KR100683586B1 - Brake shoe of railway vehicles - Google Patents

Abstract

A composite brake shoe for railway vehicle is provided to prevent heat crack and to shorten brake time by keeping the coefficient of friction evenly over the whole speed range, to apply for railway vehicles running at high speed by increasing thermal endurance and abrasion resistance, and to decrease the manpower for inspection and to contribute to safety operation of railway vehicles by using for a long term after mounting and extending the replacement period. The composite brake shoe(2) for railway vehicles comprises 25~30 weight percent graphite, 8~10 weight percent cashew, 2~6 weight percent Kevlar, 2~4 weight percent NBR(Nitrile Butadiene Rubber), 6~15 weight percent Talc, 10~18 weight percent super resins, 20~30 weight percent mineral fiber and 1~5 weight percent carbon; or, 2~3 weight percent steel wool, 28~33 weight percent mineral fiber, 15~18 weight percent super resins, 8~12 weight percent graphite, 13~17 weight percent barium, 15~18 weight percent coke, 5~7 weight percent cashew and 2~4 weight percent Kevlar.

Description

Synthetic wheelbarrows for railway vehicles {Brake shoe of railway vehicles}

1 is a state in which a synthetic wheelbarrow for a railroad vehicle according to the present invention is mounted on a railroad car.

2 is a perspective view of a synthetic wheelbarrow for a railway vehicle according to the present invention;

* Brief description of symbols for the main parts of the drawing

1: wheel 2: synthetic wheelbarrow

3: reinforcement plate 4: stopper

5: center staple 6: pad

7: brake head 10: bogie

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite wheelbarrow for railroad cars, and more particularly, to a composite wheelbarrow for railroad cars, which is mixed with various additive materials so as to stabilize friction characteristics of wheelbarrows used in railroad cars.

In the case of a railroad car, a braking device is installed in a trolley that supports the body and the wheel is fixed. This brake device generally presses a wheelbarrow on the wheel face of the wheel and controls or stops the speed of the railroad car by its frictional force. Conventionally, a wheelset made of cast iron or the like has been developed and used, but problems such as poor wear resistance and excessive noise caused by the cast iron wheelbarrow have been produced.In the 1980s, nonferrous wheelsets made of asbestos and resin were mainly manufactured. Has been used.

After that, as the asbestos used in the non-ferrous wheelbarrow has been found to be harmful to the human body as a whole research on the main raw materials synthesized asbestos substitute and active asbestos-free wheelbarrow has been developed and used.

However, the conventional non-asbestos type wheelbarrow is difficult to adjust the friction coefficient which has an absolute influence on the braking performance, so that the phenomenon of the friction coefficient greatly changes according to the train speed. For example, there is a problem that the braking effect is not sufficiently exhibited due to the nonuniformity of the friction coefficient, such as the friction coefficient is formed higher than the reference value at a low speed, but is formed lower as the high speed.

In addition, a conventional wheeled wheel has a problem in that the life of the stepped portion or the braking disk of the wheel, which is the counterpart material, causes thermal cracking or surface blackening, thereby shortening the lifespan.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and the composite wheel for a railway vehicle to prevent thermal cracking and shorten the braking distance by maintaining the friction coefficient of the composite wheelbarrow used in the railway vehicle uniformly in the entire speed band. The purpose is to provide the ruler.

In addition, the present invention is to provide a synthetic wheelbarrow for railway vehicles that can increase the heat resistance and wear resistance of the synthetic wheelbarrow can be used for a long time to extend the replacement cycle to contribute to the reduction of inspection manpower and safe operation of the railway vehicle There is another purpose.

Synthetic wheelbarrow for railroad cars according to the present invention, in the wheelbarrow for railroad cars, 25-30 wt% graphite, 8-10 wt% Kash, 2-6 wt% Kevlar, 2-4 wt% NBR, talc 6-15 It is characterized in that the weight percent, 10-18% by weight of super resin, 20-30% by weight of mineral fiber and 1-5% by weight of carbon are composed of the mixing composition ratio.

