JP2015522125A - How to control a defect injector - Google Patents

Abstract

In particular, a control method for shutting off a fluid discharge valve having a leakage fault is described as a control method used in an engine. The valve is connected in series after a flow fuse that is adapted to shut off when the flow of fluid through the flow fuse exceeds a predetermined flow value. Controlling to release a fluid flow that exceeds the predetermined flow value after the step of detecting a leakage fault of the valve, thereby triggering a flow fuse to shut off the valve from the fluid supply. Continue. The predetermined flow value may be a value representing a flow characteristic including a cumulative flow rate measured by volume or mass. When the valve is an internal combustion engine fuel injector, the detecting step evaluates at least one of the operating parameters of the engine.

Description

  The present invention relates to a method for controlling a fluid discharge valve. Fluid discharge valves are typically used, for example, in combustion engines, where these valves are used to release fuel, lubricants, water or other fluids of gas or liquid.

  The term discharge valve is intended to encompass all types of valves suitable for controlling the discharge or spraying of fluid from a discharge valve. The fluid released is a gas or a liquid, in particular a fuel, a lubricant such as oil, an aqueous emulsion or solution, or water. In a special case where a discharge valve is used to release fuel or other liquid or gas into a cylinder of a combustion engine, the emitter is referred to as an injector.

  The discharge valve to which the control according to the invention is concerned is a valve that is connected to a line in which the discharged fluid exists under pressure. A typical example of this is an engine fuel injector with a common rail system. Of course, this discharge valve is for spraying lubricant on the sliding surface, or for spraying additives such as urea or water containing solution in the piping around the engine (intake piping and / or exhaust piping). Can be a discharge valve.

  If they are dangerous to the environment in terms of pressurized fluid accidents, a discharge valve with a corresponding flow fuse is incorporated into the pipe or line connected to the source of pressurized fluid. This flow fuse is triggered when the fluid flow flows through the flow fuse at a value exceeding the design flow value and is designed to shut off the fluid supply to the corresponding discharge valve or valve. When the pipe ruptures, the actual fluid mass or / and flow rate can form the basis for triggering the flow fuse. However, not only can the actual fluid mass or flow rate be a decisive parameter for determining the flow value, but other characteristics of the fluid flow, such as pressure loss, temperature changes, etc. are parameters that represent the flow value. Can be used.

  In addition, the flow fuse has a fluid reservoir to allow for a maximum discharge volume within a limited time, for example followed by a closing period of the discharge valve, so that the flow fuse is for maximum discharge and refilling. It is designed to be triggered when the average flow rate or the absolute flow rate for calculating the period including the closing time of is exceeded. Such a flow fuse will work properly in the event of a failure such that the discharge valve is fully open.

  Of course, the flow fuse must be designed to always allow the maximum discharge / average flow to be discharged from the corresponding discharge valve in any allowed operating state of the machine in which the discharge valve is used. Don't be. Therefore, the allowable value for triggering the fuse needs to be set on the safe side from the viewpoint of allowing the discharge valve to discharge the fluid.

  Since flow fuses are mechanical systems that operate in different situations, the required strength of these structures (solid spring solids, high flow, high pressure) is usually a parameter for triggering flow fuses. This reduces the sensitivity to and this requires increasing the tolerance to avoid unnecessary triggers.

  In view of the above, there is a possibility that slight leakage from the discharge valve can occur permanently or intermittently, which is not detected by the flow fuse and the flow fuse will not be triggered.

  In relation to the small amount of leakage described above, a shutoff valve that can be manually shut off by manual operation or power drive is added to the piping to shut off the fluid supply to the discharge valve when a small amount of leakage occurs. It is conceivable to provide them. However, providing this additional shut-off valve is expensive, and providing the shut-off valve in the piping increases the number of parts to be sealed.

  Accordingly, it is an object of the present invention to provide a method for shutting off a fluid discharge valve with a leak failure.

  This object is achieved with the method according to claim 1, advantageous aspects being described in the dependent claims.

  In accordance with the present invention, a method for shutting off a fluid discharge valve having a leakage fault is used in a device to which a valve is connected following a flow fuse, the flow fuse having a predetermined fluid flow through the flow fuse. When the flow value is exceeded, the flow fuse falls into the cut-off state. The method of the present invention includes the steps of detecting a valve leakage failure and injecting a fluid flow that exceeds a predetermined flow value, thereby dropping the flow fuse into a shut-off condition and shutting the valve from a fluid supply. A step of controlling.

