Pavement surface cooling device and pavement surface cooling method

Abstract

The objective is to provide a pavement cooling device that can rapidly reduce the temperature of a paved road surface made of asphalt mixture. [Solution] A pavement surface cooling device 1) comprising: a tank 7 provided on a road roller 15 for storing water 17 inside; a water cooling device 9 provided on the road roller 15 for cooling the water 17 in the tank 7 to a predetermined temperature lower than room temperature; a mist spray nozzle 11 provided on the road roller 15 for discharging the water 17 cooled by the water cooling device 9 in a mist form; and a blower 13 provided on the road roller 15 for sending the mist-like water 17 discharged by the mist spray nozzle 11 toward the surface of the asphalt mixture 5 laid for paving the road 3.

Description

[[Technical Field]]

[0001] The present invention relates to a paved road surface cooling device and a paved road surface cooling method, and particularly relates to an apparatus for cooling a high-temperature asphalt mixture laid on a road. [[Background Art]]

[0002] Conventionally, mist sprinkling has been employed as a technology for rapidly reducing the temperature of an asphalt mixture used in asphalt paving. The asphalt mixture used for road paving is manufactured by being heated to a high temperature (160°C or higher). This is attributed to the fact that asphalt itself is a material that softens when the temperature rises. Conversely, when the temperature drops, asphalt hardens and can be used as a road material with ensured strength. Accordingly, an asphalt mixture cannot be used as a road material unless it cools down. Road specifications stipulate that the temperature of the asphalt mixture at which traffic can be opened after paving construction is 50°C. Here, Patent Document 1 can be cited as a patent document related to conventional technologies. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 11-158810 [[Summary of the Invention]] [[Problems to be Solved by the Invention]]

[0004] Most of the asphalt paving constructed in recent years has reached the time for renovation. In addition, recent asphalt paving is required to have high durability and long service life. For example, whereas paving is generally laid in a single layer with a thickness of about 5 cm, construction with a thick layer of 10 cm or more is now required. As a result, a problem has occurred in that the temperature of the laid asphalt mixture does not drop, so traffic cannot be opened at an early time.

[0005] Furthermore, opening the road to traffic while the internal temperature of the asphalt mixture is still high has resulted in rutting occurring soon after paving. Therefore, a challenge is to quickly reduce the temperature of the paved asphalt.

[0006] The present invention aims to provide a pavement surface cooling device and a pavement surface cooling method that can rapidly reduce the temperature of a paved road surface laid with an asphalt mixture. [Means for solving the problem]

[0007] A pavement surface cooling device according to an aspect of the present invention is a pavement surface cooling device comprising: a tank provided on a road roller for storing water inside; a water cooling device provided on the road roller for cooling the water in the tank to a predetermined temperature lower than ambient temperature; a mist spray nozzle provided on the road roller for discharging the water cooled by the water cooling device in a mist form; and a blower provided on the road roller for sending the mist water discharged by the mist spray nozzle toward the surface of the asphalt mixture laid for road paving.

[0008] In a pavement surface cooling device according to an aspect of the present invention, a plurality of tanks are provided, and the water contained in at least one of these tanks is cooled by the water cooling device and discharged by the mist spray nozzle.

[0009] A pavement surface cooling device according to an aspect of the present invention is a pavement surface cooling device in which a plurality of tanks are provided, at least one of these plurality of tanks is a first group of tanks, the other tanks of this plurality of tanks are a second group of tanks, the water in the first group of tanks can be cooled to a predetermined temperature lower than ambient temperature by the water cooling device, the road roller is provided with wheel nozzles that discharge water toward the wheels of the road roller, and when the ambient temperature is low, the water in the first group of tanks is kept at ambient temperature without being cooled by the water cooling device, and the water in the first group of tanks and the water in the second group are discharged from the wheel nozzles.

[0010] A pavement surface cooling device according to an aspect of the present invention is provided with a plurality of tanks, at least one of which is a first group of tanks, and the other tanks are a second group of tanks, and the device is provided on the road roller and discharges water toward the wheels of the road roller and a discharge mechanism that switches the water discharge mode between the atomizing spray nozzle and the wheel nozzle so that water is discharged in one of the first, second, or third discharge modes. The pavement surface cooling device has a mode switching unit, wherein the first discharge mode is such that the water from the first group of tanks and the water from the second group of tanks are discharged from the wheel nozzle without cooling the water from the first group of tanks, the second discharge mode is such that the water from the first group of tanks is cooled by a water cooling device and the water from the second group of tanks is discharged from the wheel nozzle, and the third discharge mode is such that the water from the first group of tanks is cooled by the water cooling device and the cooled water is discharged from the wheel nozzle and the mist spray nozzle.

[0011] In a pavement surface cooling device according to an aspect of the present invention, the blower is configured to include a cylindrical housing provided on the main body of the road roller and a blade installed inside the housing that rotates to generate airflow, the central axis of the cylindrical housing extending diagonally with respect to the surface of the laid asphalt mixture, and the rotation of the blade draws air into the housing from the upper opening of the cylindrical housing and blows air out of the housing from the lower opening of the cylindrical housing, the blown air is configured to reach the surface of the laid asphalt mixture directly, the mist spray nozzle is provided on the housing and the mist-like water discharged from the mist spray nozzle is configured to be sent to the surface of the laid asphalt mixture by the air blown out from the lower opening of the cylindrical housing.

[0012] A pavement surface cooling method according to an aspect of the present invention is a pavement surface cooling method for cooling an asphalt mixture laid for paving a road, comprising a cooling step of cooling water to a predetermined temperature lower than room temperature, and a spraying step of spraying the water cooled in the cooling step in the form of a mist onto the surface of the asphalt mixture.

