JP2009002187A - Driving method of fuel injection pump and fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection pump surely moving a plunger by a predetermined distance. <P>SOLUTION: The fuel injection pump comprises the plunder 110 which sucks and pressure-transfers fuel by reciprocation, releases the fuel toward a return passage 121a in an initial region of a pressure-transfer stroke and pressure-transfers the fuel to an injection jet 212 in a later region of the pressure-transfer stroke, an coil 140 for excitation, and an control means 50 for controlling energization of the coil to cause the plunger to perform purge drive Tp which does not achieve fuel injection and/or fuel injection drive Tinj which injects fuel, wherein the control means 50 performs pulse energization on the coil with an optimum pulse width according to a current value or a voltage value of the coil. With this, even if the current value (voltage value) of the coil varies, the plunger can be moved by a predetermined stroke amount, vapor can be efficiently discharged in the purge drive, and fuel can be injected with high accuracy in the fuel injection drive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel injection pump driving method and a fuel injection device that are applied to supply fuel to an internal combustion engine (hereinafter referred to as an engine), and more particularly, to a fuel injection that is applied to an engine mounted on a motorcycle or the like. The present invention relates to a pump driving method and a fuel injection device.

  As a fuel injection pump (or fuel injection device) applied to an engine mounted on a motorcycle or the like, a plunger that sucks and pumps fuel by reciprocation, a coil for excitation that exerts an electromagnetic driving force on the plunger, and a drive control of the plunger Control means (control unit), etc., and the fuel led from the fuel tank by the feed pipe is pumped by the electromagnetically driven plunger pump, and the fuel is returned to the fuel tank by the return pipe in the initial region of the pumping stroke. In addition, there is known a method in which fuel is injected from an injection nozzle toward an intake passage in a later stage region of the pressure feed stroke (see, for example, Patent Document 1).

In this fuel injection pump, based on the operating state of the engine, coil current, power supply voltage, temperature information such as the environment, etc., by conducting pulse energization with a pulse width that does not lead to fuel injection to the coil, The plunger is purge driven.
However, the purge driving is performed with the same pulse width that does not lead to fuel injection regardless of the current value flowing through the coil or the voltage value applied to the coil. It was a thing.
Therefore, in the fuel injection pump, when the current value flowing through the coil or the voltage value applied to the coil in the purge drive is equal to or higher than a predetermined level, the plunger 1 is connected to the return port 2 as shown in FIG. from the rest position P ₀ having an open, moved by a predetermined purge stroke Sp halfway position P ₁ substantially closing the discharge port 2 as shown in FIG. 10 (b), the vapor mingled in the initial region of the delivery stroke When the fuel is compressed and discharged from the discharge port 2 toward the return pipe, but the current value flowing through the coil is small or the voltage value applied to the coil is low and does not reach a predetermined level, as shown in FIG. The plunger 1 cannot move until the predetermined purge stroke amount Sp is reached, and the vapor cannot be discharged sufficiently. . In particular, there is a problem that this tendency appears remarkably in a high temperature environment and when an alcohol mixed fuel is used.
JP 2003-227432 A

  The present invention has been made in view of the above points, and an object of the present invention is to determine the value of a current flowing in the coil or the coil due to fluctuations in the power supply voltage or the like without structurally changing the fuel injection pump. Even if the voltage applied to the battery fluctuates, the vapor can be discharged efficiently and reliably without being affected by the fluctuation, and the generated vapor can be discharged efficiently, especially at high temperatures when using alcohol-mixed fuel. It is another object of the present invention to provide a fuel injection pump driving method and a fuel injection device capable of improving the idling stability or startability by efficiently discharging vapor even during idling or restarting.

In the fuel injection pump driving method according to the present invention, the fuel is sucked and pumped by reciprocation, and the fuel is released to the return passage in the initial region of the pumping stroke, and the fuel is directed to the injection port in the latter region of the pumping stroke. A plunger to be pumped, an exciting coil for exerting an electromagnetic starting force on the plunger, a purge drive that does not lead to fuel injection to the plunger and / or a fuel injection drive to inject fuel according to the operating state of the engine A fuel injection pump driving method comprising a control means for controlling energization to a coil to be performed, wherein the control means pulses the coil with a pulse width corresponding to a current value flowing through the coil or a voltage value applied to the coil. Energization is performed (that is, pulse energization with an optimal pulse width).
According to this configuration, the coil is subjected to pulse energization control so as to cause the plunger to perform purge driving that does not lead to fuel injection or fuel injection driving that injects fuel according to the operating state of the engine. A flowing current value or voltage value is detected, an optimum pulse width corresponding to the detected current value or voltage value is set, and the coil is pulse-energized with the optimum pulse width. Therefore, even if the current value flowing through the coil or the voltage value applied to the coil fluctuates, the plunger is not affected by this fluctuation, and the plunger is moved by a predetermined stroke amount (a constant purge stroke amount during the purge driving, the fuel injection driving In this case, it can be moved stably over a certain injection stroke amount). As a result, the vapor can be efficiently discharged in the purge drive, and the vapor can be efficiently discharged in the initial region and the predetermined amount of fuel can be injected with high accuracy in the later region in the fuel injection drive. Can do.

