The present invention relates to milling machines that are used in road surface repairs. Milling machines are typically utilized to remove a layer or layers of road surfaces in preparation for resurfacing. Milling machines are typically equipped with a milling drum and a moldboard. The moldboard may be located behind the milling drum and form part of a milling chamber that encloses the drum. Typically, milling machines are followed by a sweeper to clean up excess debris, aggregate, and fragments that remain on the milled surface. The drum and moldboard may be configured to direct milling debris toward a conveyer, which directs the debris to a dump truck to take off site.
Failure to clean the milled surface before resurfacing may result in poor bonding between the new layer and the milled surface. Typically, a sweeper is used to remove the debris and a distributor truck applies a tack coat to promote bonding between the milled surface and new layer of pavement. Generally, the sweepers that follow a milling machine are inefficient and the excess dust left may result in weak bonds between the new pavement and the milled surface.
BRIEF SUMMARY OF THE INVENTION
In one aspect of the present invention, a motorized vehicle comprises a vehicle frame. The vehicle frame comprises a forward end and a rearward end. A rotary degradation drum may be connected to an underside of the frame with a moldboard. The moldboard is disposed rearward to the rotary degradation drum and forms part of a milling chamber. The moldboard comprises an end disposed opposite the underside of the vehicle. A plurality of nozzles may be disposed proximate the end of the moldboard and configured to direct a fluid into the milling chamber. A heating mechanism may be configured to heat the fluid directed into the milling chamber.
A fluid reservoir may be disposed proximate at least one engine and/or an exhaust manifold disposed within the vehicle frame. The heating mechanism may comprise a heat exchanger configured to cool an engine of the machine. The heat exchanger may comprise at least in part, a pathway configured to circulate fluid within the engine. The pathway may connect the heat exchanger with a fluid reservoir and/or a fluid channel connected to the plurality of nozzles. The pathway may form a loop between the engine and the fluid reservoir or fluid channel. The heating mechanism may comprise a heat exchanger with the vehicle's exhaust system. The heating mechanism may also comprise a boiler, a resistive heater, an engine or combinations thereof configured to heat the fluid.
In another embodiment of the present invention, a method for paving a road may comprise providing a road milling machine with a rotary degradation drum and a moldboard forming part of a milling chamber, heating the fluid directed into the milling chamber, passing the milling machine over a pavement structure, heating the pavement structure with the fluid as the milling machine passes over the pavement structure, and paving a new layer of pavement over the pavement structure while the pavement structure is still warm.
The step of providing may further comprise the moldboard comprising a plurality of nozzles configured to direct a fluid into the milling chamber. The step of heating the fluid may comprise a heating mechanism in fluid communication with a reservoir and the plurality of nozzles. The heating mechanism may comprise a heat exchanger with the at least one engine or an exhaust manifold. The fluid may comprise steam, polymers, clays, oils, foams, wetting agents, surfactants, binding agents, or combinations thereof. The method may further comprise an additional step of degrading the pavement structure during the step of heating the pavement structure.
a is a cross-sectional view of an embodiment of a milled surface.
b is a cross-sectional view of an embodiment of a milled surface.
a is an orthogonal diagram of an embodiment of a milling machine.
b is a cross-sectional view of an embodiment of a milling chamber.
A paving machine may follow directly behind the milling machine. The present invention, which will be described in more detail below, puts the milled road surface into a condition ideal for paving. For example, the present invention is configured to clean the road surface, thereby eliminating a sweeper machine that is typically incorporated into milling trains. Also, the present invention is configured to heat the milled road surface, thereby providing a surface that is able to bond readily to a fresh layer of pavement. By paving immediately after the milling machine while the milled road surface is still hot, the need for a tact coat may be reduced or eliminated. In some embodiments, additives such as oils, clays, surfactants, wetting agents, binding agents, polymers, and combinations thereof may be deposited on the milled road surface by the milling machine. Thus, the present invention is capable of significantly reducing the milling/paving train and significantly reduce the time and cost associated with resurfacing roads.
The fluid reservoir may contain any fluid capable of cleaning the road surface. In some embodiments, water is the preferred. Additives, such as additives such as oils, clays, surfactants, wetting agents, binding agents, polymers, and combinations may be mixed with the liquid in the fluid reservoir. In other embodiments, additives may be stored on the milling machine separately. In such embodiments, the additives may be added to the fluid before the fluid exits the nozzles or the additives may be added to the road surface separately. The additives may be added through by spraying, misting, foaming, fogging, or combinations thereof. In some embodiments, the additives may be heated with the fluid, heated separately, or heated from contact with the heated milling surface. While some embodiments include additives to the fluid, other embodiments do not include the use of additives.