[0013] In the pavement surface cooling method according to an aspect of the present invention, the spraying step involves discharging the cooled water from a mist spray nozzle to form a mist, and then using a blower to bring this mist-like water to the surface of the asphalt mixture.

[0014] In a pavement surface cooling method according to an aspect of the present invention, the mist spray nozzle and the blower are installed on a road roller that compacts the laid asphalt mixture, and the spraying step is a step in which the road roller moves while the mist-like water reaches the surface of the asphalt mixture. [Effects of the Invention]

[0015] According to the present invention, the temperature of the paved road surface on which the asphalt mixture has been laid can be reduced more quickly. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows a pavement surface cooling device according to an embodiment of the present invention, and a tire-type roller on which this pavement surface cooling device is installed. [Figure 2] This figure shows a tank and piping system of a tire-type roller on which a pavement surface cooling device according to an embodiment of the present invention is installed, and is a diagram showing a first discharge mode. [Figure 3] This figure shows a tank and piping system of a tire-type roller on which a pavement surface cooling device according to an embodiment of the present invention is installed, and also shows a second discharge configuration. [Figure 4] This figure shows a tank and piping system of a tire-type roller on which a pavement surface cooling device according to an embodiment of the present invention is installed, and is a diagram showing a third discharge mode. [Figure 5] This figure shows a mist spray nozzle and a blower in a pavement surface cooling device according to an embodiment of the present invention. (b) is a VB-VB cross section in (a). (c) is an enlarged view of the VC section in (b). (d) and (e) are figures corresponding to (c), showing modified configurations of the mist spray nozzle. [Figure 6] This figure shows a tire-type roller before the installation of a pavement surface cooling device according to an embodiment of the present invention. [Figure 7] This figure shows the tank and piping system of a tire-type roller before the installation of a pavement surface cooling device according to an embodiment of the present invention. [Figure 8] This figure shows the tank of a tire-type roller before the installation of a pavement surface cooling device according to an embodiment of the present invention. [Figure 9] This figure shows the piping system of a tire-type roller before the installation of a pavement surface cooling device according to an embodiment of the present invention. [Figure 10]It is a diagram showing the surface of a laid asphalt mixture and cooling water. MODE FOR CARRYING OUT THE INVENTION

[0017] A paved road surface cooling device 1 according to an embodiment of the present invention, as shown in FIG. 1 and the like, cools an asphalt mixture 5 laid (paved) on, for example, a roadbed (not shown) for paving a road 3. The paved road surface cooling device 1 is configured to include a tank (water tank) 7, a water cooling device (chiller) 9, an atomizing spray nozzle (mist nozzle; spray nozzle) 11, and an air blower (blower fan) 13.

[0018] Here, one predetermined horizontal direction among the paved road surface cooling device 1 and a road roller 15 is defined as the front-rear direction, another predetermined horizontal direction orthogonal to the front-rear direction is defined as the width direction, and a direction orthogonal to both the front-rear direction and the width direction is defined as the vertical direction.

[0019] The tank 7 is provided on the road roller 15. Water 17 can be introduced into the tank 7 from a water supply port (not shown), and the water 17 introduced into the tank 7 is stored inside the tank 7.

[0020] The water cooling device 9, the atomizing spray nozzle 11, and the air blower 13 are also provided on the road roller 15. The water cooling device 9 is capable of cooling the water 17 in the tank 7 to a predetermined temperature lower than normal temperature (for example, a temperature in a range from 10°C to 40°C) (for example, 5°C to 25°C).

[0021] The atomizing spray nozzle 11 is configured to turn the water 17 cooled by the water cooling device 9 into mist and discharge the mist. The air blower 13 is configured to send the mist-like water 17 discharged from the atomizing spray nozzle 11 toward the surface of the asphalt mixture 5. The mist-like water 17 discharged from the atomizing spray nozzle 11 is configured to reach the asphalt mixture 5 laid (paved) for paving the road 3.

[0022] The water cooling device 9 is capable of cooling the water 17 stored in the tank 7. The water cooling device 9 may also be capable of cooling the water 17 coming out of the tank 7, for example, just before it is discharged through the mist spray nozzle 11. Furthermore, the pavement surface cooling device 1 is equipped with a pump (not shown) for discharging water from the mist spray nozzle 11. This pump is also provided on the road roller 15. The pump pressurizes the water 17 to a pressure higher than atmospheric pressure, and this pressurized water 17 is discharged from the mist spray nozzle 11.

[0023] The particle size of the mist-like water 17 discharged from the atomizing spray nozzle 11 (immediately after discharge) is, for example, about 1 μm to 20 μm. More preferably, it is about 1 μm to 10 μm. Furthermore, the mist-like water 17 is sprayed almost uniformly onto the surface of the laid asphalt mixture 5.

[0024] Furthermore, it may be considered that some of the water 17 evaporates during the time it takes for the mist-like water 17 to reach the surface of the asphalt mixture 5 after being discharged from the mist spray nozzle 11. That is, the particle size of the mist-like water 17 immediately after being discharged from the mist spray nozzle 11 may be made slightly larger, so that the particle size of the mist-like water 17 just before it reaches the surface of the asphalt mixture 5 is, for example, about 1 μm to 20 μm, and more preferably about 1 μm to 10 μm.

[0025] As shown in Figure 10(b), the water 17 discharged from the mist spray nozzle 11 and blown by the blower 13 reaches the surface of the laid asphalt mixture 5, causing a large number of water droplets to temporarily cover a portion of the surface of the laid asphalt mixture 5. However, the entire surface of the laid asphalt mixture 5 is not covered with water, and other parts of the surface of the asphalt mixture 5 remain exposed.

