Fuel injection control device for a vehicle, vehicle control method and fuel injection control program for a vehicle

Abstract

Control device (150) for a vehicle for controlling a fuel injection device (101, 101A-101D) with a valve (214) that comes into contact with and is separated from a valve seat (218), a mover (202) that actuates the valve (214), an electromagnet (205) that generates a magnetic attraction force to attract the mover (202) to form a space for introducing a fuel between the valve seat (218) and the valve (214), and a solid core (207) that attracts the mover (202) by the magnetic attraction force, wherein the control device (150) comprises a control unit that performs: a first current control for the electromagnet (205) by a first current waveform (601) by switching a polarity of a voltage applied to the electromagnet (205) before the mover (202) or the valve (214) collides with a fixed area to a polarity that is reversed to the polarity of the voltage applied before the mover (202) or the valve (214) collides with the fixed area, when an injection quantity of the fuel that is injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is a set value or more; and a second current control for the electromagnet (205) by a second current waveform (602), such that a current greater than a holding current (610) that keeps the mover (202) or the valve (214) in a state of contact with the fixed area flows to the electromagnet (205) until the mover (202) or the valve (214) collides with the fixed area when the amount of fuel injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is less than the set value.

Description

Technical area

[0001] The present invention relates to a control device for a vehicle for controlling a fuel injection device of an internal combustion engine, a method for controlling the fuel injection for a vehicle and a program for controlling the fuel injection for a vehicle. State of the art

[0002] Recently, stricter emissions regulations and environmental protection have led to a demand for lean combustion in engines, where the fuel is burned in a leaner state than in a theoretical air-fuel ratio. With lean combustion, the combustion rate is slow and the combustion becomes unstable because the fuel is in a lean state, and therefore the pressure in an engine cylinder varies with each cycle, which can be a limitation of lean combustion. Therefore, with lean combustion, it is necessary to suppress the fluctuation of the fuel injected (injection quantity) with each injection from the fuel injector to minimize this variation for each cycle.

[0003] Generally, the amount of fuel injected by the fuel injection device is controlled by the pulse width of an injection pulse issued by an engine control unit (ECU). An electromagnetic fuel injection device with a normally closed valve comprises a biasing device for generating a force in the valve closing direction and a drive unit with an electromagnet, a solid core, and a mover. Current is supplied to the electromagnet in the drive unit, generating a magnetic attraction between the solid core and the mover. The mover then moves in a valve opening direction at a time when the magnetic attraction exceeds a biasing force in the valve closing direction. The valve is then separated from a valve seat and begins to open at the time the mover collides with the valve.Then, when the power supply to the electromagnet is stopped, the magnetic attraction generated between the solid core and the mover is reduced, and the valve begins to close at a time when the magnetic attraction becomes smaller than the preload force in the valve closing direction.

[0004] To quickly switch the valve from a closed to an open state, a drive circuit of the electromagnetic fuel injector first applies a high voltage from a high-voltage source to the electromagnet when the injection pulse is issued by the ECU. It then performs a control operation to rapidly increase the current to the electromagnet. Afterward, the valve is separated from the valve seat and moves toward the solid core. The control circuit then manages the switching to deliver a constant current to the electromagnet by switching from an applied voltage to a low voltage.

[0005] Since the injection quantity of the fuel injection device is determined by an integral value of the valve displacement amounts, it is necessary to keep the movement of the valve at the same level for each injection in order to suppress any variation for each injection (injection variation).

[0006] WO 2015 / 004 988 A1 discloses a method for selecting a reference fuel injector from a plurality of fuel injectors based on information about a response delay time when opening the valve and / or a response delay time when closing the valve for each fuel injector and for correcting the control pulse widths of the other fuel injectors in order to match each of the injection quantities of the other fuel injectors to an injection quantity of the selected fuel injector.

[0007] DE 11 2017 003 720 T5 discloses a control device for controlling a fuel injection device, which includes a valve body, an electromagnet and a movable element for opening the valve body, with a control unit that controls a control voltage or a control current to be applied to the electromagnet, in which the control unit controls the control current in such a way that the control current to be supplied to the electromagnet decreases from a maximum control current after the maximum control current has been supplied to the electromagnet and before the valve body begins to open.

[0008] US Patent 2016 / 0237937A1 discloses a drive device for a fuel injection system that increases the accuracy of the injected fuel quantity by combining fuel injections with multiple injection pulse widths. The drive device controls the fuel injection system so that fuel injection occurs multiple times within a combustion cycle. This includes both a fuel injection with a target opening degree, where a valve element or a moving element of the fuel injection system reaches a control element, and a fuel injection with an intermediate opening degree, where the valve element does not reach the control element.

[0009] WO 2013 / 124890 A1 discloses a device that operates using electromagnetic force and detects the magnetic flux to determine the magnetic attraction. A control current is calculated to suppress fluctuations in the magnetic flux or magnetic attraction caused by device deviations when current is applied. A distortion detection device, capable of detecting distortions in the direction of the magnetic flux in a magnetic circuit, is attached to a component of the magnetic circuit. The magnetic flux is detected based on the distortion value, and the control current is regulated accordingly.Particularly in the case of a fuel injection valve that operates electromagnetically with a solenoid, by attaching the distortion detection device to a component of the magnetic circuit outside the fuel channel, fluctuations in valve operation due to product variations and changes in environmental conditions can be suppressed, and an accurate measurement of the injection quantity can be achieved. This is accomplished by attaching the distortion detection device to a component of the magnetic circuit outside the fuel channel and determining the shape of the control current based on the detected value.

[0010] WO 2013 / 191267 A1 discloses a control device that detects the individual deviations in the amount of fuel injected by the injectors of each cylinder. The injection pulse width and the current waveform of a solenoid valve are adjusted to reduce these deviations. This regulates the injection quantity at medium valve lift when the valve body is not in contact with the solid core. The voltage between the terminals of a solenoid valve is detected for the injector of each cylinder. From the change in the induced electromotive force due to the change in the acceleration of the armature during the transition of the valve body from the open to the closed state and the subsequent separation of the armature from the valve body after contact of the valve body with the valve seat, the point in time at which the second derivative of the voltage between the terminals of the solenoid valve is at its maximum is determined.This point in time is used to determine the point in time at which the valve housing is completely closed.

[0011] JP 2006 - 220 075 A discloses a control device for a direct-injection hydrogen-powered engine, whose hydrogen injection valve is opened and closed by a control current to inject gaseous hydrogen directly into the combustion chamber. During a cold start of the engine, the control device increases the control current to the hydrogen injection valve. The degree of increase in the control current is corrected based on a parameter that takes into account the engine's freezing state. This increase in the control current closes a shut-off valve upstream of the hydrogen injection valve, interrupting the supply of gaseous hydrogen to the injection valve. Simultaneously, ignition of the mixture in the combustion chamber of the hydrogen engine is prevented.

[0012] JP 2017-57798A discloses a control unit that injects and regulates a control current into the fuel injection device. Once the control current reaches its maximum value, the control unit regulates the fuel injection device by injecting an initial control current that is smaller than the maximum value. This adjusts the value of this initial control current to correct the amount of fuel injected by the fuel injection device. Summary of the invention: Technical problem

[0013] One objective of the technology disclosed in WO 2015 / 004 988 A1 is to correct the drive pulse width for each fuel injector in order to supply fuel to each cylinder and to suppress relative variation in the amount of fuel injected to each cylinder. However, the technology disclosed in WO 2015 / 004 988 A1 does not mention that it reduces injection quantity variation from the fuel injector (valve).

[0014] The present invention was made in view of these circumstances, and one objective of the present invention is to suppress a variation in the displacement of a valve for each injection and to reduce an injection variation in the injection quantity. Solution to the problem

[0015] A vehicle control device according to one aspect of the present invention controls a fuel injection device comprising a valve that comes into contact with and is separated from a valve seat, an actuator that drives the valve, an electromagnet that generates a magnetic attraction force to attract the actuator in order to create a space for introducing fuel between the valve seat and the valve, and a solid core that attracts the actuator by the magnetic attraction force. The vehicle control device includes a control unit that performs control of a current supplied to the electromagnet.

[0016] The control unit performs an initial current control for the electromagnet by means of an initial current waveform, switching the polarity of a voltage applied to the electromagnet before the mover or valve collides with a fixed area to a polarity that is reversed to the polarity of the voltage applied before the mover or valve collides with the fixed area, when the amount of fuel injected until the valve comes back into contact with the valve seat after the valve has been separated from the valve seat is a set value or greater.

[0017] Additionally, the control unit performs a second current control for the electromagnet by means of a second current waveform, so that a current greater than a holding current, which keeps the mover or valve in a state where it is in contact with the fixed area, flows to the electromagnet until the mover or valve collides with the fixed area when the amount of fuel injected until the valve comes back into contact with the valve seat after the valve has been separated from the valve seat is less than the set value. Advantageous effects of the invention

[0018] According to the present invention, it is possible to suppress a fluctuation in the displacement of the valve for each injection and to reduce an injection fluctuation in the injection quantity in a range from a small injection quantity to a large injection quantity.

