Valve element with composite guide structure, safety valve comprising valve element and working method of safety valve

Abstract

The invention discloses a valve element with a composite guide structure, a safety valve comprising the valve element and a working method of the safety valve and belongs to the technical field of safety valves. The valve element is a rotary body integrally machined and formed, the sealing end of a valve element body is a spherical sealing face, the outer side wall is a valve clack guiding face and an oil storage groove, and the upper end is a spring guiding face. The outer end of the spherical sealing face is a cutting plane, the inner diameter of the shell is in clearance fit with the guide face of the valve clack, one end of the spring sleeves the outer side of the spring guide face of the valve element in a clearance mode, the other end of the spring is connected with the inner wall of the shell in an assembled mode, and the chamfer of the shell is attached to the spherical sealing face of the valve element. Coaxiality of valve element movement is guaranteed, the problems that a pure spherical valve element is large in vibration and unstable in sealing performance are solved, repeated precision of pressure control is improved, sealing reliability is enhanced, erosive wear is reduced, and the service life is prolonged.

Description

Technical Field

[0001] This invention relates to a valve core with a composite guiding structure, a safety valve containing the valve core, and a method for operating the same, belonging to the field of safety valve technology. Background Technology

[0002] In the aerospace field, safety valves are core devices ensuring the safe operation of lubricating oil pump systems. Their working principle is as follows: when the lubricating oil pressure at the safety valve inlet exceeds the rated value, the valve automatically opens, connecting the oil supply pump inlet and outlet. Within a limited time, the oil supply outlet pressure is reduced to the relief pressure, thereby maintaining the overall pressure differential balance of the lubricating oil pump system and ensuring the safe and stable operation of the lubrication system.

[0003] The core performance of a safety valve must meet four key requirements: precise opening pressure, rapid opening and closing response, tight sealing, and long-term operational reliability. However, existing valve core designs generally suffer from performance contradictions, making it difficult to simultaneously meet all core requirements: when using a steel ball as a pure spherical valve core, although it possesses good self-centering properties, it lacks an effective guiding structure, exhibiting problems such as large vibration amplitude and high vibration frequency during testing. After multiple cyclic tests, the sealing performance of the safety valve becomes unstable, and the repeatability of pressure control is poor. When using a plunger-type valve core, the guiding performance is improved, but the sealing surface is extremely sensitive to uneven wear, and there is also a defect of high flow resistance. In addition, traditional bottom-guided valve cores, even if they can ensure excellent centering, have their guiding surfaces directly exposed to the high-speed scouring lubricating oil medium, making them prone to erosion and wear, and easily causing jamming under thermal expansion or impurity intrusion, seriously affecting the reliability of valve operation. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a valve core with a composite guiding structure, a safety valve containing the valve core, and a method for operating the valve core.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a valve core with a composite guiding structure, wherein the valve core is a rotary body integrally machined, including a valve core body, the sealing end of the valve core body is a spherical sealing surface, the outer end of the spherical sealing surface is a cutting plane, the spherical sealing surface is used to cooperate with the chamfer of the housing to achieve sealing; the side of the outer wall of the valve core body adjacent to the spherical sealing surface is a valve disc guiding surface, which is used to cooperate with the inner diameter of the housing; an oil storage groove is provided on the side of the outer wall of the valve core body away from the spherical sealing surface, the oil storage groove is used to store lubricating medium; the upper end of the valve core body is a spring guiding surface, which is used to cooperate with the inner diameter of the spring to achieve radial positioning of the spring.

[0006] Furthermore, the spring guide surface includes an initial guide surface of a spherical surface arranged vertically and a top guide surface of a cylindrical surface.

[0007] Furthermore, the radius of the initial guiding surface is SR4.15.

[0008] Furthermore, the number of oil storage tanks is at least one, and when the number of oil storage tanks is greater than one, all oil storage tanks are arranged parallel to each other along the axial direction of the valve core body.

[0009] The present invention discloses a safety valve with a valve core having a composite guiding structure, comprising a housing, a spring, and a valve core; the inner diameter of the housing is clearance-fitted with the valve disc guiding surface of the valve core, one end of the spring is clearance-fitted onto the outer side of the spring guiding surface of the valve core, the other end of the spring is assembled and connected to the inner wall of the housing, and the chamfer of the housing is fitted with the spherical sealing surface of the valve core.

[0010] Furthermore, the surface roughness of the spring guide surface is 1.6.

[0011] Furthermore, the chamfer angle of the housing is 45°-60°, and the surface roughness of the chamfer is no greater than 1.6.

