Beam type pipe joint design method and beam type pipe joint

Abstract

The invention discloses a beam-type pipe joint design method and a beam-type pipe joint. The beam-type pipe joint design method comprises the following steps: establishing a conceptual model only comprising two parts, namely a female joint and a male joint; a sealing structure is designed on the conceptual model, the design comprises design of a contact surface and design of a cantilever beam, and the contact surface is the surface where a female connector and a male connector make contact in the installation state; mounting functional design is carried out on the conceptual model, including design of an external thread on a male joint and design of a compression surface between a female joint and an outer sleeve nut; transition structures are designed at the positions, where stress concentration exists, of the conceptual model, so that stress concentration at all the positions is reduced; and designing the conduit connecting parts on the female joint and the male joint on the conceptual model according to the conduit structure to obtain the structures of the female joint and the male joint. The design method provided by the invention has good universality, and has practical application significance for realizing standardized and reasonable design of the beam type pipe joint.

Description

Technical Field

[0001] The invention belongs to the technical field of beam type pipe joints, and in particular relates to a beam type pipe joint design method and a beam type pipe joint. Background Art

[0002] As aircraft performance improves, hydraulic systems are facing higher pressure requirements. Aviation hydraulic fittings are essential hydraulic accessories, and leaks in any of them can cause hydraulic system failures or even major accidents. Currently, traditional flared or non-flared fittings are still widely used on domestic aircraft. These traditional fittings' pressure resistance is no longer sufficient to meet the pressure requirements of hydraulic systems.

[0003] Due to their inherent sealing properties, beam-type pipe joints possess strong sealing properties, effectively meeting the high-pressure requirements of hydraulic systems. Due to their connection method, beam-type pipe joints are detachable and can be repeatedly assembled and disassembled, offering promising application prospects in new pipe joints. Currently, the configurations of beam-type pipe joints are relatively limited, and their design still relies heavily on the designer's experience, limiting their application. Summary of the Invention

[0004] The object of the present invention is to provide a beam type pipe joint design method and a beam type pipe joint, so as to solve the problems existing in the design and application of the beam type pipe joint.

[0005] The present invention is achieved through the following technical solutions: The beam type pipe joint design method includes the following steps: A conceptual model consisting of only two parts, a female connector and a male connector, is established. The conceptual models of the female connector and the male connector are axisymmetric structures relative to the axis. The female connector is designed with a rotating cantilever beam structure, and the cantilever beam of the female connector is arranged in the direction of the axis. Design the sealing structure on the conceptual model, including the design of the contact surface and the design of the cantilever beam. The contact surface is the surface where the female connector and the male connector come into contact when installed. Conduct installation functional design on the conceptual model, including the design of the external thread on the male connector and the design of the pressure surface between the female connector and the outer nut; Design transition structures at locations where stress concentration exists on the conceptual model to reduce stress concentration at various locations; The catheter connection parts on the female connector and the male connector are designed on the conceptual model according to the catheter structure, and the structures of the female connector and the male connector are obtained.

[0006] In some embodiments of the present invention, the design of the contact surface should satisfy the requirement that a cavity can be formed between the contact surfaces of the female connector and the male connector in the installed state, and during the installation process, the contact surface of the male connector can first contact the side of the cantilever beam close to the axis, and then contact the side of the cantilever beam away from the axis.

[0007] In some embodiments of the present invention, the design of the cantilever beam should satisfy the requirement that the maximum principal stress of the cantilever beam in the installed state is greater than the yield strength of the material and less than the tensile strength of the material, and the cantilever beam structure should satisfy the three basic assumptions of beam bending: linear elasticity assumption, small deformation assumption, and flat section assumption.

[0008] In some embodiments of the present invention, the external threads on the male connector match the internal threads on the outer nut, and the pressure-bearing surface of the female connector fits with the closing end surface of the outer nut.

[0009] In some embodiments of the present invention, the design of the transition structure includes rounding the sharp corners of the cantilever beam root, the pressure surface root, and the contact surface.

[0010] In some embodiments of the present invention, the design of the conduit connection portion should ensure that the connection of the conduit does not interfere with the installation of the beam pipe joint, and the conduit connection portion is sufficiently far away from the sealing surface of the beam pipe joint.