[0019] Objects, configurations and effects other than those described above will be evident from the following description of the embodiments. Brief description of the drawings Fig. 1] Fig. Figure 1 is a schematic view showing an example of a fuel injection system with a fuel injection device and a control device according to a first embodiment of the present invention. Fig. 2] Fig. Figure 2 is a view showing an example of a longitudinal section of the fuel injection device according to the first embodiment of the present invention, and is a view showing a configuration example of a drive circuit and an engine control unit (ECU) connected to the fuel injection device. Fig. 3] Fig. Figure 3 is an enlarged cross-sectional view showing an example of the construction of a drive unit of the fuel injection device according to the first embodiment of the present invention. Fig. 4] Fig. Figure 4 is a timing diagram showing a relationship between a general injection pulse for controlling the fuel injection device, a control voltage and a control current supplied to the fuel injection device, and the displacement amounts of a valve and a mover, as well as a time. Fig. 5] Fig. Figure 5 is a circuit diagram showing an example of the drive circuit and the ECU of the fuel injection device. Fig. 6] Fig. Figure 6 is a timing diagram showing a relationship between the injection pulse, the drive current supplied to the fuel injection device, an operating time of a switching element of the fuel injection device, a voltage at the terminals of an electromagnet and the displacement amounts of the valves and the mover, as well as a time according to the first embodiment of the present invention. Fig. 7] Fig. Figure 7 is a diagram showing a relationship between an injection quantity when the fuel injection device is driven by the drive current waveform of Fig. 6 is controlled, and shows a standard deviation (σ) of an injection quantity fluctuation and an injection pulse width. Fig. 8] Fig. Figure 8 is a diagram showing a relationship between a voltage at the terminals of an electromagnet and a drive current supplied to a fuel injection device, and a time, according to a first modification of the first embodiment of the present invention. Fig. 9] Fig. Figure 9 is a diagram showing a relationship between a drive current supplied to a fuel injection device and a displacement amount of a valve and a time according to a second embodiment of the present invention. Fig. 10] Fig. Figure 10 is a diagram showing an injection timing and injection duration for an intake stroke and a compression stroke according to a third embodiment of the present invention. Fig. 11] Fig. Figure 11 is a diagram showing an injection timing and injection duration for an intake stroke and a compression stroke according to a fourth embodiment of the present invention. Fig. 12] Fig. Figure 12 is a diagram showing a relationship between an injection quantity and a standard deviation (σ) of an injection quantity variation and an injection pulse width according to a fifth embodiment of the present invention. Description of the embodiments

[0020] Examples of embodiments of the present invention (hereinafter referred to as "embodiments") are described below with reference to the accompanying drawings. In this description and the accompanying drawings, components that have essentially the same functions or configurations are identified by the same reference numerals, and redundant descriptions are omitted. <Erste Ausführungsform> [Fuel injection system configuration]

[0021] The following describes a configuration of a fuel injection system according to a first embodiment of the present invention with reference to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 described.

[0022] First, a sketch of a fuel injection system according to the first embodiment is presented with reference to Fig. 1 described. Fig. Figure 1 shows an embodiment of a fuel injection system 1 according to the first embodiment. The fuel injection system 1 is an example in which the present invention is applied to an engine with direct injection in the cylinder (an example of an internal combustion engine), but the present invention is not limited to this example. In this description, the engine with direct injection in the cylinders is simply referred to as the “engine”.

[0023] As in Fig. As shown in Figure 1, the fuel injection system 1 comprises four fuel injection devices 101A to 101D and a control device 150. The cylinder direct injection engine according to the present embodiment comprises four cylinders 108 (engine cylinders). The control device 150 is, for example, a control device for a vehicle for controlling the fuel injection devices 101. In the following description, where the fuel injection devices 101A to 101D are not distinguished, they are referred to as the “fuel injection devices 101”.

[0024] The fuel injection devices 101A to 101D are each installed in the cylinders 108 of the fuel injection system 1, so that an air-fuel mixture is drawn from an injection port 219 (see Fig. 2 (described below) the fuel injection device is injected directly into the combustion chambers 107. The fuel is routed to a fuel line 105 after being pressurized by a fuel pump 106, and the fuel is delivered through the fuel line 105 to the fuel injection devices 101A to 101D. A pressure sensor 102 for measuring fuel pressure in the fuel line 105 is installed at one end of the fuel line 105. The fuel pressure varies depending on the balance between the flow rate of fuel delivered by the fuel pump 106 and the amount of fuel injected by the fuel injection devices 101 into each of the fuel chambers 107. The amount of fuel delivered by the fuel pump 106 is controlled based on a measurement by the pressure sensor 102 at a predetermined pressure as the setpoint.

[0025] The fuel injection of each of the fuel injectors 101A to 101D is controlled by the pulse width of an injection pulse sent by an engine control unit (ECU) 104 (hereinafter referred to as the "injection pulse width"). That is, the amount of injected fuel is determined based on the injection pulse width supplied to the fuel injectors 101. An injection pulse width command is input to a control circuit 103, which is provided for each fuel injector 101. The control circuit 103 determines a waveform of a control current based on a command from the ECU 104 (sometimes abbreviated as "current") and supplies the control current of the waveform to the fuel injector 101 for a time based on the injection pulse width.Note that the control circuit 103 can be mounted as a component or as a substrate integrated with the ECU 104. In the present embodiment, a device in which the control circuit 103 and the ECU 104 are integrated is referred to as the control device 150.

[0026] Next, a configuration and basic operating principle of the fuel injection device 101 and the control device 150 will be described. Fig. Figure 2 shows an example of a longitudinal section of the fuel injection device 101 and a configuration example of the drive circuit 103 and the ECU 104 connected to the fuel injection device 101.

[0027] The ECU 104 receives signals indicating the engine's condition from various types of sensors (not shown) and calculates the injection pulse width or injection timing to control the amount of fuel injected by the fuel injection device 101, depending on the internal combustion engine's operating condition. The ECU 104 is also equipped with an analog-to-digital converter (ADC) and an input / output (I / O) port to receive signals from these sensors. The injection pulse output by the ECU 104 is fed into the driver circuit 103 via a signal line 110. The driver circuit 103 controls a voltage applied to an electromagnet (coil) 205 and supplies a current. The ECU 104 communicates with the driver circuit 103 via a communication line 111.The ECU 104 can switch the drive current generated by the drive circuit 103 according to the pressure of the fuel to be supplied to the fuel injection device 101 and the operating condition, or change set values ​​of the current and a time via the communication line 111.

[0028] Next, the design and operation of the fuel injection device 101 will be described with reference to the longitudinal section of the fuel injection device 101. Fig. 2 and Fig. 3 described. Fig. Figure 3 is an enlarged cross-sectional view showing an example of the construction of a drive unit for the fuel injection device 101. In particular, a relationship between a mover 202, a valve 214 and a solid core 207 is described.

[0029] The in the Fig. 2 and Fig. The fuel injection device 101 shown in Figure 3 is an electromagnetic fuel injection device equipped with a normally closed electromagnetic valve. Inside the fuel injection device 101 is a substantially rod-shaped valve 214. An opening cup 216, in which a valve seat 218 is formed, is located opposite a distal end of the valve 214. The injection port 219 for injecting the fuel is formed in the valve seat 218. A spring (hereinafter referred to as the "first spring") 210, which biases the valve 214 in a valve closing direction (downward), is provided on an upper section of the valve 214. When the electromagnet 205 is energized, a magnetic attraction force acts on the actuator 202 to move it, and the valve 214 moves in conjunction with the actuator 202.When the electromagnet 205 is not excited, the valve 214 is biased in the valve closing direction by the first spring 210, the valve 214 comes into contact with the valve seat 218 and the fuel is sealed (valve closed state).

[0030] A concave section 202C is formed in an upper end face 202A of the mover 202, extending towards a lower end face 202B of the mover 202. An intermediate element 220 is provided within the concave section 202C. The intermediate element 220 is located midway between the mover 202 and the solid core 207. A concave section 220A extends upwards into a lower face of the intermediate element 220. The concave section 220A is configured to have a diameter (inner diameter) and a depth such that a stepped section 329 (flange section), formed in an annular shape on an outer circumferential surface of a head section 214A, fits into the concave section 220A.That is, the diameter (inner diameter) of the concave section 220A is larger than a diameter (outer diameter) of the stepped section 329, and a depth dimension of the concave section 220A is larger than a dimension between an upper end face and a lower end face of the stepped section 329. A through-hole 220B is formed in a bottom (bottom surface 220E) of the concave section 220A, through which a projection 331 of the head section 214A penetrates.

