WO2016147948A1 - Internal-combustion engine and method of forcibly regenerating collecting device - Google Patents
Internal-combustion engine and method of forcibly regenerating collecting device Download PDFInfo
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- WO2016147948A1 WO2016147948A1 PCT/JP2016/057139 JP2016057139W WO2016147948A1 WO 2016147948 A1 WO2016147948 A1 WO 2016147948A1 JP 2016057139 W JP2016057139 W JP 2016057139W WO 2016147948 A1 WO2016147948 A1 WO 2016147948A1
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- fuel
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- injection valve
- fuel injection
- supply pipe
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
- F01N3/025—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/36—Arrangements for supply of additional fuel
Definitions
- the present invention relates to an internal combustion engine and a method for forcibly regenerating a collection device. More specifically, the present invention prevents fuel leakage from a fuel injection valve disposed in an exhaust pipe of the internal combustion engine, and the leaked fuel is crystallized.
- the present invention relates to an internal combustion engine that avoids clogging a nozzle of a fuel injection valve and a forced regeneration method for a collection device.
- PM partate matter contained in exhaust gas
- This collection device has a porous honeycomb structure, and when exhaust gas permeates through the porous wall, PM contained in the exhaust gas is collected and deposited on the porous wall.
- PM of a predetermined value or more accumulates on the porous wall and becomes clogged, the exhaust resistance increases.
- Patent Document 1 Japanese Patent Application Laid-Open No. 2010-106680
- Patent Document 2 An apparatus for performing forced regeneration control for removing combustion has been proposed.
- As means for increasing the temperature of the exhaust gas in the regeneration control of the collection device unburned fuel is supplied to the exhaust gas by direct injection from a fuel injection valve arranged in the exhaust pipe, and the unburned fuel is removed.
- a means using heat generated by oxidation with an oxidation catalyst arranged upstream of the collection device can be exemplified.
- the fuel injection valve arranged in the exhaust pipe is supplied with fuel whose pressure has been increased by the pressure feed pump. Even when the fuel is not injected, the fuel leaks from the injection port of the fuel injection valve due to this fuel pressure. There is a problem of getting out. Then, the fuel leaking from the nozzle hole of the fuel injection valve may crystallize and the nozzle hole may be clogged (coking phenomenon), which may cause a situation where fuel cannot be injected.
- an on-off valve is interposed between a pressure feed pump (supply pump) and a fuel injection valve, and the on-off valve opens when fuel is injected and stops fuel injection. When configured to close.
- the present invention has been made in view of the above problems, and its object is to prevent fuel leakage from a fuel injection valve arranged in an exhaust pipe of an internal combustion engine, and the leaked fuel is crystallized to produce fuel. It is an object of the present invention to provide a forced regeneration method for an internal combustion engine and a collection device that avoids clogging an injection nozzle.
- An internal combustion engine of the present invention for solving the above problems includes a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from a cylinder passes, and a storage for storing fuel injected from the fuel injection valve
- a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from a cylinder passes
- a storage for storing fuel injected from the fuel injection valve
- an internal combustion engine comprising a tank, a fuel supply pipe that connects the storage tank and the fuel injection valve, a pressure feed pump that pumps fuel to the fuel injection valve, and a control device that controls the fuel injection valve
- An opening / closing valve interposed in the fuel supply pipe between the fuel injection valve and the pressure feed pump, and the control device opens the opening / closing valve before the injection start time of the fuel injection valve,
- the fuel supply pipe is opened, and the control is performed to close the on-off valve and shut off the fuel supply pipe before the injection stop time of the fuel injection valve.
- the forced regeneration method of the collection device of the present invention for solving the above-described problem is directed to exhausting fuel from a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from the cylinder of an internal combustion engine passes.
- a forced regeneration method of a collection device that injects into a pipe and burns and removes particulate matter deposited on a collection device disposed downstream of the fuel injection valve and forcibly regenerates, at the start of forced regeneration,
- An on-off valve interposed between the fuel injection valve and a pressure pump for pumping fuel from the storage tank to the fuel injection valve via the fuel supply pipe is opened to open the fuel supply pipe, and the fuel is supplied to the fuel injection valve.
- the on-off valve is closed before the fuel injection from the fuel injection valve arranged in the exhaust pipe is stopped. Since a period during which the fuel injection valve is opened is provided even after the valve is closed, high-pressure fuel does not remain between the on-off valve and the fuel injection valve. That is, the pressure applied to the fuel injection valve can be made zero or the pressure can be made close to zero, and the fuel can be prevented from leaking from the nozzle of the fuel injection valve due to the remaining fuel pressure. As a result, it is possible to avoid the phenomenon (coking phenomenon) in which the fuel leaking from the nozzle of the fuel injection valve arranged in the exhaust pipe is crystallized and clogging the nozzle. The frequency of replacement and maintenance of the injection valve can be suppressed.
- FIG. 1 is an explanatory view illustrating a first embodiment of the internal combustion engine of the present invention.
- FIG. 2 is an explanatory view illustrating the operation of the fuel injection valve of FIG. 1, the operation of the on-off valve, and the relationship of the pressure of the fuel supply pipe between the fuel injection valve and the on-off valve.
- FIG. 3 is a flowchart illustrating the forced regeneration method of the collection device of the present invention.
- FIG. 4 is an explanatory view illustrating a second embodiment of the internal combustion engine of the present invention.
- FIG. 1 illustrates the configuration of the first embodiment of the engine 10 of the present invention.
- the engine 10 directly injects fuel into the exhaust pipe 23 from a fuel injection valve 32 disposed in the exhaust pipe 23 to forcibly regenerate the collection device 26.
- the intake air is sucked into the intake pipe 16 from the outside, is compressed by the compressor 18 of the turbocharger 17, becomes high temperature, and is cooled by the intercooler 19. Thereafter, the flow rate is adjusted by the intake throttle 20, and the air is drawn into the cylinder 13 from the intake valve 11 through the intake manifold 21.
- the exhaust gas is exhausted from the cylinder 13 through the exhaust valve 15 to the exhaust manifold 22 to the exhaust pipe 23 to drive the turbine 24 of the turbocharger 17. After that, it is purified by an oxidation catalyst 25 and a collection device 26 arranged in order from the downstream side of the turbine 24, and an SCR catalyst (not shown) and released to the atmosphere.
- a part of the exhaust gas is cooled by an EGR cooler 28 provided in the EGR passage 27 and then supplied to the intake pipe 16 by the EGR valve 29 and mixed with the intake air.
- particulate matter (hereinafter referred to as PM) accumulates in the collection device 26, and if the amount of PM deposited exceeds a predetermined amount, the exhaust resistance increases. Therefore, in this engine 10, continuous regeneration for oxidizing and removing PM spontaneously deposited on the collection device 26 with exhaust gas having a high temperature according to the operating state of the engine 10, and exhaust gas passing through the collection device 26. Forced regeneration is performed in which the temperature of the gas is forcibly increased to burn and remove the PM deposited on the collection device 26.
- This continuous regeneration occurs when the temperature of the exhaust gas becomes 250 ° C. or more due to the operating state of the engine 10, and the PM deposited on the collection device 26 by the oxidation action of nitrogen dioxide generated by the oxidation catalyst 25 is increased. It is oxidized and does not require special control.
- the fuel injection valve 32 disposed in the exhaust pipe 23 by the control device 31.
- the fuel is injected from the control, and the temperature of the exhaust gas passing through the collection device 26 is forcibly raised, so that the PM deposited on the collection device 26 is removed by combustion.
- the fuel is pumped up from the storage tank 33 by the pressure feed pump 34, and directly injected into the exhaust pipe 23 from the fuel injection valve 32 disposed in the exhaust pipe 23 via the fuel supply pipe 35.