In addition, the synthetic wheelbarrow for railroad cars according to the present invention, in the wheelbarrow for railroad cars, 2 to 3% by weight of steel wool, 28 to 33% by weight of mineral fiber, 15 to 18% by weight of super resin, and 8 to 12% by weight of graphite. , 13 to 17% by weight of barium, 15 to 18% by weight of coke, 5 to 7% by weight of cashews and 2 to 4% by weight of kebra is characterized by consisting of a composition ratio.

1 is a state diagram in which a synthetic wheelbarrow for a railroad car is mounted on a railroad car, and FIG. 2 is a perspective view of a composite wheelbarrow for a railroad car.

As shown in FIG. 1, the synthetic wheelbarrow for a railroad car has the composite wheelbarrow 2 fitted into and fixed to the brake head 7 fixed to the frame of the trolley 10 so that the composite wheelbarrow 2 can be used during braking of the railroad car. Is in close contact with the wheel surface of the wheel, the braking action is made by the friction force.

The composite wheelbarrow 2 is formed into a bent body to correspond to the answer surface of the wheel 1, and a reinforcement plate 3 is attached to and fixed to the rear surface to reinforce the strength of the composite wheelbarrow 2 which is in close contact with high pressure. In the reinforcement plate 3, the wheels of the wheels (not shown) penetrate the center wheels 5 for fixing the wheels 2 to attach the wheels 2 to the brake head 7. The stopper 4 is formed in the upper and lower portions so that the composite wheelbarrow 2 mounted on the brake head 7 is fixed at the upper and lower portions of the brake head 7 so as not to be twisted.

As described above, the composite wheelbarrow for a railroad car fixedly coupled to the brake head is made of a mixture of various components to facilitate heat dissipation during braking, improve friction, and improve wear resistance and stability.

EMBODIMENT OF THE INVENTION Hereinafter, the synthetic wheelbarrow for railroad cars which concern on this invention is demonstrated in detail.

Table 1 below is a table showing the component ratio of the composite wheelbarrow for railway vehicles according to the first embodiment of the present invention, Table 2 is a table showing the wear amount test results of the composite wheelbarrow having the component ratio shown in Table 1, Table 3 Table 1 is a table showing the average friction coefficient and hot spot temperature of the synthetic wheelbarrow having the component ratio shown in Table 1, Table 4 is a table showing the component ratio of the composite wheelbarrow for a railway vehicle according to a second embodiment of the present invention, Table 5 It is a table which shows the wear amount and average friction coefficient of the synthetic wheelbarrow which have the component ratio shown in 4.

1. First embodiment

Synthetic wheelbarrow for a railway vehicle according to the first embodiment of the present invention, based on Super Resin, Mineral Fibers, Graphite, Cashoe, Kevlar, NBR (Nitrile Butadiene Rubber) ), Talc, carbon is made of a mixed composition.

The super resin is a binder in consideration of moldability, which bonds mineral fibers, graphite, cashews, kebra, NBR, talc, carbon, and the like to each other, and serves to reinforce the strength and heat resistance of the mixed material.

The graphite, which serves as a lubricant, serves to create stability to the coefficient of friction and to reduce noise.

The talc, which serves as a flame retardant or filler, fills the voids of the composition, improves strength and wear resistance, and improves friction characteristics at high temperatures.

The carbon serves as a reinforcing agent to increase the strength of the rubber part and also prevents wear on the surface of the wheelset.

The NBR is intended to have abrasion resistance so as to minimize abrasion occurring during braking, and to have acid resistance to withstand the acid attached to the tread portion of the wheel or the surface of the reinforcing plate 3.

The above-mentioned mineral fiber has high thermal conductivity and functions to transfer thermal energy generated by friction between the synthetic wheel and the wheel to the wheel. These mineral fibers are components that affect strength, coefficient of friction and modulus of elasticity, and play a role of enhancing wear resistance and friction.

The cashews and kebras described above are organic fibers having high modulus of elasticity and high strength. The organic fiber is to strengthen the heat resistance ability, strength and bonding strength and to create the appropriate working conditions in the manufacturing process, the cashew and kebra serves to increase the damping force, increase the bond reinforcement and improve the workability . Organic fibers can also be applied to acrylic fibers or aramid pulp with a specific gravity of 1.17 and a length of 5 to 9.5 mm.