[0011] In some embodiments of the present invention, the designed distance between the conduit connecting portion and the sealing surface of the beam pipe joint is determined according to the sealing width and sealing pressure of the beam pipe joint under the conduit connection load.

[0012] On the other hand, the present invention also provides a beam type pipe joint adopting the beam type pipe joint design method, comprising a female joint, a male joint and an outer sleeve nut; A rotary cantilever beam structure is provided at one end of the female connector, and an annular groove is provided on the sealing end surface of the male connector. The annular groove is V-shaped, and the inner side of the sealing end surface of the male connector is higher than the outer side, so that the inner side of the sealing end surface of the male connector first contacts the sealing end surface of the cantilever beam during installation.

[0013] In some embodiments of the present invention, the sealing cooperation structure between the female connector and the male connector can ensure that the maximum principal stress of the cantilever beam in the installed state is greater than the yield strength of the material and less than the tensile strength of the material.

[0014] In some embodiments of the present invention, both the female connector and the male connector are provided with a catheter connecting portion for crimping a catheter.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a specific and feasible design idea for the design of beam-type pipe joints and gives a specific design process of beam-type pipe joints. The design method has good universality and has practical application significance for realizing the standardized and rational design of beam-type pipe joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a conceptual model diagram of a beam-type pipe joint according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the sealing structure design of an embodiment of the present invention.

[0019] Figure 3 This is a functional structural design diagram for an embodiment of the present invention.

[0020] Figure 4 This is a design diagram of a stress concentration elimination structure according to an embodiment of the present invention.

[0021] Figure 5 This is a structural design diagram of the catheter connection part according to an embodiment of the present invention.

[0022] in: 11. Female connector, 12. Male connector, 101. Cantilever beam, 102. Annular groove, 103. Sealing end face, 104. External thread, 105. Pressure surface, 106. Catheter connecting portion. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0024] Reference Figure 1 The beam-type pipe joint consists of a female joint, a male joint, and an outer sleeve nut, wherein the female joint is a structural component with a rotary cantilever beam, the male joint is a structural component with an external thread structure connected to the outer sleeve nut, and the outer sleeve nut is a structural component with an internal thread structure threadedly connected to the male joint.

[0025] In the structure of the beam-type pipe joint, the outer nut is sleeved on the female joint and rotated between one end and the female joint. The other end of the outer nut is connected to the external thread of the male joint through the internal thread. In this way, when the outer nut is tightened, the female joint and the male joint can be connected, and the sealing end faces of the female joint and the male joint are pressed together to form a sealed fit.

[0026] The present invention provides a beam type pipe joint design method, comprising the following steps: 1. Establish a conceptual model; Reference Figure 1 The established conceptual model only includes two parts, the female connector 11 and the male connector 12, without considering the external thread of the male connector. The female connector and the male connector are axisymmetric models.

[0027] The female connector has a rotary cantilever beam structure, and the design features of the rotary cantilever beam structure include but are not limited to the cantilever end being arranged toward the axis.

[0028] 2. Sealing structure design; Design features of the sealing structure include: 1) After the beam type pipe joint is installed, an annular cavity structure is formed between the contact surfaces of the female joint and the male joint; 2) During installation, the order of contact between the female connector and the male connector is first with the side of the cantilever beam close to the axis, and then with the side of the cantilever beam away from the axis; 3) After the beam-type pipe joint is installed, the maximum principal stress of the cantilever beam 101 should be greater than the yield strength of the cantilever beam material and less than the tensile strength. The maximum principal stress of the cantilever beam can be determined using finite element analysis or other methods.

[0029] 4) The rotating cantilever beam structure conforms to the three basic assumptions of beam bending: linear elasticity assumption, small deformation assumption, and flat section assumption.

[0030] Design results of the sealing structure on the conceptual model refer to Figure 2 shown.

[0031] 3. Installation function design; Select standard outer shell nut according to the catheter specifications and design size requirements.

