阅读说明：本技术 一种基于液体体积加载的椭球壳轴长尺寸控制方法及系统 (Ellipsoid shell shaft length size control method and system based on liquid volume loading ) 是由 苑世剑 崔晓磊 于 2019-11-04 设计创作，主要内容包括：本发明公开了一种基于液体体积加载的椭球壳轴长尺寸控制方法及系统。该方法包括：确定成形前预制壳体的体积计算模型以及成形后椭球壳体的体积计算模型；基于此,确定成形前预制壳体与成形后椭球壳体的体积差计算模型；根据成形后椭球壳体的目标轴长尺寸,确定成形前预制壳体的结构尺寸；将成形后椭球壳体的目标轴长尺寸以及成形前预制壳体的结构尺寸代入体积差计算模型,得到成形后椭球壳体与成形前预制壳体的体积差,记为目标体积量；向成形前预制壳体中注入体积为目标体积量的液体,以获取成形后的椭球壳体。本发明的成形工艺简单,容易实施,成形时不需要考虑材料及壁厚差异,壳体轴长尺寸精度可控可调,适合于现场制造大尺寸椭球容器。(The invention discloses an ellipsoid shell axial length size control method and system based on liquid volume loading. The method comprises the following steps: determining a volume calculation model of the prefabricated shell before forming and a volume calculation model of the ellipsoid shell after forming; based on the volume difference, determining a volume difference calculation model of the pre-formed shell and the formed ellipsoid shell; determining the structural size of the prefabricated shell before forming according to the target axial length size of the ellipsoid shell after forming; substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into a volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume; and injecting liquid with the volume of the target volume quantity into the prefabricated shell before forming so as to obtain the formed ellipsoidal shell. The forming process is simple and easy to implement, the difference of materials and wall thickness does not need to be considered during forming, the length and the precision of the shaft of the shell are controllable and adjustable, and the forming method is suitable for manufacturing large-size ellipsoidal containers on site.)

1. A method for controlling the axial length of an ellipsoidal shell based on liquid volume loading is characterized by comprising the following steps:

determining a volume calculation model of the prefabricated shell before forming and a volume calculation model of the ellipsoid shell after forming, wherein the prefabricated shell before forming is formed after liquid loading to obtain the ellipsoid shell after forming; the pre-formed shell before forming is symmetrical about the center of the shell, and the pre-formed shell before forming is composed of a plurality of sections of ellipsoidal shells, wherein the ellipsoidal shells from different ellipsoids are arranged in the plurality of sections of ellipsoidal shells;

determining a volume difference calculation model of the prefabricated shell before forming and the ellipsoid shell after forming according to the volume calculation model of the prefabricated shell before forming and the volume calculation model of the ellipsoid shell after forming;

obtaining a target axial length dimension of the formed ellipsoid shell, wherein the target axial length dimension is determined according to requirements;

determining the structural size of the prefabricated shell before forming according to the target axial length size of the ellipsoid shell after forming;

substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into the volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume;

and manufacturing the pre-formed shell according to the structural size of the pre-formed shell, and injecting liquid with the volume of the target volume into the pre-formed shell to obtain the formed ellipsoidal shell.

2. The method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to claim 1, wherein the pre-formed shell is derived from two different ellipsoids, which are respectively identified as a first ellipsoid and a second ellipsoid, the upper ellipsoidal shell and the lower ellipsoidal shell (first ellipsoidal shell) of the pre-formed shell are derived from the first ellipsoid, the middle ellipsoidal shell (second ellipsoidal shell) of the pre-formed shell are derived from the second ellipsoid,

3. The method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to claim 2, wherein the determining a volume calculation model of the preformed shell before forming specifically comprises: determining a volume calculation model of the prefabricated shell before forming asWherein, V₀Volume of prefabricated shell before shaping, a₁Is the length of the semimajor axis of the first ellipsoid, a₂Is the length of the semimajor axis of the second ellipsoid, α₀In order to realize the tensile and compressive stress dividing angle,

4. the method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to claim 3, wherein determining a volume difference calculation model of the pre-formed shell and the post-formed ellipsoidal shell according to the volume calculation model of the pre-formed shell and the volume calculation model of the post-formed ellipsoidal shell specifically comprises:

according toDetermining a volume difference calculation model, wherein delta V is the volume difference between the prefabricated shell before forming and the ellipsoid shell after forming, and lambda_FIs the axial length ratio of the ellipsoidal shell after shaping.

