JP3721302B2 - Asphalt emulsion spray rate controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an asphalt emulsion spray amount control apparatus in which the asphalt emulsion spray amount is controlled by the pressure of an asphalt emulsion feed line.
[0002]
[Prior art]
In mobile vehicles such as asphalt distributors and finishers that spray asphalt emulsion, in order to spray a certain amount of emulsion, pressurize the inside of the tank with compressed air and use that pressure to spray the asphalt emulsion from the sprayer nozzle. A tank pressurization system that sprays a certain amount and discharges asphalt emulsion from the nozzle of the spraying device by controlling the driving of this tank by providing a pump between the tank and the spraying device. There is a pump system to spray.
[0003]
The tank pressurization method has been widely used conventionally, and a pump method has been conventionally known as described in, for example, JP-A-10-237817. The conventional emulsion dispersion control device of the pump system described in the above publication compares the required dispersion amount of emulsion with the limit application amount, and when the required application amount is equal to or greater than the limit application amount, the electromagnetic switching valve The spray nozzle opening command is output to the output, the emulsion pump rotation speed is calculated, and the command signal is output to the proportional valve so that the rotation speed is reached.
[0004]
[Problems to be solved by the invention]
Both the conventional tank pressurization method and pump method have the following problems.
That is, in the tank pressurization method, when the traveling speed of the moving vehicle accelerates or decelerates and the spraying speed by the spraying device changes when the tank internal pressure is constant, the tank internal pressure also changes following the speed change. However, the internal pressure change of the tank is slow and the responsiveness is not very good, and it is difficult to increase the internal pressure by laws and structures. Therefore, since it is impossible to cope with a change in the traveling speed of the moving vehicle, it is not always possible to expect a certain amount of emulsion dispersion.
[0005]
In the case of a pump system, the emulsion discharge amount is changed according to the number of revolutions of the pump, so that the driving state of the pump is changed even if the traveling speed of the moving vehicle is accelerated or decelerated or the spraying width is changed. It is possible to correspond relatively accurately only by controlling. However, asphalt emulsion, the discharge amount changes greatly even with the same pump rotation depending on the properties (especially viscosity), especially when the moving vehicle is low speed, because the pump rotates at low speed, the discharge amount due to viscosity is greatly affected, A certain amount of spraying conditions cannot be met. Also, asphalt emulsions vary greatly in viscosity due to changes in type and temperature, so it is difficult to always control a certain amount of spraying conditions even with a pump system.
In addition, when using the pump system, gear pumps are almost always used to discharge asphalt emulsions. However, gear pumps have poor volumetric efficiency, and when there is a change in viscosity or pressure in the emulsion, the discharge rate is constant even when rotating. Changes, so a certain amount of spraying conditions cannot be met.
Accordingly, it is an object of the present invention to always spray a constant amount regardless of the conditions of the emulsion, and without being affected by changes in speed, spread width and pressure of the moving vehicle. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an asphalt emulsion storage tank and a spray device are installed in a moving vehicle, and an asphalt emulsion feed line is provided between the storage tank and the spray device. The asphalt emulsion supply pump is provided in the middle of the feed line, and is installed between the feed line between the feed pump and the spray device, and between the storage tank and the spray device. A bypass line having a pressure regulating valve is connected between the return line and a pipe line including a storage tank is formed, and when the pressure in the feed line becomes higher than a set value, the pressure regulating valve the bitumen emulsion feed line is supplied to the storage tank from the bypass line and return line, by controlling the driving of the supply pump, pump and spraying Controlling the pressure of the feed line between the location, characterized in that the application rate of bitumen emulsion discharged from spraying apparatus so and constant.
