WO2023127916A1

WO2023127916A1 - Method for controlling hot air joint heater

Info

Publication number: WO2023127916A1
Application number: PCT/JP2022/048376
Authority: WO
Inventors: 厚司倉田
Original assignee: 建機メンテナンス株式会社
Priority date: 2021-12-28
Filing date: 2022-12-27
Publication date: 2023-07-06
Also published as: JPWO2023127916A1

Abstract

[Problem] To provide a method for controlling a hot air joint heater that can easily control the hot air temperature, hot air volume, and air pressure, and that can improve joining productivity of asphalt joints. [Solution] An ON/OFF circuit for a spark-plug ignition 23 and a timer relay circuit 24 are connected to a first relay circuit 20, and a temperature controller 26 is also connected thereto via an open/close relay circuit of a gas valve 27. Furthermore, supplying and stopping gas to a side heater 11 and ignition of the spark plug are performed only by turning at least one toggle switch 18 on and off, and opening/closing operation of the gas valve 27 is automatically controlled by a signal from the temperature controller 26.

Description

Hot air joint heater control method

The present invention relates to a hot-air joint heater used for spreading asphalt mixture on a road surface, and particularly to its control method.

　The surface and base layers of asphalt pavement are formed using asphalt mixture manufactured under appropriate temperature and quality control. There are manual construction and machine construction for this method of heating and leveling asphalt mixture, and it is adopted according to the scale and type of work, but currently most of the construction is done by machine, and a special machine called asphalt finisher is used. be done.

In general asphalt layer construction, the asphalt mixture transported by dump truck is supplied to the asphalt finisher and laid evenly to obtain the desired finished width and thickness. The temperature of the asphalt mixture during spreading should not drop below about 110°C, and the asphalt finisher should be operated continuously at a constant speed as much as possible to ensure flatness.

Also, when constructing the surface layer asphalt mixture on top of the base layer asphalt mixture, an emulsion called tack coat is sprayed to improve the adhesion of the layers.

The asphalt finisher is a self-propelled machine that consists of a hopper that stores the asphalt mixture, a tractor section that has a prime mover and traveling device, and a screed that spreads the asphalt mixture evenly. Then, the asphalt mixture is stored in the hopper, and the bar feeder at the bottom of the hopper feeds it to the front of the screed behind, spreads the mixture left and right with the screw, and spreads it evenly with the screed. At that time, the angle of the screed is changed to adjust the spread thickness of the asphalt mixture, and the width of the screed is expanded and contracted left and right to adjust the spread width (width). In order to repair the asphalt road surface, the road surface is pre-heated by a road surface heater to soften it, and then the road surface is scraped out and compaction work is performed.

For example, in Patent Document 1, while heating the end that will be the joint of the existing first lane asphalt pavement, when spreading the asphalt mixture that will be the second lane asphalt pavement, the seam equipped with a magnetron A method has been proposed in which a heating device is used to irradiate the edges of the asphalt with microwaves to heat the edges to an appropriate temperature, and then the asphalt mixture is spread evenly.

In addition, as a device for spreading asphalt mixture evenly on the lower road surface such as unpaved roadbed, asphalt pavement and its cut surface, concrete pavement surface, etc., a hopper for storing asphalt mixture and asphalt It is known that a mixture delivery device, an emulsion spray nozzle, and a screed are provided, and the asphalt mixture is delivered from a hopper and spread evenly with a screed while the emulsion is sprayed on the lower road surface by the spray nozzle. (See Patent Document 2.). In addition, the road heater for melting the frozen roadbed and roadbed includes a rolling roller that is horizontally supported by a movable working machine and that is drilled around the roller to extend from the internal space to the outside. A hole for blowing out hot air, a heating device arranged toward the inner space of the roller, and a heat insulating cover wound around the rolling surface of the roller except for the lower part with a required gap. A road heater for pavement construction (see Patent Document 3).

According to the leveling machine disclosed in Patent Document 1, it is possible to perform asphalt pavement at a low cost comprehensively without using an asphalt distributor, which is a dedicated dispersion vehicle for emulsion.