- the temperature of the exhaust gas is raised. Since the ignition temperature of PM is as high as 600 degrees, the temperature of the exhaust gas passing through the collection device 26 during forced regeneration is raised to a high temperature of 600 degrees or more.
- the temperature of the exhaust gas is controlled so that the temperature of the exhaust gas does not exceed the upper limit of the heat resistance of the collecting device 26 by the temperature sensor 36 interposed between the oxidation catalyst 25 and the collecting device 26. It is adjusted by control.
- the pumping pump 34 Since the pumping pump 34 is connected to a crankshaft (not shown) of the engine 10 and is driven by the power of the engine 10, it is always driven when the engine 10 is in operation. For this reason, if fuel leaks from the injection port of the fuel injection valve 32 due to constant pressure of the pumped fuel on the fuel injection valve 32 and the leaked fuel crystallizes, the fuel injection valve. There is a possibility that a phenomenon (coking phenomenon) occurs in which the 32 nozzle holes are clogged.
- the engine 10 of the present invention is configured to include the on-off valve 40 interposed in the fuel supply pipe 35 between the fuel injection valve 32 and the pressure feed pump 34, and the control device 31 includes the fuel injection valve.
- the on / off valve 40 is opened before the injection start time t2 of 32 and the fuel supply pipe 35 is opened, and the on / off valve 40 is closed and the fuel supply pipe 35 is shut off before the injection stop time t4 of the fuel injection valve 32. It is configured to perform control.
- the on-off valve 40 is an electromagnetic valve that opens when the controller 31 is energized and opens the fuel supply pipe 35 and closes and shuts off the fuel supply pipe 35 when the energization is stopped.
- the on-off valve 40 may be a hydraulic valve.
- the on-off valve 40 may be disposed in the fuel supply pipe 35 between the fuel injection valve 32 and the pressure feed pump 34.
- the control device 31 is a control device that controls the injection of the fuel injection valve 32 in the forced regeneration described above, and also performs the injection control of the injector 14 in which the injection port is arranged in the cylinder 13.
- the control device that controls the on-off valve 40 may be a separate control device.
- FIG. 2 shows the relationship between the operation of the fuel injection valve 32 disposed in the exhaust pipe 23, the operation of the on-off valve 40, and the pressure of the fuel supply pipe 35 between the fuel injection valve 32 and the on-off valve 40. .
- the on-off valve 40 is energized and opened (turned on) at a valve opening time t1 set before the injection start time t2 when fuel is injected from the fuel injection valve 32 (turned on).
- the filling time ⁇ t1 between the valve opening time t1 and the injection start time t2 is preferably set to a time for filling the fuel supply pipe 35 between the fuel injection valve 32 and the on-off valve 40 with fuel. .
- the on-off valve 40 stops the injection of fuel from the fuel injection valve 32 (turns off). Energization is stopped and closed (turned off) at the valve closing time t3 set before the time t4.
- the on-off valve 40 when the on-off valve 40 is closed at the valve closing time t3 set before the injection stop time t4, the fuel pumped up by the pressure pump 34 is blocked by the on-off valve 40. Since the fuel is injected from the fuel injection valve 32 until the pressure release time ⁇ t2 between the valve closing time t3 and the injection stop time t4 has elapsed, the fuel supply between the fuel injection valve 32 and the on-off valve 40 As the fuel filling amount filled in the pipe 35 becomes zero, the pressure in the fuel supply pipe 35 becomes zero from the pressure P1. As a result, the fuel injection valve 32 is in a state where no fuel pressure is applied after the fuel injection is stopped.
- the pressure release time ⁇ t2 from the valve closing time t3 to the injection stop time t4 is set to a time when the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 becomes zero. desirable.
- the filling time ⁇ t1 and the pressure release time ⁇ t2 are set based on the amount of fuel filled in the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 at the time of fuel injection. It is proportional to the distance L1 of the fuel supply pipe 35 between the valve 32 and the valve 32. Therefore, the longer the distance L1, the longer the filling time ⁇ t1 and the pressure release time ⁇ t2.
- the filling time ⁇ t1 and the pressure release time ⁇ t2 may be equivalent.
- the on-off valve 40 is opened to open the fuel supply pipe 35 and fuel is supplied to the fuel injection valve 32. After the on-off valve 40 is opened, the fuel injection is performed. Injecting fuel from the valve 32.
- the step of closing the on-off valve 40 and shutting off the fuel supply pipe 35 to stop the supply of fuel to the fuel injection valve 32 and the on-off valve 40 are closed, and then the fuel injection Injecting fuel from the valve 32 and releasing the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32; and after releasing the pressure of the fuel supply pipe 35, the fuel injection valve 32 is injected. And stopping.
- step S10 the control device 31 determines whether or not the differential pressure ⁇ P1 detected by the differential pressure sensor 30 is greater than or equal to the start determination value Pa. If the differential pressure ⁇ P1 is less than the start determination value Pa in step S10, the amount of PM deposited on the collection device 26 is small and there is no need to perform forced regeneration, so this forced regeneration method is completed. On the other hand, if the differential pressure ⁇ P1 is greater than or equal to the start determination value Pa in step S10, the process proceeds to step S20.
- step S20 the control device 31 energizes the on-off valve 40 to perform control to open the on-off valve 40.
- the control device 31 counts the elapsed time t from the opening of the on-off valve 40, and proceeds to step S50 when the elapsed time t reaches the filling time ⁇ t1. Steps S20 to S40 are performed, that is, the fuel supply pipe 35 from the on-off valve 40 to the fuel injection valve 32 is filled with fuel by opening the on-off valve 40 before the fuel injection valve 32 for the filling time ⁇ t1. To do.
- step S50 the control device 31 conducts control to energize the fuel injection valve 32 and start injection of the fuel injection valve 32.
- unburned fuel is supplied to the exhaust gas, and the unburned fuel is oxidized by the oxidation catalyst 25, thereby raising the temperature of the exhaust gas. Then, the temperature of the exhaust gas is raised to 600 degrees, and the PM deposited on the collection device 26 is removed by combustion.
- the fuel is continuously injected from the fuel injection valve 32 until the injection is stopped in step S100, but it is determined whether or not the temperature T1 detected by the temperature sensor 36 exceeds the upper limit value Tmax. If the value exceeds the upper limit value Tmax, control for stopping the fuel injection from the fuel injection valve 32 may be performed.
- step S60 it is determined whether or not the differential pressure ⁇ P2 detected by the differential pressure sensor 30 by the control device 31 is less than the end determination value Pb. If the differential pressure ⁇ P2 is greater than or equal to the end determination value Pb in step S60, the process returns to step S50 and fuel injection from the fuel injection valve 32 is continued. On the other hand, if the differential pressure ⁇ P2 is less than the end determination value Pb in step S60, the process proceeds to step S70.
- step S70 the control device 31 performs control to stop energization of the on-off valve 40 and close the on-off valve 40.
- step S80 and step S90 the elapsed time t from when the control device 31 closes the on-off valve 40 is counted, and when the elapsed time t reaches the pressure release time ⁇ t2, the process proceeds to step S100.
- Steps S70 to S90 are performed, that is, by closing the on-off valve 40 before the fuel injection valve 32 for the pressure release time ⁇ t2, the fuel is blocked by the on-off valve 40 and the fuel is injected from the on-off valve 40.
- the supply of fuel to the fuel supply pipe 35 up to the valve 32 is stopped, and the fuel filled in the fuel supply pipe 35 from the on-off valve 40 to the fuel injection valve 32 is injected from the fuel injection valve 32, and the on-off valve 40 To the fuel injection valve 32, the pressure of the fuel supply pipe 35 is released to zero.
- step S100 the control device 31 performs control to stop energization of the fuel injection valve 32 and stop fuel injection from the fuel injection valve 32, and this forced regeneration method is completed.
- control may be performed to inject fuel from the fuel injection valve 32 until a preset regeneration time ⁇ t3 elapses.