[0007]
In the invention according to claim 2 of the present application, an asphalt emulsion storage tank and a dispersion device are installed in a moving vehicle, and an asphalt emulsion feed line and a return line are connected between the storage tank and the dispersion device. And an asphalt emulsion supply pump provided in the middle of the feed line, and between a feed line between the supply pump and the spraying device and a return line installed between the storage tank and the spraying device. A bypass line with a pressure regulating valve is connected to form a pipeline including a storage tank, and when the pressure in the spraying device becomes higher than a set value, the pressure regulating valve removes the asphalt emulsion in the feed line. supplies to the storage tank from the bypass line and return line, by controlling the driving of the supply pump to control the pressure of the spraying device, spraying device Always characterized by being adapted to a constant application rate of bitumen emulsions et discharged.
[0008]
Further, according to a third aspect of the present invention, in the first or second aspect, the driving state of the asphalt emulsion supply pump is controlled by a speed signal of a moving vehicle and a pressure signal of an injection nozzle of the asphalt emulsion. It is the composition which is done.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below based on the embodiments shown in the drawings.
FIG. 1 is a schematic system diagram showing an embodiment of the present invention. A moving vehicle (not shown) for spraying asphalt emulsion is provided with a storage tank 1 for asphalt emulsion and a spraying apparatus 2 for asphalt emulsion. ing. As the moving vehicle, an asphalt distributor is representative, and it can be applied to an asphalt finisher.
[0010]
The spraying device 2 has a configuration in which a spray bar 22 is provided at the tip of the branch pipe 21 and a plurality of spray nozzles 23 are provided in parallel on the spray bar 22.
[0011]
An asphalt emulsion feed line 3 and a return line 4 are connected to the storage tank 1 and the spraying device 2, and an emulsion pump 5 is provided in the middle of the feed line. The suction side feed line 31 is between the two and the discharge side feed line 32 is between the pump 5 and the spraying device 2.
[0012]
By connecting the bypass line 6 between the discharge side feed line 32 and the return line 4 and providing the pressure regulating valve 7 in the middle of the bypass line 6, the discharge side feed line 32 becomes higher than the set pressure. In this case, a part of the emulsion flowing through the discharge-side feed line 32 can be returned from the return line 4 to the storage tank 1 by the operation of the pressure regulating valve 7.
[0013]
In addition, a filter 33 is provided in the middle of the suction side feed line 31, and a three-way switching valve 34 is provided at a connecting portion of the feed line 3, the return line 4 and the spraying device 2, and usually the emulsion in the feed line 3 is sprayed. In the state where the pump 5 is driven but the spraying device 2 is not operated, the three-way switching valve 34 is switched to circulate the emulsion in the feed line 3 from the return line 4 to the storage tank 1.
[0014]
The moving vehicle is provided with a control box 8, the control box 8 is provided with a control unit 9 and a calculation unit 10 electrically connected to the control unit 9, and a motor 51 for driving the pump 5 and the control unit 9 is electrically connected. Further, a drive adjustment mechanism 52 of the pump 5 is connected to the control unit 9.
[0015]
The discharge side feed line 32 is provided with a pressure gauge 11 for detecting and displaying the pressure of the asphalt emulsion flowing in the line 32, and a pressure signal from the pressure gauge 11 is input to the calculation unit 10.
[0016]
The calculation unit 10 is connected to the spray amount adjusting means 12 of the spray device 2 and is also supplied with the output signal of the drive detector 53 of the pump 5, and the nozzle signal 13 of the nozzle to be used, the speed of the moving vehicle. A signal 14 can be input.
[0017]
The spraying amount adjusting means 12 sets the spraying amount of the asphalt emulsion per unit area from the spraying device 2 and is manually input. The nozzle signal 13 related to the type of nozzle is manually input as a coefficient between the injection pressure and the injection amount at which the emulsion is injected from the injection port of each nozzle, and the speed signal 14 is continuously detected by detecting the speed of the moving vehicle. Automatically. The drive adjustment mechanism 52 from the control unit 9 to the pump 5 is a valve that adjusts the oil amount to the motor 51 if the pump 5 is a hydraulic pump, and an inverter control unit if the pump 5 is an electric pump. Can be achieved.
[0018]
Since the speed signal 14 of the moving vehicle is related to the spray amount of the spraying device 2, the speed signal 14 is input from the speed sensor of the moving vehicle to the calculation unit 10.
