CN109334351B

CN109334351B - Polyurethane solid tire and manufacturing method thereof

Info

Publication number: CN109334351B
Application number: CN201811274512.1A
Authority: CN
Inventors: 徐言军; 孙红雨; 汪帅
Original assignee: Jinan Aomolnya Mining Equipment Co ltd
Current assignee: Jinan Aomolnya Mining Equipment Co ltd
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2022-01-28
Anticipated expiration: 2038-10-30
Also published as: CN109334351A

Abstract

The invention discloses a polyurethane solid tire and a corresponding manufacturing method. The heat-conducting wheel rim comprises a rim, a hub and a polyurethane rubber layer, wherein the polyurethane rubber layer is attached to the outer surface of the rim through a bonding process.

Description

Polyurethane solid tire and manufacturing method thereof

Technical Field

The invention relates to the technical field of solid tires, in particular to a solid tire used on engineering vehicles in industrial and mining occasions.

Background

Taking an engineering forklift as an example, in factories, mines and other occasions, polyurethane solid tires are generally used, and the solid tires can better meet the following requirements: puncture resistance, tearing resistance, no need of inflation, high utilization rate, low maintenance rate and other special requirements.

Wherein, polyurethane solid tyre according to the combination mode with the rim, can subdivide into: the tire rim is characterized by comprising a bonding type structure and a non-bonding type structure, wherein the bonding type structure is that polyurethane is directly poured and vulcanized on the rim to form an integral structure. The non-adhesive structure is that the polyurethane elastomer is fixed on the rim by adopting a mechanical sleeving manner. In either form, there is a problem of internal heat generation of the polyurethane elastomer.

With regard to the problem of internal heat generation of the elastomer in a solid tire, the applicant has combined the practical work and made a great deal of research, further combined with the prior technical documents, examples and other data, for solving the technical problems existing in the following schemes.

The "cast polyurethane elastomer (CPUE) is superior to a rubber material in physical properties, but the internal heat generation is a major factor affecting the practicability of a polyurethane tire", which is disclosed in "tire industry" impurity, 2004, volume 24, information of the literature, "research on internal heat generation test of polyurethane solid tire" (author houchun min, zhang ying, jialin cai, beijing university institute of science and engineering of machinery and vehicles). And a research process for the internal heat generation mechanism of a polyurethane solid tire is disclosed in the literature, and factors influencing the internal heat generation are given as follows:

A. the self formula components of the polyurethane;

B. loading and loading; the highest temperature of the model load wheel is increased along with the increase of the load, the temperature gradually tends to be stable after reaching the highest value, and the highest temperature under the load of 750 kg is 96 ℃.

C. The operating speed of the wheel; the highest temperature of the polyurethane solid tire model bogie wheel is increased along with the increase of the rotating speed, and gradually becomes stable after the temperature reaches the maximum value, and the highest temperature is 92 ℃ at the rotating speed of 440r min < -1 >. That is, the increase of the load leads to the overall temperature increase of the model bogie wheel, but the temperature is not changed in different cases; the increase of the rotating speed not only causes the overall temperature of the model loading wheel to be increased, but also generates a large amount of heat due to the friction between the rotary drum and the surface of the tire to be increased, thereby causing the temperature of the part of the tire body close to the surface to be increased.

D. Ambient temperature; the convection heat dissipation effect of the air flow on the surface of the tire is influenced.

E. Rim thickness (thickness of polyurethane); that is, the thicker the rim thickness, the more severe the internal heat generation and the worse the heat dissipation. This is because the distance of the outer points from the surface is reduced, and therefore heat dissipation is fast and the temperature is low; the temperature of the middle point is slightly reduced, and the temperature difference between the inner point and the middle point is also reduced, which shows that a steady-state temperature field is formed in the wheel rim, and the temperature rise is stable; the maximum temperature of each point is reduced, which shows that the temperature rise of the tire can be reduced by reducing the thickness of the wheel rim.

Of the five indexes, in mine vehicles, the load and the load are relatively large, and the rotation speed of the wheel is a main source of heat generated inside the polyurethane solid tire.

The technical route for avoiding the internal heat generation mainly comprises two steps, namely, the internal organization mechanism of the solid tire after vulcanization is changed by changing and optimizing the composition formula, but because the polyurethane is a block high molecular polymer consisting of a soft segment and a hard segment, the molecular bond of the material is easy to generate heat under the condition of high speed and heavy load, and the heat generation performance of the material is not greatly influenced even if the process is optimized. The second method is to improve the heat dissipation path of the heat inside the polyurethane elastomer, i.e., to dissipate the internal heat in time and to achieve the heat balance between heat generation and heat dissipation early, for example, to achieve the heat balance point between heat dissipation and heat generation about 60 degrees celsius (the heat balance point between heat dissipation and heat generation in the prior art is 100 degrees celsius or more).