- step S70 it is preferable to perform step S70 by calculating back the pressure release time ⁇ t2 so that step S100 is performed when the regeneration time ⁇ t3 is reached.
- the on-off valve 40 is closed before the fuel injection from the fuel injection valve 32 disposed in the exhaust pipe 23 is stopped.
- high-pressure fuel does not remain between the on-off valve 40 and the fuel injection valve 32. That is, since the pressure of the fuel applied to the fuel injection valve 32 can be made zero, it is possible to prevent the fuel from leaking from the injection port of the fuel injection valve 32 due to the fuel pressure.
- the pressure release time ⁇ t2 is set to the time when the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 becomes zero.
- the pressure is not necessarily zero, and the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 may be a pressure at which fuel does not leak from the injection port of the fuel injection valve 32.
- the pressure release time ⁇ t2 may be set to a time when the pressure of the fuel supply pipe 35 approaches zero.
- FIG. 4 illustrates the configuration of the second embodiment of the engine 10 of the present invention.
- the opening / closing valve 40 is arranged in a fuel supply pipe 35 in the vicinity of the fuel injection valve 32. According to this configuration, the distance L1 of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 can be made shorter than in the first embodiment, and the pressure release time ⁇ t2 can be further shortened.
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Abstract
An engine 10 is provided with an on-off valve 40 interposed in a fuel supply pipe 35 between a fuel injection valve 32 and a pressure-feed pump 34. A control device 31 is configured in such a way as to open the on-off valve 40 earlier than an injection start time t2 of the fuel injection valve 32, thereby opening the fuel supply pipe 35, and to close the on-off valve 40 earlier than an injection stop time t4 of the fuel injection valve 32, thereby shutting off the fuel supply pipe 35, and it is therefore possible to prevent fuel leaking from the fuel injection valve 32, which is disposed in an exhaust pipe 23 of the engine 10, and to prevent fuel that has leaked from crystallizing and clogging the fuel injection valve 32 injection port.
Description
本発明は、内燃機関及び捕集装置の強制再生方法に関し、より詳細には、内燃機関の排気管に配置された燃料噴射弁からの燃料漏れを防止して、漏れ出した燃料が結晶化して燃料噴射弁の噴口に詰まることを回避する内燃機関及び捕集装置の強制再生方法に関する。
The present invention relates to an internal combustion engine and a method for forcibly regenerating a collection device. More specifically, the present invention prevents fuel leakage from a fuel injection valve disposed in an exhaust pipe of the internal combustion engine, and the leaked fuel is crystallized. The present invention relates to an internal combustion engine that avoids clogging a nozzle of a fuel injection valve and a forced regeneration method for a collection device.
ディーゼルエンジンにおいては、排気ガスが通過する排気管に配置した捕集装置により、排気ガスに含有されるＰＭ（粒子状物質）を捕集している。この捕集装置は、多孔質のハニカム構造を有しており、排気ガスが多孔質の壁を透過した際に、排気ガスに含有したＰＭがその多孔質の壁に捕集されて堆積する。この多孔質の壁に所定値以上のＰＭが堆積して目詰りすると、排気抵抗が増加する。
In a diesel engine, PM (particulate matter) contained in exhaust gas is collected by a collection device arranged in an exhaust pipe through which the exhaust gas passes. This collection device has a porous honeycomb structure, and when exhaust gas permeates through the porous wall, PM contained in the exhaust gas is collected and deposited on the porous wall. When PM of a predetermined value or more accumulates on the porous wall and becomes clogged, the exhaust resistance increases.
そこで、例えば、日本出願の特開２０１０－１０６６８０号公報（特許文献１）に記載されているように、捕集装置を通過する排気ガスの温度を上昇させて、捕集装置に堆積したＰＭを燃焼除去する強制再生制御を行う装置が提案されている。この捕集装置の再生制御における排気ガスの温度を上昇させる手段としては、排気管に配置された燃料噴射弁からの直接噴射により、排気ガスへ未燃燃料を供給して、その未燃燃料を捕集装置の上流に配置された酸化触媒で酸化して発生する熱を利用した手段を例示できる。
Therefore, for example, as described in Japanese Patent Application Laid-Open No. 2010-106680 (Patent Document 1), the temperature of exhaust gas passing through the collection device is raised, and the PM deposited on the collection device is increased. An apparatus for performing forced regeneration control for removing combustion has been proposed. As means for increasing the temperature of the exhaust gas in the regeneration control of the collection device, unburned fuel is supplied to the exhaust gas by direct injection from a fuel injection valve arranged in the exhaust pipe, and the unburned fuel is removed. A means using heat generated by oxidation with an oxidation catalyst arranged upstream of the collection device can be exemplified.
しかし、排気管に配置された燃料噴射弁においては、圧送ポンプにより圧力が高くなった燃料が供給されており、燃料を噴射しない場合にも、この燃料圧力により燃料噴射弁の噴口から燃料が漏れ出るという問題が生じている。そして、燃料噴射弁の噴口から漏れ出た燃料が結晶化して噴口が詰まる現象（コーキング現象）により、燃料を噴射できなくなる事態に陥るおそれがある。
However, the fuel injection valve arranged in the exhaust pipe is supplied with fuel whose pressure has been increased by the pressure feed pump. Even when the fuel is not injected, the fuel leaks from the injection port of the fuel injection valve due to this fuel pressure. There is a problem of getting out. Then, the fuel leaking from the nozzle hole of the fuel injection valve may crystallize and the nozzle hole may be clogged (coking phenomenon), which may cause a situation where fuel cannot be injected.
特許文献１に記載の装置には、圧送ポンプ（サプライポンプ）と燃料噴射弁との間に開閉弁を介設しており、その開閉弁が燃料を噴射するときに開き、燃料の噴射を停止するときに閉じるように構成されている。
In the apparatus described in Patent Document 1, an on-off valve is interposed between a pressure feed pump (supply pump) and a fuel injection valve, and the on-off valve opens when fuel is injected and stops fuel injection. When configured to close.
しかし、燃料を噴射しないときに開閉弁を閉じても、開閉弁と燃料噴射弁との間に残留した圧力の高い燃料によって燃料噴射弁内の燃料には圧力が掛かり、燃料噴射弁の噴口から燃料が漏れ出てしまう。
However, even if the on-off valve is closed when fuel is not injected, the fuel in the fuel injection valve is pressurized by the high-pressure fuel remaining between the on-off valve and the fuel injection valve, and the fuel is injected from the nozzle of the fuel injection valve. Fuel leaks out.
本発明は、上記の問題を鑑みてなされたものであり、その課題は、内燃機関の排気管に配置された燃料噴射弁からの燃料漏れを防止して、漏れ出した燃料が結晶化して燃料噴射弁の噴口に詰まることを回避する内燃機関及び捕集装置の強制再生方法を提供することである。
The present invention has been made in view of the above problems, and its object is to prevent fuel leakage from a fuel injection valve arranged in an exhaust pipe of an internal combustion engine, and the leaked fuel is crystallized to produce fuel. It is an object of the present invention to provide a forced regeneration method for an internal combustion engine and a collection device that avoids clogging an injection nozzle.