In the driving method having the above configuration, the control unit can employ a configuration in which the pulse energization (pulse energization with an optimum pulse width corresponding to the current value or voltage value of the coil) is performed in purge driving.
According to this configuration, when the engine is in a predetermined state (for example, an operation state in which vapor is easily generated in the fuel or a high-temperature stop state), the plunger does not reach the fuel injection (in the initial region of the pressure stroke). In this purge drive, an optimum pulse width is set according to the current value or voltage value of the coil, and the coil is energized with this optimum pulse width. The Therefore, the plunger can be moved by a predetermined purge stroke amount without being affected by fluctuations in the current value flowing through the coil or the voltage value applied to the coil. Accordingly, the vapor can be efficiently discharged toward the return passage under the operating condition where the vapor is easily generated.

In the driving method having the above configuration, the control unit may employ a configuration in which the pulse width is set to be larger than the predetermined width when the current value or voltage value of the coil is smaller than the predetermined level.
According to this configuration, when the current value (or voltage value) of the coil is smaller than the predetermined level, the coil is pulse-energized with a pulse width larger than the predetermined level. And a predetermined purge drive or fuel injection drive can be performed by the plunger.

In the driving method having the above configuration, the control unit can employ a configuration in which the pulse is energized to the coil based on a pulse width set in advance according to a current value flowing through the coil or a voltage value applied to the coil. .
According to this configuration, the optimum pulse width corresponding to the current value flowing through the coil or the voltage value applied to the coil is obtained in advance and stored as a map in the storage unit included in the control means, and the detected actual current value or Since the pulse width corresponding to the voltage value can be read from the stored map and the coil can be energized based on the read pulse width information, the calculation process is simplified and the energization control is simplified. Is done.

In the driving method configured as described above, the control means performs the above-described pulse energization (pulse energization with an optimum pulse width according to the current value or voltage value of the coil) based on the predetermined temperature information in the engine operating state. A configuration can be employed.
According to this configuration, the above pulse is applied to the coil based on predetermined temperature information such as fuel temperature, ambient temperature around the engine related to the fuel temperature, surface temperature of the fuel injection pump, coil temperature, and the like. Since energization is performed, more accurate energization control can be performed according to the operating state of the engine.

In the driving method configured as described above, the control unit performs purge driving when the engine is in an idle operation state, and performs the pulse energization in the purge driving (pulse energization with an optimum pulse width according to the current value or voltage value of the coil). ) Can be adopted.
According to this configuration, when the engine is in the idling operation state, the purge driving that does not inject the fuel is performed between the fuel injection driving for injecting the fuel, and the pulse energization is performed in the purge driving. Even in a small state, the generated vapor can be efficiently discharged without being affected by fluctuations in the current value or voltage value of the coil, and the generation of vapor can be suppressed by obtaining a cooling action.

In the driving method configured as described above, the control means performs purge driving when the power source for starting the engine is turned on before starting, and also applies the pulse energization (to the coil current value or voltage value) in the purge driving. It is possible to adopt a configuration that performs pulse energization with an optimal pulse width according to the response.
According to this configuration, before starting or restarting the engine, the purge drive without injecting fuel is performed in the range of the initial region of the pumping stroke, and the pulse current is supplied in this purge drive. Alternatively, the accumulated vapor can be discharged in advance without being affected by fluctuations in the voltage value, and engine startability, particularly restartability can be improved.

Further, the fuel injection device of the present invention sucks and pumps fuel by reciprocation, escapes the fuel toward the return passage in the initial region of the pumping stroke, and pumps the fuel toward the injection port in the latter region of the pumping stroke. Plunger, excitation coil for applying electromagnetic starting force to the plunger, and purge driving that does not lead to fuel injection and / or fuel injection driving that injects fuel according to the operating state of the engine Therefore, the fuel injection apparatus includes a control unit that controls energization of the coil, and the control unit energizes the coil with a pulse width corresponding to a current value flowing through the coil or a voltage value applied to the coil ( That is, pulse energization with an optimal pulse width is performed.
According to this configuration, the coil is subjected to pulse energization control so as to cause the plunger to perform purge driving that does not lead to fuel injection or fuel injection driving that injects fuel according to the operating state of the engine. A flowing current value or voltage value is detected, an optimum pulse width corresponding to the detected current value or voltage value is set, and the coil is pulse-energized with the optimum pulse width. Therefore, even if the current value flowing through the coil or the voltage value applied to the coil fluctuates, the plunger is not affected by this fluctuation, and the plunger is moved by a predetermined stroke amount (a constant purge stroke amount during the purge driving, the fuel injection driving In this case, it can be moved stably over a certain injection stroke amount). As a result, the vapor can be efficiently discharged in the purge drive, and the vapor can be efficiently discharged in the initial region and the predetermined amount of fuel can be injected with high accuracy in the later region in the fuel injection drive. Can do.