For the heat dissipation problem, in the current domestic and foreign research, among the technical means used, the most common is to preset heat dissipation holes and heat dissipation lines on the polyurethane elastomer, that is, to increase the heat dissipation amount by increasing the heat dissipation surface, so that the air flow exchange is performed between the tire surface and the nearby space, and this technical means can usually achieve the purpose of cooling down at 5 to 10 degrees celsius, that is, the balance point can be lowered, but the reduction range is not very obvious, and there is an obvious negative effect, which is combined with patent documents, such as the solid tire of publication No. CN1369386A applied by japan cauldron mountain rubber industry co-ltd 2001, and the solution to the problem is:

the ratio of the height to the width of the section of the tire is designed to be 15-80%, namely, a heat dissipation path is shortened through a flattening scheme, meanwhile, a plurality of discontinuous holes 000 are arranged on the side surfaces of the left side and the right side, a tread groove 002 is arranged on the tread, rapid heat dissipation is realized through the areas of the holes (blind holes) and the tread groove, and the problem that a heat balance point of heat dissipation and heat generation moves downwards is realized. However, the arrangement of the holes can increase heat dissipation, and during operation, the tire is repeatedly crushed and deformed, so that stress points exist, and a tear crack 003 is easily generated, and referring to the pattern shown in fig. 1, the generation of the tear crack causes the reduction of the service life.

For another example, the tearing problem of the heat dissipation holes (through holes or blind holes) disclosed and analyzed in the publication No. CN2639036Y applied in 2003 by taiwan shun rubber industry gmbh of taiwan, the applicant can reduce the possibility of tearing by optimizing the heat dissipation holes to be circular arc transition, but the tearing problem still exists, that is, the problem is not really solved.

Any arrangement of the heat dissipation holes and the heat dissipation grooves weakens the durability of the urethane rubber in terms of strength, that is, improvement of heat dissipation is premised on sacrificing strength and durability. The invention aims to provide a solid tire with both heat dissipation and strength through improvement.

The patent documents for reference about the arrangement of the heat dissipation holes are more, the advantages and the disadvantages are not analyzed one by one in space, and readers can study and analyze the advantages and the disadvantages.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a polyurethane solid tire which is used for solving the problems that in the existing solid tire manufacturing process, heat dissipation holes/grooves are commonly used for increasing the heat dissipation effect, and meanwhile, the existence of the heat dissipation holes/grooves can reduce the overall strength of the tire and the overall service life.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the polyurethane solid tire comprises a rim, a hub and a polyurethane rubber layer, wherein the polyurethane rubber layer is attached to the outer surface of the rim through a bonding process.

Further, a tread groove is provided in the tread portion of the urethane rubber layer or a side shallow groove is provided in the side surface.

Further, the heat conduction component is a composite structure of heat conduction rubber and graphene fiber yarns.

Further, the graphene fiber wires may be entirely located in the heat-conducting rubber substrate, or a part of the graphene fiber wires is partially located in the heat-conducting rubber substrate and partially exposed, and either one of the graphene fiber wires and the heat-conducting rubber substrate is selected.

The heat conducting member further comprises a first annular body and a second annular body which are concentrically arranged, and a transition connecting body connected between the two annular bodies, wherein the first annular body is attached to the hub, and the second annular body is approximately positioned in the center of the polyurethane rubber layer.

Furthermore, a radiator extends towards two sides of the second annular body, and an expanded shape is arranged on one radiator.

Furthermore, a steel wire mesh cylinder is sleeved on the heat radiation body.

Further, a composite reinforcing layer is provided on the surface of the rim, and a cord is provided in the reinforcing layer.

A method for manufacturing a polyurethane solid tire,

step one, preparing a heat conducting component: the formula proportion of the heat-conducting component is as follows: the weight percentage of the material is as follows: 45-55% of polyurethane resin, 40-20% of heat conducting powder, 10-20% of flame retardant and the rest of foaming agent and graphene fiber filament are fully mixed, stirred uniformly, poured into a mold and subjected to high-temperature hot-press molding for later use;

step two, preparing a rim steel ring, forming a plurality of barbs on the outer surface of the annular steel billet through an anvil process, hardening the barb structure through a heat treatment process, and welding a hub part for later use;

and step three, sleeving the whole heat conduction member on the rim, centering the heat conduction member, placing the whole steel ring in a mold, pouring or injecting a polyurethane raw powder material into the tire manufacturing mold, and performing high-temperature hot press molding to obtain the solid tire.