上記の課題を解決するための本発明の内燃機関は、筒内から排出される排気ガスが通過する排気管に配置された燃料噴射弁と、該燃料噴射弁から噴射される燃料を貯蔵する貯蔵タンクと、該貯蔵タンク及び該燃料噴射弁を接続する燃料供給管と、該燃料噴射弁へ燃料を圧送する圧送ポンプと、該燃料噴射弁を制御する制御装置と、を備えた内燃機関において、前記燃料噴射弁と前記圧送ポンプとの間の前記燃料供給管に介設された開閉弁を備え、前記制御装置を、前記燃料噴射弁の噴射開始時刻よりも前に前記開閉弁を開いて前記燃料供給管を開放し、前記燃料噴射弁の噴射停止時刻よりも前に前記開閉弁を閉じて前記燃料供給管を遮断する制御を行う構成にしたことを特徴とするものである。
An internal combustion engine of the present invention for solving the above problems includes a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from a cylinder passes, and a storage for storing fuel injected from the fuel injection valve In an internal combustion engine comprising a tank, a fuel supply pipe that connects the storage tank and the fuel injection valve, a pressure feed pump that pumps fuel to the fuel injection valve, and a control device that controls the fuel injection valve, An opening / closing valve interposed in the fuel supply pipe between the fuel injection valve and the pressure feed pump, and the control device opens the opening / closing valve before the injection start time of the fuel injection valve, The fuel supply pipe is opened, and the control is performed to close the on-off valve and shut off the fuel supply pipe before the injection stop time of the fuel injection valve.
また、上記の課題を解決するための本発明の捕集装置の強制再生方法は、内燃機関の筒内から排出される排気ガスが通過する排気管に配置された燃料噴射弁から燃料を該排気管に噴射し、該燃料噴射弁よりも下流に配置された捕集装置に堆積された粒子状物質を燃焼除去して強制再生する捕集装置の強制再生方法において、強制再生の開始時に、前記燃料噴射弁と、貯蔵タンクから燃料供給管を経由して該燃料噴射弁へ燃料を圧送する圧送ポンプとの間に介設された開閉弁を開いて該燃料供給管を開放し、燃料を該貯蔵タンクから該燃料供給管を経由して該燃料噴射弁に供給するステップと、前記開閉弁を開いた後に、前記燃料噴射弁から燃料を噴射して前記排気管に燃料を供給するステップと、を含み、強制再生の停止時に、前記開閉弁を閉じて前記燃料供給管を遮断して、前記燃料噴射弁への燃料の供給を停止するステップと、前記開閉弁を閉じた後に、前記燃料噴射弁から燃料を噴射して、前記開閉弁と前記燃料噴射弁との間の前記燃料供給管の圧力を抜くステップと、前記燃料供給管の圧力を抜いた後に、前記燃料噴射弁の噴射を停止するステップと、を含むことを特徴とする方法である。
In addition, the forced regeneration method of the collection device of the present invention for solving the above-described problem is directed to exhausting fuel from a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from the cylinder of an internal combustion engine passes. In a forced regeneration method of a collection device that injects into a pipe and burns and removes particulate matter deposited on a collection device disposed downstream of the fuel injection valve and forcibly regenerates, at the start of forced regeneration, An on-off valve interposed between the fuel injection valve and a pressure pump for pumping fuel from the storage tank to the fuel injection valve via the fuel supply pipe is opened to open the fuel supply pipe, and the fuel is supplied to the fuel injection valve. Supplying the fuel injection valve from the storage tank via the fuel supply pipe; and after opening the on-off valve, injecting fuel from the fuel injection valve and supplying fuel to the exhaust pipe; And when the forced regeneration is stopped, the on-off valve Closing the fuel supply pipe to stop the supply of fuel to the fuel injection valve; closing the on-off valve; then injecting fuel from the fuel injection valve; A step of releasing the pressure of the fuel supply pipe between the fuel injection valve and a step of stopping the injection of the fuel injection valve after releasing the pressure of the fuel supply pipe. is there.
本発明の内燃機関及び捕集装置の強制再生方法によれば、排気管に配置された燃料噴射弁からの燃料の噴射を停止するよりも前に開閉弁を閉じることで、言い換えれば、開閉弁を閉じた後でも燃料噴射弁を開弁している期間を設けるので、開閉弁と燃料噴射弁との間に圧力の高い燃料を残留させることがない。すなわち燃料噴射弁に掛かる圧力をゼロにする、あるいは圧力をゼロに近づけることが可能になり、残留した燃料の圧力によって燃料噴射弁の噴口から燃料が漏れ出ることを防ぐことができる。これにより、排気管に配置された燃料噴射弁の噴口に漏れ出た燃料が結晶化して噴口が詰まる現象（コーキング現象）を回避できるので、燃料噴射弁から燃料を噴射できない不具合やコーキング現象による燃料噴射弁の交換や整備の頻度を抑制できる。
According to the forced regeneration method of the internal combustion engine and the collection device of the present invention, the on-off valve is closed before the fuel injection from the fuel injection valve arranged in the exhaust pipe is stopped. Since a period during which the fuel injection valve is opened is provided even after the valve is closed, high-pressure fuel does not remain between the on-off valve and the fuel injection valve. That is, the pressure applied to the fuel injection valve can be made zero or the pressure can be made close to zero, and the fuel can be prevented from leaking from the nozzle of the fuel injection valve due to the remaining fuel pressure. As a result, it is possible to avoid the phenomenon (coking phenomenon) in which the fuel leaking from the nozzle of the fuel injection valve arranged in the exhaust pipe is crystallized and clogging the nozzle. The frequency of replacement and maintenance of the injection valve can be suppressed.
以下、本発明の内燃機関及び捕集装置の強制再生方法について説明する。図１は、本発明のエンジン１０の第一実施形態の構成を例示している。このエンジン１０は、排気管２３に配置された燃料噴射弁３２から排気管２３の内部に直接燃料を噴射して、捕集装置２６の強制再生を行うものである。
Hereinafter, the forced regeneration method of the internal combustion engine and the collection device of the present invention will be described. FIG. 1 illustrates the configuration of the first embodiment of the engine 10 of the present invention. The engine 10 directly injects fuel into the exhaust pipe 23 from a fuel injection valve 32 disposed in the exhaust pipe 23 to forcibly regenerate the collection device 26.
このエンジン１０においては、運転中に吸気バルブ１１からピストン１２が往復する筒内１３に吸入された吸入空気と、インジェクタ１４から筒内１３に噴射された燃料とが混合されて燃焼して、排気ガスとなって排気バルブ１５から排気されている。
In the engine 10, during operation, the intake air sucked into the cylinder 13 where the piston 12 reciprocates from the intake valve 11 and the fuel injected from the injector 14 into the cylinder 13 are mixed and burned, and the exhaust gas is exhausted. The gas is exhausted from the exhaust valve 15.
吸入空気は、外部から吸気管１６へ吸入されて、ターボチャージャ１７のコンプレッサ１８により圧縮されて高温になり、インタークーラー１９で冷却されている。その後に、吸気スロットル２０により流量が調節されて、吸気多岐管２１を経て吸気バルブ１１から筒内１３に吸入されている。
The intake air is sucked into the intake pipe 16 from the outside, is compressed by the compressor 18 of the turbocharger 17, becomes high temperature, and is cooled by the intercooler 19. Thereafter, the flow rate is adjusted by the intake throttle 20, and the air is drawn into the cylinder 13 from the intake valve 11 through the intake manifold 21.
排気ガスは、筒内１３から排気バルブ１５を経由して排気多岐管２２から排気管２３へ排気されて、ターボチャージャ１７のタービン２４を駆動させている。その後に、タービン２４の下流から順に配置された酸化触媒２５及び捕集装置２６、並びに図示しないＳＣＲ触媒で浄化されて大気へと放出されている。また、排気ガスの一部は、ＥＧＲ通路２７に設けられたＥＧＲクーラー２８で冷却された後に、ＥＧＲバルブ２９により吸気管１６に供給されて吸入空気に混合されている。
The exhaust gas is exhausted from the cylinder 13 through the exhaust valve 15 to the exhaust manifold 22 to the exhaust pipe 23 to drive the turbine 24 of the turbocharger 17. After that, it is purified by an oxidation catalyst 25 and a collection device 26 arranged in order from the downstream side of the turbine 24, and an SCR catalyst (not shown) and released to the atmosphere. A part of the exhaust gas is cooled by an EGR cooler 28 provided in the EGR passage 27 and then supplied to the intake pipe 16 by the EGR valve 29 and mixed with the intake air.