[0026] As shown in Figure 5, the blower 13 is composed of a housing 23 and blades 25. The housing 23 is formed in a cylindrical shape (for example, a cylindrical shape) and is integrally provided with the main body 21 of the road roller 15. The blades 25 are installed inside the housing 23. The rotation of the blades 25 by an actuator such as a motor 26 generates an airflow 31. The direction of the airflow 31 is in the direction of extension of the central axis of the cylindrical housing 23.

[0027] The central axis of the cylindrical housing 23 extends at an angle to the surface of the laid asphalt mixture 5 (for example, a plane extending horizontally). The rotation of the blades 25 draws air into the housing 23 through the upper opening 27 and blows air 31 out of the housing 23 through the lower opening 29. This blown air 31 is configured to directly reach the surface of the laid asphalt mixture 5.

[0028] The atomizing spray nozzle 11 is, for example, integrally mounted on the outside of the housing 23. The atomizing spray nozzle 11 discharges mist-like water 17 (almost all of the water 17), which is then delivered to the surface of the laid asphalt mixture 5 by air 31 blown out from the lower opening 29 of the cylindrical housing 23.

[0029] The road roller 15 compacts the laid (leveled) asphalt mixture 5. Generally, road rollers 15 used to compact asphalt pavement compact the asphalt mixture 5 by spraying water 17 onto the tires (wheels) 19 from a wheel nozzle (tire nozzle) (not shown) while compacting (see Figure 9, etc.) in order to prevent the asphalt mixture 5 from sticking to the tires (wheels) 19. The water 17 at this time also has the effect of lowering the temperature of the pavement (asphalt mixture) 5.

[0030] For example, a tire-type roller using rubber tires as the wheels 19 may be used as the road roller 15, but a road roller with iron wheels 19 may also be used as the road roller 15.

[0031] The wheels 19 of the road roller 15 are designed to rotate relative to the main body 21 of the road roller 15. The road roller 15 is placed on the laid asphalt mixture 5, and as the wheels 19 of the road roller 15 rotate, the road roller 15 moves while compacting the asphalt mixture 5.

[0032] The discharge of water 17 from the atomizing spray nozzle 11 and the blowing of air by the blower 13 are performed, for example, while the road roller 15 is moving at a predetermined speed over the laid asphalt mixture 5.

[0033] The amount of water 17 discharged from the mist spray nozzle 11 (amount of water per unit time) is, for example, a constant value. The airflow rate of the blower 13 (airflow rate of the blower per unit time) is also, for example, a constant value. Airflow rate of blower 13 Qm 3 / min represents the area of ​​the air outlet of the blower in Am 2 Assuming that the air velocity at the air outlet of the blower is Vm / min, Q can be expressed as Q = AV.

[0034] The atomizing spray nozzle 11 is configured to discharge mist-like water 17 on the outside of the housing 23, for example (see Figures 5(a) to (d)). The atomizing spray nozzle 11 is configured to discharge mist-like water 17 towards the air 31 blown out from the housing 23 near the lower opening 29 of the housing 23 (see Figure 5(d)).

[0035] The blower 13 and the mist spray nozzle 11 are installed, for example, on the main body 21 of the road roller 15, behind the driver's seat 33 of the road roller 15. The blower 13 is configured to blow air 31 and mist-like water 17 towards the rear portion of the laid asphalt mixture 5 of the road roller 15.

[0036] The atomizing spray nozzle 11 may also be configured to discharge mist-like water 17 inside the housing 23 (see Figure 5(e)).

[0037] Let's explain the pavement surface cooling device 1 and the road roller 15 in more detail. The pavement surface cooling device 1 is installed on the road roller 15, for example, by modifying a part of the existing road roller 15.

[0038] The road roller 15 before the installation of the pavement surface cooling device 1 will be described with reference to Figures 6 to 9. The road roller 15 consists of a main body 21 and wheels 19, and the tanks 7 (7A, 7B, 7C) are provided in the main body 21. As described above, the water 17 contained in the tanks 7 (7A, 7B, 7C) is sprayed (discharged) toward the wheels 19 by piping 35 and nozzles (wheel nozzles) not shown (see Figure 9).

[0039] Multiple tanks 7 are provided. Of these multiple tanks 7 (7A, 7B, 7C), at least one tank 7A is designated as the first group of tanks (the first tank). The other tanks 7B and 7C (tanks other than the first tank 7A) are designated as the second group of tanks (the second tank). The water 17 in the first group of tanks 7A can be cooled to a predetermined temperature lower than room temperature by a water cooling device 9.

[0040] Tank 7B and Tank 7C are connected by piping (not shown), and the water 17 in Tank 7B and the water 17 in Tank 7C can, for example, move back and forth between Tank 7B and Tank 7C. Alternatively, Tank 7B and Tank 7A may also be connected by piping (not shown). In this case, a two-way valve (for example, a solenoid two-way valve) is provided in the middle of the piping (not shown). The flow path of the piping (not shown) can be opened and closed. When the flow path of the piping (not shown) is open, the water 17 in Tank 7B and the water 17 in Tank 7A can move back and forth between Tank 7B and Tank 7A. Under normal conditions, the flow path of the piping (not shown) is closed. Reference numeral 37 in Figure 9, etc., indicates a scraper for cleaning the wheel 19.

