Several new concepts related to the design of rubber shoes I

Improvements and improvements in any rubber product are inseparable from the design concept, and rubber shoes are no exception. Consumers’ requirements for rubber shoes are nothing more than long service life, comfortable wearing, light weight and not easy to produce fatigue, which is beneficial to the protection of the feet and lower limbs, and has a beautiful and smooth contour shape. These requirements generally relate to mechanics, aesthetics, and physiological mechanics. Here is a brief introduction to several design concepts related to physiological mechanics.

The concept was originally proposed to improve the design of sports shoes and was later extended to other rubber shoe varieties. It is based on the transfer of force during exercise. The main point is that when a person is exercising or walking, the wearer pays a certain amount of energy, and the human body passes the shoes to the ground, but some of them pass through the shoes in the form of reaction. The return to the human body, the return of this force can also be regarded as compensation for the energy of the human body. If the return rate is 20%, it can be understood that when the human body moves next time, it can save 20% of energy. It is inferred that the runner can run 20% of the energy expenditure. Then, for ordinary people to go out, it is also possible to reduce the same amount of physical exertion, and its significance is no small matter. Linked to reality, this new concept can be extended to all footwear, including the following aspects.

1) Improved formula design Because the energy return is directly related to the resilience of the sole, since the outsole is directly in contact with the ground, the better the elasticity, the more energy is returned to the human body, the more labor-saving the wearer wears, the more effective the fatigue is. it is good. Starting from the formulation design, the rubber with good resilience (such as natural rubber and high rubber content) should be used. The insole should adopt a microporous structure.

2) The use of air cushions Nike’s patented inflatable plastic mats introduced in the early 1980s is a successful masterpiece in this field, which has been popular and has not deteriorated. The construction of the air cushion is not complicated, and the material is also common. The polyethylene film is used as a raw material, processed into a capsule shape, and then inflated and sealed, and embedded in the heel portion during molding.

3) The tubular rod was developed and applied to the product by another famous shoe manufacturer, ReebOk Footwear Company, with good results. It is made of Hytrel resin (a thermoplastic elastomer material produced by DuPont) and is made into a tubular rod embedded in the heel. The high resilience of this material makes the energy return.

4) Using sheet-like parts Another shoe company, EtOnik, chose a fiber sheet called “Dynamic Reaction Sheet” as a return piece, which was inserted into the arch of the foot and also returned energy to the human body. Moreover, the softer the texture of the sheet, the higher the bending frequency and the better the returning effect.

Wedge structure

Variety specifications

Depending on the raw materials used and the processing methods, the V-ribbed belt can be divided into two types: polyurethane (using casting process) and rubber type (using molding process). The rubber type V-ribbed belts are divided into H, J, K, L, and M specifications according to the sectional size from small to large.

New varieties

As the performance of automobiles continues to change and improve, new varieties of V-ribbed belts are constantly being introduced.

(1) The wedge of the toothed V-ribbed belt is cut into a tooth shape, similar to the trimmed V-belt. This can improve the flexibility of the belt and accelerate the heat dissipation to meet the heat dissipation requirements of the engine after the vehicle speed is increased. According to the research of Goodyear, the damage of the toothed V-ribbed belt after 167h under high temperature conditions is only equivalent to the damage of the ordinary V-ribbed belt after 66h under the same conditions.

(2)Flocking V-ribbed belts A major disadvantage of conventional V-ribbed belts is that they are noisy during operation, especially on rainy days. After the flocking layer is applied to the wedge, the noise is greatly reduced. Flocking can be obtained from aramid fibers.

(3) Elastic V-ribbed belts Some household appliances (such as washing machines, dry cleaning machines and fitness equipment) often need to adjust the distance of the transmission during use. Therefore, the multi-ribbed belts should be equipped with sufficient elastic deformation adaptability to ensure There is no need to frequently adjust the distance during the entire use of the machine.

(4) EPDM rubber V-ribbed belt With the continuous increase of the speed of the car, the temperature of the engine part of the car is also rising, requiring the tape to withstand a high temperature of 170 ° C in an instant. The neoprene used in the past has been overwhelmed. Therefore, EPDM rubber began to enter the V-ribbed belt field. However, the ethylene-propylene rubber V-ribbed belt is not ideal for high temperature resistance, tear resistance, wear resistance and dynamic performance, and needs further improvement and improvement.

V-ribbed belt

There are many types of tapes, and the total can be divided into conveyor belts and transmission belts. The former is mainly used for transportation of materials in mines, docks and factories; the latter is used for mechanical transmission, and the application is wider, and it is as large as heavy machinery, and it is inseparable from household appliances.

According to different uses and different requirements, the classification of the transmission belt is also becoming more and more refined. It was originally divided into a flat transmission belt (named as a non-working surface in the form of a flat shape, referred to as a flat belt) and a V-belt (a cross-section is wedge-shaped, because the transmission route is two The angular shape, also known as the two-pointed belt in the past, is two major categories. However, with the different transmission requirements, many new varieties are found between them, which play the role of mutual complementarity. The V-ribbed belt is one of them.

(1) Product introduction and structure

The V-ribbed belt combines the advantages of the flat belt and the V-belt. It is structured with a flat belt as the base and the inner surface is arranged with equidistant longitudinal wedges (the wedge angle is usually 40°). Therefore, the belt combines the length of the two.