排気ガスを浄化していくと捕集装置２６には、粒子状物質（以下、ＰＭという）が堆積し、そのＰＭの堆積量が所定量を超えると排気抵抗が増加してしまう。そこで、このエンジン１０においては、エンジン１０の運転状態に応じて温度の高い排気ガスで自然発生的に捕集装置２６に堆積したＰＭを酸化除去する連続再生と、捕集装置２６を通過する排気ガスの温度を強制的に昇温して捕集装置２６に堆積したＰＭを燃焼除去する強制再生とを行っている。
As the exhaust gas is purified, particulate matter (hereinafter referred to as PM) accumulates in the collection device 26, and if the amount of PM deposited exceeds a predetermined amount, the exhaust resistance increases. Therefore, in this engine 10, continuous regeneration for oxidizing and removing PM spontaneously deposited on the collection device 26 with exhaust gas having a high temperature according to the operating state of the engine 10, and exhaust gas passing through the collection device 26. Forced regeneration is performed in which the temperature of the gas is forcibly increased to burn and remove the PM deposited on the collection device 26.
この連続再生は、エンジン１０の運転状態により排気ガスの温度が２５０度以上になった場合に生じており、酸化触媒２５で生成された二酸化窒素の酸化作用により捕集装置２６に堆積したＰＭが酸化除去されており、特別な制御を必要としない。
This continuous regeneration occurs when the temperature of the exhaust gas becomes 250 ° C. or more due to the operating state of the engine 10, and the PM deposited on the collection device 26 by the oxidation action of nitrogen dioxide generated by the oxidation catalyst 25 is increased. It is oxidized and does not require special control.
また、強制再生においては、差圧センサ３０で検出された差圧ΔＰ１が予め設定された開始判定値Ｐａ以上になったときに、制御装置３１により、排気管２３に配置された燃料噴射弁３２から燃料を噴射する制御が行われて、捕集装置２６を通過する排気ガスの温度を強制的に昇温することで、捕集装置２６に堆積したＰＭが燃焼除去される。
Further, in the forced regeneration, when the differential pressure ΔP1 detected by the differential pressure sensor 30 becomes equal to or higher than a preset start determination value Pa, the fuel injection valve 32 disposed in the exhaust pipe 23 by the control device 31. The fuel is injected from the control, and the temperature of the exhaust gas passing through the collection device 26 is forcibly raised, so that the PM deposited on the collection device 26 is removed by combustion.
この強制再生では、燃料が、貯蔵タンク３３から圧送ポンプ３４により汲み上げられ、燃料供給管３５を経由して、排気管２３に配置された燃料噴射弁３２から排気管２３に直接噴射され、その未燃燃料が酸化触媒２５で酸化することによって、排気ガスの温度を昇温している。なお、ＰＭの着火温度は６００度と高温であることから、強制再生時に捕集装置２６を通過する排気ガスの温度を６００度以上の高温に昇温している。また、このとき、酸化触媒２５と捕集装置２６との間に介設された温度センサ３６により捕集装置２６の耐熱性の上限値を超えないように排気ガスの温度は気筒内における燃料噴射制御などにより調節されている。
In this forced regeneration, the fuel is pumped up from the storage tank 33 by the pressure feed pump 34, and directly injected into the exhaust pipe 23 from the fuel injection valve 32 disposed in the exhaust pipe 23 via the fuel supply pipe 35. As the fuel is oxidized by the oxidation catalyst 25, the temperature of the exhaust gas is raised. Since the ignition temperature of PM is as high as 600 degrees, the temperature of the exhaust gas passing through the collection device 26 during forced regeneration is raised to a high temperature of 600 degrees or more. At this time, the temperature of the exhaust gas is controlled so that the temperature of the exhaust gas does not exceed the upper limit of the heat resistance of the collecting device 26 by the temperature sensor 36 interposed between the oxidation catalyst 25 and the collecting device 26. It is adjusted by control.
圧送ポンプ３４は、エンジン１０の図示しないクランク軸に連結されてエンジン１０の動力によって駆動しているため、エンジン１０の運転時には常時駆動している。そのため、燃料噴射弁３２には、圧送された燃料の圧力が常時掛かることに起因して燃料噴射弁３２の噴口から燃料が漏れ出て、その漏れ出た燃料が結晶化してしまうと燃料噴射弁３２の噴口が詰まる現象（コーキング現象）が生じるおそれがある。
Since the pumping pump 34 is connected to a crankshaft (not shown) of the engine 10 and is driven by the power of the engine 10, it is always driven when the engine 10 is in operation. For this reason, if fuel leaks from the injection port of the fuel injection valve 32 due to constant pressure of the pumped fuel on the fuel injection valve 32 and the leaked fuel crystallizes, the fuel injection valve. There is a possibility that a phenomenon (coking phenomenon) occurs in which the 32 nozzle holes are clogged.
そこで、本発明のエンジン１０においては、燃料噴射弁３２と圧送ポンプ３４との間の燃料供給管３５に介設された開閉弁４０を備えて構成されると共に、制御装置３１が、燃料噴射弁３２の噴射開始時刻ｔ２よりも前に開閉弁４０を開いて燃料供給管３５を開放し、燃料噴射弁３２の噴射停止時刻ｔ４よりも前に開閉弁４０を閉じて燃料供給管３５を遮断する制御を行うように構成される。
Therefore, the engine 10 of the present invention is configured to include the on-off valve 40 interposed in the fuel supply pipe 35 between the fuel injection valve 32 and the pressure feed pump 34, and the control device 31 includes the fuel injection valve. The on / off valve 40 is opened before the injection start time t2 of 32 and the fuel supply pipe 35 is opened, and the on / off valve 40 is closed and the fuel supply pipe 35 is shut off before the injection stop time t4 of the fuel injection valve 32. It is configured to perform control.
開閉弁４０は、制御装置３１によって通電されると開いて燃料供給管３５を開放し、通電が停止されると閉じて燃料供給管３５を遮断する電磁弁で構成される。なお、この開閉弁４０は油圧弁で構成してもよい。また、開閉弁４０は、燃料噴射弁３２と圧送ポンプ３４との間の燃料供給管３５に配置されればよい。
The on-off valve 40 is an electromagnetic valve that opens when the controller 31 is energized and opens the fuel supply pipe 35 and closes and shuts off the fuel supply pipe 35 when the energization is stopped. The on-off valve 40 may be a hydraulic valve. The on-off valve 40 may be disposed in the fuel supply pipe 35 between the fuel injection valve 32 and the pressure feed pump 34.
制御装置３１は、上記に記載した強制再生における燃料噴射弁３２の噴射を制御する他、筒内１３に噴口が配置されたインジェクタ１４の噴射制御なども行っている制御装置である。なお、開閉弁４０を制御する制御装置を別体の制御装置としてもよい。
The control device 31 is a control device that controls the injection of the fuel injection valve 32 in the forced regeneration described above, and also performs the injection control of the injector 14 in which the injection port is arranged in the cylinder 13. The control device that controls the on-off valve 40 may be a separate control device.
図２は、排気管２３に配置された燃料噴射弁３２の動作と、開閉弁４０の動作と、燃料噴射弁３２及び開閉弁４０の間の燃料供給管３５の圧力との関係を示している。
FIG. 2 shows the relationship between the operation of the fuel injection valve 32 disposed in the exhaust pipe 23, the operation of the on-off valve 40, and the pressure of the fuel supply pipe 35 between the fuel injection valve 32 and the on-off valve 40. .
開閉弁４０は、燃料噴射弁３２から燃料が噴射される（オンになる）噴射開始時刻ｔ２よりも前に設定された開弁時刻ｔ１に通電されて開く（オンになる）。
The on-off valve 40 is energized and opened (turned on) at a valve opening time t1 set before the injection start time t2 when fuel is injected from the fuel injection valve 32 (turned on).