[0041] The piping indicated by reference numeral 36 in Figure 1 is for supplying an anti-adhesion agent (e.g., oil) to the surface of the wheel 19 (e.g., the surface in contact with the asphalt mixture 5) to prevent the asphalt mixture 5 from adhering to the wheel 19. The anti-adhesion agent is supplied to the piping 36 by a pump (not shown) from an anti-adhesion agent tank (not shown) installed on the road roller 15. Also, the piping 36 is omitted in part of Figure 6 and in Figure 8.

[0042] In a road roller 15 equipped with a pavement surface cooling device 1, the water cooling device 9, blower 13, generator 39, and control unit (not shown) of the pavement surface cooling device 1 are provided in the main body 21. In the road roller 15 equipped with the pavement surface cooling device 1, water 17 in tank 7A is cooled by the water cooling device 9 and discharged from the mist spray nozzle 11. The generator 39 generates the electricity used by the pavement surface cooling device 1.

[0043] When transporting the road roller 15, the canopy 61 of the road roller 15 is folded down and the road roller 15 is loaded onto the transport truck. Therefore, it is desirable that the upper end of the pavement cooling device 1 be positioned lower than the position of the road roller 15 with its canopy 61 folded down. Furthermore, the operation of the pavement cooling device 1 is performed by an operating unit (not shown) located in the driver's seat 33.

[0044] As shown in Figure 5(a), for example, multiple atomizing spray nozzles 11 are provided. As described above, the multiple atomizing spray nozzles 11 are located on the outside of the housing 23 of the blower 13, near the lower opening 29. Furthermore, the multiple atomizing spray nozzles 11 are positioned to equally distribute the outer circumference of the housing 23.

[0045] Multiple atomizing spray nozzles 11 are installed in an annular (torus-shaped) pipe 59. The pipe 59 is supplied with water 17 that was in tank 7A and has been cooled by the water cooling device 9. The water 17 flowing through the pipe 59 is discharged from each of the multiple atomizing spray nozzles 11.

[0046] In the configuration shown in Figure 1, etc., a cylindrical outlet duct (not shown) may be provided at the lower opening 29 of the housing 23 of the blower 13, allowing the direction of airflow from the blower 13 to be changed and adjusted. Furthermore, the housing 23 of the blower 13 may be attached to the main body 21 of the road roller 15 via a blower support (not shown). The direction of airflow from the blower 13 may then be adjusted by changing the orientation of the housing 23 of the blower 13.

[0047] Next, a method for cooling the paved road surface will be described. The paved road surface cooling method is carried out, for example, by a paved road surface cooling device 1.

[0048] The pavement surface cooling method involves cooling aphalt mixture 5 laid (leveled) on the roadbed, for example, for paving a road 3, and comprises a cooling step and a spraying step (spraying step).

[0049] In the cooling process, the water 17 is cooled to a predetermined temperature lower than room temperature. In the spraying process, the water 17 cooled in the cooling process is turned into a mist and sprayed (sprayed) onto the surface of the asphalt mixture 5. This spraying is done to accelerate the cooling rate of the laid asphalt mixture 5 by the heat of vaporization of the water 17.

[0050] In the spraying process, the water 17 is sprayed in such a way that a large number of water droplets in a mist form cover a portion of the surface of the laid asphalt mixture 5 (see Figure 10(b)).

[0051] Furthermore, rapidly lowering the temperature of the asphalt mixture 5 would adversely affect the pavement surface, so the spraying process is performed after normal compaction (compaction to ensure a certain degree of compaction) is completed. Immediately after normal compaction, the temperature of the asphalt mixture 5 is approximately 60°C to 65°C. By spraying water onto the asphalt mixture 5 immediately after normal compaction in the spraying process, the temperature of the asphalt mixture 5 can be quickly reduced to below 50°C. It should be noted that when the spraying process is performed, water 17 is not discharged from, for example, a wheel nozzle (not shown).

[0052] In the spraying process, cooled water 17 is discharged from a mist spray nozzle 11 to form a mist, and this mist water 17 is sent towards the surface of the asphalt mixture 5 using a blower 13 to reach the surface of the asphalt mixture 5.

[0053] The atomizing spray nozzle 11 and the blower 13 are installed on a tire-type roller 15 that compacts the laid (leveled) asphalt mixture 5.

[0054] In the spraying process, the road roller 15 is moved at a predetermined speed over the laid asphalt mixture 5, while the misted water 17 is sent toward the surface of the asphalt mixture 5 and reaches the surface of the asphalt mixture 5.

[0055] The amount of water 17 discharged from the atomizing spray nozzle 11 during the spraying process is small. If the amount of water 17 discharged from the atomizing spray nozzle 11 during the spraying process is large, the condition shown in Figure 10(c) will occur, and the cooling efficiency of the asphalt mixture 5 will decrease.

[0056] The pavement surface cooling device 1 is equipped with a mist spray nozzle 11 that discharges water 17 cooled by a water cooling device 9 in a mist form. The pavement surface cooling device 1 is also equipped with a blower 13 that sends the mist-like water 17 discharged by the mist spray nozzle 11 to the surface of the asphalt mixture 5 laid for paving the road 3. This makes it possible to quickly lower the temperature of the pavement surface on which the asphalt mixture 5 has been laid.

[0057] In other words, in the pavement surface cooling device 1, as shown in Figure 10(a), mist-like water 17 is on the surface of the laid asphalt mixture 5. Subsequently, as shown in Figure 10(b), the mist-like water 17 reaches the surface of the laid asphalt mixture 5.