Table 1 below shows the component ratios of the composite wheelbarrow for a railroad car according to the first embodiment of the present invention.

Synthetic wheelbarrow according to the first embodiment of the present invention, as shown in Table 1, 25-30 wt% graphite, 8-10 wt% Kash, 2-6 wt% Kevlar, 2-4 wt% NBR, Talc 6 15 wt%, 10-18 wt% of super resin, 20-30 wt% of mineral fiber and 1-5 wt% of carbon consist of mixing ratio.

Herein, the super resin is a binder for maintaining moldability. When less than 10% by weight is included, the strength of the super resin decreases, and when it contains 18% by weight or more, the strength increases and the friction coefficient decreases. When the graphite is a lubricant, the friction coefficient is sharply increased when less than 25% by weight is included, and when 30% by weight or more is included, the frictional force is rapidly lowered, thereby making it difficult to secure the frictional coefficient.

In addition, when the talc contains less than 6% by weight, the friction coefficient is excessively high, and when the talc is included by 15% by weight or more, the friction coefficient decreases and the phenomenon occurs, and the mineral fiber has a high thermal conductivity. When less than 20% by weight is included, it is easily worn or friction coefficient is lowered, and when more than 30% by weight is included, it is possible to damage the wheel during braking due to its rigidity, the cashew, 2% If less is included, the thermal resistance capacity is reduced or the bonding strength between each mixture is lowered, if more than 6% by weight, the bonding strength between each mixture is too strong to damage the wheel.

In addition, when the NBR is included in less than 2% by weight, the friction coefficient is significantly lowered, the braking force is weakened, when more than 4% by weight, the wheelbarrow sticks to the wheels, the carbon is If less than 1% by weight, wear is easily generated, and when more than 5% by weight is included to damage the wheel, the kebra is less than 2% by weight, the binding force is weakened, 6% If more than% is included, the wheel may be damaged.

Tables 2 and 3 below show the test results of the composite wheels as shown in Table 1 according to the test items and test methods approved by KOLAS.

Table 2 below shows the wear amount of the synthetic wheelbarrow, and is a result of measuring the wear amount of the left and right synthetic wheelbarrows, respectively. As shown in Table 2, it can be seen that the wear amount of the synthetic wheelbarrow is 33.60 × 10 ^-3 mm, which does not deviate from the test standard wear amount of 40 × 10 ^-3 mm.

Table 3 below shows the average friction coefficient of the synthetic wheelbarrow, which is measured 10 times while adjusting the speed of the railroad car to 35, 65, 95, and 110 km / h.

As shown in Table 3, the average friction coefficient of the composite wheel according to the first embodiment of the present invention is 0.275 when the speed of the railway vehicle is 35km / h, 0.217 when 65km / h, and 0.149 when 95km / h. , 0.127 at 110km / h, and the highest value of Wheel Temp. Is 268.1 ℃ when the speed of railroad cars is 110km / h, which shows very stable friction coefficient and wheel temperature. It can be secured.

As described above, the manufacturing process of the composite wheel for a railway vehicle according to the first embodiment of the present invention is performed by a process such as thermoforming, heat treatment, grinding, painting, and the like.

2. Second Embodiment

Synthetic wheelbarrow for a railway vehicle according to the second embodiment of the present invention is made of a mixed composition of steel wool, mineral fiber, graphite, barium, coke, cashew, kebra based on super resin.

The super resin is a binder in consideration of formability, and is used as a binder of steel wool, mineral fiber, graphite barium, coke, cashew, kevlar, and the like, and serves to reinforce the strength and heat resistance of the mixed material. And mineral fibers serve to transfer the thermal energy generated by friction between the wheel and the synthetic wheel to the wheel, the graphite serves as a lubricant, and the barium fills the pores of the composition and improves strength and wear resistance. In addition, the coke serves to reinforce the bonding force, the cashew and kebra serves to enhance the damping force and bonding force and improve workability.

Table 4 below shows the component ratios of the composite wheelbarrow for railroad cars according to the second embodiment of the present invention.