In the apparatus having the above-described configuration, the control unit can employ a configuration in which the pulse energization (pulse energization with an optimal pulse width corresponding to the current value or voltage value of the coil) is performed in purge driving.
According to this configuration, when the engine is in a predetermined state (for example, an operation state in which vapor is easily generated in the fuel or a high-temperature stop state), the plunger does not reach the fuel injection (in the initial region of the pressure stroke). In this purge drive, an optimum pulse width is set according to the current value or voltage value of the coil, and the coil is energized with this optimum pulse width. The Therefore, the plunger can be moved by a predetermined purge stroke amount without being affected by fluctuations in the current value flowing through the coil or the voltage value applied to the coil. Accordingly, the vapor can be efficiently discharged toward the return passage under the operating condition where the vapor is easily generated.

In the apparatus having the above configuration, the control unit may employ a configuration in which the pulse width is set to be larger than the predetermined width when the current value or voltage value of the coil is smaller than the predetermined level.
According to this configuration, when the current value (or voltage value) of the coil is smaller than the predetermined level, the coil is pulse-energized with a pulse width larger than the predetermined level. And a predetermined purge drive or fuel injection drive can be performed by the plunger.

In the apparatus having the above-described configuration, the control unit may employ a configuration in which the above-described pulse energization is performed on the coil based on a pulse width set in advance according to a current value flowing through the coil or a voltage value applied to the coil.
According to this configuration, the optimum pulse width corresponding to the current value flowing through the coil or the voltage value applied to the coil is obtained in advance and stored as a map in the storage unit included in the control means, and the detected actual current value or Since the pulse width corresponding to the voltage value can be read from the stored map and the coil can be energized based on the read pulse width information, the calculation process is simplified and the energization control is simplified. Is done.

In the apparatus having the above-described configuration, the control means performs the above-described pulse energization (pulse energization with an optimal pulse width corresponding to the current value or voltage value of the coil) based on predetermined temperature information in the engine operating state. Can be adopted.
According to this configuration, the above pulse is applied to the coil based on predetermined temperature information such as fuel temperature, ambient temperature around the engine related to the fuel temperature, surface temperature of the fuel injection pump, coil temperature, and the like. Since energization is performed, more accurate energization control can be performed according to the operating state of the engine.

In the apparatus having the above-described configuration, the control unit performs purge driving when the engine is in an idle operation state, and the above-described pulse energization in the purge driving (pulse energization with an optimal pulse width according to the current value or voltage value of the coil). The configuration can be adopted.
According to this configuration, when the engine is in the idling operation state, the purge driving that does not inject the fuel is performed between the fuel injection driving for injecting the fuel, and the pulse energization is performed in the purge driving. Even in a small state, the generated vapor can be efficiently discharged without being affected by fluctuations in the current value or voltage value of the coil, and the generation of vapor can be suppressed by obtaining a cooling action.

In the apparatus having the above-described configuration, the control means performs purge driving when the power source for starting the engine is turned on before starting, and performs the pulse energization (depending on the current value or voltage value of the coil) in the purge driving. Further, it is possible to adopt a configuration in which pulse energization is performed with an optimum pulse width.
According to this configuration, before starting or restarting the engine, the purge drive without injecting fuel is performed in the range of the initial region of the pumping stroke, and the pulse current is supplied in this purge drive. Alternatively, the accumulated vapor can be discharged in advance without being affected by fluctuations in the voltage value, and engine startability, particularly restartability can be improved.

  According to the fuel injection pump driving method and the fuel injection device having the above-described configuration, even if there is no structural change to the fuel injection pump or the like, it is affected by fluctuations in the current value flowing through the coil or the voltage value applied to the coil. Vapor can be discharged efficiently and reliably, especially when alcohol-mixed fuel is used, the vapor discharge efficiency can be increased to improve high-temperature performance, and temperature rise can be suppressed during idle operation. The generated vapor can be efficiently discharged, and the vapor generated in a high temperature atmosphere can be reliably discharged to improve the startability at the time of restart or the like.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 7 show an embodiment of a fuel supply system including a fuel injection device to which a driving method of a fuel injection pump according to the present invention is applied. FIG. 1 shows the fuel supply of an engine mounted on a motorcycle. FIG. 2 is a cross-sectional view of the fuel injection device, FIG. 3 is a time chart showing drive pulses and plunger strokes when the fuel injection pump is purge driven or fuel injection driven, and FIG. 4 is a plunger operation. FIG. 5 is a graph showing the relationship between the pulse width and the injection amount change rate with respect to the current value flowing through the coil, and the relationship between the current value and the pulse width, and FIGS. 6 and 7 are operating states before and after engine start. FIG. 8 and FIG. 9 are timing charts showing the state of purge driving and fuel injection driving pulses, coil current, and fuel injection in FIG. Drive pulse di- driving and the fuel injection drive, it is a time chart showing coil current, and the state of fuel injection. In FIG. 1, the fuel injection device shown in FIG. 2 is schematically shown with a part thereof omitted, and the return passage 121a in the cylinder 120 shown in FIG. 1 is shown outside the cylinder 120 in FIG.