However, the above-mentioned conventional asphalt mixture spreading machine is equipped only with an emulsion spray nozzle and auxiliary equipment such as a pump and an emulsion tank for pressure-feeding the emulsion to the nozzle, and the decomposition speed of the sprayed emulsion is external. There is a problem that it is affected by temperature, wind, etc., and as a result, the adhesive strength of the emulsion is affected.

JP 2004-143826 A JP-A-4-203006 JP 2016-75043 A Utility Model Registration No. 3212830

In addition, the above-mentioned conventional heating device has the drawback that the deep part of the road surface is not sufficiently heated, and the asphalt that has been plowed is immediately cooled, resulting in insufficient temperature during the subsequent rolling compaction process. In order to solve this drawback, it is necessary to sufficiently heat the road surface.

Currently, when constructing asphalt joints, it is common practice to use direct-fired joint heaters and handle burners attached to the side of the asphalt finisher. For this reason, the compound material solidifies while waiting for the compound dump truck and during the manual work, and the work efficiency decreases especially in winter. In addition, since the road surface joints are poorly connected, defects such as cracks appear immediately after the pavement work is completed.

The direct-fired joint heater is attached to the side of the asphalt finisher, but the weight of the heater is heavy, and it takes time and effort to attach and detach it, requiring a great deal of labor from the workers. In addition, since the flame of the hand burner hits the asphalt pavement surface directly, the pavement surface is discolored. Furthermore, depending on where it is attached to the finisher, the hand burner may move due to vibrations or the like, causing a safety problem such as the burning of the worker's clothing. Also, since the heating power is weak, it is difficult to connect the joints.

Conventionally, there is a method in which a heating device is installed immediately after the road surface raking device, but there is a problem that the equipment cost increases and a sufficient heating temperature cannot be obtained. 4 proposes a hot-air joint heater. This hot-air joint heater includes a hot-air generator including a gas burner and an air blower, a front heater provided with a plurality of hot-air ejection holes directed toward the road surface, and hot air from the hot-air generator. It consists of a pipe-shaped side heater that is connected to a hot air duct and has multiple hot air ejection holes oriented to the road surface. The road surface can be repaired quickly by applying heat necessary for post-processes such as rolling compaction to the position where heat is scraped and to the asphalt immediately after scraping.

The present invention relates to the improvement of this hot air joint heater, and provides a control method for a hot air joint heater that can easily control the hot air temperature, hot air volume, and air pressure, and can increase the bonding productivity of asphalt joints. intended to

For this reason, the present invention includes a hot air generator including a gas burner and an air blower, a front heater provided with a plurality of hot air ejection holes directed toward the road surface, and hot air from the hot air generator. It consists of a pipe-shaped side heater that is connected to a hot air duct and has multiple hot air ejection holes oriented to the road surface. A control system for a hot air joint heater that applies heat necessary for post-processes such as rolling compaction to the asphalt at the scraping position and immediately after scraping, comprising supplying and stopping gas to the side heater and igniting it. A first feature is that the ignition of the plug is automatically controlled only by turning on/off at least one switch. A second feature is that the hot air blowing pipe of the side heater is branched into a front duct pipe and a rear duct pipe instead of the front heater, and the hot air is blown out from each of the hot air blowing holes.
In addition, the hot air generating device includes an air blower that sucks air from the outside air, heats the air with a front gas burner and sends it out as hot air, and an air blower that blows hot air from the air blower. It consists of a hot air blowing skirt box with a hot air duct and a side gas burner and a side heater that are connected by branching the hot air duct. A third feature is to control to stop the supply of .
In addition, the switch is connected to the on/off circuit of the power supply, the on/off relay circuit of the spark plug (ignition), the open/close relay circuit of the gas valve, and the power supply relay circuit of the blower fan, and is connected to the start/stop switch line of the vehicle. A fourth feature is that
A fifth feature is that an ignition ON/OFF relay circuit is connected to a timer relay, and a gas valve open/close relay circuit is connected to a temperature controller.
gas supply means for turning on/off the supply of gas by opening and closing a gas valve; a power supply for applying voltage to the ignition electrode; a grounded shield box; A sixth feature is that the gas valve is arranged in the shield box, comprising control means for controlling opening and closing and applying amplitude modulation to the high-frequency power applied to the ignition electrode in synchronization with the opening and closing of the valve. and A seventh feature is that the gas is supplied from a propane gas cylinder.

