JP3995366B2 - Screed heating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screed heating device for heating a screed in a screed device used in a road paving vehicle such as an asphalt finisher.
[0002]
[Prior art]
In a screed device that smoothes the paving surface by spreading asphalt heating mixture etc., to prevent the mixture etc. from adhering to the screed plate, and to iron the paving surface smoothly, etc. It is necessary to heat the screed comprising the screed plate. The screed plate is one of the components of the screed device, and acts as a trowel when the asphalt heating mixture or the like is spread and the pavement surface is finished smoothly.
[0003]
Conventionally, as this type of screed heating device, for example, there is a combustor type screed heating device with a blower whose gas piping diagram is shown in FIG. In this combustor-type screed heating device with a blower, when the main cock 71 is opened, gas supply proceeds from the LPG cylinder 70 to the front of the electromagnetic on-off valve 72. When the electromagnetic on-off valve 72 is energized, the electromagnetic on-off valve 72 opens. Thus, the gas supply proceeds to the front of the manual cocks 73, 74, 75, 76. Here, if the manual cocks 73, 74, 75, 76 are opened, gas is supplied to the combustors 83, 84, 85, 86. If an ignition operation is performed in the combustors 83-86, the gas is combusted and hot air is generated. . This hot air is blown to the screed plate by the air blown from the blowers 93, 94, 95, 96, and the screed is heated.
[0004]
In such a conventional screed heating apparatus, the supply amount of gas to the combustors 83 to 86 with a blower is constant during the operation with the set supply amount. The gas supply amount is set in consideration of weather conditions such as outside air temperature, work environment, etc., every season or every work day. In addition, the air flow rate is set accordingly. If the supply amount of gas is constant, the amount of hot air generated by burning the gas is also constant. Accordingly, the screed can be heated in a constant state by blowing a constant amount of hot air by a constant amount of air.
[0005]
[Problems to be solved by the invention]
However, in the conventional burner-type screed heating device with a blower, when the screed can be heated to the optimum temperature, the manual cocks 73 to 76 are operated to stop the gas supply by the operator's judgment, and the screed is heated. Is stopped. The optimum heating temperature of the screed varies depending on the working conditions and the like, but is a temperature at which the mixture does not adhere to the screed plate, smooth laying can be performed, and the screed does not become too hot. Further, when the screed has cooled, the manual cocks 73 to 76 are operated according to the judgment of the operator, the supply of gas is resumed, and the heating is performed again. For this reason, in order to keep the screed at the optimum temperature, it is necessary to repeat the gas supply / stop operation at the operator's discretion. Therefore, in the conventional screed heating device, the operator must always pay attention to the screed temperature, and the operation of the manual cocks 73 to 76 is also required every time the gas is supplied / stopped. large.
[0006]
In addition, since the temperature of the screed can be raised only in a constant heating state, if the operator misses the timing of the heating stop operation, the screed continues to be heated even if it exceeds the optimum temperature and becomes overheated. . Further, in the work in a cold district or the like, when the heating is stopped, the screed is rapidly cooled, and thus the screed may continue to be heated. In such a case, the screed is overheated. If the operation is repeated while the screed is still overheated, the screed plate wears faster and the life of the screed plate is shortened.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve such problems, and in a screed heating apparatus that heats a screed that spreads a heating mixture and smoothes a paved surface, heats the screed by burning fuel. , A first fuel supply path for controlling the supply of the fuel to the combustor by a valve, for example, an electromagnetic valve, and a first fuel supply path in parallel with the first fuel supply path, for example, by a throttle valve A second fuel supply path through which a predetermined amount of fuel flows and a valve of the first fuel supply path when a predetermined time has elapsed to stop or greatly reduce the flow of fuel through the first fuel supply path reduction is, that suppresses the controller to the amount of the sum of the amount and the predetermined amount that has been reduced by a predetermined amount or a first fuel supply path to the fuel supply amount of the second fuel supply passage to the combustor, the combustor A blower that blows the generated hot air onto the screed, and the controller controls the blower together with the valve to control the amount of blown air according to the amount of generated hot air when the predetermined time has elapsed. It is characterized by.