  As shown in FIG. 1, the fuel supply system includes a fuel tank 10 for a two-wheeled vehicle, a fuel injection device M including an electromagnetically driven fuel injection pump 100 and an injection nozzle 200 disposed in an intake passage Ea of an engine E, and fuel. The feed pipe 20 to be supplied, the low pressure filter 30 disposed in the middle of the feed pipe 20, the return pipe 40 that forms a return passage for returning a part of the supplied fuel (surplus fuel) to the fuel tank 10, and the fuel injection pump 100 A control unit 50 as a control means for controlling driving, a battery 60 as a power source, a key switch 70 for turning on / off the entire system and starting the engine E are provided.

1 and 2, the fuel injection pump 100 includes a plunger 110 that reciprocates in the direction of the axis L, an inner yoke 121 that slidably accommodates the plunger 110, and a cylinder 120 that includes a passage member 122, and a plunger 110. A return spring 130 that is biased to a rest position, an excitation coil 140 wound around a bobbin 140a disposed outside the cylinder 120, an outer yoke 150 disposed outside the bobbin 140a, and defined on the tip side of the cylinder 120 An inlet check valve 160 (that is, a valve body 161 and a spring 162 that biases the valve body 161 in the valve closing direction) that allows only a flow toward the inside of the pressure feeding chamber C, and a return passage 121 a formed in the cylinder 120. Spill valve 170 (ie, valve body 171 A spring 172 for urging 171 in the valve closing direction, a filter case 180, a connector 191 connected to the feed pipe 20, a connector 192 connected to the return pipe 40, and a wiring connector 193 that integrally define the wiring case 193 190 and the like.
Here, the passage member 122 has a cylindrical pressure feeding chamber C that slidably receives the tip of the plunger 110, a supply port 122a that supplies fuel into the pressure feeding chamber C, and a passage that returns fuel mixed with vapor from the pressure feeding chamber C. It is formed to include a discharge port 122b for discharging to 121a.

  As shown in FIGS. 1 and 2, the injection nozzle 200 allows only discharge of fuel from the discharge passage 211 and the nozzle body 210 that define the injection port 212 located on the downstream side of the pressure feeding chamber C and the discharge passage 211. The valve 220 (that is, the valve body 221 and the spring 222 that biases the valve body 221 in the valve closing direction) and the poppet valve 230 that opens when the fuel is equal to or higher than the predetermined pressure (that is, the poppet valve 231 and the poppet valve 231 are closed) A spring 232) or the like that biases in the direction.

In the fuel injection device M configured as described above, as shown in FIGS. 3 and 4, when the coil 140 is pulse-energized to generate an electromagnetic driving force so as to perform fuel injection driving Tinj, the plunger 110 is moved to a rest position P. ₀ (position shown in FIG. 4 (a)) starts the fuel pumping stroke, and in the initial region, the purge stroke amount Sp is moved, and the plunger 110 closes the discharge port 122b midway position P ₁ (FIG. 4). (Position shown in (b)), the vapor-mixed fuel pressurized to a predetermined pressure passes through the opened spill valve 170 and is discharged from the return passage 121a to the return pipe 40.
When the plunger 110 further moves forward from the initial region to move the injection stroke amount Sinj and reaches the end position P ₂ (the position shown in FIG. 4C) in the late region, the pressure is increased to a predetermined level or more in the pressure feeding chamber P. The fuel that has been made opens the check valve 220 and opens the poppet valve 230, and is injected in the form of a mist from the injection port 212 into the intake passage Ea.

On the other hand, when the energization of the coil 140 is cut off, the plunger 110 is pushed back to the rest position P ₀ by the urging force of the return spring 130. At this time, the inlet check valve 160 is opened, the fuel is sucked from the feed pipe 20 toward the pressure feeding chamber C, and it waits for the next injection.