Since the hot-air joint heater of the present invention is constructed as described above, it has the following excellent effects.
(1) Cold asphalt and warm asphalt do not mix, so bonding is difficult, but by heating, cold asphalt and warm asphalt mix, making bonding easier and preventing cracks in the joints of asphalt pavement. can be prevented.
(2) Since the composite material is heated to a constant temperature with hot air even during the waiting time for transporting and dumping the composite material and during the manual handling work, the composite material does not solidify. Therefore, it also leads to shortening of work time such as rake work.
(3) The asphalt surface is not discolored because a blower is used instead of an open flame to send hot air evenly.
(4) Since it is not an open flame, it does not spread to the worker's clothing, etc., so it is highly safe. Because of its lightweight and compact structure, disassembly, attachment and detachment work can be done by one person in about five minutes.
(5) Even when the outside temperature is low or the wind is strong, the pavement can be satisfactorily carried out without being adversely affected by them.
(6) Not only can the underlying road surface be heated before the emulsion is sprayed, but even if it is damp with rainwater or the like, the water is removed by heating, resulting in better pavement.
(7) Both the front heater and the side heater can be controlled manually as well as automatically. In particular, if the gas does not ignite when the asphalt finisher is started, the temperature controller does not sense the flame, so the gas supply is stopped for safety.
(8) Since the switch for gas ignition and the starter switch are interlocked, usability is improved.
(9) Based on the detection signal of the hot air sensor, the hot air temperature, air volume, air pressure, etc. can be accurately kept within a certain range. Drying productivity can be remarkably improved.
(10) Both the front heater and the side heater can be easily attached and detached with a single bolt when mounted on the asphalt finisher body.

1 is a front perspective view showing a state in which a hot-air joint heater according to the present invention is attached to an asphalt finisher; FIG. FIG. 2 is a side perspective view showing a state in which the hot-air joint heater according to the present invention is attached to an asphalt finisher; BRIEF DESCRIPTION OF THE DRAWINGS (a) is a front view, (b) is a side view which shows the hot-air heating apparatus (front heater) of the hot-air joint heater which concerns on this invention. It is a bottom view of Fig.2 (a). It is a block diagram which shows a side heater typically. (a) is a front view schematically showing the appearance of the control box. (b) is a plan view. 1 is a circuit diagram of a hot air joint heater control system according to the present invention; FIG. 4 is an external plan view of the control box; FIG. FIG. 11 is a side view showing another embodiment of the side heater; FIG. 4 is a perspective view schematically showing another embodiment of the hot-air joint heater according to the present invention; FIG. 11 is a front view schematically showing an attached state of the hot-air joint heater shown in FIG. 10;

Embodiments of this generation will be described below based on the examples shown in the drawings.

1 to 4 show an embodiment of the hot air joint heater according to the present invention.
The device of the present invention is used by being attached to a self-propelled vehicle such as an asphalt finisher AF. An asphalt finisher is, for example, a self-propelled vehicle equipped with a hopper for storing asphalt mixture, an asphalt mixture delivery device, an emulsion (asphalt) spray nozzle, and a screed. While spreading the asphalt mixture on the unpaved roadbed, the asphalt mixture is sent out from the hopper by the feeding device onto the dispersed emulsion on the roadbed and spread evenly with a screed.

1 and 2 are perspective views showing the appearance of a hot-air joint heater according to the present invention. It is generally composed of a pipe-shaped side heater 11 to which a hot air duct 15 is connected. That is, the hot air joint heater according to the present invention sucks outside air from the open surface of the blower cover 5, heats the sucked outside air in the combustion cylinder 3 with the gas burner 2, and turns it into hot air at the joint part of the asphalt road surface. erupt into In addition, the amount of heat required for scraping can be applied to the scraping position and to the asphalt immediately after scraping, for subsequent processes such as rolling compaction. Both the front heater 1 and the side heater 11 can be easily attached and removed with a single bolt to the asphalt finisher body AF.