[0058] In the state shown in Figure 10(b), the entire surface of the laid asphalt mixture 5 is not covered with water 17 (see Figure 10(c)), but rather only a portion of the surface of the laid asphalt mixture 5 is covered with water 17A, 17B, and 17C. This promotes the evaporation of the water indicated by reference numerals 17A, 17B, and 17C, and the heat of vaporization of the water 17A, 17B, and 17C efficiently removes the heat contained in the laid asphalt mixture 5, allowing the laid asphalt mixture 5 to cool down quickly. This makes it possible to avoid the formation of ruts at the paving work site and shorten the time that traffic must be stopped at the paving work site.

[0059] In Figure 10(b), the water indicated by reference numeral 17A represents water immediately after it reaches the surface of the asphalt mixture 5. In Figure 10(b), the water indicated by reference numeral 17B represents water after a short predetermined first time has elapsed since it reached the surface of the asphalt mixture 5. In Figure 10(b), the water indicated by reference numeral 17C represents water after a short predetermined second time has elapsed since it reached the surface of the asphalt mixture 5. The second time is longer than the first time. Also, because water 17A, 17B, and 17C gradually evaporate due to the heat of the asphalt mixture 5, the volume of water 17A > the volume of water 17B > the volume of water 17C.

[0060] In contrast, if water 17 is sprayed without being atomized into a mist, as shown in Figure 10(c), almost the entire surface of the laid asphalt mixture 5 becomes covered with a film of water, which slows down the evaporation rate of water 17. As a result, the cooling rate of the laid asphalt mixture 5 decreases.

[0061] Furthermore, in the pavement surface cooling device 1, the water 17 contained in some of the tanks 7A, which are originally provided on the road roller 15, is cooled by the water cooling device 9 and discharged from the mist spray nozzle 11. This allows the pavement surface cooling device 1 to be constructed without the need to provide a separate tank to hold the water 17 discharged by the mist spray nozzle 11. Moreover, the asphalt mixture 5 can be efficiently spread and cooled using only one road roller 15.

[0062] Furthermore, the pavement surface cooling device 1 cools the asphalt mixture 5 by discharging water 17 contained in the tank 7A from the mist spray nozzle 11. This prevents adverse effects (such as the formation of tire marks) even when the tire-type roller 15 is used on the paved road surface (asphalt mixture 5).

[0063] In contrast, consider a scenario where the road surface cooling device 1 is installed on a four-wheeled truck. In this case, there is a higher risk of tire marks from the four-wheeled truck remaining on the asphalt mixture 5. Also consider a scenario where the road surface cooling device 1 is installed away from the edge of the road in the width direction of the road. In this case, problems such as the widening of the restricted zone in the width direction of the road 3 will occur.

[0064] The pavement surface cooling device 1 has a mist spray nozzle 11 installed in the housing 23 of the blower device 13. Furthermore, the mist-like water 17 discharged by the mist spray nozzle 11 is delivered to the surface of the laid asphalt mixture 5 by air 31 blown out from the lower opening 29 of the cylindrical housing 23 of the blower device 13. As a result, even if the mist spray nozzle 11 is far from the surface of the laid asphalt mixture 5, the mist-like water 17 discharged by the mist spray nozzle 11 can be accurately delivered to the surface of the laid asphalt mixture 5.

[0065] Furthermore, some of the mist-like water 17 discharged by the atomizing spray nozzle 11 evaporates before reaching the surface of the laid asphalt mixture 5, and the heat of vaporization of this water lowers the temperature of the air. This cooled air also cools the surface of the laid asphalt mixture 5, thereby quickly lowering the temperature of the paved road surface on which the asphalt mixture 5 is laid.

[0066] By the way, in order to avoid as much as possible large changes in the mass of mist-like water 17 that reaches the surface of the asphalt pavement (laid asphalt mixture 5) due to climate change, the following may be done. That is, the pavement surface cooling device 1 may be equipped with at least one of the following sensors: a temperature detection sensor for detecting the temperature of the air, a humidity detection sensor for detecting the humidity of the air, a solar radiation detection sensor for detecting the amount of solar radiation, and a wind speed detection sensor for detecting the wind speed. Then, according to the detection results of the above sensors, at least one of the following physical quantities may be changed. Examples of physical quantities include the discharge rate of water 17 from the mist spray nozzle 11 (discharge rate per unit time), the particle size of the mist-like water discharged from the mist spray nozzle 11, the temperature of the water discharged from the mist spray nozzle 11, and the flow rate of the blower 13.

[0067] For example, as the temperature detected by the temperature detection sensor increases, the amount of water discharged from the mist spray nozzle 11 may be increased, or the temperature of the water discharged from the mist spray nozzle 11 may be decreased. Alternatively, for example, as the wind speed detected by the wind speed detection sensor increases, the amount of water 17 discharged from the mist spray nozzle 11 may be increased, and the flow rate of the blower 13 may be increased.

[0068] Here, the pavement surface cooling device 1 will be described in more detail with reference to Figures 2 to 4. As mentioned above, the road roller 15 is equipped with wheel nozzles (not shown) that discharge water toward the wheels 19 of the road roller 15.

[0069] In the pavement surface cooling device 1, when the temperature is low, such as in winter, the water 17 in the first group of tanks 7A is kept at room temperature (approximately the same temperature as the ambient temperature) without being cooled by the water cooling device 9. The water 17 (room temperature water) 17 in the first group of tanks 7A and the water 17 (room temperature water) 17 in the second group of tanks 7B and 7C are mixed, for example, and discharged from the wheel nozzle (see Figure 2). When the temperature is low, such as in winter, it means that the ambient temperature is 0°C to 15°C, more preferably 0°C to 12°C, and even more preferably 0°C to 10°C.