In addition, when the coil 140 is repeatedly energized and de-energized with a predetermined level of current value (or voltage level of a predetermined level) to perform the purge drive Tp that does not lead to fuel injection, the plunger 110 is in the rest position P _0. reciprocates the purge stroke Sp of ~ intermediate position P _1, the fuel vapor mingled in pumping chamber C is discharged towards the injection nozzle 200 (i.e., is injected toward the intake passage Ea) that Instead, it is only discharged from the return passage 121a to the return pipe 40.
That is, the plunger 110 sucks and pumps the fuel by reciprocation, releases the fuel toward the return passage 121a in the initial region of the pumping stroke, and pumps the fuel toward the injection port 212 in the latter region of the pumping stroke. It is supposed to be.

  As shown in FIG. 1, the control unit 50 as a control means performs various arithmetic processes and generates a control signal such as a CPU 51, a pump drive circuit 52 for driving the fuel injection pump 100, an engine E, and a fuel. A detection circuit 53 that detects various state quantities in the injection device M and outputs them to the control unit 51, detects the state of the key switch 70 (whether the power is on), the voltage of the battery 60, etc., and outputs them to the control unit 51 And a storage unit 55 in which various control information including engine operation information is stored.

The pump drive circuit 52 has an optimum drive frequency and optimum pulse width based on the control signal of the control unit 51 according to the operation state of the engine E and the state quantity such as the current value flowing through the coil 140 or the voltage value applied to the coil 140. Is set, and the coil 140 is subjected to pulse energization.
The detection circuit 43 includes a current value energized to the coil 140 by the pump drive circuit 52, a voltage value applied to the coil 140, the frequency of the drive pulse, the opening of the throttle valve Eb, the temperature of the engine E detected by the temperature sensor Ec, and the like. These various state quantities are detected, and the detected information is output to the control unit 51.
The detection circuit 54 detects the voltage value of the battery 60, the state of the key switch 70, that is, whether the power is on or at the start position, and outputs the detection information to the control unit 51. It has become.

The storage unit 55 includes various control information including engine operation information, an optimum pulse width value according to the current value flowing through the coil 140, an optimum pulse width value according to the voltage value applied to the coil 140, and a power source. The optimal pulse width value corresponding to the voltage value of the battery 60 is stored in advance as a control map.
For example, in order to generate an electromagnetic driving force that moves the plunger 110 by a predetermined stroke amount, current values (A) I1, I2, I3, I4, I5... (Where I1 <I2 <I3 <I4 <I5 < As the optimum pulse width (ms) corresponding to (...), values W11, W12, W13, W14, W15 of the pulse width (ms) obtained in advance (W11>W12>W13>W14>)W15> ...) and the optimum pulse width corresponding to the voltage value (v) V1, V2, V3, V4, V5 ... (where V1 <V2 <V3 <V4 <V5 <...). As the control information, the pulse width (ms) values W21, W22, W23, W24, W25... (Where W21>W22>W23>W24>W25>. Mapped and remembered

  The control unit 51 is responsible for overall control by issuing various control signals based on various information detected by the detection circuits 53 and 54. The control information detected by the detection circuit 54 (for example, the coil 140). A comparison circuit (not shown) that compares an actual current value flowing through the coil or an actual voltage value applied to the coil 140 and a control map (information indicating the relationship between the current value or voltage value and the pulse width) stored in the storage unit 55 in advance. And a determination circuit (not shown) for determining the optimum pulse width, drive frequency, and the like based on the output signal of the comparison circuit.

That is, the control unit (control means) 50 controls the driving of the fuel injection pump 100 according to the operating state of the engine E based on various information detected by the detection circuits 53 and 54. Specifically, according to the operating state of the engine E, the coil 140 is subjected to pulse energization control so that the plunger 110 performs a purge drive Tp that does not lead to fuel injection or a fuel injection drive Tinj that injects fuel. In addition, an optimum pulse width corresponding to the value of the current flowing through the coil 140 or the voltage value applied to the coil 140 is set, and pulse energization control of the coil 140 is performed with this optimum pulse width.
Therefore, even if the current value flowing through the coil 140 or the voltage value applied to the coil 140 fluctuates, the plunger 110 is moved by a predetermined stroke amount (a constant purge stroke amount during the purge drive Tp) without being affected by this fluctuation. In the case of Sp, fuel injection drive Tinj, it can be moved stably over a certain injection stroke amount Sinj). Thus, the vapor can be efficiently discharged in the purge drive Tp, and the fuel is efficiently discharged in the initial region and the predetermined amount of fuel is injected with high accuracy in the later region in the fuel injection drive Tinj. Can be made.

Next, driving of the fuel injection pump 100 in the fuel supply system will be described with reference to the time charts of FIGS. 6 and 7 and the time charts of FIGS.
First, when the key switch 70 is turned on (power is turned on), the control unit 51 issues a control signal to the pump drive circuit 52, and the pump drive circuit 52 is connected to the plunger 110 as shown in FIG. In order to perform purge drive Tp that does not lead to fuel injection, the coil 140 is pulsed with a predetermined pulse width Wp.