[0008]
In such a configuration, when the valve is controlled and opened by the controller, fuel is supplied to the combustor through the first fuel supply path and the second fuel supply path. Since the flow rate of the fuel flowing through the second fuel supply path is suppressed to a predetermined amount, most of the fuel supply to the combustor is performed via the first fuel supply path. When an ignition operation is performed in the combustor that has been supplied with fuel, the fuel burns to generate hot air, and the screed is heated.
[0009]
When a predetermined time has elapsed and the screed temperature reaches the optimum temperature, the controller controls the valve to stop or significantly reduce the flow of fuel through the first fuel supply path. Accordingly, the amount of fuel supplied to the combustor is reduced to a predetermined amount flowing through the second fuel supply path, and the amount of hot air generated in the combustor is reduced. Accordingly, the temperature of the screed does not increase thereafter and is maintained at the optimum temperature.
[0010]
Moreover, co the controller is predetermined time elapses, and also controls the blower together with the valve of the first fuel supply path, the blower reduces the air volume to the air blowing amount commensurate with the amount of supply of fuel.
[0011]
Further, the present invention is characterized in that the controller operates the blower until a predetermined time has elapsed even after the heating operation of the combustor is stopped. In such a configuration, although the heating operation of the combustor is stopped, the blower continues to blow until a predetermined time elapses, thereby cooling the screed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment in which the screed heating apparatus according to the present invention is applied to a screed apparatus for an asphalt finisher will be described.
[0013]
The asphalt finisher is a road paving vehicle comprising a main body portion having a hopper for stacking an asphalt heating mixture, and a screed device that is pulled by the main body and spreads the asphalt heating mixture and finishes the paved surface smoothly.
[0014]
FIG. 1 is a fuel piping diagram of the screed heating apparatus according to the present embodiment. The gas supply path from the LPG cylinder 10 to the combustors 5, 6, 7, and 8 with the blower passes through the main cock 9 and the electromagnetic opening / closing valve 1 and then branches into two paths, one of which has the electromagnetic opening / closing valve 2. The other fuel supply path α is the second fuel supply path β having the throttle valve 3 provided in parallel with the first fuel supply path α. The two paths α and β are merged again after passing through the electromagnetic on-off valve 2 and the throttle valve 3 to form one path. The combined path is then divided into four paths by the manifold 4 and each of the combustors 5, 6, 6 with blowers via manual cocks 15, 16, 17, 18 and throttle valves 11, 12, 13, 14. 7 and 8 are distributed.
[0015]
The electromagnetic on-off valve 1 controls the supply of gas flowing from the LPG cylinder 10 through the original cock 9. The electromagnetic on-off valve 2 controls the flow of gas using the path α as a supply path. The throttle valve 3 suppresses the gas flow using the path β as a supply path to a predetermined amount. The combustors 5, 6, 7, and 8 with the blower send the wind for blowing hot air to the screed to the portions of the combustors 5 a, 6 a, 7 a, and 8 a that combust the supplied gas to generate hot air. , 6b, 7b, 8b. The blowers 5b, 6b, 7b, 8b are configured by fans 5c, 6c, 7c, 8c that rotate and send wind and motors 5m, 6m, 7m, 8m shown in FIG.
[0016]
FIG. 2 is an electric circuit diagram of the screed heating device according to the present embodiment. When a predetermined time has elapsed, the electromagnetic on-off valve 2 is controlled to stop the flow of fuel through the first fuel supply path α. FIG. 3 is a diagram illustrating a configuration of a controller that suppresses the amount of fuel supplied to the combustors 5a to 8a to a predetermined amount by a second fuel supply path β.
[0017]
The motors 5m, 6m, 7m, and 8m and the a contacts 31a, 32a, 33a, and 34a of the power supply off-delay timers 31, 32, 33, and 34 are connected in series via a power supply. The a contacts 31a to 34a are closed when the power-off delay timers 31 to 34 are energized, and energize the motors 5m to 8m. The power-off delay timers 31 to 34 open the a contacts 31a to 34a when a predetermined time elapses after the energization is cut off.