[0070] Furthermore, when it is necessary to discharge water 17 from the atomizing spray nozzle 11 at low temperatures, the water (room temperature water) from the first group of tanks 7A is used to enable the discharge of water 17 from the atomizing spray nozzle 11.

[0071] As described above, in the pavement surface cooling system 1, when the ambient temperature is low, the water 17 in the first group of tanks 7A is not cooled by the water cooling system 9. In addition, in the pavement surface cooling system 1, when the ambient temperature is low, the room temperature water 17 in the first group of tanks 7A and the room temperature water 17 in the second group of tanks 7B and 7C are discharged from the wheel nozzles.

[0072] This allows the afphalt mixture 7 to be cooled while the afphalt mixture 5 laid for paving is compacted, without unnecessarily operating the cooling device 9. In addition, since the water 17 from the first group of tanks 7A and the water 17 from the second group of tanks 7B and 7C can be used, the interval between replenishing the water 17 to each of the tanks 7A, 7B, and 7C can be extended.

[0073] Furthermore, the pavement surface cooling device 1 is configured to include a discharge mode switching unit 63. The discharge mode switching unit 63 switches the water discharge mode between the atomizing spray nozzle 11 and the wheel nozzle so that water 17 is discharged in one of the following discharge modes: a first discharge mode, a second discharge mode, or a third discharge mode.

[0074] The first discharge mode is the discharge mode of water 17 when the temperature is low, such as in winter, and the road roller 15 is used as a normal road roller 15. When the road roller 15 is used as a normal road roller 15, it means when the loader roller 15 is compacting the asphalt mixture 5.

[0075] Furthermore, in the first discharge mode, as described above and as shown in Figure 2, the water 17 in the first group of tanks 7A and the water 17 in the second group of tanks 7B and 7C are discharged from the wheel nozzle without cooling the water 17 in the first group of tanks 7A by the water cooling device 9.

[0076] To explain further, in the first discharge mode, water 17 at room temperature (approximately the same temperature as ambient temperature) is contained in the first group tank 7A and the second group tanks 7B and 7C. This room temperature water 17 is then discharged from the wheel nozzle while the road roller 15 is compacting the asphalt mixture 5 at approximately this temperature. When the road roller 15 is compacting the asphalt mixture 5 in the first discharge mode, the discharge of water 17 from the atomizing spray nozzle 11 is stopped.

[0077] Furthermore, for example, when the road roller 15 has finished compacting the asphalt mixture 7, the discharge of water 17 from the wheel nozzles in the first discharge mode is stopped. After the road roller 15 has finished compacting the asphalt mixture 5, water (room temperature water in the first group of tanks 7A) 17 is discharged from the atomizing spray nozzles 11 as needed.

[0078] In the above description, when it is necessary to discharge water 17 from the atomizing spray nozzle 11, the water is discharged from the atomizing spray nozzle 11 after the discharge of water 17 from the wheel nozzle has finished in the first discharge mode. Here, the timing of the discharge of water 17 from the wheel nozzle and the timing of the discharge of water from the atomizing spray nozzle 11 may be changed as appropriate. For example, the discharge of water 17 from the wheel nozzle and the discharge of water 17 from the atomizing spray nozzle 11 in the first discharge mode may be performed almost simultaneously. Alternatively, the discharge of water from the atomizing spray nozzle 11 may be started before the discharge of water from the wheel nozzle has finished in the first discharge mode.

[0079] The second discharge mode is the discharge mode of water 17 when the road roller 15 is used as a normal road roller 15 during seasons other than winter (spring, summer, and autumn). Furthermore, the second discharge mode is the discharge mode of water 17 when it is necessary to cool the asphalt mixture 5 compacted in paving work quickly. During seasons other than winter, the temperature is moderate or high. That is, the temperature is 15°C to 45°C, more preferably 20°C to 40°C, and even more preferably 25°C to 40°C.

[0080] Furthermore, in the second discharge configuration, as shown in Figure 3, the water 17 in the first group of tanks 7A is cooled by the water cooling device 9, and the water (room temperature water) 17 in the second group of tanks 7B and 7C is discharged from the wheel nozzle.

[0081] In the second discharge mode, as described above, the first group of tanks 7A contains water 17 cooled by the water cooling device 9, and the second group of tanks 7B and 7C contain room temperature water 17. In the second discharge mode, the room temperature water 17 in the second group of tanks 7B and 7C is discharged from the wheel nozzles while the road roller 15 is compacting the asphalt mixture 5 at this temperature. Also, while the road roller 15 is compacting the asphalt mixture 5, the discharge of water 17 from the atomizing spray nozzles 11 is stopped.

[0082] To further explain, in the second discharge mode, for example, when the compaction of the asphalt mixture 5 by the road roller 15 is completed, the discharge of water 17 from the wheel nozzle is stopped. Also, in the second discharge mode, after the compaction of the asphalt mixture 5 by the road roller 15 is completed, water 17 cooled by the water cooling device 9 (cooled water in the first group of tanks 7A) is discharged from the atomizing spray nozzle 11.

[0083] In the above description, the water (cooled water) 17 from the atomizing spray nozzle 11 is discharged after the discharge of water 17 from the wheel nozzle has finished in the second discharge mode. Here, the timing of the discharge of water 17 from the wheel nozzle and the timing of the discharge of water 17 from the atomizing spray nozzle 11 may be changed as appropriate. For example, the discharge of water 17 from the wheel nozzle and the discharge of water 17 from the atomizing spray nozzle 11 in the second discharge mode may be performed almost simultaneously. Alternatively, the discharge of water 17 from the atomizing spray nozzle 11 may be started before the discharge of water 17 from the wheel nozzle has finished in the second discharge mode.