5. An ellipsoidal shell axial length dimension control system based on liquid volume loading, comprising:

the volume calculation model determining module is used for determining a volume calculation model of the prefabricated shell before forming and a volume calculation model of the ellipsoid shell after forming, and the prefabricated shell before forming is formed after liquid loading to obtain the ellipsoid shell after forming; the pre-formed shell before forming is symmetrical about the center of the shell, and the pre-formed shell before forming is composed of a plurality of sections of ellipsoidal shells, wherein the ellipsoidal shells from different ellipsoids are arranged in the plurality of sections of ellipsoidal shells;

the volume difference calculation model determining module is used for determining a volume difference calculation model of the pre-formed shell and the formed ellipsoid shell according to the volume calculation model of the pre-formed shell and the volume calculation model of the formed ellipsoid shell;

the acquisition module of the target axial length of the formed ellipsoid shell is used for acquiring the target axial length of the formed ellipsoid shell, and the target axial length is determined according to the requirement;

the structure size determining module of the pre-formed shell before forming is used for determining the structure size of the pre-formed shell before forming according to the target axial length size of the ellipsoid shell after forming;

the target volume calculation module is used for substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into the volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume;

and the ellipsoidal shell manufacturing module is used for manufacturing the pre-formed shell according to the structural size of the pre-formed shell, and injecting liquid with the volume of the target volume into the pre-formed shell to obtain the molded ellipsoidal shell.

6. The liquid volume loading based ellipsoidal shell axial length dimension control system of claim 5, wherein the pre-shaped shell is from two different ellipsoids, designated as a first ellipsoid and a second ellipsoid, wherein the upper ellipsoidal shell and the lower ellipsoidal shell (first ellipsoidal shell) of the pre-shaped shell are from the first ellipsoid, and the middle ellipsoidal shell (second ellipsoidal shell) of the pre-shaped shell are from the second ellipsoid;

the volume calculation model determination module includes:

a volume calculation model determination unit for determining a volume calculation model of the pre-fabricated shell before forming as

7. the liquid volume loading-based ellipsoidal shell axial length dimension control system of claim 6, wherein the volume difference calculation model determination module specifically comprises:

a volume difference calculation model determination unit for determining a volume difference based on

8. A liquid-filled system for the method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to any one of claims 1 to 4, comprising:

a liquid filling subsystem for injecting liquid into the pre-formed shell of any of claims 1-4;

the flow meter is used for metering the liquid flow output by the liquid filling subsystem;

a control subsystem for determining a volume of liquid to be injected into the pre-formed shell based on the metering data from the flow meter and for controlling the filling subsystem to stop filling when the volume of liquid reaches a target volume amount as set forth in any one of claims 1-4.

Technical Field

The invention relates to the technical field of manufacturing of ellipsoidal containers, in particular to a method and a system for controlling the axial length of an ellipsoidal shell based on liquid volume loading.

Background

The ellipsoid container is widely applied to the fields of petrochemical engineering, water supply engineering, pressure containers, architectural decoration and the like. In particular, the axial length ratio λ (the ratio of the length of the major axis to the length of the minor axis) is greater than

The flat ellipsoid has the advantages of low gravity center, small wind load bearing capacity, beautiful appearance and the like, and is an ideal structure of the water tank of the large water tower. In addition, in the field of aerospace, the bottom of the fuel storage tank of the carrier rocket is generally of a flat ellipsoid structure, and the fuel storage tank has the advantages of effectively saving space, high structural bearing performance and the like.

The traditional forming and manufacturing method of the ellipsoidal container is that a shell plate is subjected to block die pressing and then welded into a whole ball, and the method needs a large-scale die and a press machine, so that the manufacturing cost is high, and once the diameter and the wall thickness of a product are changed, the die needs to be manufactured again, so that the adaptability to the change of the product is poor. For a large ellipsoidal container, multiple sets of molds are needed to meet the requirement, which makes the manufacturing cost and the period of the ellipsoidal container too high.