このように、開閉弁４０が噴射開始時刻ｔ２よりも前に設定された開弁時刻ｔ１に開かれると、貯蔵タンク３３から圧送ポンプ３４により汲み上げられた燃料が燃料供給管３５を経由して燃料噴射弁３２に供給され、燃料噴射弁３２及び開閉弁４０の間の燃料供給管３５の圧力を圧力Ｐ１まで上昇する。これにより、燃料噴射弁３２からの燃料噴射を可能にする。従って、開弁時刻ｔ１と噴射開始時刻ｔ２との間の充填時間Δｔ１は、燃料噴射弁３２と開閉弁４０との間の燃料供給管３５に燃料が充填される時間に設定されることが好ましい。
As described above, when the on-off valve 40 is opened at the valve opening time t1 set before the injection start time t2, the fuel pumped up from the storage tank 33 by the pressure pump 34 is supplied to the fuel via the fuel supply pipe 35. The pressure is supplied to the injection valve 32, and the pressure of the fuel supply pipe 35 between the fuel injection valve 32 and the on-off valve 40 is increased to the pressure P1. Thereby, fuel injection from the fuel injection valve 32 is enabled. Therefore, the filling time Δt1 between the valve opening time t1 and the injection start time t2 is preferably set to a time for filling the fuel supply pipe 35 between the fuel injection valve 32 and the on-off valve 40 with fuel. .
燃料噴射弁３２から燃料を噴射する強制再生により捕集装置２６に堆積したＰＭが燃焼除去された後に、開閉弁４０は、燃料噴射弁３２の燃料噴射が停止される（オフになる）噴射停止時刻ｔ４よりも前に設定された閉弁時刻ｔ３に通電が停止されて閉じる（オフになる）。
After the PM accumulated in the collecting device 26 is burned and removed by forced regeneration by injecting fuel from the fuel injection valve 32, the on-off valve 40 stops the injection of fuel from the fuel injection valve 32 (turns off). Energization is stopped and closed (turned off) at the valve closing time t3 set before the time t4.
このように、開閉弁４０が噴射停止時刻ｔ４よりも前に設定された閉弁時刻ｔ３に閉じると、圧送ポンプ３４により汲み上げられた燃料が開閉弁４０により堰止される。そして、閉弁時刻ｔ３から噴射停止時刻ｔ４までの間の圧力開放時間Δｔ２が経過するまで、燃料噴射弁３２から燃料が噴射されるので、燃料噴射弁３２と開閉弁４０との間の燃料供給管３５に充填されていた燃料の充填量がゼロになることに伴って、燃料供給管３５の圧力が圧力Ｐ１からゼロになる。これにより、燃料噴射弁３２は、燃料噴射が停止された後には燃料の圧力が掛からない状態となる。
Thus, when the on-off valve 40 is closed at the valve closing time t3 set before the injection stop time t4, the fuel pumped up by the pressure pump 34 is blocked by the on-off valve 40. Since the fuel is injected from the fuel injection valve 32 until the pressure release time Δt2 between the valve closing time t3 and the injection stop time t4 has elapsed, the fuel supply between the fuel injection valve 32 and the on-off valve 40 As the fuel filling amount filled in the pipe 35 becomes zero, the pressure in the fuel supply pipe 35 becomes zero from the pressure P1. As a result, the fuel injection valve 32 is in a state where no fuel pressure is applied after the fuel injection is stopped.
従って、閉弁時刻ｔ３から噴射停止時刻ｔ４までの間の圧力開放時間Δｔ２は、開閉弁４０と燃料噴射弁３２との間の燃料供給管３５の圧力がゼロになる時間に設定されることが望ましい。
Therefore, the pressure release time Δt2 from the valve closing time t3 to the injection stop time t4 is set to a time when the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 becomes zero. desirable.
充填時間Δｔ１及び圧力開放時間Δｔ２は、燃料の噴射時に開閉弁４０から燃料噴射弁３２までの間の燃料供給管３５に充填される燃料の充填量に基づいて設定され、開閉弁４０から燃料噴射弁３２までの間の燃料供給管３５の距離Ｌ１に比例する。そのため、距離Ｌ１が長いほど充填時間Δｔ１及び圧力開放時間Δｔ２は長くなる。なお、充填時間Δｔ１及び圧力開放時間Δｔ２は同等の時間になる場合もある。
The filling time Δt1 and the pressure release time Δt2 are set based on the amount of fuel filled in the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 at the time of fuel injection. It is proportional to the distance L1 of the fuel supply pipe 35 between the valve 32 and the valve 32. Therefore, the longer the distance L1, the longer the filling time Δt1 and the pressure release time Δt2. The filling time Δt1 and the pressure release time Δt2 may be equivalent.
次に、このエンジン１０における捕集装置２６の再生方法のうちの強制的に排気ガスの温度を昇温する強制再生方法について、図３のフローチャートを参照しながら説明する。
Next, a forced regeneration method for forcibly increasing the temperature of the exhaust gas among the regeneration methods of the collection device 26 in the engine 10 will be described with reference to the flowchart of FIG. *
この強制再生方法は、強制再生を開始する際に、開閉弁４０を開いて燃料供給管３５を開放し、燃料を燃料噴射弁３２に供給するステップと、開閉弁４０を開いた後に、燃料噴射弁３２から燃料を噴射するステップと、を含む。そして、強制再生を停止する際に、開閉弁４０を閉じて燃料供給管３５を遮断して、燃料噴射弁３２への燃料の供給を停止するステップと、開閉弁４０を閉じた後に、燃料噴射弁３２から燃料を噴射して、開閉弁４０と燃料噴射弁３２との間の燃料供給管３５の圧力を抜くステップと、燃料供給管３５の圧力を抜いた後に、燃料噴射弁３２の噴射を停止するステップと、を含む方法である。
In this forced regeneration method, when the forced regeneration is started, the on-off valve 40 is opened to open the fuel supply pipe 35 and fuel is supplied to the fuel injection valve 32. After the on-off valve 40 is opened, the fuel injection is performed. Injecting fuel from the valve 32. When stopping forced regeneration, the step of closing the on-off valve 40 and shutting off the fuel supply pipe 35 to stop the supply of fuel to the fuel injection valve 32 and the on-off valve 40 are closed, and then the fuel injection Injecting fuel from the valve 32 and releasing the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32; and after releasing the pressure of the fuel supply pipe 35, the fuel injection valve 32 is injected. And stopping.
まず、ステップＳ１０では、制御装置３１が、差圧センサ３０で検出した差圧ΔＰ１が開始判定値Ｐａ以上か否かを判定する。このステップＳ１０で差圧ΔＰ１が開始判定値Ｐａ未満の場合には、捕集装置２６に堆積したＰＭの堆積量は少なく、強制再生を行う必要がないため、この強制再生方法は完了する。一方、ステップＳ１０で差圧ΔＰ１が開始判定値Ｐａ以上の場合には、ステップＳ２０へ進む。
First, in step S10, the control device 31 determines whether or not the differential pressure ΔP1 detected by the differential pressure sensor 30 is greater than or equal to the start determination value Pa. If the differential pressure ΔP1 is less than the start determination value Pa in step S10, the amount of PM deposited on the collection device 26 is small and there is no need to perform forced regeneration, so this forced regeneration method is completed. On the other hand, if the differential pressure ΔP1 is greater than or equal to the start determination value Pa in step S10, the process proceeds to step S20.