[0019]
The present invention is configured as described above, and before working with a moving vehicle, in order to set the spray amount per unit area of the emulsion, the spray amount is input from the spray amount adjusting means 12 to the calculation unit 10. Further, the drive state of the pump 5 is input from the drive adjustment mechanism 52 to the control unit 9 and the nozzle signal 13 is input to the calculation unit 10. The spray amount means that the internal pressure of the discharge side feed line 32 is set.
[0020]
When the preliminary input operation is completed, a predetermined emulsion is supplied to the storage tank 1 and the moving vehicle is transported to the work site. When the control unit 9 and the calculation unit 10 are operated, the pump 5 is driven by the motor 51 and moved. The vehicle is driven and the emulsion is pumped to the feed line 3, and a set amount of emulsion is sprayed from each spray nozzle 23 of the spraying device 2.
[0021]
As described above, the spray amount and the pump driving status are input and set in advance, the nozzle signal is input, and the speed signal 14 is continuously input to the calculation unit 10 when the moving vehicle is traveling. . Then, based on this input signal, the arithmetic unit 10 inputs a control signal to the control unit 9, and the control unit 9 controls the operation of the pump 5 by controlling the driving of the motor 51, so that the speed of the moving vehicle changes. Even if the temperature of the spray nozzle changes, the viscosity of the emulsion changes, the spread width changes, and the number of nozzles changes, the internal pressure of the discharge side feed line 32 is kept constant, and each spray of the spray device 2 The amount of the emulsion sprayed from the nozzle 23 per unit area can be made constant.
[0022]
Since the pressure gauge 11 always detects the internal pressure of the discharge-side feed line 32 and inputs it to the calculation unit 10 when the mobile vehicle is traveling, a pressure larger than the set spraying amount stored in the calculation unit 10 is applied. When it occurs in the discharge side feed line 32, the arithmetic unit 10 inputs a control signal to the control unit 9 to control the rotation of the motor 51, weakens the drive of the pump 5, and the amount of emulsion to be pumped to the discharge side feed line 32. Reduce the spray amount to the set amount.
[0023]
Moreover, when the internal pressure of the discharge side feed line 32 becomes smaller than the set pressure, the spraying amount decreases. In this case, when the signal of the pressure gauge 11 is input to the calculation unit 10, the control unit 9 controls the motor 51 so as to increase the rotation of the pump 5, thereby increasing the drive of the pump 5 and pumping the emulsion to the discharge side feed line 32. The amount is increased and the amount sprayed from the injection nozzle is increased to maintain the set amount.
[0024]
Thus, according to the present invention, by constantly detecting the internal pressure of the discharge side feed line and making it constant, the nozzle has a fixed relationship between the discharge pressure and the flow rate even if the viscosity of the asphalt emulsion changes. Since the emulsion spraying amount from the spray nozzle of the spraying device is made constant, even if the emulsion viscosity changes due to temperature change, or the traveling speed of the moving vehicle changes, the spraying amount per unit area remains constant Therefore, even when the driving state of the pump is controlled in order to achieve this, it is possible to always act appropriately.
[0025]
Another embodiment of the present invention shown in FIG. 2 has a configuration in which the emulsion pressure is controlled in the emulsion flow path in the spraying device 2. That is, the pressure gauge 11 is connected to the branch pipe 21 and the spray bar 22 of the spraying device 2 to display the emulsion pressure, and the pressure signal is input to the calculation unit 10 to keep the spraying amount of the emulsion constant. .
[0026]
In the embodiment shown in FIG. 1, it is necessary to calculate the pressure loss at the feed line 3 and the spraying device 2. However, in the embodiment shown in FIG. There is no need to do so, and it is possible to guarantee a highly accurate and highly accurate application rate.
The reference numerals not described in FIG. 2 have the same configuration as the same reference numerals in FIG.