In order to solve the problems existing in the manufacture of the ellipsoidal container, an integral non-mold hydraulic forming method of the ellipsoidal container is proposed and developed. The ellipsoidal shell has different curvatures at each position, so that the stress states at each position during hydroforming are different, and the ellipsoidal shell is not subjected to simple bulging deformation. Research shows that the ellipsoidal container can be shaped smoothly and has inseparable relation with its axial length ratio lambda

The ellipsoidal shell is hydroformed (lambda 1 is a spherical container), so that qualified products can be smoothly formed; and ratio to axial length

Under the action of internal pressure, because the part near the equatorial belt is subjected to the action of latitudinal compressive stress, instability and wrinkling occur in the forming process, and qualified products cannot be formed. For axial length ratio

The problem of unstable wrinkling of the equatorial belt during the hydroforming of an ellipsoidal container is solved by providing a method for hydroforming an ellipsoidal container having a biaxial length ratio (patent No. ZL 201310628487.3). The basic idea is as follows: design of pre-fabricated shell before hydraulic forming of ellipsoidal containerIn a biaxial length ratio structure, the area between the equatorial line generating circumferential buckling and the tension-compression dividing angle is provided with a section of axial length ratio

The ellipsoidal shell of the other section replaces the ellipsoidal shell of the other section

Thereby ensuring that the biaxial length is not stressed by compressive stress in the overall latitudinal direction of the ellipsoid container under the action of internal pressure. With the increase of the internal pressure, the biaxial length ratio prefabricated shell gradually generates plastic deformation, the minor axis obviously extends along with the increase of the internal pressure, the major axis only slightly contracts along with the increase of the internal pressure, and finally when the internal pressure reaches a certain value (generally 1.0-1.1 p)_s，p_sYield internal pressure) of the two sections of the ellipsoidal shells become the same, and the axial length ratio is formedThe ellipsoidal container of (a). As the internal pressure continues to increase, the axial length ratio λ of the ellipsoidal container gradually decreases.

In the die-free hydraulic forming, the shell is in a state without external restraint, so that how to control the precision of the curvature radius of the shell is the key of the die-free hydraulic forming of the shell. As mentioned above, control is currently performed primarily by means of pressure loading. For spherical containers, a quantitative relationship model of forming pressure versus diameter (forming pressure) can be usedWhere p is the forming pressure, t is the wall thickness, d is the diameter of the spherical vessel, σ_sIs the container material yield strength), the shell diameter is regulated and controlled by controlling the forming pressure. However, in the axial length ratio

In the hydraulic forming of the ellipsoid shell, because the curvature radii of all parts of the ellipsoid shell are different, the two pole parts are firstly deformed, then the high-latitude area of the shell is deformed and gradually expanded to the equatorial area, and finally the equatorial area is deformed. And for two axesThe length is more complex than that of the ellipsoidal shell by hydraulic forming. Therefore, the dimensional accuracy of the major axis and the minor axis of the ellipsoidal shell cannot be controlled by a pressure loading method. To axial length ratio

The specific size of the double axial length ratio ellipsoid prefabricated shell used and the internal pressure at which the ellipsoid container of the target size can be obtained cannot be determined in advance.

Disclosure of Invention

The invention aims to provide a method and a system for controlling the length of an ellipsoid shell shaft based on liquid volume loading, so that the forming process of an ellipsoid container is simple and easy to implement, the difference of materials and wall thickness is not required to be considered during forming, the precision of the length of the shell shaft is controllable and adjustable, and the method and the system are suitable for manufacturing large-size ellipsoid containers on site.