Further, the barbed points of the barbs are non-perpendicular to the tire tread surface.

The invention has the beneficial effects that: the present invention has more excellent heat dissipation performance, and how the excellent heat dissipation performance is achieved, the following is a detailed description of specific examples.

Drawings

Fig. 1 illustrates a prior art heat sink groove configuration.

Fig. 2 shows a heat dissipation channel according to the present invention.

Fig. 3 is a configuration diagram of a heat conductive member.

Fig. 4 is a partial sectional view of the heat conductive member.

Fig. 5 is another pattern of the heat conductive member.

Fig. 6 is a structural view of the second embodiment.

FIG. 7 is a structural view of the third embodiment.

In the figure: the combination of 100 rims, 110 barbs,

200 of the wheel hub, wherein the wheel hub is provided with a hub body,

300 layers of urethane rubber, 310 tread grooves,

400 heat conducting members, 410 fiber wires, 420 heat conducting rubber matrix, 430 first ring body, 440 second ring body, 450 transition connecting body, 460 heat radiating body, 470 expansion shape, 480 steel wire mesh cylinder,

500 composite reinforcement layers.

Detailed Description

The essence of the invention lies in that the heat radiation performance of the polyurethane solid tire is greatly improved, the service life of the tire is effectively ensured, and the overall strength, especially the tearing strength of the tire is not reduced compared with the traditional non-perforated polyurethane solid tire.

The wheel rim comprises a wheel rim 100, a wheel hub 200 and a polyurethane rubber layer 300, wherein the polyurethane rubber layer 300 is attached to the outer surface of the wheel rim, in the embodiment, an adhesive structure is adopted for attachment, and a tread groove 310 or a side shallow groove is arranged on the tread part or the side part of the polyurethane rubber layer according to needs.

In this embodiment, the innovation point is that the mode of creatively introducing the heat conduction rubber enables the heat inside the polyurethane rubber to be rapidly dissipated, and the heat dissipation efficiency is improved. And is structurally suboptimal and compensates for the strength reduction that this improvement brings.

First embodiment, referring to fig. 2, one of the preferred embodiments, including but not limited to the embedding manner shown in fig. 2, a heat conducting member 400 is embedded inside the polyurethane rubber layer, and the heat conducting member is preferably a composite structure of heat conducting rubber and graphene fiber wires, or a composite structure of heat conducting rubber and steel wire mesh cylinders, and the following detailed description is provided with respect to the composite structure and style.

The structure of the present invention will be more specifically understood by the manufacturing process of the heat conductive member in conjunction with fig. 3 and 4.

The heat-conducting component is formed by compounding guide rubber and graphene fiber yarns, and the formula proportion of the heat-conducting rubber adopts the following mode: the raw materials comprise the following components in percentage by mass: 45-55% of polyurethane resin, 40-20% of heat conducting powder, 10-20% of flame retardant and the balance of foaming agent and graphene fiber, wherein the strength and fatigue resistance of the heat conducting rubber are reduced by at least 30% compared with the performance of single-component polyurethane rubber through estimation, namely, the overall strength is reduced. Graphene fiber, it is general, select for use length to be centimetre level, for example 5 centimetres, 3 centimetres of length graphene fiber, the existence of cellosilk can further improve the holistic intensity of heat conduction component to and holistic thermal conductivity, make holistic thermal conductivity obtain effectual transformation.

Generally, the fiber filaments 410 may be entirely located in the heat-conductive rubber matrix 420, or partially located in the heat-conductive rubber matrix and partially exposed to form a caterpillar-like floss structure.

In general outline, the heat conducting member 400 includes a first annular body 430 and a second annular body 440 concentrically arranged, and a transition connecting body 450 connected between the two annular bodies, wherein the first annular body 430 is attached to the hub, and the second annular body is located approximately at the center of the polyurethane rubber layer, i.e., the portion where heat accumulation is most serious. On the second ring 440, a heat sink 460 extends towards both sides, and an expansion 470 is disposed on one end of the heat sink. That is, the heat radiator 460 is provided along the axial direction of the axle, and radiates heat through the largest heat radiation path.

The heat conducting member 400 is manufactured by a glue injection mold forming method, and is prepared by firstly, fully mixing and stirring polyurethane resin, heat conducting powder, a flame retardant, a foaming agent and graphene fiber filaments in proportion, pouring the mixture into a mold, and then performing high-temperature hot press forming, wherein the obtained heat conducting member is made of a material with uniform heat conducting performance in view of section characteristics.