As shown in FIGS. 2 to 4, the hot air generator (front heater) 1 includes a combustion cylinder 3 in which a gas jetting nozzle 2a of a gas burner 2 is accommodated, and an air blower box 4 having an air fan 19. is connected to The temperature of the hot air is detected by a temperature sensor, and the amount of gas supplied to the gas burner 2 is adjusted to control the amount of combustion. Equipped with a hot air control circuit that The diameter of the gas injection nozzle 2a is preferably 0.5 to 10 mm, particularly 0.7 to 0.8 mm, and can be appropriately adjusted according to working conditions.

As shown in FIGS. 3 and 4, the combustion cylinder 3 is mounted on the surface plate 6 together with the blower cover 5, and hot air is blown from the hot air blowing skirt box 7 provided below. A plurality of hot air blowing holes 9 and hot air blowing holes 10 are formed in the bottom plate 8 of the hot air blowing skirt box 7, and the asphalt road surface immediately after being scraped is heated by the hot air blown out.

As shown in FIG. 5, the side heater 11 is configured by inserting a side gas burner 12 connected to a hot air duct 15 from above a burner mounting bracket (including a T-shaped socket) 13 and holding the burner position fixing bolt 12a at a desired position. and a hot air blowing pipe 14 having a plurality of hot air blowing holes 17 oriented toward the road surface in the left and right direction at the lower end of the hot air blowing pipe 14 connected to each other. The hot air sent from the compressor is directly blown out.

The hot air joint heater according to the present embodiment configured as described above (fuel is propane gas: propane pressure 0.05 MPa, front hot air blowing temperature: 230 ° C., side heater hot air blowing temperature: 160 ° C.-180 ° C.. By the front heater The emulsion is dried by blowing hot air (230°C).The fuel propane gas is supplied from the main gas tank of the asphalt fisher body, but the pressure is 0.05 MPa, so there is no need to adjust the same amount, and the same gas pressure can be stressed. In addition, the combustion efficiency of the gas is improved, and energy saving can be achieved.

In this way, by softening the mixed material by blowing out hot air (160°C to 180°C) from the side heater 11, the efficiency of the raking work is increased and the finished surface of the pavement joint is improved. The mixture does not cool down during paving work, while the mixture is waiting, or when the finisher is stopped, and the mixture can be kept soft even when restarting. Since it is not a direct flame, discoloration of the mixture does not occur.

In addition, the hot air temperature is suitable to be about 250°C to 300°C in order to prevent deterioration of the asphalt. Either one of the front heater 1 and the side heater 11 may be used instead of using both depending on the outside air temperature and asphalt conditions.

　Fig. 6 shows a control box 30 equipped with a hot air control circuit for the side heater 11, Fig. 7 shows its control system circuit, and Fig. 8 shows a plan view of its appearance. The hot air control circuit consists of two toggle switches 18, which are a power on/off circuit, an ignition on/off relay circuit 20 that is the first relay circuit, and a gas valve 27 that is the second and third relay circuits. It is connected to the

circuits

21 and 22 and the power supply relay circuit of the air supply fan 19 of the air supply blower 4, and is also connected to the start/stop switch line of the asphalt finisher (vehicle). As the gas valve 27, a fluid control solenoid valve (multi-rex valve: CKD GAB312-3-0-03A-DCV: trade name: manufactured by CKD Corporation) was used. In the figure, 32 is a thermocouple (which measures temperature difference), and the ignition plug 6 is connected to the igniter 16 .

That is, the first relay circuit 20 is connected with a timer relay circuit 24 to an ON/OFF circuit of an ignition 23 for spark plugs, and a temperature controller 26 having a digital display panel is connected via an open/close relay circuit of a gas valve 27. It is connected to the. Gas supply to the side heater 11, stoppage and ignition can be performed only by turning on/off at least one toggle switch 18. FIG. The opening/closing operation of the gas valve 27 can be automatically controlled by signals from the temperature controller 26 . In the figure, 33 is a metal connector for power supply, 33a is its cover, 34 is a coupler for gas supply, and 34a is its cap.