次いで、ステップＳ２０では、制御装置３１が開閉弁４０に通電して、開閉弁４０を開く制御を行う。次いで、ステップＳ３０及びステップＳ４０では、制御装置３１が、開閉弁４０が開いてからの経過時間ｔをカウントして、経過時間ｔが充填時間Δｔ１に達したときにステップＳ５０へ進む。このステップＳ２０～ステップＳ４０を実施する、すなわち、充填時間Δｔ１だけ燃料噴射弁３２よりも先に開閉弁４０を開くことで、開閉弁４０から燃料噴射弁３２までの燃料供給管３５に燃料を充填する。
Next, in step S20, the control device 31 energizes the on-off valve 40 to perform control to open the on-off valve 40. Next, in step S30 and step S40, the control device 31 counts the elapsed time t from the opening of the on-off valve 40, and proceeds to step S50 when the elapsed time t reaches the filling time Δt1. Steps S20 to S40 are performed, that is, the fuel supply pipe 35 from the on-off valve 40 to the fuel injection valve 32 is filled with fuel by opening the on-off valve 40 before the fuel injection valve 32 for the filling time Δt1. To do.
次いで、ステップＳ５０では、制御装置３１が燃料噴射弁３２に通電して、燃料噴射弁３２の噴射を開始する制御を行う。このステップＳ５０によって、排気ガスに未燃燃料を供給し、その未燃燃料を酸化触媒２５で酸化することによって、排気ガスの温度を昇温する。そして、その排気ガスの温度を６００度まで昇温して、捕集装置２６に堆積したＰＭを燃焼除去する。
Next, in step S50, the control device 31 conducts control to energize the fuel injection valve 32 and start injection of the fuel injection valve 32. In step S50, unburned fuel is supplied to the exhaust gas, and the unburned fuel is oxidized by the oxidation catalyst 25, thereby raising the temperature of the exhaust gas. Then, the temperature of the exhaust gas is raised to 600 degrees, and the PM deposited on the collection device 26 is removed by combustion.
なお、ステップＳ１００で噴射を停止するまでは、燃料噴射弁３２から連続的に燃料を噴射するが、温度センサ３６で検出した温度Ｔ１が上限値Ｔｍａｘを超えるか否かを判定し、温度Ｔ１が上限値Ｔｍａｘを超えるようであれば、燃料噴射弁３２からの燃料の噴射を停止する制御を行うとよい。
The fuel is continuously injected from the fuel injection valve 32 until the injection is stopped in step S100, but it is determined whether or not the temperature T1 detected by the temperature sensor 36 exceeds the upper limit value Tmax. If the value exceeds the upper limit value Tmax, control for stopping the fuel injection from the fuel injection valve 32 may be performed.
次いで、ステップＳ６０では、制御装置３１が差圧センサ３０で検出した差圧ΔＰ２が終了判定値Ｐｂ未満か否かを判定する。このステップＳ６０で差圧ΔＰ２が終了判定値Ｐｂ以上の場合には、ステップＳ５０へと戻り、燃料噴射弁３２からの燃料の噴射を継続する。一方、ステップＳ６０で差圧ΔＰ２が終了判定値Ｐｂ未満の場合には、ステップＳ７０へ進む。
Next, in step S60, it is determined whether or not the differential pressure ΔP2 detected by the differential pressure sensor 30 by the control device 31 is less than the end determination value Pb. If the differential pressure ΔP2 is greater than or equal to the end determination value Pb in step S60, the process returns to step S50 and fuel injection from the fuel injection valve 32 is continued. On the other hand, if the differential pressure ΔP2 is less than the end determination value Pb in step S60, the process proceeds to step S70.
次いで、ステップＳ７０では、制御装置３１が開閉弁４０への通電を停止して、開閉弁４０を閉じる制御を行う。次いで、ステップＳ８０及びステップＳ９０では、制御装置３１が開閉弁４０を閉じてからの経過時間ｔをカウントして、経過時間ｔが圧力開放時間Δｔ２に達したときにステップＳ１００へ進む。
Next, in step S70, the control device 31 performs control to stop energization of the on-off valve 40 and close the on-off valve 40. Next, in step S80 and step S90, the elapsed time t from when the control device 31 closes the on-off valve 40 is counted, and when the elapsed time t reaches the pressure release time Δt2, the process proceeds to step S100.
このステップＳ７０～ステップＳ９０を実施する、すなわち、圧力開放時間Δｔ２だけ燃料噴射弁３２よりも先に開閉弁４０を閉じることで、開閉弁４０で燃料を堰止して、開閉弁４０から燃料噴射弁３２までの燃料供給管３５への燃料の供給を停止すると共に、開閉弁４０から燃料噴射弁３２までの燃料供給管３５に充填された燃料を燃料噴射弁３２から噴射して、開閉弁４０から燃料噴射弁３２までの燃料供給管３５の圧力を抜いて、ゼロにする。
Steps S70 to S90 are performed, that is, by closing the on-off valve 40 before the fuel injection valve 32 for the pressure release time Δt2, the fuel is blocked by the on-off valve 40 and the fuel is injected from the on-off valve 40. The supply of fuel to the fuel supply pipe 35 up to the valve 32 is stopped, and the fuel filled in the fuel supply pipe 35 from the on-off valve 40 to the fuel injection valve 32 is injected from the fuel injection valve 32, and the on-off valve 40 To the fuel injection valve 32, the pressure of the fuel supply pipe 35 is released to zero.
次いで、ステップＳ１００では、制御装置３１が燃料噴射弁３２への通電を停止して、燃料噴射弁３２からの燃料の噴射を停止する制御を行って、この強制再生方法は完了する。なお、ステップＳ６０で差圧ΔＰ１を判定する代わりに、予め設定された再生時間Δｔ３が経過するまで、燃料噴射弁３２から燃料を噴射する制御としてもよい。この場合には、再生時間Δｔ３に達したときに、ステップＳ１００が行われるように、圧力開放時間Δｔ２を逆算してステップＳ７０を行うようにすることが好ましい。
Next, in step S100, the control device 31 performs control to stop energization of the fuel injection valve 32 and stop fuel injection from the fuel injection valve 32, and this forced regeneration method is completed. Instead of determining the differential pressure ΔP1 in step S60, control may be performed to inject fuel from the fuel injection valve 32 until a preset regeneration time Δt3 elapses. In this case, it is preferable to perform step S70 by calculating back the pressure release time Δt2 so that step S100 is performed when the regeneration time Δt3 is reached.
上記の第一実施形態のエンジン１０及び捕集装置２６の強制再生方法によれば、排気管２３に配置された燃料噴射弁３２からの燃料の噴射を停止するよりも前に開閉弁４０を閉じることで、開閉弁４０と燃料噴射弁３２との間に圧力の高い燃料を残留させることがない。すなわち燃料噴射弁３２に掛かる燃料の圧力をゼロにすることができるので、燃料圧力によって燃料噴射弁３２の噴口から燃料が漏れ出ることを防ぐことができる。
According to the forced regeneration method of the engine 10 and the collection device 26 of the first embodiment, the on-off valve 40 is closed before the fuel injection from the fuel injection valve 32 disposed in the exhaust pipe 23 is stopped. Thus, high-pressure fuel does not remain between the on-off valve 40 and the fuel injection valve 32. That is, since the pressure of the fuel applied to the fuel injection valve 32 can be made zero, it is possible to prevent the fuel from leaking from the injection port of the fuel injection valve 32 due to the fuel pressure.
これにより、燃料噴射弁３２の噴口に漏れ出た燃料が結晶化して噴口が詰まる現象（コーキング現象）を回避できるので、燃料噴射弁３２から燃料を噴射できない不具合やコーキング現象による燃料噴射弁３２の交換や整備の頻度を抑制できる。
As a result, a phenomenon (coking phenomenon) in which the fuel leaking into the injection port of the fuel injection valve 32 is crystallized and the injection port is clogged can be avoided. The frequency of replacement and maintenance can be suppressed.