In a further modification, referring to fig. 5, a steel wire mesh tube 480 is pre-sleeved on the heat dissipation body of the polyurethane rubber body, and is usually made of stainless steel wires. That is to say, local strengthening is carried out through the mode of set wire net section of thick bamboo on the radiator, and the wire net section of thick bamboo of tube-shape itself has certain elasticity simultaneously, combines the elasticity of polyurethane rubber body itself, can obtain the elastic characteristic, the durability that are basically the same as polyurethane rubber layer, avoids taking place to tear, the crackle with the polyurethane rubber layer department of elastic component contact position for solid tyre's bulk strength obtains effectual assurance.

The manufacturing method of the tire comprises the steps of firstly preparing the heat conducting component for standby, and simultaneously welding the hub and the rim part to form an integral steel ring.

Regarding the production of the steel rim, firstly, a plurality of barb-shaped protrusions are formed on the outer surface of the annular rim 100 part through a banquette process, and the barb structure is hardened through a heat treatment process, and optimally, the barb tips of the barbs 110 are not vertical to the rolling surface of the tire, that is, the barb tips of the barbs are preferentially oriented in an inclined direction.

The hub part is of a three-dimensional structure and consists of a plurality of annular steel billets and reinforcing rib plates, wherein one steel billet is provided with a reserved bolt hole for being in bolt connection with an axle.

The second step, with the whole suit of heat conduction component on the rim, set up centrally, and with the holistic placing of steel ring in the mould, then pour into or pour into the former powder material of polyurethane into the tire preparation mould, high temperature hot briquetting again, make solid tyre promptly, the solid tyre who makes has the heat conduction component in the solid tyre, heat conduction component intercommunication generates heat portion and rim, and the air in outside, through the heat conduction component, the leading-in air and the rim near with inside themogenesis that can be timely, because the rim is metal parts, be hot good conductor, so can be better distribute the heat, be favorable to the inside themogenesis rapid diffusion of polyurethane. In fact, the reinforcing ribs are associated with the rim, further increasing the heat dissipation effect.

Usually, the tread of the solid tire is provided with pattern grooves, so that the solid tire can prevent skidding and has a heat dissipation function, and the details are not repeated.

Example two

Referring to fig. 6, a composite reinforcing layer 500 is arranged on the surface of the rim, and cords, which may be non-metallic cords or stainless steel wire mesh cords, are arranged in the reinforcing layer, so that the same effect is achieved.

EXAMPLE III

Referring to fig. 7, in the present embodiment, the heat conducting member is not provided with a heat radiator and is not expanded, that is, the heat radiation path exists only between the portion where heat generation is serious and the rim, and the heat radiation is performed by the heat radiation performance of the rim, which also has a partial heat radiation effect.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention and do not limit the scope of the present invention, and various modifications and improvements of the present invention by those skilled in the art without departing from the spirit of the present invention are intended to fall within the scope of the present invention defined by the claims.

Claims

1. The polyurethane solid tire comprises a rim, a hub and a polyurethane rubber layer, wherein the polyurethane rubber layer is attached to the outer surface of the rim through a bonding process, the polyurethane solid tire also comprises a heat conducting component arranged in the polyurethane rubber layer, at least part of the heat conducting component is positioned in the center of a heat generating area of the polyurethane rubber layer, and at least part of the heat conducting component is attached to the surface of the rim,

the heat conducting component is a composite structure of heat conducting rubber and graphene fiber yarns, and comprises a first annular body, a second annular body and a transition connecting body, wherein the first annular body and the second annular body are concentrically arranged, the transition connecting body is connected between the two annular bodies, the first annular body is attached to the hub, and the second annular body is approximately positioned in the center of the polyurethane rubber layer; a radiator extends towards two sides of the second annular body, and an expanded shape is arranged on the radiator at one end; the heat radiation body is sleeved with a steel wire mesh cylinder.

2. The solid polyurethane tire as claimed in claim 1, wherein a tread groove is provided in the tread portion of the polyurethane rubber layer or a side shallow groove is provided in the side.

3. The solid polyurethane tire of claim 1, wherein the graphene fiber filaments are entirely located in the thermally conductive rubber matrix, or the graphene fiber filaments are partially located in the thermally conductive rubber matrix and partially exposed, or both.

4. The solid polyurethane tire of claim 1 wherein a composite reinforcing layer is provided on the surface of the rim, and cords are provided within the reinforcing layer.

5. A method for manufacturing a polyurethane solid tire,

6. The method of claim 5, wherein the barbs have their barbed tips non-perpendicular to the tire tread surface.