In this embodiment, a solid state timer H3N-2 (trade name: manufactured by Omron Corporation) was used as the ignition of the spark plug, the interlocking of the start/stop switch, and the timer relay circuit 20. As the second and

third relay circuits

21 and 22 connected to the temperature controller 26, mini power relay G2R-2-SD (trade name: manufactured by Omron Corporation) was used. As the temperature controller 26, a digital PID temperature control controller RKC C100KF02-V (trade name: manufactured by Rika Kogyo Co., Ltd.) was used.

The hot-air joint heater of this embodiment automatically controls the opening and closing of the gas valve 27 by the electromagnetic valve 28 according to the detection signal of the temperature controller 26, and the temperature, air volume, wind pressure, etc. of the hot air can be accurately kept within a certain range. In addition, since manual adjustment work is not required, the drying productivity of asphalt joints can be remarkably increased. Also, for example, it is possible to control the amount of hot air and the wind pressure by adjusting the rotational speed of the air supply fan 19 of the air supply blower 4 .

That is, a gas ignition relay 20 and a gas valve 27 for controlling energization of an ignition plug 23, and a switch 18 connected to the ignition plug 23 and interlocked with the start/stop of the asphalt finisher (vehicle) AF, A first relay circuit 20 for ignition, a second relay circuit 21 for controlling the front heater, and a third relay circuit 22 for controlling the side heater 11 are automatically interlocked by operating at least one switch. If the ignition plug 23, which is a switch for gas ignition, and the asphalt finisher (vehicle) AF start/stop switch line are interlocked, usability will be improved.

When the ignition of the gas burner is automatically controlled, it is ignited when the asphalt finisher AF starts and is extinguished when it is stopped. Are better.

9 to 11 show another embodiment of the device of the present invention. For the sake of convenience, the same reference numerals are given to the same components as in the first embodiment.
In this embodiment, instead of the front heater 1 of the first embodiment, the hot air blowing pipe 14 of the side heater 11 is branched into a front duct pipe 14a and a rear duct pipe 14b from the combustion cylinder 3, and hot air is blown out from the hot air blowing holes 17 respectively. It is designed to blow out, contributing to the compactness of the entire device.

In addition, propane gas as fuel is supplied from an LP gas cylinder 35 mounted on the asphalt finisher AF via a fixed base 37. A bifurcated coupler 38 is connected to the regulator 36 of the LP gas cylinder 35 , and air is supplied to the left and right strainers 3 . Such a configuration makes it easy to attach and detach the entire device, and it can be easily transferred to a different vehicle.

With the above configuration, even if the asphalt finisher is stopped, hot air always hits the road surface, making the mixture soft and easy to work with. In addition, the joint heater and the emulsion (adhesive) of the center joint are also heated to the point where bubbles are generated, so that the mixture is well adhered to each other and the center joint is less likely to crack. The heat is sufficient, but the joint heater does not emit flames, only hot air. Discoloration can be prevented because flames do not hit the mixture directly.

In winter or in cold regions, the screed side side temperature can be sufficiently heated by the hot air joint heater, and the compound material at the corners of the side plate and mold board is soft, so raking work on the left and right sides can be performed smoothly. There is no need to stop the asphalt finisher other than waiting for the compound dump.

The hot air burner type applies hot air of 150°C to 200°C to the mixture to soften it, and since it is not exposed to direct flame, the mixture does not discolor. In addition, malfunction due to flame can be prevented.

　The joint side of the asphalt pavement, the screed side brake, and the bottom of the step are warmed with hot air of 150-200°C, and the compound material at the corners of the moldboard is also soft, so there is less catching and less damage to the pavement.

Even mixed materials with poor properties (recycled materials, etc.) retain their flexibility, and during leveling work with a rake, the entire mixed material does not move as a whole, so the work can be done smoothly, saving the labor of workers. lead to mitigation.
Although it was necessary to temporarily stop the finisher when repair work occurred, paving work can be continued without stopping, improving work efficiency. The pavement finish will be fine.