[0012] Furthermore, the calculation process for the outer diameter of the top guide surface is as follows:

[0013] Step 1: Calculate the mean diameter of the spring in its free state. :

[0014]

[0015] In the formula:

[0016] This indicates the outer diameter of the spring in its free state;

[0017] Indicates the diameter of the spring steel wire cross section;

[0018] Step 2: Calculate the inner diameter of the spring in its free state. :

[0019]

[0020] Step 3: Calculate the change in the inner diameter of the spring :

[0021]

[0022] In the formula:

[0023] This represents the spring pitch, where, Indicates coefficient;

[0024] Step 4: Calculate the inner diameter under the compressed spring state. :

[0025]

[0026] Step 5: Calculate the outer diameter of the top guide surface :

[0027]

[0028] In the formula:

[0029] This indicates the gap between the inner diameter and the top guide surface when the spring is compressed.

[0030] The present invention discloses a method for operating a safety valve with a valve core having a composite guiding structure, the method comprising the following steps:

[0031] S1: Insert the spring axially into the spring guide surface of the valve core to ensure that the axis of the spring coincides with the axis of movement of the valve core;

[0032] S2: Insert the valve core equipped with the spring from one end of the housing, so that the valve disc guide surface of the valve core fits with the inner diameter of the housing, and fill the oil reservoir with lubricating medium.

[0033] S3: When the system pressure does not exceed the set value, the elastic force of the spring acts on the valve core, so that the spherical sealing surface fits tightly with the chamfer of the housing, thereby achieving system sealing;

[0034] S4: When the system pressure exceeds the set value, the pressure acts on the spherical sealing surface through the fluid, generating thrust and overcoming the elastic force of the spring, pushing the valve core to move axially, the spring is compressed, and the fluid is depressurized through the gap between the valve core and the housing;

[0035] S5: When the system pressure drops below the set value, the elastic restoring force of the spring pushes the valve core to return to its axial position, and the spherical sealing surface once again fits against the chamfer of the housing, restoring the safety valve to a sealed state.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] This invention, through a multi-stage composite guiding structure of the valve core (with the spring guide surface and the valve disc guide surface working together), ensures the coaxiality of the valve core movement, improves the problems of large vibration and unstable sealing performance of pure spherical valve cores, and enhances the repeatability of pressure control. The self-centering design of the spherical sealing surface avoids the risk of uneven wear of the sealing surface of the plunger-type valve core, enhancing sealing reliability. The oil reservoir can store lubricating medium, reducing friction between the valve core and the housing, and solving the jamming problem of traditional structures. The non-bottom guiding design of the valve core avoids the guide surface being directly exposed to high-speed media erosion, reducing erosion wear and extending service life. At the same time, the integrated design of the spring guide surface simplifies the component structure, improves the reliability of assembly and operation, and ultimately achieves the core performance requirements of the safety valve: accurate opening, rapid response, tight sealing, and long-term reliable operation. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the valve core structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the safety valve of the present invention. Detailed Implementation

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] A valve core with a composite guiding structure is a rotary body integrally machined, comprising a valve core body 1. The sealing end of the valve core body 1 is a spherical sealing surface 5, and the outer end of the spherical sealing surface 5 is a Φ8.8 cutting plane, which ensures that the bottom surface does not generate stress concentration while reducing the weight of the valve core and improving operational sensitivity. The spherical sealing surface 5 is used to achieve a seal by chamfering with the housing 8; the spherical radius of the spherical sealing surface 5 is SR9±0.03, and the runout tolerance is 0.01, ensuring that the axis of the spherical sealing surface 5 is highly coincident with the theoretical rotation axis of the valve core, improving the self-centering ability of the spherical sealing surface 5, preventing the spherical sealing surface 5 from being eccentric, ensuring the valve core's ability to resist erosion and its wear resistance, thereby improving the service life of the safety valve. The side of the outer wall of the valve core body 1 adjacent to the spherical sealing surface 5 is a valve disc guiding surface 4, which is used to fit with the inner diameter of the housing 8; the inner diameter of the housing 8 is... Based on this, the diameter of the valve disc guide surface 4 is designed to be... The gap between the two is 0.02-0.06 mm. Guiding between the two is ensured by reducing the gap between the housing 8 and the valve disc guide surface 4. The gap between the valve disc guide surface 4 and the inner diameter of the housing 8 is very small. During the axial movement of the valve core inside the housing 8, the friction between the inner diameter of the housing 8 and the outer circumference of the valve core will hinder the movement of the valve core, leading to jamming of the safety valve. To solve this problem, an oil reservoir 6 is provided on the outer side of the valve core body 1 away from the spherical sealing surface 5. The oil reservoir 6 is used to store lubricating medium. The width of the oil reservoir 6 is 2-4 mm, and the depth is 0.5-mm, reducing the contact area between the outer circumference of the valve core and the inner diameter of the housing 8, thus reducing friction. The upper end of the valve core body 1 is a spring guide surface, used to cooperate with the inner diameter of the spring 7 to achieve radial positioning of the spring 7.