[0031] A spring (hereinafter referred to as the "third spring") 234 is held between the intermediate element 220 and a cap 232. A spring seat, against which one end of the third spring 234 rests, is formed on an upper end surface 220C of the intermediate element 220. The third spring 234 pre-tensions the mover 202 in the valve closing direction from the fixed core 207.

[0032] The lid-like cap 232 is arranged above the intermediate element 220. A flanged section 232A, projecting in a radial direction, is formed on an upper end section of the cap 232, and a spring seat, against which the other end of the third spring 234 rests, is formed on a lower end face of the flanged section 232A. A cylindrical section 232B is formed downwards on the lower end face of the flanged section 232A of the cap 232, and an upper section (head section 214a) of the valve 214 is pressed into and secured in the cylindrical section 232B.

[0033] As such, the cap 232 and the intermediate element 220 form the spring seat of the third spring 234. Therefore, the diameter (inner diameter) of the through-hole 220B of the intermediate element 220 is smaller than the diameter (outer diameter) of the flange section 232A of the cap 232. Furthermore, the diameter (outer diameter) of the cylindrical section 232B of the cap 232 is smaller than the inner diameter of the third spring 234.

[0034] The cap 232 receives a preload force from the first spring 210 from above and a preload force (target load) from the third spring 234 from below. The preload force of the first spring 210 is greater than the preload force of the third spring 234. This causes the cap 232 to be pressed against the projection 331 formed on the upper part of the valve 214 by the difference between the preload force of the first spring 210 and the preload force of the third spring 234. No force is exerted on the cap 232 in the direction (downwards in the drawing) in which the valve 214 extends from the projection 331 of the valve 214. The cap 232 can also be pressed into place and attached to the projection 331 without being welded.

[0035] Furthermore, it is necessary to provide a certain gap between the lower end face of the flange section 232A of the cap 232 and the upper end face 220C of the intermediate element 220 in order to accommodate the third spring 234. Therefore, the length of the cylindrical section 232B of the cap 232 is slightly fixed.

[0036] Intermediate member 220 is described again. A in Fig. Figure 2 of the fuel injection device 101 depicts a state in which the valve 214 absorbs the preload force generated by the first spring 210 and the magnetic attraction force does not act on the mover 202. In this state, a distal end 214B (seat section) of the valve 214 rests against the valve seat 218, and thus the fuel injection device 101 is in a closed and stable state.

[0037] In the closed state of the valve, the intermediate element 220 absorbs the preload force of the third spring 234, and a bottom surface 220E of the concave section 220A formed in the intermediate element 220 abuts the upper end surface of the stepped section 329 of the valve 214. That is, the size (dimension) of a gap G3 between the bottom surface 220E of the concave section 220A formed in the intermediate element 220 and the upper end surface of the stepped section 329 of the valve 214 is zero. The bottom surface 220E of the concave section 220A formed in the intermediate element 220 and the upper end surface of the stepped section 329 of the valve 214 form a contact surface at which the intermediate element 220 abuts the valve 214.

[0038] A zero spring (hereinafter referred to as the “second spring”) 212 is arranged between the lower end surface 202B of the mover 202 and a stop surface 303 formed inside a nozzle holder 201 (cylindrical section 240 with a large diameter). Since the mover 202 receives a preload force from the second spring 212 and is then biased towards the solid core 207, a bottom surface 202D of the concave section 202C formed in the mover 202 abuts a lower end surface 220D of the intermediate element 220. The preload force of the second spring 212 is less than the preload force of the third spring 234. Therefore, the mover 202 is unable to push back the intermediate element 220, which is biased downwards by the third spring 234, and thus the movement of the mover 202 in an upward direction (valve opening direction) is stopped by the intermediate element 220 and the third spring 234.

[0039] The depth dimension of the concave section 220A of the intermediate element 220 is greater than the height (dimension between the upper end face and the lower end face) of the stepped section 329 of the valve 214. Therefore, in the Fig. In the state shown (closed state of the valve), the bottom surface 202D of the concave section 202C formed in the mover 202 does not abut the lower end surface of the stepped section 329 of the valve 214, and a gap G2 with a size (dimension) of D2 is formed between the bottom surface 202D of the concave section 202C and the lower end surface of the stepped section 329. The size D2 of the gap G2 is smaller than the size (dimension) D1 of a gap G1 formed between the upper end surface 202A (surface facing the solid core 207) of the mover 202 and a lower end surface 207B (surface facing the mover 202) of the solid core 207 (D2 < D1).As described herein, the intermediate element 220 is an element for forming the gap G2 of size D2 between the mover 202 and the lower end face of the stepped section 329 of the valve 214, and the intermediate element 220 can also be referred to as a gap-forming element.

[0040] The third spring 234 pushes the intermediate element (gap-forming element) 220 in the valve closing direction (downwards), and the intermediate element 220 serves in the valve-closed state of Fig. 3 as the upper end surface (reference position) of the stepped section 329 of the valve 214. In this state, the lower end surface 220D of the intermediate element 220 abuts the mover 202, so that the gap G2 with size D2 is formed between the lower end surface of the stepped section 329, which is an engagement section of the valve 214, and the bottom surface 202D of the concave section 202C, which is an engagement section of the mover 202. The bottom surface 220E of the concave section 220A abuts the upper end surface (reference position) of the stepped section 329 of the valve 214, so that the intermediate element 220 serves as the upper end surface of the stepped section 329.

[0041] Here, the preload forces of the three springs described above are described again. Among the first spring 210, the second spring 212, and the third spring 234, the spring force (preload force) of the first spring 210 is the greatest. The spring force (preload force) of the third spring 234 is the next highest, and the spring force (preload force) of the second spring 212 is the lowest.

[0042] In the present embodiment, the diameter of the through-hole formed in the mover 202 is smaller than the diameter of the stepped section 329 of the valve 214. Therefore, during a valve opening operation (switching from the closed to the open state) or a valve closing operation (switching from the open to the closed state), the lower end face of the stepped section 329 of the valve 214 engages the lower end face 202D of the concave section 202C formed in the mover 202, and the mover 202 moves in conjunction with the valve 214. In a case where a force moving the valve 214 upwards or a force moving the mover 202 downwards acts independently, the valve 214 and the mover 202 can move independently. However, mover 202 moves in separate directions.The operation of the mover 202 and the valve 214 is described in detail below.

[0043] In the present embodiment, an outer circumferential surface of the mover 202 is in contact with an inner circumferential surface of the nozzle holder 201 (housing element), so that the movement of the mover 202 is guided in a vertical direction (valve opening and closing direction). Furthermore, an outer circumferential surface of the valve 214 is in contact with an inner circumferential surface of the through-hole of the mover 202, so that the movement of the valve 214 is guided in a vertical direction (valve opening and closing direction). That is, an inner circumferential surface of the nozzle holder 201 acts as a guide when the mover 202 moves in an axial direction. In addition, an inner circumferential surface of the through-hole of the mover 202 acts as a guide when the valve 214 moves in an axial direction. The distal end 214B of the valve 214 is guided through a guide hole of an annular guide element 215.The valve 214 is guided by the inner circumferential surface of the nozzle holder 201, the through-bore of the mover 202 and the guide element 215 in such a way that it moves straight back and forth in the axial direction.

[0044] Note that in the present embodiment, it was described that the upper end face 202A of the mover 202 abuts the lower end face 207B of the solid core 207, but the present invention is not limited to this example. A projection can be provided on one or both of the upper end face 202A of the mover 202 and the lower end face 207B of the solid core 207, so that the projection and the end face or projections can abut each other. In this case, the gap G1 described above becomes a gap between a stop section near the mover 202 and a stop section near the solid core 207.

[0045] The description will be... Fig. 2. The solid core 207 is pressed into an inner circumferential section of the large-diameter cylindrical section 240 of the nozzle holder 201, and both parts are welded and joined at a press-fit contact position. The solid core 207 is a component that exerts a magnetic attraction on the mover 202, attracting it in the valve opening direction. A gap formed between an inner section of the large-diameter cylindrical section 240 of the nozzle holder 201 and the ambient air is sealed by welding and joining the solid core 207. The solid core 207 has a through-hole (center hole) in its center, the diameter of which is slightly larger than the diameter of the intermediate element 220, which serves as the fuel passage.The head section 214A of the valve 214 and the cap 232 are inserted without contact into the inner circumference of a lower end section of the through-hole of the solid core 207.

[0046] A lower end of the first spring 210, used to set an initial load, abuts a spring receiving surface formed on the upper end face of the cap 232, which is located near the head part 214A of the valve 214. The upper end of the first spring 210 is held by an adjusting pin 224 (see Fig. 1) is inserted into the inner section of the through-hole of the solid core 207, so that the first spring 210 is held between the cap 232 and the adjusting pin 224. A fixed section of the adjusting pin 224 is set to provide an initial load at which the first spring 210 can press the valve 214 against the valve seat 218.