[0032] The installation function design is divided into the design of the external thread 104 on the male connector and the design of the pressure surface on the female connector. The external thread refers to the thread on the male connector that is connected to the outer nut, and the pressure surface 105 refers to the surface of the female connector that is squeezed by the closing end of the outer nut during the tightening process.

[0033] The design requirements for external threads are: the external threads of the male connector match the internal threads of the outer nut.

[0034] The design requirements for the pressure surface are: the pressure surface of the female connector fits in with the inner surface of the closing end of the outer nut.

[0035] Reference to design results of installation functions on conceptual models Figure 3 shown.

[0036] 4. Design to eliminate stress concentration; Transition design is performed on the areas of the female and male connectors where stress concentration may occur to eliminate stress concentration. This includes rounding off sharp corners such as the root of the rotating cantilever beam, the root of the pressure surface, and the contact surface cavity.

[0037] Reference to the design results of the transition structure on the conceptual model Figure 4 shown.

[0038] 5. Catheter connection design.

[0039] Select a conduit connection method based on actual use requirements, obtain a standard conduit model from the corresponding aviation pipe joint standard, and design a conduit connection portion 106 on the female and male connectors. The design requirements for the conduit connection portion are as follows: 1) The connection of the conduit will not cause interference with the installation of the beam pipe joint.

[0040] 2) The conduit connection must be sufficiently far from the beam joint's sealing surface. The design distance between the conduit connection and the beam joint's sealing surface can be determined using finite element analysis (FEM) by calculating the joint's sealing width and sealing pressure under the conduit connection load. For example, FEM calculations show that the conduit connection load affects the beam joint's sealing width by no more than 0.1 mm, while its effect on the sealing pressure does not exceed 10 MPa.

[0041] The conceptual model of the beam pipe joint designed by the above method steps is referenced Figure 5 shown.

[0042] The process of designing a beam type pipe joint using the beam type pipe joint design method of the present invention will be described in detail below with reference to specific embodiments.

[0043] Step 1: Build a conceptual model The conceptual model of the beam pipe joint is established according to the requirements. Figure 1 shown.

[0044] Step 2: Sealing structure design According to the design requirements of the sealing structure, the cavity structure formed between the contact surfaces in this embodiment is realized by grooving the end face of the male connector, and the inner side of the raised portion of the contact end face of the male connector must exceed the outer side, so that the inner side of the contact end face of the male connector first contacts the contact end face of the female connector during installation.

[0045] Finite element calculation method is used to obtain that after installation, the maximum principal stress of the cantilever beam reaches the yield strength of the material but does not reach the tensile strength. The sealing structure designed is as follows Figure 2 shown.

[0046] Step 3: Installation function design In this embodiment, the outer diameter of the conduit is 8 mm. Considering the weight requirement, the outer nut with the thread specification MJ14×1.5 in HB20190-2014 is selected. According to the design requirements of the installation function, the outer thread specification of the male connector is also designed to be MJ14×1.5, and the pressure surface on the female connector is designed to be consistent with the inner surface of the closing end of the outer nut. The design of the installation function is as follows: Figure 3 shown.

[0047] Step 4: Design to eliminate stress concentration According to the requirements of eliminating stress concentration, fillet design is performed at sharp corners such as near the cavity structure of the female and male connectors, the root of the cantilever beam, and the root of the pressure surface, such as Figure 4 shown.

[0048] Step 5: Catheter connection design Internal rolling is selected as the connection method between the conduit and the pipe joint, and the conduit connection part is designed according to the standard pipe sleeve model in HB6058-2008 (extruded non-flared pipe sleeve).

[0049] Finite element calculations show that the influence of rolling load on sealing width and sealing pressure is within the design envelope, and the distance between the conduit connection position and the sealing surface of the beam pipe joint meets the design requirements.

[0050] The structure of the designed female connector and male connector is as follows: Figure 5 shown.

[0051] The present invention also provides a beam type pipe joint designed by adopting the beam type pipe joint design method.

[0052] Reference Figure 5 In some embodiments of the present invention, the beam-type pipe joint includes a female joint 11, a male joint 12 and a sleeve nut; a rotary cantilever beam structure is provided at one end of the female joint 11, and an annular groove 102 is provided on the sealing end surface 103 of the male joint 12. The annular groove 102 has a V-shaped structure, and the inner side of the sealing end surface of the male joint is higher than the outer side, so that during installation, the inner side of the sealing end surface of the male joint first contacts the sealing end surface of the cantilever beam.