Multi-ribbed belt outline drawing

The strong layer of the V-ribbed belt is located in the base portion of the flat belt and is not located at the wedge portion like the V-belt. Compared with the flat transmission belt, the V-ribbed belt working surface is composed of a plurality of wedge bodies, thereby increasing the contact surface and frictional force with the pulley, and thus is not easy to slip, thereby improving the transmission efficiency. Compared with the group V belt, there are two merits:

First, the load distribution along the bandwidth is more uniform;

Secondly, the belt body is thinner, and the centrifugal stress and bending stress with respect to the V belt are smaller than that of the ordinary rubber belt. Therefore, a smaller transmission wheel can be configured, and less energy is consumed during operation, and a higher power is obtained. The transmission ratio plays a role in energy saving and consumption reduction. In summary, the V-ribbed belt is a promising transmission tape. Especially in automobiles, it is used in large quantities as an engine drive belt.

Two-piece assembled tire

In recent years, in the field of large-scale engineering tires, a variety of new varieties with unique shapes and different structures and traditional tires have emerged in the field of large-scale engineering tires. Two-piece assembled tires are one of them. It is a new concept product designed and launched by the Akron Center in the United States and is now produced at the Topeka Tire Factory in Kansas, USA. The specific varieties cover large bus tires, agricultural tires and off-road tires for engineering construction machinery, which are suitable for large and heavy vehicles.

(1) Structural characteristics

Ordinary tires consist of two parts, inner and outer tires. The inner tube has a relatively simple effect, that is, it provides air pressure, and the structure is also very simple. After inflation, it maintains a certain internal pressure, which acts as a cushioning and supporting function to keep the vehicle stable and safe while driving. Two-piece tires are also divided into inner and outer parts, namely the tread and the carcass. Both parts are reinforced with steel cords, but the division of labor between them is not as distinct as the inner and outer tires of ordinary tires. Although the two components are independent of each other, the contact faces have circumferential ribs (located on the inner surface of the tread) and grooves (located on the outer surface of the carcass). The spacing between the ribs and the ribs is equal to the spacing between the grooves and the grooves. After assembly, the ribs on the inner surface of the tread are located in the grooves on the outer surface of the tire to form a good engagement and fixation. Under the action of air pressure, the carcass is inflated and then the tread is pressed outwards, thereby playing a strong interlocking effect.

It can be seen that the inner and outer parts are purely mechanical and pneumatic, and are not dependent on adhesive or mechanical parts. In this way, loading and unloading or maintenance is very convenient, and the user can disassemble, assemble or replace it by ordinary tools. This two-piece tire is dimensionally compatible with the current range of tire specifications and therefore has good versatility and fit with the rim.

(2) Product advantages

First, the matching between the inner and outer parts is strong, which can shorten the time and workload of the tire change and disassembly of the general engineering vehicle, and the required time is only half of that of the ordinary tire.
Second, the section is wide and the protection effect on the carcass is good.
Third, the payload is large, the pressure distribution of the entire tread is very uniform, and the heat is low during driving.
Fourth, when driving under off-road conditions, it is better to prevent cutting and piercing of sharp objects such as gravel on the road surface, which is beneficial to improving the service life of the tire and reducing the damage rate.
Fifth, the driving stability is good, which helps to lighten the driver’s fatigue.

A new member of the tire family – Electric Tires

According to the traditional classification concept of force tires, it can be divided into bicycle tires and trolley tires.
Tricycle tires and motorcycle tires and other major categories.

However, with the development of the products, some varieties are gradually eliminated and shrink, such as trolley tires; while others are marketable and develop rapidly. In recent years, with the growing popularity of electric vehicles, many people in urban and rural areas have begun to own electric vehicles, and the output of electric tires has also skyrocketed. The changes in the annual output of electric vehicles in recent years can fully explain this point. It was 2 million vehicles before 2003, and it surged to 5.5 million in 2004. In 2006, it reached 18 million. Calculated according to the original two of each new car, that is, 36 million, plus the replacement of the old tire volume, the current total annual demand may be no less than 50 million. Therefore, according to industry experts’ estimates, electric tires are expected to form a new, independent product line.

The emergence of electric vehicles and the popularity of the majority of users is the inevitable result of the increasing income of the people, so the electric tires, one of its main accessories, came into being.

As a promising new product, electric tires should have a complete set of production technical information, independent and perfect product standards. Although it is a type of tire, it is not equivalent to the requirements of other tires. For example, the speed of an electric vehicle is between the bicycle and the motorcycle, and the weight of the vehicle is also between the two. Then, as a matching component, electric tires should consider the commonalities between product design and performance indicators, and also pay attention to different points and treat them differently.

For example, since the speed of the electric vehicle is larger than that of the bicycle and the diameter of the tire is small, the strength of the carcass should be higher than that of the bicycle tire, and the size of the skeleton material used or the number of layers of the skeleton layer cannot be equal to the number of layers of the bicycle tire. Especially because of the fast driving speed, the safety factor of the product needs to be paid more attention, and the safety factor should be properly enlarged. In particular, it is necessary to combine the quality problems that affect the driving safety that consumers have seen. It should be improved and improved through product structure design and raw material selection. Ensure safe and reliable use.