[0042] Furthermore, the spring guide surface includes an initial guide surface 2 of spherical surfaces arranged vertically and a top guide surface 3 of cylindrical surfaces. The initial guide surface 2 is a key component for the fit between the valve core and the inner diameter of the spring. The spherical surface acts as a guide, helping the top of the valve core to fit into the inner diameter of the spring. After the spherical surface completes the coarse guidance, the top guide surface 3 of the cylindrical surface provides fine guidance for the valve core. At the same time, the spherical design reduces the contact area between the top guide surface 3 and the inner diameter of the spring, reducing starting friction and making the valve core move more smoothly and controllably from rest to the moment of starting motion, thus improving the sensitivity and repeatability of the action.

[0043] Furthermore, the initial guide surface 2 has a radius of SR4.15 to ensure a smooth transition with the top guide surface 3.

[0044] Furthermore, the number of oil storage tanks 6 is at least one. When the number of oil storage tanks 6 is greater than one, all oil storage tanks 6 are evenly distributed parallel to each other along the axial direction of the valve core body 1.

[0045] The present invention discloses a safety valve with a valve core having a composite guiding structure, comprising a housing 8, a spring 7, and a valve core; the inner diameter of the housing 8 is clearance-fitted with the valve disc guiding surface 4 of the valve core, one end of the spring 7 is clearance-fitted onto the outer side of the spring guiding surface of the valve core, and the other end of the spring 7 is assembled and connected to the inner wall of the housing 8; the chamfer of the housing 8 fits against the spherical sealing surface 5 of the valve core to form a sealing pair and perform a sealing function.

[0046] Furthermore, to prevent adhesive wear caused by contact between the inner diameter of the spring and the spring guide surface when the spring 7 deflects, the surface roughness of the spring guide surface is 1.6, thereby reducing the coefficient of friction between the inner diameter of the spring 7 and the spring guide surface.

[0047] Furthermore, the chamfer angle of the housing 8 is 45°-60°, and the surface roughness of the chamfer is no greater than 1.6.

[0048] Furthermore, the top guide surface 3 is a crucial component ensuring the valve core's guiding capability. During design, the minimum clearance between the diameter of the top guide surface 3 and the inner diameter of the spring 7 under compressed conditions must be considered to prevent jamming. Therefore, a dimensional chain calculation is performed on the valve core to analyze the clearance between the spring 7 and the valve core. The calculation process for the outer diameter of the top guide surface 3 is as follows:

[0049] Step 1: Calculate the mean diameter of the spring in its free state. :

[0050]

[0051] In the formula:

[0052] This indicates the outer diameter of the spring in its free state;

[0053] Indicates the diameter of the spring steel wire cross section;

[0054] Step 2: Calculate the inner diameter of the spring in its free state. :

[0055]

[0056] Step 3: Calculate the change in the inner diameter of the spring :

[0057]

[0058] In the formula:

[0059] This represents the spring pitch, where, This represents a coefficient, ranging from 0.28 to 0.5.

[0060] Step 4: Calculate the inner diameter under the compressed spring state. :

[0061]

[0062] Step 5: Calculate the outer diameter of the top guide surface 3 :

[0063]

[0064] In the formula:

[0065] This indicates the gap between the inner diameter and the top guide surface 3 when the spring is compressed, and is set to 0.285–0.527 mm to ensure that the two do not get stuck.

[0066] The present invention discloses a method for operating a safety valve with a valve core having a composite guiding structure, the method comprising the following steps:

[0067] S1: Insert spring 7 axially into the spring guide surface of the valve core to ensure that the axis of spring 7 coincides with the axis of movement of the valve core;

[0068] S2: Insert the valve core equipped with spring 7 from one end of housing 8, so that the valve disc guide surface 4 of the valve core fits with the inner diameter of housing 8, and fill the oil reservoir 6 with lubricating medium.

[0069] S3: When the system pressure does not exceed the set value, the elastic force of the spring 7 acts on the valve core, so that the spherical sealing surface 5 and the chamfer of the housing 8 fit tightly together, thereby achieving system sealing;

[0070] S4: When the system pressure exceeds the set value, the pressure acts on the spherical sealing surface 5 through the fluid, generating thrust and overcoming the elastic force of the spring 7, pushing the valve core to move axially, the spring 7 is compressed, and the fluid is depressurized through the gap between the valve core and the housing 8.