That is, the control unit 51 performs various arithmetic processes based on the state quantities detected by the detection circuits 53 and 54 (the voltage value applied to the coil 140 or the voltage value of the battery 60), and sends control signals to the pump drive circuit 52. To emit. Based on these control signals, the pump drive circuit 52 sets an optimum pulse width Wp corresponding to a predetermined voltage value Va applied to the coil 140 as shown in FIG. Perform pulse energization.
Then, the plunger 110 moves by a predetermined purge stroke amount Sp corresponding to the initial region of the pressure feed stroke, and compresses the fuel in the pressure feed chamber C by a predetermined amount without injecting the fuel, and discharges the fuel mixed with vapor. It discharges from the exit 122b toward the return passage 121a.

  Thus, before the engine E is started, the plunger 110 is purge-driven Tp in the initial region of the pressure feed stroke, so that the vapor staying in the pressure feed chamber C is discharged in advance, and in particular after the high load operation, the engine E When the engine E is started again after being stopped and left as it is, a large amount of vapor may remain, but the generated vapor is discharged in advance and the engine E is started smoothly. be able to. In particular, when alcohol mixed fuel is used, vapor can be discharged efficiently.

Here, based on the state quantity (for example, the voltage value applied to the coil 140 or the voltage value of the battery 60) detected by the detection circuits 53 and 54, the control unit 51 detects that the detected voltage value Vb is a voltage value at a predetermined level. If it is determined that it is lower than Va (Vb <Va), this determination information is issued to the pump drive circuit 52. Then, as shown in FIG. 7, the pump drive circuit 52 has an optimum pulse width Wp ′ corresponding to the low voltage value Vb, that is, a pulse width Wp ′ (Wp ′> Wp) larger than a predetermined width (Wp). Is set, and pulse energization is performed on the coil 140 with the set pulse width Wp ′.
Then, the coil 140 generates a predetermined level of electromagnetic driving force, and the plunger 110 reliably moves the purge stroke amount Sp corresponding to the initial region of the pumping stroke without stopping in the middle of the purge stroke amount Sp. While the fuel in the pumping chamber C is compressed by a predetermined amount without injecting the fuel, the fuel mixed with vapor is discharged from the discharge port 122b toward the return passage 121a.

In this way, when the voltage value applied to the coil 140 is smaller than a predetermined level, the pulse width is set larger and the coil 140 is energized with a pulse, whereby the plunger 110 is moved to a predetermined stroke amount, that is, constant. The purge stroke amount Sp can be moved, and the plunger 110 can be caused to perform a predetermined purge drive Tp.
Therefore, even when the voltage value is low, the predetermined purge driving Tp is performed before the engine E is started, so that the vapor staying in the pressure feeding chamber C is discharged in advance, and the engine E after the high load operation as described above. When the engine E is started again after being stopped and left as it is, a large amount of vapor may remain, but the generated vapor is discharged in advance and starts the engine E smoothly. be able to.

  The purge driving Tp is preferably performed for a predetermined time after the key switch 70 is turned on by measuring a time by providing a timer (not shown) or the like. In addition, a counter (not shown) is provided to count the number of pulses so that it is performed a predetermined number of times. Thereby, useless driving after the vapor is completely discharged is avoided, and power consumption is reduced.

  Subsequently, the control unit 51 determines whether or not the engine E has been started by turning the key switch 70 to the start position. If it is determined that the engine E has not yet been started, the fuel injection is continued until the engine is started. When it is determined that the engine E has been started by repeating the start mode, it is determined whether the engine E is in an idling operation state based on various detection information detected by the detection circuits 53, 54, and the like.

  Here, when the control unit 51 determines that the engine E is not in the idle operation state, the control unit 51 responds to the operation state based on the detection information detected by the detection circuits 53 and 54, the control map stored in the storage unit 55, and the like. In other words, the pump drive circuit 52 has a pulse width Winj larger than the pulse width Wp in the purge drive Tp and the coil 140 so as to cause the plunger 110 to perform a predetermined fuel injection drive Tinj. The coil 140 is pulsed with an optimum pulse width corresponding to the current value or voltage value.

  On the other hand, when the control unit 51 determines that the engine E is in the idling operation state, the detection information detected by the detection circuits 53 and 54 (the current value of the coil 140, the voltage value applied to the coil 140, the voltage of the battery 60) Control signal is sent to the pump drive circuit 52 based on the value, the drive frequency of the previous purge drive Tp, and the like. Then, the pump drive circuit 52 sets an optimal pulse width for the coil 140 based on these control signals, and performs pulse energization so that the plunger 110 performs the purge drive Tp and the fuel injection drive Tinj. .