Synthetic wheelbarrow according to a second embodiment of the present invention is made of a manufacturing process of thermoforming, heat treatment, grinding, painting, etc. as usual, the mixing composition ratio is as shown in Table 4, steel wool 2-3 28% to 33% by weight mineral fiber, 15% to 18% super resin, 8% to 12% graphite, 13% to 17% barium, 15% to 18% coke, 5% to 7% cashew, and 2% kebra 4 weight percent.

Herein, when the steel wool is included in less than 2% by weight, the bonding strength is weakened, and when 3% by weight or more is included, the friction coefficient is lowered. The super resin is a binder for maintaining formability. When less than 15% by weight is included, the bonding strength is weak, the strength is lowered, when more than 18% by weight is included, the strength is increased to bring a decrease in the friction coefficient.

In addition, the graphite is a lubricant, when less than 8% by weight of friction coefficient is sharply increased, when more than 12% by weight of friction is sharply lowered to secure a friction coefficient, barium is 13 weight If less than% is included, the voids between the mixture becomes too large, if more than 17% by weight is excessively hardened to reduce the frictional force, the coke is less than 15% by weight when the bonding strength is weakened If more than 18% by weight is included, it may be excessively hardened to damage the wheels.

In addition, the mineral fiber is a raw material having high thermal conductivity, and if less than 28% by weight of the mineral fiber is easily worn or the friction coefficient is reduced, if more than 33% by weight of the self-rigidity may damage the wheel during braking When the cashews contain less than 5% by weight, the heat resistance is reduced or the bonding strength between the mixtures decreases, and when the cashews contain more than 7% by weight, the bonding strength between the mixtures is too strong to damage the wheels. When the kebra is included in less than 2% by weight, the bonding strength is weakened, and when more than 4% by weight, the wheel may be damaged by rigidity.

As described above, the test results for the composite wheel for a railway vehicle according to the second embodiment of the present invention, which can be implemented using a plurality of additives in various mixing compositions, are shown in Table 5 below.

Table 5 above is based on the test items and test methods accredited by the Korea Institute for Calibration Testing.

In particular, the test results shown in Table 5, the braking test is the moment of inertia 120kg.ms ² , pressure buoyancy 3.0Ton, wheel contact area 70% or more, braking initial friction surface temperature below 60 ℃, indoor environment 27 ℃, 42% The wear rate is calculated by the applicant's proposed cross-sectional area of 220cm ² , density 2.30g / cm ³ , and the highest temperature is the highest temperature measured 3 ~ 5mm away from the contact surface of the wheel. Is the result.

As shown in Table 5, the average friction coefficient of the synthetic wheelbarrow according to the second embodiment of the present invention is a vehicle speed of 0.110 at 110 km / h, 0.107 at 95 km / h, 0.194 at 65 km / h, It can be seen that it is 0.176 at 35 km / h, and that the wear amount is 35.38 × 10 ^-3 mm (17.9 g), and that the hot spot temperature shows that the maximum temperature is 231 ° C. The average friction coefficient, the wear amount, and the heat spot As the temperature is very stable, railroad cars can secure safe braking performance.

The above-described embodiment is for the most preferred example of the present invention, and the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit thereof.

According to the synthetic wheelbarrow for a railroad vehicle according to the present invention as described above, the friction coefficient of the wheelbarrow used in the railroad car is maintained uniformly in the entire speed band, thereby preventing the effects of thermal cracking and shortening the braking distance. have.

In addition, according to the present invention, the heat resistance and wear resistance of the synthetic wheelbarrow are increased, so that it can be applied to a railroad car traveling at high speed. It is effective to reduce the cost and contribute to the safe operation of railway vehicles.

Claims (2)

In a synthetic wheelbarrow for a railroad car, 25-30 wt% graphite, 8-10 wt% cashew, 2-6 wt% kebra, 2-4 wt% NBR, 6-15 wt% talc, 10-18 wt% super resin, 20-30 wt% mineral fiber And 1 to 5% by weight of carbon in a mixed composition ratio. In a synthetic wheelbarrow for a railroad car, 2-3% steel wool, 28-33% mineral fiber, 15-18% super resin, 8-12% graphite, 13-17% barium, 15-18% coke, 5-7% cashew Synthetic wheelbarrow for railway vehicles, characterized in that the composition composition ratio of 2% to 4% by weight and Kevlar.

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