[0047] In a state where the initial load of the first spring 210 is set, the lower end face 207B of the solid core 207 is configured to face the upper end face 202A of the mover 202 with a magnetic attraction gap (gap G1) of approximately 40 to 100 µm between the lower end face 207B of the solid core 207 and the upper end face 202A of the mover 202. Note that each of the constituent elements in Fig. 2 is enlarged regardless of any dimensional ratio thereof.

[0048] Furthermore, a cup-shaped housing 203 is attached to an outer circumference of the large-diameter cylindrical section 240 of the nozzle holder 201. A through-hole 213 is provided in the center of a base of the housing 203, and the large-diameter cylindrical section 240 of the nozzle holder 201 is inserted into the through-hole 213. A portion of an outer circumferential wall of the housing 203 forms an outer circumferential yoke, which faces the outer circumferential surface of the large-diameter cylindrical section 240 of the nozzle holder 201. The annular or cylindrical electromagnet 205 is arranged in an annular space formed between the housing 203 and the large-diameter cylindrical section 240.

[0049] The electromagnet 205 consists of an annular coil former 204, which is open radially outwards and has a groove with a U-shaped cross-section and a copper wire 206 wound around the groove. A rigid conductor 209 is attached to the beginning and end of the winding of the electromagnet 205. The conductor 209, the solid core 207, and the outer circumference of the large-diameter cylindrical section 240 of the nozzle holder 201 are formed by injecting an insulating resin from an inner circumference of an upper end opening of the housing 203 to be covered with a resin mold. An annular magnetic passage is formed in the solid core 207, the mover 202, the large-diameter cylindrical section 240 of the nozzle holder 201, and the housing (outer circumferential yoke section) 203 to surround the electromagnet 205.

[0050] The fuel supplied to the fuel injection device 101 is fed from the fuel line 105 located upstream of the fuel injection device 101 and flows through a first fuel passage bore 231 to the distal end of the valve 214. The fuel is sealed by the seat section formed at the end of the valve seat 218 of the valve 214 and the valve seat 218. In the valve-closed state, a differential pressure is generated between the upper and lower sections of the valve 214 by the fuel pressure, and the valve 214 is forced in the valve-closing direction by the fuel pressure and a force corresponding to a pressure-bearing area of ​​one inner diameter of the seat section at a valve seat position.Furthermore, in the closed state of the valve, the gap G2 is formed between the contact surface of the valve 214 and the mover 202 (the lower end surface of the stepped section 329 and the bottom surface 202D of the concave section 202C) and the intermediate element 220. As such, the mover 202 and the valve 214, with the gap G2 formed between them, are arranged axially in a state in which the valve 214 is seated in the valve seat 218.

[0051] The operation of the fuel injection device 101, configured as described above, is described. When the electromagnet 205 is energized, a magnetic flux flows between the solid core 207 and the mover 202 through a magnetic field generated by a magnetic circuit, and the magnetic attraction acts on the mover 202. The mover 202 begins to move toward the solid core 207 when the magnetic attraction acting on the mover 202 exceeds the load on the third spring 234. At this point, as the valve 214 comes into contact with the valve seat 218, the mover 202 is in a state where no fuel is flowing. Since the movement of the mover 202 is an idle movement, it is performed independently of the valve 214, which maintains the differential pressure due to the fuel pressure.Therefore, the mover 202 can move at a high speed without being affected by fuel pressure or similar factors.

[0052] Furthermore, even when the fuel pressure in cylinder 108 is increased, it is necessary to apply a strong load to the first spring 210 to suppress fuel injection. This means that the load of the first spring 210 does not act on valve 214 when the valve is closed, allowing valve 214 to move at high speed.

[0053] When the displacement of the mover 202 reaches the size of the gap G2, the mover 202 transmits a force to the valve 214 through the stop surface (the bottom surface 202D of the concave section 202C) to pull the valve 214 upwards in the valve opening direction. In this case, the mover 202 is moving freely and collides with the valve 214 while it possesses kinetic energy. Therefore, the valve 214 receives the kinetic energy of the mover 202 and begins to move at high speed in the valve opening direction.

[0054] A differential pressure, generated according to the fuel pressure, acts on the valve 214. The differential pressure acting on the valve 214 is generated due to a pressure decrease of the fuel near the distal end 214B of the valve 214, corresponding to a pressure decrease caused by a decrease in static pressure, which is caused by a Bernoulli effect after the flow rate of the fuel at the seat section is increased in an area where the flow cross-sectional area near the seat section of the valve 214 is small.

[0055] Thus, the differential pressure acting on valve 214 is largely influenced by the flow cross-sectional area near the seat portion. Therefore, the differential pressure increases when the displacement of valve 214 is small and decreases when the displacement is large. Consequently, due to the idle movement of the actuator 202, valve 214 opens with interference at the point when it begins to open from the closed position. The displacement becomes small, and the valve opening process becomes difficult due to a large differential pressure. Therefore, the valve opening process of the fuel injection device 101 can also be performed under conditions of higher fuel pressure.Furthermore, it is possible to adjust the preload force of the first spring 210 to a greater force within a fuel pressure range required for the valve opening process. By adjusting the first spring 210 to a greater force, the time required for the valve closing process described below can be reduced, thus enabling effective control of even the smallest injection quantity.

[0056] After the valve 214 initiates the valve opening process, the mover 202 collides with the fixed core 207. At the moment of collision, the mover 202 rebounds, but is then pulled towards the fixed core 207 by the magnetic attraction acting upon it, and finally comes to a stop. Because a force is exerted on the mover 202 towards the fixed core 207 by the second spring 212 at this point, the amount of rebound displacement can be reduced, and the time until rebound is achieved can be shortened. If the rebound is small, the time during which a gap is formed between the mover 202 and the fixed core 207 is shortened, thus enabling stable operation even with a smaller injection pulse width.

[0057] In this way, the mover 202 and the valve 214 are stopped in the open position after the valve opening process is complete. In the open position, a gap (an example of a space) is formed between the valve 214 and the valve seat 218, and the fuel is injected from the injection port 219 into the combustion chambers 107. The fuel flows downstream (through the injection port 219) after passing through the central hole (through hole) provided in the solid core 207, the fuel through hole provided in the mover 202, and the fuel through hole provided in the guide element 215.

[0058] Then, when the excitation of the electromagnet 205 is blocked, the magnetic flux generated in the magnetic circuit disappears, and the magnetic attraction acting on the mover 202 also disappears. When the magnetic attraction acting on the mover 202 disappears, the valve 214 is pushed back into a closed position by a force generated by the load of the first spring 210 and the fuel pressure, in which the valve 214 comes into contact with the valve seat 218. [Control circuit of the control device]

[0059] Next, a configuration of the control device 150 of the fuel injection device 101 will be described with reference to Fig. 5 described.

[0060] Fig. Figure 5 is a diagram showing an example of the drive circuit 103 and the ECU 104 of the fuel injection device 101.

[0061] The control device 150 comprises the drive circuit 103 and the ECU 104. The ECU 104 incorporates, for example, an integrated drive circuit (IC) 502 and a central processing unit (CPU) 501 as an arithmetic processing unit. The CPU 501 (an example of a control unit) receives signals indicating the engine's state, which, in addition to the pressure sensor 102, are output by various types of sensors, such as an air / air pressure sensor, an oxygen sensor, and a crankshaft angle sensor (not shown). A combination of the CPU 501 and the driver IC 502 can be referred to as a control unit. Note that the ECU 104 may also contain the drive circuit 103.

[0062] The fuel line 105, provided upstream of the fuel injection device 101, is connected to the pressure sensor 102 (see Fig. 1) The air / air sensor measures the amount of air flowing into cylinder 108 (engine cylinder). The oxygen sensor detects the oxygen concentration in the exhaust gas expelled from cylinder 108. The CPU 501 calculates the injection pulse width (injection pulse width Ti) or the injection timing to control the amount of fuel injected by the fuel injector 101 according to the operating condition of the internal combustion engine, based on signals received from various types of sensors.

[0063] Furthermore, the CPU 501 calculates a suitable injection pulse width Ti (i.e., the injection quantity) or injection timing according to the operating state of the internal combustion engine and outputs the injection pulse width Ti to the drive IC 502 of the fuel injection device 101 via a communication line 504. Subsequently, the switching elements 505, 506, and 507 are switched between excitation and de-excitation by the drive IC 502 to supply the drive current to the fuel injection device 101 (electromagnet 205). The switching elements 505, 506, and 507 are configured, for example, with FETs and transistors and can switch the fuel injection device 101 energized and de-energized.