  That is, the control unit 51 performs various arithmetic processes based on state quantities (such as a current value flowing through the coil 140) detected by the detection circuits 53 and 54, and issues a control signal to the pump drive circuit 52. Based on these control signals, the pump drive circuit 52 sets optimum pulse widths Wp and Winj corresponding to a predetermined level of current value Ia flowing through the coil 140 as shown in FIG. On the other hand, pulse energization that generates a plurality of drive pulses of purge drive Tp that does not lead to injection in the interval between a drive pulse of one fuel injection drive Tinj that injects fuel and a drive pulse of the next fuel injection drive Tinj I do. Thereby, the generated vapor can be efficiently discharged even in the idling operation state with a small fuel flow rate, the heat generated from the coil 140 can be cooled, and the generation of vapor can be suppressed.

Here, the detected current value Ib is smaller than the current value Ia at a predetermined level based on the state quantity (for example, the current value flowing through the coil 140) detected by the detection circuits 53 and 54 by the control unit 51 ( If it is determined that Ib <Ia), this determination information is issued to the pump drive circuit 52. Then, as shown in FIG. 9, the pump drive circuit 52 has an optimum pulse width Wp ′, Winj ′ corresponding to the small current value Ib, that is, a pulse width Wp ′, larger than a predetermined width (Wp, Winj). Winj ′ (Wp ′> Wp, Winj ′> Winj) is set, and pulse energization is performed on the coil 140 with the set pulse widths Wp ′ and Winj ′.
Then, the coil 140 generates a predetermined level of electromagnetic driving force, and the plunger 110 does not stop in the middle of the purge stroke amount Sp in the purge drive Tp, and the predetermined purge stroke amount Sp corresponding to the initial region of the pumping stroke. The fuel in the pumping chamber C is compressed by a predetermined amount without injecting the fuel, and the vapor-mixed fuel is discharged from the discharge port 122b toward the return passage 121a, and the fuel injection drive Tinj , The injection stroke amount Sinj is surely moved to discharge the vapor in the initial region, and the predetermined fuel necessary for the idling operation is injected from the injection port 212 in the latter region.

In this way, when the value of the current flowing through the coil 140 is smaller than a predetermined level, the pulse width is set to be larger and the coil 140 is energized with a pulse, whereby the plunger 110 is moved to a predetermined stroke amount, that is, a constant amount. The purge stroke amount Sp or a fixed injection stroke amount Sinj can be moved, and the plunger 110 can perform a predetermined purge drive Tp or fuel injection drive Tinj.
Therefore, even when the current value is small, the predetermined purge drive Tp is performed during the idling operation of the engine E. Therefore, even if the fuel flow rate is small, the generation is not affected by fluctuations in the current value or voltage value of the coil 140. Thus, the generated vapor can be efficiently discharged, and a cooling effect can be obtained, thereby suppressing the generation of vapor.

  In addition to the above-described drive control, the control unit 50 provides predetermined temperature information in the operating state of the engine E, for example, the fuel temperature, the ambient temperature around the engine E related to the fuel temperature, the surface of the fuel injection pump 100 Based on temperature information such as the temperature and the temperature of the coil 140, the coil 140 may be subjected to pulse energization with the optimum pulse width set as described above. According to this, more accurate energization control can be performed according to the operating state of the engine E.

In the above embodiment, the fuel injection device M in which the fuel injection pump 100 and the injection nozzle 200 are integrated is shown, but the same applies to a system in which both are separately disposed and connected by a fuel pipe or the like. In addition, the driving method of the present invention can be applied.
In the above embodiment, the drive control is performed so that the purge drive Tp is performed when the engine E is in the idle operation state or when the power source for starting the engine E is turned on before the start. However, the present invention is not limited to this, and even in a low-load operation state other than the idle operation, the coil 140 is similarly applied with the optimum pulse width as long as the purge drive Tp can be added. By performing the pulse energization, it is possible to increase the vapor discharge efficiency and to secure the cooling action and suppress the generation of the vapor.

It is a schematic block diagram which shows the fuel supply system which employ | adopted the fuel-injection apparatus which applies the drive method of the fuel-injection pump which concerns on this invention. It is sectional drawing which shows the fuel-injection apparatus which concerns on this invention. It is a time chart which shows the drive pulse and the stroke of a plunger at the time of carrying out purge drive and fuel injection drive of a fuel injection pump. (A) is a partial cross-sectional view showing a state where the plunger is at a rest position, (b) is a partial cross-sectional view showing a state where the plunger has moved a purge stroke amount, and (c) is a view illustrating the operation of the plunger. It is a fragmentary sectional view which shows the state which the plunger moved the amount of injection strokes. (A) is a graph which shows the relationship between the pulse width with respect to the coil current value, and the injection rate change rate, and (b) is a graph which shows the relationship between the coil current value and the pulse width. It is a time chart which shows the state of the drive pulse of purge drive and fuel injection drive, coil current, and fuel injection in the driving state before and after engine startup. It is a time chart which shows the state of the drive pulse of the purge drive and fuel injection drive, coil voltage, and fuel injection in the driving | running state before and behind engine starting. It is a time chart which shows the drive pulse of a purge drive and a fuel injection drive, a coil voltage, and the state of a fuel injection when an engine is in an idle driving | running state. It is a time chart which shows the state of the drive pulse of a purge drive and a fuel injection drive, a coil current, and a fuel injection when an engine is in an idle driving | running state. The operation | movement of the plunger by the drive method of the conventional fuel injection pump is shown, (a) is a fragmentary sectional view which shows the state which has a plunger in a rest position, (b) shows the state which the plunger moved the purge stroke amount. (C) is a partial cross-sectional view showing a state where the plunger has stopped before the purge stroke is completely moved.