[0018]
The resistor 27 and the contact a 26a of the power-on delay timer 26 and the motors 5m to 8m are connected in parallel to the power source. The power-on delay timer 26 closes the a contact 26a and opens the b contact 26b when a predetermined time has elapsed after being energized. The timers of the power-on delay timer 26 and the power-off delay timers 31 to 34 can be arbitrarily set.
[0019]
The power-on delay timer 26 and the a contacts 31a to 34a are connected in series. When the a contacts 31a to 34a are closed, the power on delay timer 26 is energized. Each gas / blower switch 21, 22, 23, 24 and the relay 25 are connected in series via a power source. The relay 25 closes the a contact 25a when energized. The a contact 25a is connected in series with the solenoid 1s via a power source, and is also connected in series with the solenoid 2s and the b contact 26b. Further, the solenoid 1s, the solenoid 2s and the b contact 26b are connected in parallel.
[0020]
The gas / blower switches 21 to 24 and the power-off delay timers 31 to 34 are connected in series. The gas / blower switches 21, 22, 23, 24, the ignition switches 41, 42, 43, 44, the igniters 51, 52, 53, 54, and the spark plugs 61, 62, 63, 64 are connected in series. Yes. Further, the ignition switches 41 to 44, the igniters 51 to 54, the spark plugs 61 to 64, and the power supply off-delay timers 31 to 34 are connected in parallel, respectively. The ignition switches 41 to 44 control energization to the igniters 51 to 54 which are ignition devices, and when the igniters 51 to 54 are energized, the spark plugs 61 to 64 are discharged to make a spark fly.
[0021]
In such a configuration, when the main cock 9 is opened, the gas in the LPG cylinder 10 advances to the front of the electromagnetic on-off valve 1. When the battery relay switch 28 is closed and the gas / blower switches 21 to 24 are closed, the relay 25 is energized and the contact a 25a is closed. When the a contact 25a is closed, the solenoid 1s of the electromagnetic on-off valve 1 is energized, the electromagnetic on-off valve 1 is opened, and the gas from the LPG cylinder 10 further advances.
[0022]
When the gas / blower switches 21 to 24 are closed, the power-off delay timers 31 to 34 are energized, and the a contacts 31a to 34a are closed. When the a contacts 31a to 34a are closed, the motors 5m to 8m are energized to rotate the fans 5c to 8c, and air blowing to the combustors 5a to 8a is started.
[0023]
When the a contacts 31a to 34a are closed, the power-on delay timer 26 is also energized, and the b contact 26b is closed until the time set in the timer elapses and the solenoid 2s of the electromagnetic on-off valve 2 is energized. When the solenoid 2s is energized, the electromagnetic on-off valve 2 is opened, and the gas supply from the LPG cylinder 10 proceeds to the front of the manual cocks 15 to 18 through the path α. The gas passing through the path β without passing through the path α also travels to the front of the manual cocks 15 to 18.
[0024]
Here, when the manual cocks 15 to 18 are opened, gas is supplied to the combustors 5 to 8 with a blower. When the ignition switches 41 to 44 are closed and the igniters 51 to 54 are energized, the spark plugs 61 to 64 are discharged. , Fly sparks. As a result, gas is ignited in the combustors 5a to 8a, combustion starts, and hot air is generated. The generated hot air is blown to the screed plate by the air blown from the blowers 5b to 8b, and the screed is heated. The amount of air blown from the blowers 5b to 8b at this time is set in advance according to the number of rotations of the fans 5c to 8c so as to match the amount of generated hot air. Heating in this state continues until the time set in the timer of the power-on delay timer 26 elapses.
[0025]
When the time set in the timer of the power-on delay timer 26 elapses, the b contact 26b is opened, the energization to the solenoid 2s is cut off, and the electromagnetic switching valve 2 is closed. Accordingly, the gas supply path α is cut off, and the gas supply path to the blower-equipped combustors 5 to 8 is only the path β through the throttle valve 3. If only the supply through the throttle valve 3 is performed, the amount of gas supplied to the blower-equipped combustors 5 to 8 is reduced to a predetermined amount, and the amount of generated hot air is also reduced accordingly.
