Design and manufacturing method of air spring rubber air bag

Abstract

The invention discloses an air spring rubber airbag design and manufacturing method, in particular to an airbag design calculation method and manufacturing method, which avoid the error of cord thread cutting angle selected from a model selection manual in the common air spring design, and improve the elastic force and stability of the air spring. The invention provides a method for designing and manufacturing a rubber air bag of an air spring. The method comprises the following steps: 1, determining design parameters such as the inner diameter, the outer diameter, the length, the wall thickness and the air pressure according to use requirements and specified requirements; 2, designing structural parameters of the air spring, and calculating a framework material cord thread angle and the like. 3, a sample is manufactured and tested, and it is ensured that the sample meets the specified requirements for elastic force and stability. Compared with a traditional design method, a formula calculation method is adopted, the angle of the framework material can be obtained more accurately, then the elastic force and stability of the air spring are optimized, and the design efficiency of the air spring is improved. The designed air spring is suitable for the fields of industry, automobiles, aviation and the like.

Description

Technical Field

[0001] The present invention relates to a design and manufacturing method of an air spring rubber airbag, and more particularly to a design and manufacturing method of a vehicle air spring rubber airbag, which belongs to the technical field of vehicle air spring shock absorption. Background Art

[0002] An air spring is a device that uses the compression and expansion of gas to generate elastic force, and is usually used in industrial, automotive, aviation and other fields.

[0003] The rubber air spring device mainly includes four parts: a rubber air spring; a force transmission - guiding mechanism; a height control mechanism, namely a height valve, etc.; and an air supply system. The air volume in the rubber air spring depends on the load on the spring. When the load increases, air needs to be supplemented, and when the load decreases, air is discharged, so that the height of the spring can be maintained and better equal - frequency performance can be obtained. Inflation and exhaust are controlled by the height control mechanism, which generally consists of a height valve and its connecting rod. The air supply system consists of an air compressor, an air storage tank, and pressure regulating valves, pressure reducing valves, safety valves, etc. installed according to different requirements.

[0004] The air spring has three major functions, namely, spring function, shock absorption function and actuation function. Figure 1 An air spring consists of a rubber airbag 1, a shock absorber rod 2, a flange 3, an intake valve 4, etc. The following takes the structure of this air spring as an example for illustration.

[0005] There is a lack of a systematic design basis for vehicle air spring airbags in China. General research mainly focuses on technical applications, such as selection, installation, testing, application development trends, etc. With the progress and development of science and technology and industry, higher requirements are put forward for the performance of rubber airbags in places such as trucks, buses, special vehicles, new energy vehicles, etc. The required rubber airbag pressure resistance, high and low temperature resistance characteristics, service life, shock absorption ability, etc. have been significantly improved.

[0006] Currently, rubber airbags are generally selected based on the load and the frequency required by the vehicle performance, using the selection diagram provided by the airbag manufacturer. There is no publicly available formula for calculating the cord angle, and each manufacturer determines it through experiments and the accumulation of past experience. As a result, the cord angle of the finished rubber airbag after forming is actually uncontrollable. Therefore, the quality consistency of the product cannot be well guaranteed. Only a large safety factor can be used to ensure quality, and at the same time, the elastic force and stability of the air spring are also unstable, which in turn affects the ride performance of the vehicle, such as the smoothness, handling stability, and riding comfort of the vehicle. With the progress and development of science and technology and industry, in many places such as new energy passenger cars, it is necessary to achieve stable elastic performance for a longer time within a limited installation space. The existing manufacturing methods are difficult to achieve. The present invention proposes a specific design method and manufacturing technology for rubber airbags. Through this method, rubber airbags that meet the design requirements can be designed and manufactured, improving the stability and durability of rubber airbags. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the defect of the existing technology that the cord angle of the skeleton material of the current rubber airbag cannot be accurately designed, and to provide a design and manufacturing method for rubber airbags. By using the present invention, the designed rubber airbag has theoretical support, and the cord angle required for forming and manufacturing can be designed by using this design method. At the same time, by using this method, the rubber airbag can obtain a better service life through a more reasonable safety factor.

[0008] To solve the above problems, the present invention adopts the following technical solutions:

[0009] Design scheme of rubber airbag:

[0010] 1) Design the required β of the rubber airbag k Calculation formula:

[0011]

[0012]

[0013] In the formula:

[0014] t max — Maximum strength of a single cord, N / cord;

[0015] P — Internal pressure of the airbag, Pa;

[0016] r k — Radius of the mid-perimeter line in the radial section of the rubber airbag, m;

[0017] r m — Radius at the tangent position of the radial section of the rubber airbag and the flange, m;

[0018] nc — Number of cord plies;

[0019] i c,k — Number of cords arranged per unit length, cords / m;

[0020] β k — Angle between the cord of the finished rubber airbag and the axis, °C;

[0021] δ1— Assumed elongation value of the cord is taken as 1.02;

[0022] r0— Radius of the formed cord fabric cylinder, m;

[0023] α0— Cutting angle of the cord, (°C);

[0024] C s — Safety factor of the rubber airbag, taken as 8 according to experience;

[0025] S— Strength of a single cord, (N / cord).

[0026] 2) Calculation of the cutting angle for cord fabric forming

[0027] If the assumed elongation value of the cord is taken as δ1 = 1.02, then the cutting angle α0 of the cord is calculated as follows:

[0028]

[0029] The calculation method for multiple layers of cord fabric is similar.

[0030] Formulate and implement the manufacturing method of the rubber airbag.

