JPH0545603Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to the structure of the roll surface in a rolling press used mainly for compaction of asphalt pavement.

(Prior Art) The roll A itself in a road roller, for example, as shown in FIG. 2, used in the compaction work of asphalt pavement is generally made of structural steel.

Moreover, the surface of the roll is generally made smooth by machining or the like and left in a pristine state.

(Problem that the invention attempts to solve) By the way, when compacting asphalt pavement is performed with a road roller equipped with such a roller,
Asphalt paving material adheres to the roller surface,
There were some inconveniences such as interfering with compaction work.

Furthermore, conventional rolls have the disadvantage that their surfaces wear quickly, lose smoothness, and have a short functional life as rolls.

Therefore, as a means to eliminate the former problem, conventionally, prior to compacting the asphalt pavement, oil such as light oil is sprayed onto the roll surface using a spraying device to prevent the asphalt pavement material from adhering. .

However, because the roll surface is smooth, the sprayed oil tends to drip down, and if the amount of sprayed oil is small,
The effect tends to fade after several rounds of compaction.

Therefore, we try to increase the amount and frequency of spraying, but on the other hand, if the amount of spraying is too large, the oil may discolor the pavement surface, dissolve asphalt components, and have a negative impact on the finished quality of the pavement surface. There is a problem with giving it.

Furthermore, no appropriate countermeasure has yet been taken for the latter abrasion of the roll surface.

Therefore, the purpose of this invention is to eliminate such inconveniences and problems, and to provide a compacting machine that can always maintain the good quality of the compacted asphalt pavement surface and has a long roll life. It was invented.

(Means for solving the problem) As a means to achieve the above purpose, the present invention has the following features:
A roll for a compaction machine comprising an iron ring roll and a coating formed on the surface thereof and having porosity and wear resistance obtained by thermally spraying a thermal spraying material selected from white alumina, chromium oxide, and tungsten carbide, particularly as described above. This paper proposes a roll for a rolling press in which the coating has a porosity of 8 to 12% and a hardness ( _HV ) of 600 to 1100.

(Function) The film formed on the surface of the roll impregnates the pores with oil such as light oil that is sprinkled on it. Furthermore, since the coating is hard, it suppresses wear on the roll itself.

(Example) FIG. 1 shows an example of a roll according to the present invention.

In this example, tungsten carbide (88% WC-12% CO) was used as a thermal spraying material and was thermally sprayed onto the iron wheel roll 1 by a plasma spraying method to form a coating 2.

At that time, the coating thickness was 0.01 to 2.0 mm, the porosity was 25%,
The hardness was extremely high, H _V 400-1500.

Therefore, light oil was sprayed onto this coating using a spraying device to impregnate the pores with oil. As a result of conducting a compaction test on the asphalt mixture, no adhesion of the asphalt mixture was observed and it was maintained for a long time.
Furthermore, from the correlation between the persistence of adhesion of the asphalt composite material and its wear resistance, it was found that the most appropriate coating thickness is 0.2 to 0.8 mm, the porosity is 12% or less, and the hardness is H _V 600 to 1100. did.

By the way, when comparing the wear resistance of a roller with a coating formed based on the above conditions and a conventional roll made of structural steel material (SS material) with exposed skin, it was found that the life of the roll of this invention is more than 10 times longer. There was found.

In addition, in this example, as described above, a case was explained in which a carbide made of tungsten carbide was used as the coating material, but instead of this,
The same effect as described above was obtained even when oxides such as white alumina and chromium oxide were used.

(Effects of the invention) As explained above, the present invention forms a porous film by thermally spraying a thermal spray material selected from white alumina, chromium oxide, and tungsten carbide on the roll surface. Once the surface of the roll is sprayed with oil such as light oil to prevent adhesion, the oil will be impregnated into the coating, and will continue to function as an anti-adhesive agent for asphalt mixtures over a long period of time. Therefore, a paved surface of high quality can always be obtained.

In addition, the coating has abrasion resistance, so it can withstand long-term use as a roll of a compaction machine. Combined with the above-mentioned function of preventing asphalt mixture from adhering, it helps improve the quality of the finish of asphalt pavement, and can be used as a road roller. The functionality and lifespan of can be greatly increased.

[Brief explanation of drawings]

The drawings show an embodiment of the roll of the rolling press according to the present invention, and FIG. 1 is a partially cutaway oblique view of the roll on which the coating is formed, and FIG. 2 is a perspective view of the road roller. 1...Roller body, 2...Coating.

Claims (1)

[Claims for Utility Model Registration] (1) An iron ring roll 1 formed on its surface, which has porosity and wear resistance obtained by thermal spraying a thermal spraying material selected from white alumina, chromium oxide, and tungsten carbide. A rolling press roll comprising a coating 2. (2) The rolling press roll according to claim (1), wherein the coating has a porosity of 8 to 12% and a hardness ( _HV ) of 600 to 1100.