[0027]
Although the present invention has been described above based on the embodiments shown in the drawings, the present invention is not limited to the above-described embodiments, and can be implemented in any way as long as the configuration described in the claims is not changed. be able to. For example, the arithmetic unit 10 can be input with another signal for controlling the pressure of the asphalt emulsion.
[0028]
【The invention's effect】
In short, according to the present invention, asphalt emulsion storage tank and spraying device are installed in a moving vehicle, and the asphalt emulsion feed line and return line are connected to the storage tank and spraying device. An asphalt emulsion supply pump is provided on the way, and by controlling the drive of the supply pump, the pressure of the feed line between the pump and the spraying device is controlled to control the amount of asphalt emulsion discharged from the spraying device. It is characterized by being always constant.
[0029]
Therefore, the amount of asphalt emulsion can be kept constant by pressure control so that the amount can be maintained reliably, and it can be set even if the viscosity of the emulsion changes with temperature or the speed of the moving vehicle changes. The amount of spraying can be guaranteed.
[0030]
By controlling the pressure in the spraying device, the spraying amount can be made constant with high accuracy without calculating the pressure loss in the emulsion flow path.
[0031]
A bypass line is connected between the feed line and the return line between the supply pump and the spraying device, and a pressure regulating valve is provided. When the pressure in the feeding line becomes higher than the setting, the pressure regulating valve Since the asphalt emulsion in the feed line is supplied from the bypass line to the return line, the flow of the asphalt emulsion becomes faster and the spraying amount can be maintained constant mechanically.
[0032]
In addition, the driving state of the asphalt emulsion supply pump is controlled by the speed signal of the moving vehicle and the pressure signal of the injection nozzle of the asphalt emulsion, which can improve the reliability of the spray amount of the emulsion. Such a configuration has great practical value.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing an embodiment of the present invention.
FIG. 2 is a schematic system diagram showing another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Storage tank 2 Spreading device 3 Feeding line 4 Return line 5 Pump 6 Bypass line 7 Pressure adjustment valve 8 Control box 9 Control part 10 Calculation part 11 Pressure gauge 12 Spreading amount adjustment means 13 Nozzle signal 14 Speed signal 21 Branch pipe 22 Spray bar 23 injection nozzle 31 suction side feed line 32 discharge side feed line 33 filter 34 three-way switching valve 51 motor 52 drive adjustment mechanism 53 drive detector

Claims (3)

Asphalt emulsion storage tank and spraying device are installed in the moving vehicle, asphalt emulsion feed line and return line are connected between the storage tank and spraying device, and asphalt emulsion supply in the middle of the feed line For the pump,
A pipe including a storage tank by connecting a bypass line having a pressure regulating valve between a feed line between the supply pump and the spraying device and a return line installed between the storage tank and the spraying device. Forming a path, and when the pressure in the feed line becomes higher than a set value, the pressure regulating valve supplies the asphalt emulsion of the feed line from the bypass line and the return line to the storage tank;
By controlling the driving of the supply pump, the pressure of the feed line between the pump and the spraying device is controlled, and the spraying amount of the asphalt emulsion discharged from the spraying device is always kept constant. Asphalt emulsion spraying amount control device. Asphalt emulsion storage tank and spraying device are installed in the moving vehicle, asphalt emulsion feed line and return line are connected between the storage tank and spraying device, and asphalt emulsion supply in the middle of the feed line For the pump,
A pipe including a storage tank by connecting a bypass line having a pressure regulating valve between a feed line between the supply pump and the spraying device and a return line installed between the storage tank and the spraying device. Forming a path, and when the pressure in the spraying device is higher than a set value, the pressure regulating valve supplies the asphalt emulsion of the feed line from the bypass line and the return line to the storage tank,
Control of the supply pump to control the pressure of the spraying device so that the spraying amount of the asphalt emulsion discharged from the spraying device is always constant. apparatus. The asphalt emulsion spray amount control device according to claim 1 or 2, wherein a driving state of the asphalt emulsion supply pump is controlled by a speed signal of a moving vehicle and a pressure signal of an injection nozzle of the asphalt emulsion.

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