[0031] 1) Calculate the number of cord fabric layers required for the rubber airbag according to the design formula.

[0032] 2) On special equipment, cut the cord fabric reinforcement at the calculated angle.

[0033] 3) On special forming equipment with an inflatable capsule, laminate and form in the order of inner rubber layer + first layer of cord fabric + second layer of cord fabric... + outer rubber layer; Inflate and shape the capsule of the forming equipment to the required semi-finished size of the rubber airbag.

[0034] The inflatable capsule is designed according to the calculated size of the semi-finished rubber airbag. The deformation after inflation meets the design requirements.

[0035] 4) On special vulcanization equipment, vulcanize the formed semi-finished rubber airbag by filling it with nitrogen.

[0036] The technical effect of the present invention lies in:

[0037] 1. The design method of the present invention takes into account both the strength limit of the cord and the change in the cord angle during the forming process of the cord fabric material, making the cord angle inside the finished rubber airbag controllable, effectively controlling the rubber airbag. Through the reasonable design of the cord angle, the service life of the rubber airbag can also be effectively extended.

[0038] 2. Compared with the rubber airbags used in the past, the performance advantages of the rubber airbag designed and processed by the present invention are specifically as follows:

[0039] According to the design method of the present invention, a reasonable cord fabric cutting angle can be effectively designed according to the calculation formula, avoiding the previous empirical processing method, and providing a calculation method and basis for the manufacturing and processing of rubber airbags. Through this design method and manufacturing technology, rubber airbags that more meet the usage requirements can be produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of the rubber airbag of the present invention DETAILED DESCRIPTION OF THE INVENTION

[0041] In specific implementation, for clearer illustration, a rubber airbag for a truck cab is taken as an example.

[0042] DETAILED TECHNICAL INDEXES

[0043] Serial Number Item Index 1 Inflation Pressure 10 bar 2 Load 5000N 3 Maximum Diameter after Inflation 125 mm 4 Diameter at Flange 82 mm 5 Number of Plies 2 plies 6 Cord Density 84 cords / 10 cm

[0044] The inner diameter of the finished airbag is 82 mm, the design pressure is 0.1 MPa, and the load is 5000 N. According to the conventional design method, by referring to the standard selection, and then through empirical judgment, one or several cutting cord angles of the manufactured semi-finished products are selected. After the product trial production is completed, through tests such as results, the best cord angle is selected from them and finalized as the cutting cord angle for product processing.

[0045] The design method of the present invention is used to solve the following:

[0046] 1. Calculation of the angle between the cord and the axis of the finished rubber airbag cord

[0047] According to the formula

[0048] In the formula, S is the selected breaking strength of the cord, 115.52 N;

[0049] C s —Safety factor of the rubber airbag, (taken as 8 according to experience);

[0050] By reverse deduction, t max = 14.44 N / strand;

[0051] Substitute into

[0052]

[0053] Substituting the data and deducing:

[0054]

[0055] Obtaining

[0056] β k = 74.283 °C

[0057] 2. Calculation of the cutting angle of the cord fabric forming

[0058]

[0059] The manufacturing method is carried out according to the following steps:

[0060] 1) Lay the inner rubber layer according to the designed thickness.

[0061] 2) The forming equipment is equipped with a forming airbag. Each layer of cord fabric that has passed the inspection is laid layer by layer at the angle designed by the method of the present invention and inflated for shaping.

[0062] 3) The special vulcanization equipment is shaped by filling nitrogen into the vulcanization capsule. The obtained semi-finished rubber airbag product is put into the mold. The mold is equipped with a vulcanization capsule, and nitrogen is filled into the capsule for vulcanization under heating and pressure.

[0063] 4) After vulcanization, it is naturally cooled in the air, the mold is removed, and a rubber airbag is obtained.

[0064] The rubber airbag designed and manufactured by the present invention has better elastic force and stability through finite element method analysis, meets the design requirements in actual tests and use, and at the same time, design adjustments can be made to improve the bearing capacity and service life according to the usage requirements.

[0065] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, rather than limitations on the embodiments. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A design method for an air spring rubber airbag, characterized in that: The core design of the air spring rubber airbag is that the rubber airbag adopts the maximum cord force and uses the thin film theory and the equilibrium profile method for rubber and cord to design and form the cord fabric forming cut-off angle; Where: t max — The maximum strength of a single cord, N / cord; P—the internal pressure of the airbag, Pa; r k —Radius of the mid-perimeter line in the radial section of the rubber airbag, m; r m — Radial section radius of rubber airbag tangent to flange plate, m; n c - Number of cord plies; i c,k — Number of cord arrangements per unit length, roots / cm; β k — Cord angle of the finished rubber airbag cord with the axis; °C δ1—the assumed extension value of the cord is taken as 1.02; r0—the radius of the formed cord fabric cylinder, M α0—the cut-off angle of the cord (℃).

2. The manufacturing method of the rubber airbag according to claim 1, Its characteristics are carried out according to the following steps: 1) Lay the inner rubber layer according to the designed thickness; 2) The forming equipment is equipped with a forming airbag. The qualified cord fabrics of each layer are laid layer by layer at the angle designed by the method described in claim 1 and inflated and shaped; 3) The special vulcanization equipment is shaped by filling nitrogen into the vulcanization capsule. The obtained semi-finished rubber airbag is put into the mold. The mold is equipped with a vulcanization capsule, and nitrogen is filled into the capsule for vulcanization under heating and pressure; 4) After vulcanization, it is naturally cooled in the air, the mold is removed, and the rubber airbag is obtained.

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