[0053] The sealing structure between the female and male connectors ensures that the maximum principal stress of the cantilever beam in the installed state is greater than the yield strength of the material and less than the tensile strength of the material. Specifically, the cantilever beam structure is designed based on the design of the annular groove on the sealing end face of the male connector to ensure that the maximum principal stress of the cantilever beam in the assembled state meets the above requirements.

[0054] Both the female connector and the male connector are provided with a conduit connection portion for crimping the conduit. Taking the crimping connection method as an example, the conduit connection portion is provided with a groove structure suitable for crimping with the conduit.

[0055] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0056] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of the present invention does not necessarily imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical" and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0057] It should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A beam type pipe joint design method, characterized in that: The following steps are involved: A conceptual model consisting of only two parts, a female connector and a male connector, is established. The conceptual models of the female connector and the male connector are axisymmetric structures relative to the axis. The female connector is designed with a rotating cantilever beam structure, and the cantilever beam of the female connector is arranged in the direction of the axis. Design the sealing structure on the conceptual model, including the design of the contact surface and the design of the cantilever beam. The contact surface is the surface where the female connector and the male connector come into contact when installed. Conduct installation functional design on the conceptual model, including the design of the external thread on the male connector and the design of the pressure surface between the female connector and the outer nut; Design transition structures at locations where stress concentration exists on the conceptual model to reduce stress concentration at various locations; The catheter connection parts on the female connector and the male connector are designed on the conceptual model according to the catheter structure, and the structures of the female connector and the male connector are obtained.

2. The beam type pipe joint design method according to claim 1, characterized in that: The design of the contact surface should satisfy the requirement that a cavity can be formed between the contact surfaces of the female connector and the male connector in the installed state, and during the installation process, the contact surface of the male connector can first contact the side of the cantilever beam close to the axis, and then contact the side of the cantilever beam away from the axis.

3. The beam type pipe joint design method according to claim 1, characterized in that: The design of the cantilever beam should satisfy the following requirements: the maximum principal stress of the cantilever beam in the installed state is greater than the yield strength of the material and less than the tensile strength of the material, and the cantilever beam structure should meet the three basic assumptions of beam bending: linear elasticity assumption, small deformation assumption, and flat section assumption.

4. The beam type pipe joint design method according to claim 1, characterized in that: The external thread on the male connector matches the internal thread of the outer nut, and the pressure surface of the female connector fits the surface of the closing end of the outer nut.

5. The beam type pipe joint design method according to claim 1, characterized in that: The design of the transition structure includes rounding the sharp corners of the cantilever beam root, the pressure surface root, and the contact surface.

6. The beam type pipe joint design method according to claim 1, characterized in that: The design of the conduit connection should ensure that the conduit connection does not interfere with the installation of the beam pipe joint, and the conduit connection is far enough away from the sealing surface of the beam pipe joint.

7. The beam type pipe joint design method according to claim 6, characterized in that: The design distance between the conduit connection portion and the sealing surface of the beam type pipe joint is determined according to the sealing width and sealing pressure of the beam type pipe joint under the conduit connection load.

8. A beam type pipe joint using the beam type pipe joint design method according to any one of claims 1 to 7, characterized in that: Including female connector, male connector and outer nut; A rotary cantilever beam structure is provided at one end of the female connector, and an annular groove is provided on the sealing end surface of the male connector. The annular groove is V-shaped, and the inner side of the sealing end surface of the male connector is higher than the outer side, so that during installation, the inner side of the sealing end surface of the male connector first contacts the sealing end surface of the cantilever beam.

9. The beam type pipe joint according to claim 8, characterized in that: The sealing matching structure between the female connector and the male connector can ensure that the maximum principal stress of the cantilever beam in the installed state is greater than the yield strength of the material and less than the tensile strength of the material.

10. The beam type pipe joint according to claim 8, characterized in that: The female connector and the male connector are both provided with a catheter connecting portion for crimping a catheter.

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