the groove of the retaining ring 9 in a matching manner; the valve 4 has an annular boss in the middle area, serving as the installation support surface and the limiting structure of the spring 5. After the air source enters the B chamber, the effective acting force range of the air source in the B chamber on the valve 4 is the φN area.

[0024] The spring 5 is sleeved on the valve 4. One end of the spring 5 is supported on the valve seat 3, and the other end is supported on the annular boss of the valve 4. After the installation of the air pressure ratio valve switch, the spring 5 is always in a compressed state.

[0025] The retaining ring 8 is an annular structure with an inner annular groove. The second O-ring 7 is installed in the inner annular groove, and the first O-ring is installed in the annular groove on the outer wall of the retaining ring 8 and the lateral stepped hole of the housing 1. One end of the retaining ring 8 abuts against the valve seat 3 and at the same time limits the annular boss of the valve 4.

[0026] The hard core 9 is of a disc structure and has a groove on the inner side, which is connected in a matching manner with the axial boss of the valve 4. The diameter of the hard core 9 is φM, which serves as the force transmission surface.

[0027] See Figure 2 , The gas source simultaneously enters the A chamber and the B chamber, and the gas source pressure is P1. After the rubber diaphragm 10 senses the air pressure, it deforms. The rubber diaphragm 10 transmits the force to the hard core and finally to the valve 4. When the pressure transmitted to the valve 4 is not sufficient to block the valve through-hole of the valve seat 3, the gas source flows out through the air outlet channel C.

[0028] See Figure 3 , The gas source simultaneously enters the A chamber and the B chamber, and the gas source pressure is P1. After the rubber diaphragm 10 senses the air pressure, it deforms. The rubber diaphragm 10 transmits the force to the hard core and finally to the valve 4. Then the air pressure in the A chamber exerts a force F1 on the valve 4. , The gas source enters the B chamber, and the air pressure in the B chamber exerts a force F2 on the valve. , During design, it is ensured that M > N, so M 2 > N 2 , F1 is greater than F2. As the gas source pressure increases, the pressure difference also gradually increases. The pressure difference drives the valve 4 to overcome the spring force and close the valve in the direction of the valve seat 3. After the valve is closed, the acting area of the gas source in the B chamber on the valve 4 is further reduced from φN to φP, and the pressure difference continues to increase. The gas source cannot enter the air outlet channel C, achieving the cut-off of the gas source. When the valve 4 is completely closed, the valve 4 blocks the valve through-hole with a diameter of φP on the valve seat 3, and the effective acting force range of the gas source in the B chamber on the valve is the φP area.

[0029] When designing this mechanism, by setting the ratio M:N of M and N greater than 1 and the stiffness of the spring, the closing air pressure of the valve can be calculated and confirmed. The larger the ratio of M and N, the greater the pressure difference formed at both ends of the valve switch in the air pressure ratio, and the easier it is for the valve to close; the smaller the ratio of M and N, the smaller the pressure difference formed at both ends of the valve switch in the air pressure ratio, and the more difficult it is for the valve to close.

Claims

1. A gas pressure ratio valve switch, which allows gas to pass through when the gas source pressure is low and blocks the gas source from passing through when the gas source pressure is high, characterized in that: The housing (1) of the air pressure ratio valve switch is internally processed with a transverse stepped hole, an air inlet channel D, an air outlet channel C, a cavity A and a cavity B. The cavity A is located outside the large-diameter stepped hole, and the cavity B is located outside the small-diameter stepped hole. The air inlet channel D is connected to the cavity A and the cavity B respectively. A rubber gasket (2), a valve seat (3) with a cup structure and a retaining ring (8) with an annular structure are sequentially installed in the small-diameter stepped hole, and the retaining ring (8) is pressed by a rubber diaphragm (10) at the large-diameter stepped hole. The valve (4) with a rotating body structure has an annular boss, and a spring (5) is pre-compressed and installed between the annular boss and the bottom of the valve seat (3). The valve seat (3) is provided with a sealing gasket at one end thereof, the size of which covers the valve through hole at the bottom of the valve seat (3). A hard core (9) with a disc-shaped structure is provided between the other end of the valve (4) and the rubber diaphragm (10). The diameter of the hard core (9) is φM. The diameter of the end face of the valve (4) where the sealing gasket is located is φN. The diameter of the valve through hole is φP, where M>N>P. The air outlet channel C is connected to the cavity in the area where the spring (5) is located. The valve (4) and the retaining ring (8) are sealed, and the retaining ring (8) and the small-diameter stepped hole are sealed.

2. The air pressure ratio valve switch according to claim 1, characterized in that: The retaining ring (8) has an inner ring groove in which a second O-ring (7) is installed, thereby achieving sealing between the valve (4) and the retaining ring (8).

3. The air pressure ratio valve switch according to claim 2, characterized in that: The small-diameter stepped hole has an inner ring groove in which a first O-type sealing ring (6) is installed, thereby achieving sealing between the retaining ring (8) and the small-diameter stepped hole.

4. The air pressure ratio valve switch according to claim 3, characterized in that: The retaining ring (8) has an annular boss at the end portion, which is clamped on the step surface of the large-diameter stepped hole.

5. The air pressure ratio valve switch according to claim 1, characterized in that: The valve (4) has an axial boss on the end surface, and the hard core (9) has a groove on the end surface that matches the axial boss.

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