[0026]
When the time set in the power-on delay timer 26 elapses, the contact a 26a is closed and the resistor 27 is energized. For this reason, the energization current to the motors 5m to 8m is shunted to the resistor 27 and is reduced. As a result, the rotational speed of the fans 5c to 8c is reduced and the blown amount is reduced. That is, when the amount of generated hot air decreases, the amount of blown air also decreases, so the screed heating state does not lower the current temperature due to the reduced amount of hot air and air blown from the heated state where the screed temperature is vigorously increased. It switches to the heat insulation state to maintain as follows. As a result, the screed continues to be kept at a constant temperature without increasing the temperature thereafter.
[0027]
Here, the heat retention temperature is set in advance to the optimum temperature of the screed, and the adjustment of the throttle amount of the throttle valve 3 and the resistance value of the resistor 27 so that the amount of hot air and the amount of air necessary to maintain the temperature are obtained. Is selected in advance. In addition, when heating is performed with the amount of hot air and the amount of air blown before reducing the amount of time it takes to reach the optimum temperature after the start of heating, the calculated time is the power on delay timer. 26 timers are preset.
[0028]
At the end of the operation, the manual cocks 15 to 18 are closed, so that the combustion is stopped and no hot air is generated, and the screed heating is completed. Further, when the gas / blower switches 21 to 24 are turned off and the energization of the relay 25 is cut off, the energization of the solenoid 1s is cut off, the electromagnetic on-off valve 1 is closed, and the sources of the paths α and β are closed. However, even if the gas / blower switches 21 to 24 are turned off, the a contacts 31a to 34a are closed until the time set in the timers of the power-off delay timers 31 to 34 elapses, so that the fans 5b to 8b are operated. The air flow to the screed continues.
[0029]
In this embodiment, after the screed is heated to the optimum temperature, when the time set in the timer of the power-on delay timer 26 elapses, the path α is cut off and the fuel supply path becomes only the path β. As a result, the screed is kept at the optimum temperature. As a result, it is not necessary for the operator to always pay attention to the temperature management or to perform the gas supply / stop operation, and the amount of work is reduced. Also, if the operator is not involved in temperature management, the operator will not forget to turn off the heating, and the screed will not be overheated. Further, since the heating of the screed is automatically switched between the heating state and the heat retaining state, it is not necessary to keep heating the screed in order to avoid the temperature of the screed from dropping immediately in the operation in a cold district or the like. For this reason, even in this case, the screed is not overheated. Therefore, the wear of the screed plate is not accelerated by excessive heat, and the life of the screed plate is extended.
[0030]
Further, since the heat retention state of the screed is continued by the gas through the path β unless the gas / blower switches 21 to 24 are turned off, the screed can always be kept at the optimum temperature until the end of the work. Accordingly, a uniform leveling surface can be obtained at all times. Even if the gas / blower switches 21 to 24 are turned off, the air is blown to the screed until the time set in the power-off delay timers 31 to 34 elapses. The plate is cooled by blowing. For this reason, this structure also acts to extend the life of the screed plate.
[0031]
In the present embodiment, the case where the electromagnetic on-off valve 2 is completely closed when the time set in the timer of the power-on delay timer 26 has elapsed and the b-contact 26b is opened has been described. However, an electromagnetic proportional valve is used instead of the electromagnetic on-off valve 2, and when the b-contact 26b is opened, the opening of the electromagnetic proportional valve is slightly opened to greatly increase the amount of gas supplied via the path α. You may comprise so that it may reduce. In this case, the sum of the flow rate of the gas flowing as a result of the reduction by the path α and the flow rate of the gas throttled by the path β is set in advance to a gas flow rate necessary for keeping the screed. Even in such a case, the same effect as the above-described embodiment can be obtained.
[0032]
In the present embodiment, the case where the present invention is applied to a screed device of an asphalt finisher has been described. However, the present invention can be applied in the same manner as the above embodiment as long as the screed device includes a heating device. .