Explanation of symbols

E Engine Ea Intake passage 10 Fuel tank 20 Feed pipe 30 Low pressure filter 40 Return pipe (return passage)
50 Control unit (control means)
51 Control Unit 52 Pump Drive Circuits 53 and 54 Detection Circuit 55 Storage Unit 60 Battery (Power Supply)
70 Key switch M Fuel injection device 100 Fuel injection pump 110 Plunger 120 Cylinder 121 Inner yoke 121a Return passage 122 Passage member C Pressure feeding chamber 122a Supply port 122b Discharge port 130 Return spring 140 Coil 140a Bobbin 150 Outer yoke 160 Inlet check valve 161 Valve body 162 Spring 170 Spill valve 171 Valve body 172 Spring 180 Filter member 190 Case 191, 192 Connector 193 Wiring connector 200 Injection nozzle 210 Nozzle body 211 Discharge passage 212 Injection port 220 Check valve 221 Valve body 222 Spring 230 Poppet valve 231 Poppet valve 232 Spring Tp Purge Drive Tinj Fuel injection drive

Claims (14)

A plunger that sucks and pumps fuel by reciprocating motion, releases the fuel toward the return passage in the initial region of the pumping stroke, and pumps the fuel toward the injection port in the latter region of the pumping stroke, and electromagnetically activates the plunger Energizing coil for controlling force and energizing the coil to perform purge driving that does not lead to fuel injection and / or fuel injection driving to inject fuel according to the operating state of the engine A method for driving a fuel injection pump comprising control means for
The control means performs pulse energization to the coil with a pulse width corresponding to a current value flowing through the coil or a voltage value applied to the coil.
A method for driving a fuel injection pump. The control means performs the pulse energization in the purge drive.
The method for driving a fuel injection pump according to claim 1. The control means sets the pulse width larger than a predetermined width when the current value or voltage value is smaller than a predetermined level.
The method for driving a fuel injection pump according to claim 1 or 2. The control means performs the pulse energization based on a pulse width set in advance according to a current value flowing through the coil or a voltage value applied to the coil.
The method for driving a fuel injection pump according to any one of claims 1 to 3. The control means performs the pulse energization based on predetermined temperature information in an engine operating state.
The method for driving a fuel injection pump according to any one of claims 1 to 4, The control means performs the purge drive when the engine is in an idle operation state and performs the pulse energization in the purge drive.
6. The method for driving a fuel injection pump according to claim 1, wherein the fuel injection pump is driven. The control means performs the purge drive when the power source for starting the engine is turned on before the start, and performs the pulse energization in the purge drive.
6. The method for driving a fuel injection pump according to claim 1, wherein the fuel injection pump is driven. A plunger that sucks and pumps fuel by reciprocating motion, releases the fuel toward the return passage in the initial region of the pumping stroke, and pumps the fuel toward the injection port in the latter region of the pumping stroke, and electromagnetically activates the plunger Energizing coil for controlling force and energizing the coil to perform purge driving that does not lead to fuel injection and / or fuel injection driving to inject fuel according to the operating state of the engine A fuel injection device comprising a control means for
The control means performs pulse energization to the coil with a pulse width corresponding to a current value flowing through the coil or a voltage value applied to the coil.
A fuel injection device. The control means performs the pulse energization in the purge drive.
The fuel injection device according to claim 8. The control means sets the pulse width larger than a predetermined width when the current value or voltage value is smaller than a predetermined level.
The fuel injection device according to claim 8 or 9, wherein The control means performs the pulse energization based on a pulse width set in advance according to a current value flowing through the coil or a voltage value applied to the coil.
The fuel injection device according to claim 8, wherein the fuel injection device is a fuel injection device. The control means performs the pulse energization based on predetermined temperature information in an engine operating state.
The fuel injection device according to claim 8, wherein the fuel injection device is a fuel injection device. The control means performs the purge drive when the engine is in an idle operation state and performs the pulse energization in the purge drive.
The fuel injection device according to claim 8, wherein the fuel injection device is a fuel injection device. The control means performs the purge drive when the power source for starting the engine is turned on before the start, and performs the pulse energization in the purge drive.
The fuel injection device according to claim 8, wherein the fuel injection device is a fuel injection device.

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