[0064] The ECU 104 is equipped with a register and a 501M memory (an example of a recording medium) that store numerical data required for engine control, such as calculating the fuel pulse width. The 501M register and memory are contained within the control unit 150 and the CPU 501 within the control unit 150, respectively. In the example of Fig. In section 5, memory 501M is located outside of the CPU 501. A computer program can be stored in memory 501M so that the CPU 501 can control the drive of the fuel injection device 101. In this case, the CPU 501 reads the computer program stored in memory 501M and executes it to implement all or part of the function for controlling the drive of the fuel injection device 101. Note that instead of the CPU 501, another arithmetic processing device, such as a microprocessing unit (MPU), can also be used.

[0065] The switching element 505 is connected between a boosting circuit 514 (high-voltage source), which provides a boost voltage VH, and a terminal on the high-voltage side of the electromagnet 205 of the fuel injection device 101 (a current-source-side terminal 590). The boost voltage VH output by the boosting circuit 514 is higher than a battery voltage VB supplied to the drive circuit 103 by a battery voltage source 520 (low-voltage source). For example, the boost voltage VH, which is an initial output voltage of the boosting circuit 514, is 60 V, and the boost voltage VH is generated by the boosting circuit 514 amplifying the battery voltage VB.

[0066] Examples of a method for implementing the boosting circuit 514 may include a method for configuring a boosting circuit by a DC / DC converter or similar device, as well as a method for configuring a boosting circuit by an electromagnet 530, a transistor 531, a diode 532, and a capacitor 533, as shown in Fig. Figure 5 illustrates this. In the case of the boosting circuit 514 configured by the latter method, when transistor 531 is switched on, a current induced by the battery voltage VB flows through the electromagnet 530 to a ground potential 534. Conversely, when transistor 531 is switched off, a high voltage generated in the electromagnet 530 is rectified by diode 532, and electrical charges accumulate in capacitor 533. Transistor 531 is repeatedly switched on and off, allowing the voltage across capacitor 533 to increase to the boost voltage VH. Transistor 531 is connected to driver IC 502 or CPU 501, and the boost voltage VH output by boosting circuit 514 can thus be detected by driver IC 502 or CPU 501.

[0067] Additionally, a diode 535 is provided between the power source-side terminal 590 of the electromagnet 205 and the switching element 505 to allow current to flow from the amplifier circuit 514 (high-voltage source) to the electromagnet 205 and to ground potential 515. Furthermore, a diode 511 is provided between the power source-side terminal 590 of the electromagnet 205 and the switching element 507 to allow current to flow from the battery voltage source 520 (low-voltage source) to the electromagnet 205 and to ground potential 515. During the excitation of the switching element 506, current does not flow from ground potential 515 towards the electromagnet 205, the battery voltage source 520, and the amplifier circuit 514.

[0068] Furthermore, the switching element 507 is connected between the battery voltage source 520, which is the low-voltage source, and the current-side terminal 590 of the fuel injection device 101. The battery voltage VB output by the battery voltage source 520 is, for example, 12 V to approximately 14 V. The switching element 506 is connected between the low-voltage-side terminal of the fuel injection device 101 and ground potential 515. The control IC 502 detects a current value flowing to the fuel injection device 101 (each section of the control circuit 103) via each of the current-sensing resistors 508, 512, and 513. The control circuit 103 generates a desired control current by switching the excitation and de-excitation of the switching elements 505, 506, and 507 according to the current value detected by the control IC 502.

[0069] Diodes 509 and 510 are designed to apply a reverse voltage to the electromagnet 205 of the fuel injection device 101 and to rapidly reduce the current supplied to the electromagnet 205. The CPU 501 communicates with the driver IC 502 via a communication line 503 and can switch the driver current generated by the driver IC 502 according to the fuel pressure supplied to the fuel injection device 101 or the operating state. Furthermore, both ends of each of resistors 508, 512, and 513 are connected to an A / D converter terminal of the driver IC 502, allowing the driver IC 502 to detect the voltage applied to both ends of each of the resistors 508, 512, and 513. [General timetable]

[0070] Next, a relationship is established between the fuel pulse output from the ECU 104, the drive voltage and drive current (excitation current) of the two ends of the connection of the electromagnet 205 of the fuel injection device 101, and the displacement amount (valve behavior) of the valve 214 of the fuel injection device 101, with reference to Fig. 4 described. Fig. Figure 4 is a timing diagram showing a relationship between a general injection pulse for controlling the fuel injection device 101, the control voltage and control current supplied to the fuel injection device 101, and the displacement amounts of the valve 214 and the mover 202, as well as time.

[0071] When the injection pulse is input to the driver circuit 103, the driver circuit 103 energizes the switching elements 505 and 506 according to the pulse width. Therefore, the driver circuit 103 applies a high voltage 401 to the electromagnet 205 by increasing the boost voltage VH to a voltage higher than the battery voltage VB, and begins supplying the drive current to the electromagnet 205. When the current supplied to the electromagnet 205 reaches a maximum drive current Ipeak preset in the ECU 104 (hereinafter referred to as the "maximum current"), the drive circuit 103 stops applying the high voltage 401.

[0072] When the switching element 506 is switched on during a switching period from the maximum current Ipeak to a predetermined current 403, and the switching elements 505 and 507 are de-energized, a voltage of nearly 0 V is applied to the electromagnet 205. The current supplied to the electromagnet 205 flows through a path consisting of the fuel injection device 101, the switching element 506, the resistor 508, the ground potential 515, and the fuel injection device 101, so that the current flowing to the electromagnet 205 is gradually reduced. The current flowing to the electromagnet 205 is reduced uniformly, thus ensuring a stable current supply to the electromagnet 205. Therefore, even in a case where the fuel pressure supplied to the fuel injection device 101 is increased, the fuel injection device 101 can stably perform the valve opening process until the mover 202 and the valve 214 reach maximum height positions.

[0073] Current 403 is a holding current for keeping the mover 202 in its maximum height position. The maximum height position is a position (G1 = 0) at which the mover 202 comes into contact with the solid core 207.

[0074] Conversely, when switching elements 505, 506, and 507 are switched off during a transition period from the maximum current Ipeak to the current 403, diode 509 and diode 510 are energized by a counter-electromotive force through an inductance of the fuel injection device 101. When diode 509 and diode 510 are energized, the current of electromagnet 205 is fed back into the amplification circuit 514, and the current supplied to the fuel injection device 101 is rapidly reduced from the maximum current Ipeak to current 402. This shortens the time it takes for the current flowing to electromagnet 205 to reach a level of current 403.Therefore, when the switching elements 505, 506 and 507 are switched off, it is possible to effectively shorten the time during which the magnetic attraction force is constant after a predetermined delay time has elapsed from the time when the current flowing to the electromagnet 205 reaches the current 403.

[0075] When the current flowing to electromagnet 205 is less than a current value 404 (almost the same level as current 403), which is required to hold valve 214 in its maximum height position, the actuator circuit 103 energizes and then de-energizes switching element 507 while simultaneously energizing switching element 506. Therefore, battery voltage VB is applied to electromagnet 205 to maintain the level of current 403. A switching period is set to maintain this predetermined current 403.

[0076] In Fig. 4. During the period of switching from the maximum current Ipeak to the current 403, after the drive current has dropped to the level of a current 410 at time t46, a switching period may be provided to carry out the control so that the current 410 is maintained, but a switching period to maintain the current 410 may not be provided.

[0077] When the fuel pressure supplied to the fuel injection device 101 becomes high, the fluid force acting on the valve 214 increases, and the time it takes for the valve 214 to reach its target opening degree becomes longer due to fluid resistance. Consequently, the time at which the valve 214 reaches its target opening degree may be delayed relative to the time at which the set maximum current Ipeak is reached. However, if the current to the electromagnet 205 decreases rapidly, the magnetic attraction force acting on the actuator 202 also decreases rapidly. Therefore, the behavior of the valve 214 becomes unstable, and in some cases, the valve may close independently of the current supply.In a case where the current is gently reduced by exciting the switching element 506 during a period of change from maximum current Ipeak to current 403, the reduction of the magnetic attraction force can be suppressed, and the stability of the valve 214 at a high fuel pressure can be ensured.

[0078] The fuel injection device 101 is driven by such a profile of the drive current supplied to the electromagnet 205. Between the time at which the high voltage 401 is applied and the time at which the current of the electromagnet 205 reaches the maximum current Ipeak, the deflection of the mover 202 begins at time t41 and the deflection of the valve 214 begins at time t42 (G2 = 0). Thereafter, the mover 202 and the valve 214 reach their maximum height positions (maximum stroke positions).

[0079] At time t43, when the mover 202 reaches its maximum height position, it collides with the fixed core 207, and a binding process occurs between the mover 202 and the fixed core 207. The valve 214 is configured to be displaced relative to the mover 202. Therefore, the valve 214 becomes separated from the mover 202, and its displacement extends beyond the maximum height position. That is, the lower end face of the stepped section 329 of the valve 214 is separated from the bottom surface 202D of the concave section 202C formed in the mover 202.