[0084] The third discharge mode is for when the temperature is moderate or high, other than in winter, and it is necessary to cool the asphalt mixture 5 compacted during paving work even earlier. In the third discharge mode, the water 17 in the first group of tanks 7A is cooled by a water cooling device 9, and this cooled water (cooling water) 17 is discharged from the wheel nozzle and the atomizing spray nozzle 11 (see Figure 4).

[0085] In the third discharge mode, as described above, the first group of tanks 7 contains water 17 cooled by the water cooling device 9, and the second group of tanks 7B and 7C contain room temperature water. The discharge of water 17 in the third discharge mode is performed, for example, after the discharge of water 17 from the wheel nozzles in the second discharge mode is completed. That is, the room temperature water 17 from the second group of tanks 7B and 7C is discharged from the wheel nozzles while the asphalt mixture 5 is compacted by the road roller 15. After this compaction is completed, the water 17 from the first group of tanks 7A, which has been cooled by the water cooling device 9, is discharged from the wheel nozzles and the atomizing spray nozzles 11.

[0086] Furthermore, in the third discharge mode, for example, the discharge of water (cooled water) 17 from the wheel nozzle and the discharge of water (cooled water) 17 from the atomizing spray nozzle 11 are performed almost simultaneously. Here, the timing of the discharge of water 17 from the wheel nozzle and the timing of the discharge of water 17 from the atomizing spray nozzle 11 may be changed as appropriate. For example, water 17 may be discharged from the wheel nozzle for a predetermined time, and then water 17 may be discharged from the atomizing spray nozzle 11 for a predetermined time. Alternatively, water 17 may be discharged from the atomizing spray nozzle 11 for a predetermined time, and then water 17 may be discharged from the wheel nozzle for a predetermined time.

[0087] In the pavement surface cooling device 1, the discharge mode switching unit 63 allows water 17 to be discharged in one of three discharge modes: a first discharge mode, a second discharge mode, or a third discharge mode. This allows the asphalt mixture 5, which has been compacted for paving, to be efficiently cooled depending on the usage conditions of the pavement surface cooling device 1.

[0088] Furthermore, in the first embodiment, as described above, when the temperature is low, the room temperature water 17 from the first group tank 7A and the room temperature water 17 from the second group tanks 7B and 7C are discharged from the wheel nozzles, so that the afphalt mixture 5 can be cooled without unnecessarily operating the cooling device.

[0089] In the second embodiment, the first group of tanks 7A contains water 17 cooled by the water cooling device 9, and the second group of tanks 7B and 7C contain room temperature water 17. The room temperature water 17 in the second group of tanks 7B and 7C is then discharged from the wheel nozzles while the road roller 15 is compacting the asphalt mixture 5 at this temperature. This allows the relatively high-temperature asphalt mixture 5 to be efficiently cooled using room temperature water 17 without unnecessarily operating the cooling device 9.

[0090] Furthermore, when the road roller 15 finishes compacting the asphalt mixture 5, the discharge of water 17 from the wheel nozzles stops, and then the water 17 cooled by the water cooling device 9 is discharged from the atomizing spray nozzles 11. This allows the relatively low-temperature asphalt mixture 5 to be cooled quickly.

[0091] In the third embodiment, the water 17 cooled by the water cooling device 9 is discharged from the wheel nozzle and the atomizing spray nozzle 11. This allows the relatively low-temperature asphalt mixture to be cooled even more quickly.

[0092] Here, we will explain in detail the piping system shown in Figures 2 to 4. Pipe 43 extends from the outlet hole 41 of water 17 in tank 7A, and pipe 47 extends from the outlet hole 45 of water 17 in tank 7B. As mentioned above, tanks 7B and 7C are connected to each other by piping (not shown). Between the two pipes 43 and 47, a two-way valve (for example, a solenoid two-way valve) 55 and a three-way valve (for example, a solenoid three-way valve) 57 are provided. The two-way valve 55 and the three-way valve 57 are connected in parallel to the two pipes 43 and 47. The three-way valve 57 is located on the opposite side from tanks 7A and 7B, with the two-way valve 55 in between. Pipe 59 extends from the three-way valve 57. The water flowing through pipe 59 is discharged from a wheel nozzle (not shown).

[0093] In the state shown in Figure 2, the two-way valve 55 is open, allowing water 17 to flow through the two-way valve 55, and then through the three-way valve 57 to pipes 47 and 43 and into pipe 59. This allows room temperature water 17 contained in tanks 7A, 7B, and 7C to be discharged from a wheel nozzle (not shown) toward the wheel 19.

[0094] In the state shown in Figure 3, the two-way valve 55 is closed, preventing water 17 from flowing through it. Water then flows from pipe 47 to pipe 59 through the three-way valve 57. This allows room temperature water 17 from tanks 7B and 7C to be discharged from the wheel nozzles toward the wheels 19.

[0095] In the state shown in Figure 4, the two-way valve 55 is closed, preventing water 17 from flowing through it. Water then flows from pipe 43 to pipe 59 through the three-way valve 57. This allows the cooled water 17 in tank 7A to be discharged from the wheel nozzle towards the wheel 19.

[0096] The pavement cooling device 1 is provided with a water supply channel (water supply channel to the atomizing spray nozzle 11) separate from the water supply channels (pipes 43, 47, 59, etc.) to the wheel nozzles. Water 17 from the cooling tank 7A is supplied to the atomizing spray nozzle 11 through the water supply channel to the atomizing spray nozzle 11. The water 17 supplied to the atomizing spray nozzle 11 using the above water supply channel is discharged from the atomizing spray nozzle 11.