  The term flow value refers to a value relating to one or more parameters of fluid flow. By setting a predetermined flow value (threshold value), the predetermined flow value becomes a flow velocity, volume flow rate, mass flow rate, total fluid volume within a predetermined period, total fluid mass within a predetermined period, or volume or mass. Can be set as an integrated flow rate measured by the above or a combination of these parameters.

  As mentioned above, the method of the present invention uses the step of detecting a leakage fault, which is separate from detecting the flow value triggered by the flow fuse.

  Preferably, when the fluid discharge valve is a fuel injector adapted to inject pressurized fuel into the internal combustion engine, the injector leakage failure is based on at least one abnormality of the engine operating condition parameter. Can be detected. Preferably, the operating condition parameter is at least one of exhaust gas temperature, cylinder pressure, fuel consumption, crankshaft speed, and crankshaft torque. A combination of these parameters can also be monitored and evaluated to detect leakage faults.

  The flow fuse is preferably triggered when the operating parameter is monitored by an engine control unit (ECU) and when the engine control unit is in the injector during one engine stroke, the engine is operating at full load. This is when the fuel is injected exceeding the maximum load fuel injection amount corresponding to the amount of fuel injected by the injector during the engine stroke. Therefore, in this situation, the fuel injection amount is set to be larger than the amount of fuel injected into the cylinder when the engine is operating at maximum load. In this way, the set value for triggering the flow fuse is exceeded and the fuse is triggered.

  Preferably, the fuel injection amount is at least 101% of the maximum load fuel injection amount, preferably at least 120%, and most preferably in a range including 130% and 170%. Preferably, the fuel injection amount is set such that the corresponding flow value (one or more parameters of the flow) is higher than a preset flow value.

  As described above, the control method according to the present invention can be applied to various machines other than the combustion engine, and can be applied to various types of fluid discharge devices other than the fuel injectors of the combustion engine and other types of machines. it can.

  Preferably, the fluid discharge valve is an ejector for releasing lubricant to the contact surface of the internal combustion engine, in particular the piston / cylinder contact surface (cylinder lining), and the leakage failure is an at least one operating condition parameter of the engine. Detected based on abnormality.

  Preferably, the operating condition parameter is at least one of lubricant consumption, exhaust gas temperature and cylinder pressure.

  Also, the fluid discharge valve may preferably be an ejector for discharging water or an aqueous solution such as a urea-containing solution supplied into the cylinder, inflow pipe and discharge pipe, where Leakage faults are detected based on the relevant system or engine operating parameters (eg, exhaust gas components, temperature, etc.). Preferably, the fluid discharge valve is a valve for injecting water into the cylinder of the engine. Such water injectors present a risk of lime-scale formation and if the water injector is left open, the switch must be turned off.

  Preferably, when the engine is provided with a fuel flow fuse, the fluid discharge valve is a fuel injector, the engine is further provided with a lubricant flow fuse, and the fluid jet discharge valve is a lubricant ejector, the fluid discharge valve Leakage fault detection includes the identification of abnormal operating parameters based on the fluid discharge valve type. Preferably, the operating parameters used for this identification include fuel consumption and lubricant pressure.

  Preferably, when the flow fuse is positioned upstream of the plurality of fluid ejection valves, the plurality of fluid discharge valves are actuated simultaneously to discharge a fluid flow that exceeds a preset flow value of the flow fuse. This triggers a drop in the flow fuse to a stopped condition so as to shut off the plurality of fluid discharge valves from the fluid supply.

  In the preferred application of the present invention described above, the engine is a direct injection engine and the fuel supply system of the engine has a common rail that is stored under pressurized fuel, and the flow fuse includes the common rail and one or more fuels. Located in the fuel pipe between the injectors. The engine can have multiple cylinders, and a flow fuse is provided in each supply pipe to one or more injectors in each cylinder.

  In a preferred form, the control method further comprises the steps of displaying an optical alarm and / or an audible alarm and / or triggering the flow fuse to drop into a shut-off state when a fault is detected. Preferably, the present control method is executed without stopping the engine.