[0080] Subsequently, the mover 202 is stopped at a predetermined maximum height position due to the magnetic attraction generated by the current 403 and the force of the second spring 212 in the valve opening direction. Furthermore, the valve 214 is inserted into the mover 202 and stopped at a position corresponding to the maximum height position, thus placing the valve 214 in the open state (time t45).

[0081] Note that in a case of a fuel injection device with a movable valve in which the valve 214 and the mover 202 are integrated, the displacement amount of the valve 214 will not exceed the maximum height position, and the displacement amounts of the mover 202 and the valve 214 will be equal to each other after reaching the maximum height positions. [Method for controlling the fuel injection of the control device]

[0082] Next, a fuel injection control method of the control device 150 for controlling the fuel injection device 101 according to the first embodiment is described with reference to the Fig. 6 and Fig. 7 described.

[0083] Fig. Figure 6 is a timing diagram showing a relationship between the injection pulse, the drive current supplied to the fuel injection device 101, an operating time of the switching element of the fuel injection device 101, a voltage Vinj at the terminals of the electromagnet 205, and the displacement amounts of the valve 214 and the mover 202, as well as time, according to the first embodiment of the present invention. Fig. 6 are the drive current, the behavior of the switching element, the voltage Vinjat the terminals and the displacement amount of the valve 214 in a case where a first current waveform 601 is used, represented by thick lines, and the drive current, the behavior of the switching element, the voltage Vinj The connections and the displacement of valve 214 in a case where a second current waveform 602 is used are shown by thin lines. The displacement of the mover 202 when using the second current waveform 602 is shown by a dotted line. Additionally, the switching element is designated "SW".

[0084] Fig. Figure 7 shows a relationship between an injection quantity when the fuel injection device 101 is driven by the drive current waveform of Fig. 6 is controlled, and a standard deviation (σ) of an injection quantity fluctuation and an injection pulse width. In Fig. 7 is a characteristic of an injection quantity when the fuel injection device 101 is controlled using the first stream waveform 601, represented by a thick line Q701, and a characteristic of an injection quantity when the fuel injection device 101 is controlled using the second stream waveform 602, is represented by a thin line Q702. (Second power control)

[0085] First, an operation of the fuel injection device 101 is described when the fuel injection device is controlled with the second current waveform 602.

[0086] As in Fig. As shown in Figure 6, when the injection pulse with injection pulse width Ti is input from the CPU 501 to the driver IC 502 via the communication line 504 at time t61, the switching element 505 and the switching element 506 are switched on, and the amplification voltage VH, which is higher than the battery voltage VB, is applied to the electromagnet 205. This supplies the drive current to the fuel injection device 101 to rapidly increase the current to current 610. When the current is supplied to the electromagnet 205, the magnetic attraction force acts between the mover 202 and the solid core 207. The mover 202 begins to move at a time when the resultant force of the magnetic attraction, which is a force in the valve opening direction, and the load of the second spring 212 exceed the load of the third spring 234, which is a force in the valve closing direction.The mover 202 then moves into the gap G2, and then the mover 202 collides with the valve 214 (G2 = 0). Therefore, the valve 214 begins to move (valve opening process), and the fuel is injected by the fuel injection device 101.

[0087] When the current reaches its maximum value at time t62, switching element 506 is energized, and switching elements 505 and 507 are de-energized. In this case, a so-called freewheeling state is created, in which the current is regenerated between ground potential 515, switching element 506, fuel injection device 101, and ground potential 515. Due to the freewheeling, a voltage of almost 0 V is applied to both ends of the electromagnet 205 of the fuel injection device 101, and thus the current is gently reduced to current 611.

[0088] Then, when the time reaches time t63, the driver IC 502 switches the excitation and de-excitation of the switching element 507 to control the current so that a current value 604, or a current value close to current value 604, is maintained. Note that the period for controlling the current to current value 604 is referred to as an initial current holding period 655. For example, the time to reach time t63 can be determined using the current value obtained by adding a value preset by the ECU 104 to the value of current 612, until the value reaches a value obtained by adding 0.1 amperes to the value of current 612 (holding current).

[0089] The CPU 501 can perform the control to supply the electromagnet 205 with a current value higher than the current value 604, which is capable of holding the valve 214 in its maximum height position until time t64 (≥ t62), when the valve 214 reaches its maximum height position. In the example of Fig. 6 is the current value of the current higher than the current value 604 in a section from time t66 to time t64.

[0090] Under conditions where the valve 214 is in a position lower than its maximum height, a gap (gap G1) forms between the mover 202 and the solid core 207. Therefore, the magnetic resistance is increased and the magnetic attraction is reduced compared to when the mover 202 is in contact with the solid core 207. Consequently, a drive current higher than current 604 is supplied to the electromagnet 205 until the mover 202 or the valve 214 reaches its maximum height. This allows the valve 214 to reach its maximum height stably, and the time required for this is reduced.

[0091] Thus, in the second current control using the second current waveform 602, the behavior of the valve 214 is stabilized before reaching its maximum height position, and any fluctuation in the displacement of the valve 214 for each injection is suppressed. Therefore, an injection fluctuation σ in the injection quantity after an injection pulse width 713 (see Fig. 7), in which valve 214 reaches its maximum height position, will be reduced.

[0092] Furthermore, in the example of Fig. 6. The boost voltage VH is applied to the electromagnet 205, increasing the current beyond the maximum current Ipeak of the first current curve 601. This supplies a large drive current to the electromagnet 205, further stabilizing the behavior of the valve 214 before it reaches its maximum height position.

[0093] However, since the mover 202 collides with the solid core 207 at high speed, the mover 202 bounces back and forth between the mover 202 and the solid core 207 or the valve 214, as shown in section 660. As a result, the injection quantity deviation σ is not reduced even after the injection pulse width 713. This problem also occurs in the case of the Fig. The current waveform shown in Figure 4 is shown. That is, such a problem can occur under the condition in which the high current value is supplied to the electromagnet 205 until the valve 214 reaches the maximum height position. (First power control)

[0094] A control method in the first current control using the first current waveform 601 as a method for solving the problem and a relationship between the injection quantity (injection pulse width) and the injection quantity variation are described. As shown by the thick line in Fig. As indicated in Figure 6, the CPU 501 controls the voltage applied to the electromagnet 205, so that the drive current is supplied to the first current waveform 601 of the electromagnet 205. The first current waveform 601 is a waveform in which the current reaches the maximum current Ipeak before the mover 202 collides with the solid core 207, and the current decreases from the maximum current Ipeak before the mover 202 collides with the solid core 207.

[0095] As in Fig. As shown in Figure 6, to prevent the mover 202 from colliding with the fixed core 207, the mover 202 is displaced towards the fixed core 207, and the switching elements 505, 506, and 507 are switched off at time t66 when the mover 202 has accelerated sufficiently. As a result, diode 509 and diode 510 are excited by a counter-electromotive force generated in the electromagnet 205 of the fuel injection device 101. Therefore, the current is fed back into the boosting circuit 514, and the current supplied to the fuel injection device 101 is rapidly reduced from the maximum current Ipeak to current 651. In this case, a reverse-polarity voltage (-VH) of a magnitude equal to the boost voltage VH is generated as a counter-electromotive force at the terminals of the electromagnet 205.

[0096] When the blocking voltage is applied to the electromagnet 205 to rapidly reduce the current, after a constant deceleration due to an eddy current, the magnetic flux generated in the magnetic circuit is reduced, and the magnetic attraction acting on the mover 202 is decreased. Subsequently, at time t67, the mover 202 and the valve 214 are decelerated, and the speed at which the mover 202 collides with the solid core 207 is reduced.

[0097] As a result, the limit created between the mover 202 and the solid core 207 and the valve 214 is reduced, and the time at which the limit of the valve 214 converges is shortened to time t68. Therefore, the injection quantity variation σ after an injection pulse width 714 (see Fig. 7) After the valve 214 has reached its maximum height position and a certain time has elapsed, the noise will be lower than when using the second current waveform 602. Furthermore, when using the first current waveform 601, the speed at which the mover 202 collides with the solid core 207 is reduced. Therefore, the drive noise generated by the fuel injection device 101 can be reduced compared to when using the second current waveform 602.

[0098] On the other hand, when using the first current waveform 601, the behavior of the valve 214 may be unstable before it reaches its maximum height position, because the mover 202 and the valve 214 are slowed down. For example, the injection quantity variation may be greater under a condition where the injection pulse width is smaller than the injection pulse width 714 than when using the second current waveform 602.

[0099] Therefore, as described above, in the first embodiment the current control for the electromagnet 205 is switched depending on the amount of fuel to be injected (injection pulse width for injecting the amount of fuel injected) until the valve 214 comes back into contact with the valve seat 218 after the valve 214 has been separated from the valve seat 218, whereby the amount of fuel injected is calculated by the CPU 501 of the control device 150.