As with the center joint, the side joint can be of course a manual type or an automatic control type. It is safe because the controller does not detect the flame and the safety device works and the gas supply is stopped if it does not ignite at the start. Thus, according to the present invention, the asphalt joint can be heated at all times. In addition, the large heating area ensures sufficient softening. Therefore, the repair speed can be increased, and labor can be saved by attaching the front heater to the front even in winter.

1 Hot air heating device (front heater)
2 front gas burner 2a gas ejection nozzle 3 combustion tube (strainer)
4 Air supply blower box 5 Gas pipe or gas hose 6 Spark plug 7 Hot air blowing skirt box 8 Bottom plate of skirt box 9 Hot air blowing hole 10 Hot air blowing hole 11 Side heater 12 Side gas burner 12a Burner position adjustment bolt 13 Burner mounting bracket (T type socket)
14 hot air blowing pipe 15 temperature controller 16 igniter 17 hot air blowing hole 18 toggle switch 19 air supply fan 20 first relay circuit (timer relay circuit)
21 Second relay circuit 22 Third relay circuit 23 Spark plug ignition 24 Timer relay 25 Earth (ground)
26 Digital display panel of temperature controller 27 Gas valve 28 Solenoid valve 29 Shield housing 30 Control box (hot air control circuit)
31 high voltage wire 32 thermocouple 33 metal connector 33a connector cover 34 coupler 34a coupler cap 35 LP gas cylinder 36 regulator 37 gas cylinder fixing base 38 bifurcated coupler AF asphalt finisher (vehicle)

Claims

A front heater provided with a hot air generator including a gas burner and an air blower, and provided with a plurality of hot air ejection holes directed toward the road surface, and a hot air duct for supplying hot air from the hot air generator are communicated. In addition, it consists of a pipe-shaped side heater with multiple hot air ejection holes oriented to the road surface. A control system for a hot air joint heater that imparts heat necessary for subsequent processes such as rolling compaction to asphalt immediately after melting, wherein gas supply and stop to the side heater and ignition of the spark plug are ignited at least once. A control method for a hot air joint heater, characterized in that it is performed only by turning on and off individual toggle switches.
2. The hot-air joint heater according to claim 1, wherein the hot-air blowing pipe of the side heater is branched into a front duct pipe and a rear duct pipe instead of the front heater, and the hot air is blown out from each of the hot-air blowing holes. control method.
A toggle switch is connected to the on/off circuit of the power supply, the on/off relay circuit of the spark plug (ignition), the open/close relay circuit of the gas valve, and the power relay circuit of the blower fan, and is connected to the start/stop switch line of the vehicle. 3. The method for controlling a hot air joint heater according to claim 1 or 2, characterized in that:
4. The hot-air joint heater according to any one of claims 1 to 3, wherein an ignition on/off relay circuit is connected to a timer relay, and a gas valve open/close relay circuit is connected to a temperature controller. control method.
gas supply means for turning on/off the supply of gas by opening and closing a gas valve; a power source for applying voltage to the ignition electrode; a grounded shield box; and opening and closing the valve so as to periodically supply the gas. 2. Control means for controlling and applying amplitude modulation to the high-frequency power applied to the ignition electrode in synchronism with opening and closing of the valve, wherein the gas valve is arranged in the shield box. A control method for a hot air joint heater according to any one of claims 4 to 4.
gas supply means for turning on/off the supply of gas by opening and closing a gas valve; a power source for applying voltage to the ignition electrode; a grounded shield box; and opening and closing the valve so as to periodically supply the gas. 2. Control means for controlling and applying amplitude modulation to the high-frequency power applied to the ignition electrode in synchronism with opening and closing of the valve, wherein the gas valve is arranged in the shield box. A control method for a hot air joint heater according to any one of claims 1 to 5.
7. The method of controlling a hot air joint heater according to claim 1, wherein the gas is supplied from a propane gas cylinder.