[0097] To further explain, the water supply channel to the mist spray nozzle 11 is comprised of a pipe 67 extending from the cooling tank 7A. A two-way valve 69 for opening and closing the water supply channel is provided in the middle of the pipe 67. The end of the pipe 67 is connected to the mist spray nozzle 11 (not shown in Figures 2 and 3).

[0098] Incidentally, instead of providing nozzle components such as a mist spray nozzle 11 or a wheel nozzle, the system may simply have holes in the pipes 59 and 67 for discharging water 17. In this specification, such simple holes are also included in the category of nozzles.

[0099] In this pavement surface cooling method, the water 17 cooled in the cooling step is turned into a mist in the spraying step and sprayed onto the surface of the asphalt mixture 5. This allows the temperature of the pavement surface on which the asphalt mixture 5 has been laid to be lowered quickly.

[0100] Furthermore, in the spraying process of the pavement surface cooling method, cooled water 17 is discharged from a mist spray nozzle 11 to form a mist, and this mist water 17 is brought to the surface of the asphalt mixture 5 using a blower 13. As a result, even if the mist spray nozzle 11 is far from the surface of the laid asphalt mixture 5, the mist water 17 can be accurately delivered to the surface of the laid asphalt mixture 5.

[0101] Furthermore, in the spraying process of the pavement surface cooling method, the road roller 15 moves along the surface, delivering a mist of water 17 to the surface of the asphalt mixture 5. This compacts and levels the laid asphalt mixture 5, while simultaneously cooling the surface of the laid asphalt mixture 5 uniformly and quickly.

[0102] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment. [Explanation of Symbols]

[0103] 1. Pavement surface cooling system 3 road 5. Asphalt mixture 7, 7A, 7B, 7C tanks 9 Water cooling system 11. Mist spray nozzle 13. Blower 15 Road Roller 17 water 21. Main body of the road roller 23 cabinets 25 feathers 27 Opening 29 Lower opening

Claims

1. A water tank is installed inside the road roller, A water cooling device provided on the road roller, capable of cooling the water in the tank to a predetermined temperature lower than ambient temperature, A mist spray nozzle is provided on the road roller and discharges water cooled by the water cooling device in a mist form, A blower is provided on the road roller and blows the mist-like water discharged by the atomizing spray nozzle toward the surface of the asphalt mixture laid for road paving, A pavement surface cooling device having the following features.

2. The pavement surface cooling device according to claim 1, wherein a plurality of tanks are provided, and the water contained in at least one of these plurality of tanks is cooled by the water cooling device and discharged by the mist spray nozzle.

3. The tanks are provided in multiple quantities, and at least one of these multiple tanks constitutes the first group of tanks, and the other tanks constitute the second group of tanks. The water in the first group of tanks can be cooled to a predetermined temperature lower than room temperature by the water cooling device. The road roller is provided with a wheel nozzle that discharges water toward the wheels of the road roller, The pavement surface cooling device according to claim 1, wherein, when the temperature is low, the water in the first group of tanks is kept at room temperature without being cooled by the water cooling device, and the water from the first group of tanks and the water from the second group of tanks is discharged from the wheel nozzles.

4. The tanks are provided in multiple quantities, and at least one of these multiple tanks constitutes the first group of tanks, and the other tanks constitute the second group of tanks. A wheel nozzle provided on the road roller for discharging water toward the wheels of the road roller, A discharge mode switching unit that switches the water discharge mode of the atomizing spray nozzle and the wheel nozzle so that water is discharged in one of the first discharge mode, second discharge mode, or third discharge mode, It has, The first discharge mode is one in which the water from the first group of tanks and the water from the second group of tanks are discharged from the wheel nozzle without cooling the water from the first group of tanks. The second discharge configuration involves cooling the water in the first group of tanks with a water cooling device and discharging the water from the second group of tanks through the wheel nozzles. The pavement surface cooling device according to claim 1, wherein the third discharge mode is to cool the water in the first group of tanks with the water cooling device and discharge the cooled water from the wheel nozzle and the mist spray nozzle.

5. The aforementioned blower is configured to include a cylindrical housing provided on the main body of the road roller, and blades installed inside the housing that rotate to generate airflow. The central axis of the cylindrical housing extends diagonally with respect to the surface of the laid asphalt mixture, and the rotation of the blades draws air into the housing from the upper opening and blows air out from the lower opening, so that the blown air directly reaches the surface of the laid asphalt mixture. The pavement surface cooling device according to any one of claims 1 to 3, wherein the atomizing spray nozzle is provided in the housing, and the mist-like water discharged by the atomizing spray nozzle is sent to the surface of the laid asphalt mixture by air blown out from the lower opening of the cylindrical housing.

6. A method for cooling a paved road surface, which involves cooling an afphalt mixture laid for road paving, A cooling process in which water is cooled to a predetermined temperature lower than room temperature, A spraying step in which the water cooled in the cooling step is turned into a mist and sprayed onto the surface of the asphalt mixture, A method for cooling pavement surfaces.

7. The method for cooling a paved road surface according to claim 6, wherein the spraying step is a step of discharging the cooled water from a mist spray nozzle to make it into a mist, and then using a blower to bring the mist-like water to the surface of the asphalt mixture.

8. The atomizing spray nozzle and the blower are installed on the road roller that compacts the laid asphalt mixture. The method for cooling a paved road surface according to claim 7, wherein the spraying step is a step of moving the road roller while bringing the misted water to the surface of the asphalt mixture.

Images