[0100] That is, in a case where a small injection quantity, which is smaller than the injection quantity in the injection pulse width 714 (an example of a set value), is required, the CPU 501 performs the second current control for the electromagnet 205 by the second current waveform 602 until the mover 202 collides with the solid core 207, so that a current greater than the current 612 (holding current), which is able to keep the mover 202 in a state in contact with the solid core 207, flows to the electromagnet 205.Furthermore, in a case where an injection quantity greater than the injection quantity (set value) in the injection pulse width 714 is required, the CPU 501 performs the first current control for the electromagnet 205 by means of the first current waveform 601 by switching a polarity of a voltage applied to the electromagnet 205 before the mover 202 collides with the solid core 207 to a polarity that is reversed to the polarity of the voltage applied before the mover 202 collides with the solid core 207.

[0101] In the present embodiment, the current control for the electromagnet 205 is achieved by switching the first and second current waveforms depending on the injection quantity of the fuel injected when the valve is open (injection pulse width), so that the change in the displacement of the valve 214 for each injection can be suppressed within a range from a small injection quantity to a large injection quantity. Therefore, the injection quantity variation of the fuel injection device 101 can be reduced. Consequently, the fuel efficiency and exhaust performance of the internal combustion engine, e.g., a direct-injection engine, are improved, leading to cost reductions.

[0102] Furthermore, the CPU 501 of the control device 150 can perform the second current control using the second current waveform 602, so that the voltage applied to the electromagnet 205, after the mover 202 collides with the solid core 207, is reduced to the set voltage at which the holding current (current 612) flows. The voltage and current applied to the electromagnet 205 are controlled in such a way that the valve 214 can stably reach its maximum height position. In the present embodiment, as shown in Fig. 6. As can be seen, the polarity of the set voltage in the second current control is the same as the polarity of the voltage before the polarity of the set voltage in the first current control is reversed by the first current waveform 601 (positive polarity in Fig. 6).

[0103] Furthermore, the valve 214 can stably reach its maximum height position if a current higher than the current 612 (holding current) is applied to the mover 202. Therefore, when using the second current waveform 602, the point at which the maximum current Ipeak is stopped does not necessarily have to be set after the valve 214 has reached its maximum height position, but can also be set before the valve 214 reaches its maximum height position.

[0104] Furthermore, in the case where the second current waveform 602 is used, even if one of the first current waveforms 601 and the second current waveform 602 is used in the injection pulse width, which is greater than the injection pulse width 715, the injection quantity variation is the same as in the case where the limit of the valve 214 is sufficiently converged at the time the injection pulse is stopped. In this case, for example, if the fuel pressure of the fuel line 105, through which the fuel is supplied to the fuel injection device 101, is high, the CPU 501 uses the second current waveform 602 so that the valve 214 stably reaches its maximum height position. On the other hand, the CPU 501 uses the first current waveform 601 when it is necessary to reduce the drive noise of the fuel injection device 101, which is caused by a low engine speed, such as...a warm idle condition is caused.

[0105] Therefore, if an instruction for the injection pulse width is received that is larger than the preset injection pulse width of 715, the CPU 501 can perform the control to switch the current waveform of the drive current according to the operating condition.

[0106] When using the first current waveform 601, if the counter-voltage is applied to the electromagnet 205, after the current reaches the maximum current I peak Once the required voltage is reached, the amplification voltage VH is applied to the electromagnet 205. The current cannot be increased due to the opposing electromotive force caused by the displacement of the mover 202 when the valve 214 is moved. However, the applied voltage is increased so that the current can reach current 612 (holding current) and the valve 214 can be held stably in the open position.

[0107] As described above, in the present embodiment the current waveform, in which the injection quantity variation can be reduced, is appropriately adjusted according to the injection quantity (or the injection pulse width). Therefore, it is possible to suppress the injection quantity variation from the small injection quantity to the large injection quantity, i.e., over the entire range from a low engine load to a high engine load.

[0108] For example, the injection quantity variation is suppressed, so that in cases where exhaust gas recirculation (EGR) is used to achieve lean combustion, where the fuel is leaner than the theoretical air-fuel ratio, or where exhaust gas is recirculated to the intake side to improve fuel efficiency, even under conditions where the combustion rate slows down, the same combustion state can be achieved for each injection and combustion stability can be improved. The present embodiment is suitable for use in the fuel injection control of internal combustion engines, which requires high accuracy of the injection quantity, e.g., when the injection quantity is very small during the combustion cycle.

[0109] Furthermore, in the first current waveform 601 and the second current waveform 602, when the injection pulse is stopped at time t69, all switching elements 505, 506, and 507 are de-energized. Then, diode 509 and diode 510 are energized by the counter-electromotive force from the inductance of the fuel injection device 101, the current is fed back into the amplification circuit 514, and the current supplied to the fuel injection device 101 is rapidly reduced by current 652, thus reaching 0 A.When the current supply is stopped, the magnetic attraction force acting on the mover 202 is reduced, and the valve 214 begins to close from a position lower than its maximum height position at the time when the force in the valve opening direction—the resultant force of the magnetic attraction, the load of the second spring 212, and the inertial force of the mover 202—is less than the force in the valve closing direction due to the load of the first spring 210 and the differential pressure acting on the valve 214. Then, at time t64, the valve 214 comes into contact with the valve seat 218, and the fuel injection is stopped.

[0110] In the first embodiment described above, during the first current control using the first current waveform 601, the voltage applied to the electromagnet 205 before the mover 202 collides with the fixed core 207 is positive, but can also be negative. The same applies to each of the following embodiments. In the first current control, the polarity of the voltage applied to the electromagnet 205 before and after the collision of the mover 202 with the fixed core 207 can be reversed. The polarity of the voltage applied before the mover 202 collides with the fixed core 207 can be appropriately selected according to the displacement directions of the mover 202 and the valve 214 and the configuration of the drive circuit 103.Thus, according to the present invention, it is possible to flexibly design the displacement directions of the mover 202 and the valve 214, the configuration of the drive circuit 103 and the polarity of the applied voltage. <Erste Modifikation der ersten Ausführungsform>

[0111] Next, a first modification of the first embodiment of the present invention will be described with reference to Fig. 8 described. Fig. Figure 8 is a diagram showing a relationship between the voltage at the terminals of the electromagnet 205 and the drive current supplied to the fuel injection device, as well as the time according to the first modification of the first embodiment of the present invention.

[0112] In the first embodiment, when the second current waveform 602 is used, a large current value is required until the valve 214 reaches its maximum height position. Therefore, the maximum current Ipeak supplied to the electromagnet 205 becomes large. Since, in this case, the heat generated by the fuel injection device 101 and the ECU 104 increases proportionally to the square of the supply current, heat generation can be problematic, which may limit the current applied to the electromagnet 205.

[0113] On the contrary, as in Fig. As shown in Figure 8, in the second current control, a current waveform 603 (third current waveform) can be used in which a maximum current Ipeak (current 613) is maintained by repeatedly applying the gain voltage VH and the battery voltage VB after the drive current has reached the maximum current Ipeak. The CPU 501 controls the voltage applied to the electromagnet 205 by switching the switching elements 505 and 507 on and off, so that the current waveform 603 can become a waveform in which the current reaches the maximum current Ipeak before the mover 202 collides with the solid core 207, and the maximum current Ipeak is maintained even after the mover 202 collides with the solid core 207. Fig. 6. The maximum current Ipeak will be maintained for a predetermined time even after time t64, when the mover 202 collides with the solid core 207. Applying the voltage to the electromagnet 205 can be achieved by repeatedly applying the boost voltage VH and the voltage from 0 V.

[0114] In Fig. Figure 8 shows the voltage at the terminals when the boost voltage VH and the battery voltage VB are applied repeatedly, represented by a solid line 801, and the driver current at that time by a solid line 803. Additionally, the voltage at the terminals when the boost voltage VH and the voltage 0 V are applied repeatedly is shown by a dashed line 802, and the driver current at that time is shown by a dashed line 804. When the boost voltage VH and the battery voltage VB are applied repeatedly (solid line 801), the voltage fluctuation across the terminals is smaller than when the boost voltage VH and the voltage 0 V are applied repeatedly (dashed line 802), and thus the behavior of valve 214 is stable.

[0115] As such, current waveform 603 is used in the second current control, making it possible to ensure the necessary current until valve 214 reaches its maximum altitude position without increasing the value of the maximum current Ipeak. Therefore, heat generation by ECU 104 is suppressed, and the variation in the displacement of valve 214 for each injection is suppressed by the second current control using current waveform 603. <Second Embodiment>

[0116] Next, a method for controlling the fuel injection by the control device 150 for controlling the fuel injection device 101 according to a second embodiment of the present invention is described with reference to Fig. 9 described. Fig. Figure 9 is a diagram showing a relationship between the drive current supplied to the fuel injection device 101 and the displacement amount of the valve as well as the time according to the second embodiment of the present invention.