  More preferably, the present control method is applicable to hydraulic systems used in piston / cylinder devices, such as a pressure amplifier for amplifying fuel injection pressure for injection from a fuel injector. In this case, the flow fuse is used in front of the pressure amplifier, and the hydraulic oil flow that triggers the flow fuse in the hydraulic circuit is controlled by the fuel injector controlling the fuel injection above the preset flow rate. Is caused.

  Preferably, by way of example, the application of the present invention in a marine engine allows for continuous operation of the engine even when there is a problem with the injector or ejector. If there is a permanent leak in the injector, the fuel will be permanently injected into the cylinder, resulting in fuel enrichment that will cause explosions and serious engine failure in the exhaust gas, exhaust gas turbocharger. On the other hand, stopping and restarting such a large engine is cumbersome and time consuming. In particular, when the ship is navigating in stormy weather, no time for stopping or restarting is obtained, or the safe navigation of the ship is jeopardized. In this case, continuous operation of the engine with a reduced number of cylinders is one choice. This is one beneficial aspect of the present invention and further advantages obtained by the present invention will become apparent from the following examples of the present invention.

1 is a schematic diagram of a fuel injection system for a 6 cylinder engine with a flow fuse for the common rail and each injector. FIG.

  FIG. 1 shows an apparatus of a fuel supply system of a two-stroke engine 10 having a common rail 1 in which fuel is stored in a high pressure state. Only the connection from the common rail 1 to the injectors 31, 32 of the cylinder 5 of the engine 10 is shown in detail in FIG. 1, and the connections to the other cylinders are # 2, # 3, # 4, # 5 and # 6. It is shown by and has the same structure. Fuel is supplied to the common rail 1 by a fuel pump 7 driven by the engine 10. Fuel is stored in the tank T. The check valve 71 is prevented from flowing back from the common rail 1 to the pump 7. A pressure control device including a pressure relief valve 8 is adapted to cooperate with the engine control unit EUC 100 to maintain the fuel pressure in the common rail 1 at a predetermined level. The ECU 100 controls the pump 7 and / or the pressure control valve 8 to supply sufficient fuel under high pressure, but avoids excessive pressurization of fuel to save energy. Alternatively, a mechanical pressure relief valve can be used in place of the active pressure control valve 8 for pressure control.

  Control of the pump 7 and the pressure control valve 8 is connected to the ECU 100 via a wiring 103 in order to transmit a signal and an electric drive power source.

  The fuel injectors 31 and 32 are connected to the common rail 21 by pipes 21 and 22, respectively. The pipe 21 is provided with a flow fuse 41, and when the flow fuse is triggered, the fuel supply to the injector 31 passing through the pipe 21 is cut off. For example, the fuel supply is kept shut off until the injection problem is solved and the flow fuse is manually reset. Similarly, a flow fuse 42 is also arranged in the pipe 22, and when triggered, the fuel supply to the fuel injector 32 through the pipe 22 is cut off. Again, for example, the fuel supply remains off until the flow fuse is artificially reset after the injection problem is solved.

  FIG. 1 further schematically shows the cylinder 5 and the piston 6 of the engine 6. In addition, control lines 101 and 102 are shown connecting the injectors 31 and 32 to the EUC 100, respectively. With these control lines, the injector is controlled to open or close by the EUC 100 so that a predetermined amount of fuel is injected into the cylinder 5 at a predetermined timing. EUC 100 and injectors 31, 32 should remain open so that EUC 100 can send an open signal to the corresponding injector 31, 32 and as long as the corresponding injector 31, 32 receives the open signal. Is adjusted so that These injectors are self-closing so that when the open signal is OFF, the corresponding injectors 31 and 32 are closed and the fuel injection into the cylinder 5 is stopped.

  The flow fuses 41 and 42 are designed to be triggered when the flow value of the fuel flowing through the flow fuse exceeds a predetermined value. The predetermined flow value may be a value related to a fluid flow parameter. For example, this flow value can be the pressure loss due to the flow fuse, the dynamic pressure of the flow acting on the trigger surface of the flow fuse, or the pressure difference between the static and / or dynamic pressure in the flow path through the flow fuse. is there. Of course, other parameters of the flow value can be selected to set the flow value and the associated threshold.