[0071] S5: When the system pressure drops below the set value, the elastic restoring force of the spring 7 pushes the valve core to return to its axial position, and the spherical sealing surface 5 is once again in contact with the chamfer of the housing 8, and the safety valve returns to a sealed state.

[0072] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0073] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A valve core with a composite guiding structure, characterized in that: The valve core is a rotary body integrally machined, including a valve core body (1). The sealing end of the valve core body (1) is a spherical sealing surface (5). The outer end of the spherical sealing surface (5) is a cutting plane. The spherical sealing surface (5) is used to achieve sealing by chamfering with the housing (8). The side of the outer wall of the valve core body (1) adjacent to the spherical sealing surface (5) is a valve disc guide surface (4), which is used to cooperate with the inner diameter of the housing (8). The side of the outer wall of the valve core body (1) away from the spherical sealing surface (5) is provided with an oil storage groove (6), which is used to store lubricating medium. The upper end of the valve core body (1) is a spring guide surface, which is used to cooperate with the inner diameter of the spring (7) to achieve radial positioning of the spring (7).

2. A valve core with a composite guiding structure according to claim 1, characterized in that: The spring guide surface includes an initial guide surface (2) of a spherical surface arranged at the top and bottom and a top guide surface (3) of a cylindrical surface.

3. A valve core with a composite guiding structure according to claim 2, characterized in that: The radius of the initial guiding surface (2) is SR4.

15.

4. A valve core with a composite guiding structure according to claim 1, characterized in that: The number of oil storage tanks (6) is at least one. When the number of oil storage tanks (6) is greater than one, all oil storage tanks (6) are arranged parallel to the axial direction of the valve core body (1).

5. A safety valve with a valve core having a composite guiding structure according to claim 3, characterized in that: It includes a housing (8), a spring (7) and a valve core; the inner diameter of the housing (8) is clearance-fitted with the valve disc guide surface (4) of the valve core, one end of the spring (7) is clearance-fitted on the outside of the spring guide surface of the valve core, the other end of the spring (7) is assembled and connected to the inner wall of the housing (8), and the chamfer of the housing (8) is in contact with the spherical sealing surface (5) of the valve core.

6. The safety valve according to claim 5, characterized in that: The surface roughness of the spring guide surface is 1.

6.

7. The safety valve according to claim 6, characterized in that: The chamfer angle of the housing (8) is 45°-60°, and the surface roughness of the chamfer is not greater than 1.

6.

8. The safety valve according to claim 7, characterized in that: The calculation process for the outer diameter of the top guide surface (3) is as follows: Step 1: Calculate the mean diameter of the spring in its free state. : In the formula: This indicates the outer diameter of the spring in its free state; Indicates the diameter of the spring steel wire cross section; Step 2: Calculate the inner diameter of the spring in its free state. : Step 3: Calculate the change in the inner diameter of the spring : In the formula: This represents the spring pitch, where, Indicates coefficient; Step 4: Calculate the inner diameter under the compressed spring state. : Step 5: Calculate the outer diameter of the top guide surface (3) : In the formula: This indicates the gap between the inner diameter and the top guide surface (3) when the spring is compressed.

9. A method for operating the safety valve according to claim 8, characterized in that: The method includes the following steps: S1: Insert the spring (7) axially into the spring guide surface of the valve core to ensure that the axis of the spring (7) coincides with the axis of motion of the valve core; S2: Insert the valve core equipped with spring (7) from one end of the housing (8) so that the valve disc guide surface (4) of the valve core fits with the inner diameter of the housing (8) and fill the oil reservoir (6) with lubricating medium. S3: When the system pressure does not exceed the set value, the elastic force of the spring (7) acts on the valve core, so that the spherical sealing surface (5) and the chamfer of the housing (8) fit tightly together, thereby achieving system sealing; S4: When the system pressure exceeds the set value, the pressure acts on the spherical sealing surface (5) through the fluid, generating thrust and overcoming the elastic force of the spring (7), pushing the valve core to move axially, the spring (7) is compressed, and the fluid is depressurized through the gap between the valve core and the housing (8); S5: When the system pressure drops below the set value, the elastic restoring force of the spring (7) pushes the valve core to return to its axial position, and the spherical sealing surface (5) is once again in contact with the chamfer of the housing (8), and the safety valve returns to a sealed state.

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