In order to achieve the purpose, the invention provides the following scheme:

a method for controlling the axial length of an ellipsoidal shell based on liquid volume loading comprises the following steps:

determining a volume calculation model of the prefabricated shell before forming and a volume calculation model of the ellipsoid shell after forming, wherein the prefabricated shell before forming is formed after liquid loading to obtain the ellipsoid shell after forming; the pre-formed shell before forming is symmetrical about the center of the shell, and the pre-formed shell before forming is composed of a plurality of sections of ellipsoidal shells, wherein the ellipsoidal shells from different ellipsoids are arranged in the plurality of sections of ellipsoidal shells;

determining a volume difference calculation model of the prefabricated shell before forming and the ellipsoid shell after forming according to the volume calculation model of the prefabricated shell before forming and the volume calculation model of the ellipsoid shell after forming;

obtaining a target axial length dimension of the formed ellipsoid shell, wherein the target axial length dimension is determined according to requirements;

determining the structural size of the prefabricated shell before forming according to the target axial length size of the ellipsoid shell after forming;

substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into the volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume;

and manufacturing the pre-formed shell according to the structural size of the pre-formed shell, and injecting liquid with the volume of the target volume into the pre-formed shell to obtain the formed ellipsoidal shell.

Optionally, the pre-fabricated shell before forming is derived from two different ellipsoids, which are respectively marked as a first ellipsoid and a second ellipsoid, the upper ellipsoid shell and the lower ellipsoid shell (first section ellipsoid shell) of the pre-fabricated shell before forming are derived from the first ellipsoid, the middle ellipsoid shell (second section ellipsoid shell) of the pre-fabricated shell before forming are derived from the second ellipsoid,

λ₁is the axial length ratio of the first ellipsoid, λ₂Is the axial length ratio of the second ellipsoid.

Optionally, the determining a volume calculation model of the prefabricated shell before forming specifically includes: determining a volume calculation model of the prefabricated shell before forming as

Wherein, V₀Volume of prefabricated shell before shaping, a₁Is the length of the semimajor axis of the first ellipsoid, a₂Is the length of the semimajor axis of the second ellipsoid, α₀In order to realize the tensile and compressive stress dividing angle,

optionally, the determining a volume difference calculation model of the preformed shell before forming and the ellipsoidal shell after forming according to the volume calculation model of the preformed shell before forming and the volume calculation model of the ellipsoidal shell after forming specifically includes:

according to

Determining a volume difference calculation model, wherein delta V is a prefabricated shell before forming and an ellipse after formingVolume difference of ball housing, λ_FIs the axial length ratio of the ellipsoidal shell after shaping.

The invention also provides a liquid volume loading-based ellipsoidal shell axial length dimension control system, which comprises:

the volume calculation model determining module is used for determining a volume calculation model of the prefabricated shell before forming and a volume calculation model of the ellipsoid shell after forming, and the prefabricated shell before forming is formed after liquid loading to obtain the ellipsoid shell after forming; the pre-formed shell before forming is symmetrical about the center of the shell, and the pre-formed shell before forming is composed of a plurality of sections of ellipsoidal shells, wherein the ellipsoidal shells from different ellipsoids are arranged in the plurality of sections of ellipsoidal shells;

the volume difference calculation model determining module is used for determining a volume difference calculation model of the pre-formed shell and the formed ellipsoid shell according to the volume calculation model of the pre-formed shell and the volume calculation model of the formed ellipsoid shell;

the acquisition module of the target axial length of the formed ellipsoid shell is used for acquiring the target axial length of the formed ellipsoid shell, and the target axial length is determined according to the requirement;

the structure size determining module of the pre-formed shell before forming is used for determining the structure size of the pre-formed shell before forming according to the target axial length size of the ellipsoid shell after forming;

the target volume calculation module is used for substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into the volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume;

and the ellipsoidal shell manufacturing module is used for manufacturing the pre-formed shell according to the structural size of the pre-formed shell, and injecting liquid with the volume of the target volume into the pre-formed shell to obtain the molded ellipsoidal shell.

Optionally, the pre-fabricated shell before forming is derived from two different ellipsoids, which are respectively marked as a first ellipsoid and a second ellipsoid, an upper ellipsoid shell and a lower ellipsoid shell (a first section ellipsoid shell) of the pre-fabricated shell before forming are derived from the first ellipsoid, and a middle ellipsoid shell (a second section ellipsoid shell) of the pre-fabricated shell before forming are derived from the second ellipsoid;

the volume calculation model determination module includes:

a volume calculation model determination unit for determining a volume calculation model of the pre-fabricated shell before forming as

Wherein, V₀Volume of prefabricated shell before shaping, a₁Is the length of the semimajor axis of the first ellipsoid, λ₁Is the axial length ratio of the first ellipsoid, λ₂Is the axial length ratio of the second ellipsoid, a₂Is the length of the semimajor axis of the second ellipsoid, α₀In order to realize the tensile and compressive stress dividing angle,

optionally, the volume difference calculation model determining module specifically includes:

a volume difference calculation model determination unit for determining a volume difference based on

Determining a volume difference calculation model, wherein delta V is the volume difference between the prefabricated shell before forming and the ellipsoid shell after forming, and lambda_FIs the axial length ratio of the ellipsoidal shell after shaping.