  For the sake of explanation, hereinafter, when an integrated value of the flow rate flowing through the flow fuse within a predetermined period is used as a flow value and other flow values are described, a necessary description is added.

Assume that one of the injectors 31, 32 has a leakage fault during operation of the engine 10. A leakage failure is when the injector cannot be closed completely, i.e. the injector does not close properly. This has various causes such as debris in the fuel and wear and breakage of the tightening surface. In this case, the failed injectors 31 and 32 should be closed while the fuel injection of the injectors 31 and 32 operates normally, that is, the injectors 31 and 32 inject a predetermined amount of fuel when controlled to open. Sometimes a small amount of fuel is always injected into the cylinder 5.
Since the predetermined flow value for triggering the flow fuse is determined by the average flow rate per unit time, the flow through the faulty injector may be too small to trigger the flow fuse.

  The ECU 100 is connected to various sensors (not shown) capable of measuring / detecting operating parameters of the engine 10 and peripheral devices (subsystems). The extra fuel that is permanently injected into the cylinder 5 from the faulty injector causes a change in the monitored operating parameter, from which it can be concluded that the injectors 31, 32 are defective.

  Monitored parameters can include exhaust gas temperature, cylinder pressure, fuel consumption, crankshaft speed and crankshaft torque. The power consumption or discharge flow rate of the fuel pump 8 can also be used as an indicator of leakage failure in combination with other parameters.

  Once a cylinder with a fault is detected, ECU 100 sets an alarm signal that provides an audio and / or visual alarm. Furthermore, the alarm is transmitted via communication means to inform the responsible person of the failure. The decision can be found by a person or automatically by a program in the ECU. If the failed injector of the two injectors 31, 32 is stopped, the cylinder is still operated at low capacity by one injector that is operating normally. Also, if both injectors 31, 32 are stopped, the individual cylinders of the engine are stopped, but the engine 10 continues to operate with the remaining cylinders (not shown).

When the injectors 31 and 32 to be stopped are identified and a signal for stopping the injectors is generated (manually or automatically by the engine control unit ECU), the ECU 100 sends an open control signal to the injectors 31 and 32. However, this open control signal is preferably considerably longer than the open control signal output by the ECU 100 when the engine 10 is operating normally and at maximum load. Due to this long open signal from the ECU 100, the injectors 31, 32 release a large amount of fuel into the cylinder 5 such that the flow value of the fuel flow exceeds a predetermined flow value for the flow fuse. As a result, the flow fuses 41 and 42 are triggered, and the supply of fuel to the injectors 31 and 32 is stopped.
Although extra fuel is injected into the cylinder, this extra injection in a single stroke of the engine does not cause any problems for engine operation. In this way, permanent leakage into the engine is stopped. The flow fuse is designed to be manually reset after the injector problem is solved. The flow fuse may also be designed such that the pressure in the fuel pipe is automatically reset when released after engine shutdown and necessary maintenance.

  In FIG. 1, the engine layout is illustrated as if each injector had its own flow fuse. It is also possible for two or more injectors of one cylinder to be connected to a common flow fuse. In order to trigger such a flow fuse, the flow value needs to be set larger than the total flow value of all the injectors of one cylinder at the maximum engine load.

  If each injector is provided with a unique flow fuse, the procedure for stopping is controlled so that only one injector in one stroke of the piston injects an excessive amount of fuel. In this way, overloading of the cylinder due to excessively rich mixture combustion in the cylinder can be avoided.

  The embodiment related to the injector that injects fuel into the engine cylinder has been described above. Injector discharges water or additives, or mixtures thereof to discharge valves that release lubricant to the sliding surface of an engine or other machine, cylinder, intake, exhaust, or other engine or other application site A similar layout can be adopted even if replaced by a discharge valve. In these applications, the common rail is replaced by other pressurized fluid accumulators and, of course, the flow fuse or fuses are designed for the expected or maximum allowable flow. The control action for these discharge valves is similar to that described above, with the flow fuses being actuated, i.e., triggered, in a manner that controls the discharge valve to discharge excess flow.

  In the above example, the flow fuse has been described as a separate element, but the flow fuse can be integral with the injector.