なお、この第一実施形態のエンジン１０においては、圧力開放時間Δｔ２が、開閉弁４０と燃料噴射弁３２との間の燃料供給管３５の圧力がゼロになる時間に設定された例を説明したが、必ずしも圧力がゼロになる必要はなく、開閉弁４０と燃料噴射弁３２との間の燃料供給管３５の圧力が、燃料噴射弁３２の噴口から燃料が漏れ出ない圧力になればよく、圧力開放時間Δｔ２を、燃料供給管３５の圧力がゼロに近づく時間に設定してもよい。
In the engine 10 of the first embodiment, the example in which the pressure release time Δt2 is set to the time when the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 becomes zero has been described. However, the pressure is not necessarily zero, and the pressure of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 may be a pressure at which fuel does not leak from the injection port of the fuel injection valve 32. The pressure release time Δt2 may be set to a time when the pressure of the fuel supply pipe 35 approaches zero.
図４は、本発明のエンジン１０の第二実施形態の構成を例示している。このエンジン１０においては、開閉弁４０が燃料噴射弁３２の近傍の燃料供給管３５に配置されて構成される。この構成によれば、開閉弁４０と燃料噴射弁３２との間の燃料供給管３５の距離Ｌ１を第一実施形態よりも短くして、より圧力開放時間Δｔ２を短縮できる。
FIG. 4 illustrates the configuration of the second embodiment of the engine 10 of the present invention. In the engine 10, the opening / closing valve 40 is arranged in a fuel supply pipe 35 in the vicinity of the fuel injection valve 32. According to this configuration, the distance L1 of the fuel supply pipe 35 between the on-off valve 40 and the fuel injection valve 32 can be made shorter than in the first embodiment, and the pressure release time Δt2 can be further shortened.
１０ エンジン
１３ 筒内
２３ 排気管
２６ 捕集装置
３１ 制御装置
３２ 燃料噴射弁
３３ 貯蔵タンク
３４ 圧送ポンプ
３５ 燃料供給管
４０ 開閉弁
ｔ１ 開弁時刻
ｔ２ 噴射開始時刻
ｔ３ 閉弁時刻
ｔ４ 噴射停止時刻
Δｔ１ 充填時間
Δｔ２ 圧力開放時間 10Engine 13 In-cylinder 23 Exhaust pipe 26 Collection device 31 Control device 32 Fuel injection valve 33 Storage tank 34 Pressure feed pump 35 Fuel supply pipe 40 On-off valve t1 Opening time t2 Injection start time t3 Closing time t4 Injection stop time Δt1 Filling Time Δt2 Pressure release time
１３ 筒内
２３ 排気管
２６ 捕集装置
３１ 制御装置
３２ 燃料噴射弁
３３ 貯蔵タンク
３４ 圧送ポンプ
３５ 燃料供給管
４０ 開閉弁
ｔ１ 開弁時刻
ｔ２ 噴射開始時刻
ｔ３ 閉弁時刻
ｔ４ 噴射停止時刻
Δｔ１ 充填時間
Δｔ２ 圧力開放時間 10
Claims (4)
- 筒内から排出される排気ガスが通過する排気管に配置された燃料噴射弁と、該燃料噴射弁から噴射される燃料を貯蔵する貯蔵タンクと、該貯蔵タンク及び該燃料噴射弁を接続する燃料供給管と、該燃料噴射弁へ燃料を圧送する圧送ポンプと、該燃料噴射弁を制御する制御装置と、を備えた内燃機関において、
前記燃料噴射弁と前記圧送ポンプとの間の前記燃料供給管に介設された開閉弁を備え、
前記制御装置を、前記燃料噴射弁の噴射開始時刻よりも前に前記開閉弁を開いて前記燃料供給管を開放し、前記燃料噴射弁の噴射停止時刻よりも前に前記開閉弁を閉じて前記燃料供給管を遮断する制御を行う構成にしたことを特徴とする内燃機関。 A fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from the cylinder passes, a storage tank that stores fuel injected from the fuel injection valve, and a fuel that connects the storage tank and the fuel injection valve In an internal combustion engine comprising a supply pipe, a pump for pumping fuel to the fuel injection valve, and a control device for controlling the fuel injection valve,
An on-off valve interposed in the fuel supply pipe between the fuel injection valve and the pressure feed pump;
The controller opens the on-off valve before the injection start time of the fuel injection valve to open the fuel supply pipe, closes the on-off valve before the injection stop time of the fuel injection valve, and An internal combustion engine configured to perform control for shutting off a fuel supply pipe. - 前記開閉弁を閉じる閉弁時刻から前記噴射停止時刻までの間の圧力開放時間を、前記開閉弁と前記燃料噴射弁との間の前記燃料供給管の燃料圧力がゼロになる時間、又はゼロに近づく時間に設定した請求項１に記載の内燃機関。 The pressure release time between the closing time of closing the on-off valve and the injection stop time is set to the time when the fuel pressure in the fuel supply pipe between the on-off valve and the fuel injection valve becomes zero, or zero The internal combustion engine according to claim 1, wherein the internal combustion engine is set to approach time.
- 前記開閉弁を、前記燃料噴射弁の近傍の前記燃料供給管に配置した請求項１又は２に記載の内燃機関。 The internal combustion engine according to claim 1 or 2, wherein the on-off valve is arranged in the fuel supply pipe in the vicinity of the fuel injection valve.
- 内燃機関の筒内から排出される排気ガスが通過する排気管に配置された燃料噴射弁から燃料を該排気管に噴射し、該燃料噴射弁よりも下流に配置された捕集装置に堆積された粒子状物質を燃焼除去して強制再生する捕集装置の強制再生方法において、
強制再生の開始時に、前記燃料噴射弁と、貯蔵タンクから燃料供給管を経由して該燃料噴射弁へ燃料を圧送する圧送ポンプとの間に介設された開閉弁を開いて該燃料供給管を開放し、燃料を該貯蔵タンクから該燃料供給管を経由して該燃料噴射弁に供給するステップと、
前記開閉弁を開いた後に、前記燃料噴射弁から燃料を噴射するステップと、を含み、
強制再生の停止時に、前記開閉弁を閉じて前記燃料供給管を遮断して、前記燃料噴射弁への燃料の供給を停止するステップと、
前記開閉弁を閉じた後に、前記燃料噴射弁から燃料を噴射して、前記開閉弁と前記燃料噴射弁との間の前記燃料供給管の圧力を抜くステップと、
前記燃料供給管の圧力を抜いた後に、前記燃料噴射弁の噴射を停止するステップと、を含むことを特徴とする捕集装置の強制再生方法。 Fuel is injected into the exhaust pipe from a fuel injection valve disposed in an exhaust pipe through which exhaust gas discharged from the cylinder of the internal combustion engine passes, and is deposited on a collection device disposed downstream of the fuel injection valve. In the forced regeneration method of the collection device that forcibly regenerates by burning off the particulate matter,
At the start of forced regeneration, the fuel supply pipe is opened by opening an on-off valve interposed between the fuel injection valve and a pressure-feeding pump that pumps fuel from the storage tank to the fuel injection valve via the fuel supply pipe. And supplying fuel from the storage tank to the fuel injection valve via the fuel supply pipe;
Injecting fuel from the fuel injection valve after opening the on-off valve,
When the forced regeneration is stopped, closing the on-off valve to shut off the fuel supply pipe and stopping the fuel supply to the fuel injection valve;
After closing the on-off valve, injecting fuel from the fuel injection valve, and releasing the pressure of the fuel supply pipe between the on-off valve and the fuel injection valve;
And a step of stopping injection of the fuel injection valve after releasing the pressure of the fuel supply pipe.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110242387A (en) * | 2018-03-08 | 2019-09-17 | 罗伯特·博世有限公司 | Hydrocarbon spraying system and its control method |
| CN110242387B (en) * | 2018-03-08 | 2022-07-01 | 罗伯特·博世有限公司 | Hydrocarbon injection system and control method thereof |
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