The invention also provides a liquid filling system for the liquid volume loading-based ellipsoidal shell axis length control method, which comprises the following steps:

the liquid filling subsystem is used for injecting liquid into the pre-fabricated shell before forming;

the flow meter is used for metering the liquid flow output by the liquid filling subsystem;

and the control subsystem determines the volume of the liquid injected into the prefabricated shell before forming according to the metering data of the flowmeter and controls the liquid filling subsystem to stop filling liquid when the volume of the liquid reaches the target volume amount.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects: the invention provides a method for controlling the axial length of an ellipsoidal shell based on liquid volume loading, which comprises the following steps: determining a volume calculation model of a prefabricated shell before forming and a volume calculation model of an ellipsoid shell after forming, wherein the prefabricated shell before forming is composed of a plurality of sections of ellipsoid shells, and the plurality of sections of ellipsoid shells are provided with ellipsoid shells from different ellipsoids; determining a volume difference calculation model of the prefabricated shell before forming and the ellipsoid shell after forming according to the volume calculation model of the prefabricated shell before forming and the volume calculation model of the ellipsoid shell after forming; obtaining a target axial length dimension of the formed ellipsoid shell, wherein the target axial length dimension is determined according to requirements; determining the structural size of the prefabricated shell before forming according to the target axial length size of the ellipsoid shell after forming; substituting the target axial length dimension of the formed ellipsoid shell and the structural dimension of the prefabricated shell before forming into a volume difference calculation model to obtain the volume difference between the formed ellipsoid shell and the prefabricated shell before forming, and recording the volume difference as a target volume; and manufacturing the pre-formed shell according to the structural size of the pre-formed shell, and injecting liquid with the volume being the target volume into the pre-formed shell to obtain the formed ellipsoidal shell. Compared with the forming method of the ellipsoid shell in the prior art, the forming method of the ellipsoid shell has the advantages of simple process, easy implementation, no need of considering material and wall thickness difference (but the existing pressure control needs to be considered) during forming, controllable and adjustable axial length and dimensional precision of the shell, and suitability for manufacturing large-size ellipsoid containers on site.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a flow chart of a method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method for controlling the axial length of an ellipsoidal shell based on liquid volume loading according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of a dual axial length ratio prefabricated housing prior to forming an ellipsoidal container in accordance with an embodiment of the present invention;

figure 4 is a schematic volume view of an ellipsoid container after forming in accordance with an embodiment of the present invention;

FIG. 5 is a schematic representation of the volume of a pre-fabricated shell having a biaxial length to ellipsoid shape prior to forming in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of an ellipsoidal shell hydroforming system based on liquid volume loading according to an embodiment of the present invention; wherein, 1-the biaxial length ratio is prefabricated into an ellipsoidal shell; 2-a flow meter; 3-a pressurizing device; 4-a water tank; 5-a control system; 6-ellipsoidal containers;

FIG. 7 shows an embodiment of the present invention where the selection of the spherical center angle θ is greater than the tensile and compressive stress dividing angle α before forming₀The biaxial length ratio of (A) is a structural schematic diagram of a prefabricated shell;

figure 8 is a diagram of a system for controlling the axial length of an ellipsoidal shell based on liquid volume loading in accordance with an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a method and a system for controlling the axial length of an ellipsoid shell based on liquid volume loading, so that the forming method of an ellipsoid container is simple, the forming process of the ellipsoid container is simple and easy to implement, the difference of materials and wall thickness is not required to be considered during forming, the precision of the axial length of the shell is controllable and adjustable, and the method and the system are suitable for manufacturing large-size ellipsoid containers on site.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.