A fuel injector, wherein the fluid discharge valve is adapted to inject pressurized fuel into the internal combustion engine, wherein a leakage failure of the injector may be detected based on at least one anomaly of the engine operating condition parameter The operating condition parameter may be at least one of exhaust gas temperature, cylinder pressure, fuel consumption, crankshaft speed, and crankshaft torque. A combination of these parameters can also be monitored and evaluated to detect leakage faults.

Preferably, an ejector is further provided for releasing lubricant to the contact surface of the internal combustion engine, in particular the piston / cylinder contact surface (cylinder lining) , the leakage failure being an abnormality of at least one engine operating condition parameter. Is detected based on

Claims (16)

A control method used in particular for an engine for stopping a fluid discharge valve with a leakage fault, said valve adapted to fall into a stopped state when the fluid flow through the flow fuse exceeds a predetermined flow value Is connected in series behind the flow fuse
Detecting the fluid failure of the valve;
A control method comprising the step of controlling the valve to release a fluid flow that exceeds the predetermined flow value, thereby dropping the flow fuse into a stopped state and disconnecting the valve from a fluid supply.   The predetermined flow value is a value representing a flow rate, a volume flow rate, a mass flow rate, a total volume flow rate within a predetermined period, a total mass flow rate within a predetermined period, or an integrated flow rate measured by volume or mass. 2. The control method according to 1.   The fluid discharge valve is a fuel injector adapted to inject pressurized fuel into a cylinder of an internal combustion engine, and a leakage failure of the injector is detected based on at least one engine operating condition parameter The control method according to claim 1 or 2.   The control method according to claim 3, wherein the operating state parameter is at least one of exhaust gas temperature, cylinder pressure, fuel consumption, crankshaft speed, and crankshaft torque.   The operating condition parameter is monitored by an engine control unit (ECU), which corresponds to the amount of fuel injected by the injector during one engine stroke when the engine is operating at full load. The control method according to claim 3 or 4, wherein fuel is injected during one stroke in an amount exceeding a fuel injection amount at full load.   6. The control method according to claim 5, wherein the injected fuel amount is at least 101%, preferably at least 120%, most preferably in the range of 130% to 170% of the fuel injection amount at full load.   The control method according to claim 1, wherein the fluid discharge valve is an ejector that discharges a lubricant to a contact surface of an internal combustion engine.   The control method according to claim 7, wherein the operating state parameter is at least one of a lubricant supply pressure, a lubricant consumption amount, an exhaust gas temperature, and a cylinder pressure.   The engine is provided with a fuel flow fuse, the fluid discharge valve is a fuel injector, the engine is further provided with a lubricant flow fuse, the fluid discharge valve is a lubricant ejector, and a leakage failure of the fluid discharge valve is detected. 9. The control method according to claim 1, wherein the detection includes a change of an operating parameter having an abnormality depending on a type of the fluid discharge valve.   The control method of claim 9, wherein the operating parameters used to detect the change include fuel consumption and lubricant pressure.   The flow fuse is provided upstream of a plurality of fluid discharge valves, and the plurality of fluid discharge valves are actuated simultaneously to discharge a fluid flow that exceeds the predetermined flow value of the flow fuse, thereby shutting off the flow fuse. The control method according to claim 1, wherein the control method drops into a state and blocks the plurality of fluid discharge valves from a fluid supply source.   The engine is a direct injection engine, the engine fuel supply system has a common rail in which fuel is stored under pressure, and the flow fuse is provided in a fuel pipe between the common rail and one or more fuel injectors. The control method according to any one of claims 1 to 11.   The control method according to claim 12, wherein the engine has a plurality of cylinders, and one flow fuse is provided in each fuel supply pipe for the one or more injectors of each cylinder.   The control method further comprises the steps of displaying an optical alarm and / or an audible alarm when a failure is detected, and / or triggering to drop the flow fuse into a shut-off state when a failure is detected. Item 14. The control method according to any one of Items 1 to 13.   The control method according to claim 1, wherein the control method is executed without stopping the engine.   The engine includes a pressure amplifier driven by a hydraulic system for increasing fuel pressure for fuel injection, and a flow fuse is provided in the hydraulic system connected to the pressure amplifier, the flow fuse including the fuel The control method of claim 3, wherein the control is triggered to impede supply of hydraulic fluid to the pressure amplifier by injecting extra flow from the injector.

Images