The fluid may be directed from the fluid reservoir 204 through the second fluid channel 212 into the fluid conduit 303 disposed in the at least one engine 202. As the fluid passes through the conduit 303, heat from the engine 202 may be transferred into the fluid replacing the need for a cooling system and radiator while heating the fluid. The fluid may exit the engine 202 and be directed to a plurality of nozzles 208 through the first fluid channel 210. The first fluid channel 210 may be thermally insulated to prevent thermal energy loss before reaching the nozzles 208. The thermal insulation may comprise insulating foam, thermally insulating pipes, or a combination thereof. In some embodiments of the present invention, the fluid directed to the plurality of nozzles 208 may be compressed to further increase the fluid temperature.
While not shown, a compressor or other compression mechanism may be configured to pressurize the fluid before it exits the nozzles. Pressurizing the fluid may allow the fluid to be at a hotter temperature while still in a liquid state. As the heated, pressurized liquid exists the nozzles, the liquid may flash to a gas. In some cases, pressure may be applied, but not enough pressure to turn the liquid into a gas.
The moldboard 405 is disposed rearward of the milling drum 110 and may push loose aggregate 403 forward into the milling area 404. A plurality of nozzles 406 may be disposed on the rear side of the moldboard and aligned to force the aggregate forward. The plurality of nozzles 406 may be in fluid communication with the fluid reservoir. As the milling machine 104 moves forward the plurality of nozzles may eject a fluid into the milling chamber forcing aggregate into the milling area 404 where the milling drum may pick it up.
The fluid ejected from the nozzles may be heated. As the heated fluid exits, the fluid may take the form of either liquid or gas. The heated fluid may push the aggregate forward and then rapidly evaporate leaving the milled surface dry. A heated, dry milled surface may be ideal for bonding with a fresh layer of pavement.
a discloses a first milled surface 901 using a milling drum with tungsten carbide bits. The first milled surface 901 may comprise a plurality of peaks 903 and valleys 905 formed from the inconsistent pick heights' of the drum. In order for the milling machine to reach a required removal depth 907, the drum must be positioned at a level that allows the shortest (or most worn) bit to cut at the required removal depth. Unfortunately, the other picks have greater heights; therefore, they will cutter deeper into the road surface than required. The result is an uneven road surface with the majority of the milled surface cut deeper than required. Thus, resurfacing job is more costly than necessary because more pavement must be replaced and additional energy used to cut deeper than necessary was wasted.
b discloses a second milled surface 911 using a milling drum with polycrystalline diamond bits and heated fluid. The second milled surface 911 may comprise a plurality of peaks 903 and valleys 905. However, the distance between the peaks 903 and valleys 905 is significantly less. Polycrystalline diamond bits may wear at a significantly reduced rate than tungsten carbide bits, thus, reducing the distance between the peaks 903 and valleys 905. As the distance is reduced, less pavement is removed to reach the required removal depth 907. Thus, the diamond enhanced teeth provide greater energy efficiency and reduce replace material costs.
a discloses an additional heating element 1000 positioned along the fluid path 210. Thus, if the engine fails to exchange the desired heat with the fluid, the additional heating element may bring the fluid to the desired temperature. The additional heating element may be a boiler, an open flame, a resistive heater, or combinations thereof. Additionally, a pressurizing mechanism may be configured to increase the pressure exerted on the fluid to help influence the fluid's temperature.
b discloses that the fluid is not heated by the engine, but it heated by a heating element, which may be selected from the group consisting of resistive heaters, boilers, open flames, or combinations thereof
This application is a continuation-in-part of U.S. patent application Ser. No. 12/888,876, which is a continuation-in-part of U.S. patent application Ser. No. 12/145,409, which was a continuation-in-part of U.S. patent application Ser. Nos. 11/566,151; 11/668,390; and 11/644,466. All of these documents are herein incorporated by reference for all that they disclose.
Number | Date | Country | |
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Parent | 12888876 | Sep 2010 | US |
Child | 12978208 | US | |
Parent | 12145409 | Jun 2008 | US |
Child | 12888876 | US | |
Parent | 11566151 | Dec 2006 | US |
Child | 12145409 | US | |
Parent | 11668390 | Jan 2007 | US |
Child | 11566151 | US | |
Parent | 11644466 | Dec 2006 | US |
Child | 11668390 | US |