[0033]
【The invention's effect】
As described above, according to the present invention, the heating of the screed controlled by the air supply amount according to the amount of generated hot air by controlling the fuel supply valve and the blower automatically changes from the heated state to the heat retaining state. Therefore, it is not necessary for the operator to always pay attention to the temperature management of the screed, and it is not necessary to perform an operation for adjusting the temperature. As a result, the amount of work is reduced and the burden on the operator is reduced. In addition, the screed is not overheated and the screed wear is not accelerated by excessive heat, thereby extending the life of the screed. In addition, since the screed can be continuously kept at the optimum temperature, a uniform leveling surface can always be obtained until the end of the work.
[0034]
In addition, in a screed heating device equipped with a blower, if the blower continues to blow until a predetermined time has elapsed even after the heating operation of the combustor has stopped, the high temperature at the end of the leveling operation The screed can be cooled and the life of the screed can be extended.
[Brief description of the drawings]
FIG. 1 is a fuel piping diagram of a screed heating apparatus according to an embodiment of the present invention.
FIG. 2 is an electrical circuit diagram of a screed heating apparatus according to an embodiment of the present invention.
FIG. 3 is a fuel piping diagram of a conventional screed heating device of a combustor type with a blower.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 ... Electromagnetic on-off valve 1s, 2s ... Solenoid 3 ... Throttle valve 5, 6, 7, 8 ... Combustor 5a, 6a, 7a, 8a with a blower ... Combustor 5b, 6b, 7b, 8b ... Blower 5c, 6c 7c, 8c: Fans 5m, 6m, 7m, 8m ... Motor 9 ... Original cocks 15, 16, 17, 18 ... Manual cocks 21, 22, 23, 24 ... Gas / blower switch 25 ... Relay 25a ... Relay 25a Contact 26 ... Power on delay timer 26a ... a contact 26b of power on delay timer 26 ... b contact 27 of power on delay timer 26 ... Resistors 31, 32, 33, 34 ... Power off delay timers 31a, 32a, 33a, 34a ... a contacts 41, 42, 43, 44 of the power-off delay timers 31, 32, 33, 34 ... ignition switches 51, 52, 53, 54 ... igniters 61, 62, 3,64 ... spark plug

Claims (3)

In a screed heating apparatus for heating a screed that spreads a heating mixture and smoothes a paved surface, a combustor that generates hot air to burn the fuel and heat the screed, and supply of the fuel to the combustor A first fuel supply path controlled by a valve; a second fuel supply path provided in parallel to the first fuel supply path for flowing a predetermined amount of the fuel; and the valve when a predetermined time has elapsed. Is controlled to stop or significantly reduce the flow of the fuel through the first fuel supply path, and the amount of fuel supplied to the combustor is set to the predetermined amount or the first by the second fuel supply path. provided that suppresses controller to the amount of the sum of the amount and the predetermined amount that has been reduced by the fuel supply line, and a blower the hot air generated by the combustor is blown into the screed, the controller Screed heating device and controls also controls said predetermined time has elapsed the blower together with the valve in the air blowing amount corresponding to the generation amount of the hot air. In a screed heating apparatus for heating a screed that spreads a heating mixture and finishes a smooth paved surface, a combustor that generates hot air to burn the fuel and heat the screed, and supply of the fuel to the combustor A first fuel supply path controlled by a solenoid valve; a second fuel supply path provided in parallel to the first fuel supply path and allowing a predetermined amount of the fuel to flow through the throttle valve; and a predetermined time When the time elapses, the solenoid valve is controlled to stop or greatly reduce the flow of the fuel through the first fuel supply path, and the fuel supply amount to the combustor is set to the predetermined amount by the second fuel supply path. Or a controller that suppresses the sum of the amount reduced in the first fuel supply path and the predetermined amount, and a blower that blows the hot air generated in the combustor onto the screed. Wherein the controller screed heating apparatus and controlling the air blow rate corresponding to the generation amount of control to the hot air also between the predetermined time has elapsed the blower together with the solenoid valve. The screed heating device according to claim 1 or 2 , wherein the controller operates the blower until the predetermined time has elapsed even after the heating operation of the combustor is stopped.

Images