[0117] In a case where the injection quantity is smaller than the injection quantity when the valve 214 closes after reaching its maximum height position, it is advantageous to implement half-stroke control to actuate the valve 214 in a half-stroke state, where it does not reach its maximum height position. In the half-stroke state, however, the displacement of the valve 214 is not limited by a stopper (e.g., the fixed core 207). Therefore, the displacement of the valve 214 can vary due to a slight change in force. Since the magnetic attraction force is strongly influenced by the magnetic resistance, the magnetic resistance decreases when the distance between the mover 202 and the fixed core 207 decreases, and the magnetic attraction force increases.Furthermore, due to the influence of the eddy current, the magnetic attraction does not temporarily become zero even when the injection pulse is stopped and the current flowing to electromagnet 205 is 0 A, and the magnetic attraction decreases over time. However, if the magnetic attraction is too strong, valve 214 can reach its maximum height position even if ECU 104 stops the output of the injection pulse.

[0118] In contrast, in a case where the half-stroke control, which initiates the movement of the mover 202 in the valve closing direction, is performed before the mover 202 collides with the solid core 207, the control can be performed using the first current waveform 601 as shown in Fig. The process is carried out as shown in Figure 6. The CPU 501 performs the control such that the counter-voltage is applied to the electromagnet 205 after the mover 202 has been accelerated, and the mover 202 reaches its maximum height position through the current 610. Therefore, it is possible to control the injection quantity in the half-stroke state while simultaneously suppressing a rapid increase in the magnetic attraction force acting on the mover 202.

[0119] Furthermore, in the case where half-stroke control is performed, it is not necessary to supply energy for the valve 214 to reach its maximum height position. Therefore, the maximum current during half-stroke control can be lower than when using the first current waveform 601.

[0120] In Fig. Figure 9 is a current waveform 901, indicated by a dashed line, an example of the current waveform at the time of half-lift control. In the current waveform 901 at the time of half-lift control, a maximum current IHL, which is a maximum value, can be smaller than the maximum current Ipeak of the first current waveform 601. In current waveform 901, the maximum current IHL is smaller than the maximum current Ipeak. Therefore, a slope 920 of the deflection of valve 214 according to current waveform 901 is smaller than a slope 620 of the deflection of valve 214 according to the first current waveform 601. Therefore, it is possible to control the injection quantity in the half-lift state while simultaneously suppressing the rapid increase in the magnetic attraction force.Each of the displacements 911a, 911b and 911c represents a change in the displacement amount when the direction of movement of the valve 214 is switched from the valve opening direction to the valve closing direction at each point of the current waveform 901. <Dritte Ausführungsform>

[0121] Next, a method for controlling the fuel injection of the control device 150 for controlling the fuel injection device 101 according to a third embodiment of the present invention is described with reference to the Fig. 1, Fig. 5 and Fig. 6 and 10 are described. Fig. Figure 10 illustrates an injection timing and injection duration for each intake stroke and compression stroke when performing split injection during a combustion cycle.

[0122] In the method for controlling fuel injection according to the third embodiment, a first injection 1003 is carried out during an intake stroke 1001 to form a homogeneous air mixture in cylinder 108. This injection occurs at a time when the flow in cylinder 108 is strong, in order to inject a large quantity of fuel. Then, in order to form a rich air mixture during the compression stroke 1002, which allows the fuel to ignite more readily around a spark plug than air, a second injection 1004 is preferably carried out. The injection duration of the second injection is shorter than that of the first injection 1003, in order to inject a small quantity of fuel required for one combustion cycle. In this description, an air mixture containing a larger quantity of fuel than the theoretical air-fuel ratio is referred to as "rich".

[0123] Since in this case the injection quantity for injection 1004 is smaller than for injection 1003, the injection 1003 of the intake stroke 1001 is carried out using the first current waveform 601 according to the first embodiment (see Fig. 6) is carried out, and the injection 1004 of the compression stroke 1002 is performed using the second stream waveform 602 (or the stream waveform 603) according to the first embodiment (see Fig. 6) carried out. The injection quantity fluctuation is suppressed by implementing such fuel injection control, thus suppressing fluctuations in homogeneity during the intake stroke 1001. Furthermore, fluctuations in the air-fuel mixture forming around the spark plug during the compression stroke 1002 are suppressed, and combustion stability is improved.

[0124] Particularly under conditions where a three-way catalytic converter is activated at engine start, the ignition timing can be retarded (retarded) from top dead center to increase exhaust gas loss, thereby controlling the temperature of the catalytic converter. In cases where the ignition timing is retarded, combustion becomes unstable. Therefore, fuel injection control, which ensures combustion stability, is effective by injecting fuel in the second half of the compression stroke, creating a rich air-fuel mixture around the spark plug. In this case, the fuel injected during the compression stroke accounts for 40% or less of the total injection quantity during a single combustion cycle.This means that a large amount of fuel can be injected in the intake stroke 1001 to form a homogeneous air mixture, and a smaller amount of fuel than in the intake stroke 1001 can be injected in the compression stroke 1002 to form a rich air mixture around the spark plug.

[0125] In the fuel injection control method according to the third embodiment, as described above, the injection 1003 of the intake stroke 1001 is carried out using the first current waveform 601 according to the first embodiment, and the injection in the compression stroke 1002 is carried out using the second current waveform 602 (or the current waveform 603) according to the first embodiment. As such, the CPU 501 of the control device 150 can be controlled to perform each of the first current control for the electromagnet 205 using the first current waveform 601 and the second current control using the second current waveform 602 (or the current waveform 603) for the electromagnet 205 at least once during a combustion cycle.

[0126] According to such a method for controlling fuel injection, the injection quantity fluctuation in the intake stroke 1001 and in the compression stroke 1002 can be suppressed. <Vierte Ausführungsform>

[0127] Next, a fuel injection control method of the control device 150 for controlling the fuel injection device 101 according to a fourth embodiment is described with reference to the Fig. 1, Fig. 5 and Fig. 6 and 11 described. Fig. Figure 11 illustrates an injection timing and duration for an intake stroke and a compression stroke when split injection is performed during a combustion cycle. Fig. 11 will use the same reference numbers for the same configurations as in Fig. 10 used.

[0128] In the method for controlling the fuel injection according to the fourth embodiment, a first injection 1103 is carried out at the time when the flow in the intake stroke 1001 is strong, and a large quantity of fuel is injected to form a homogeneous air mixture in the cylinder 108. A second injection 1104 with a smaller quantity than in the injection 1103 is then carried out at the time when the flow is reduced.

[0129] Since the injections after the second injection are performed to fine-tune the injection quantity, the injection quantity is generally small. Therefore, since the injection quantity at the second injection 1104 is smaller than at the first injection 1103, the injection 1103 of the intake stroke 1001 is performed using the first current waveform 601 according to the first embodiment, and the subsequent injection 1104 is performed using the second current waveform 602 (or the current waveform 603) according to the first embodiment. As such, the CPU 501 of the control device 150 can be controlled to execute each of the first current control using the first current waveform 601 and the second current control using the second current waveform for the electromagnet 205 at least once during a combustion cycle.

[0130] In this method of controlling fuel injection, fluctuations in the injection quantity are suppressed. Therefore, variations in homogeneity during the intake stroke 1001 are suppressed, and combustion stability is improved. <Modifikation der vierten Ausführungsform>

[0131] Furthermore, if two or more injections are carried out during the combustion cycle, the CPU 501, which is built into the ECU 104 of the control device 150, can perform current control in a case where the amount of fuel injected by the fuel injection device 101 at any given time is equal to or less than a preset threshold (set value) in the ECU 104, such that the number of times the second current control is carried out using the second current waveform 602 (or the current waveform 603) is greater than the number of times the first current control is carried out using the first current waveform 601.

[0132] The fuel injection control system is designed for situations where a tiny amount of fuel needs to be injected, which occurs when two or more injections are performed during the combustion cycle. This means that even when only a minute amount of fuel needs to be injected, fluctuations in the injection quantity during the combustion cycle are suppressed. <Fünfte Ausführungsform>

[0133] Next, a fuel injection control method of the control device 150 for controlling the fuel injection device 101 according to a fifth embodiment is described with reference to the Fig. 1, Fig. 5 and Fig. 12 described. Fig. Figure 12 illustrates a relationship between an injection quantity and a standard deviation (σ) of an injection quantity fluctuation and an injection pulse width according to the fifth embodiment of the present invention. Fig. 12 In the case where the fuel pressure is not higher than in the first embodiment, an injection quantity and an injection quantity fluctuation are indicated by a thick dashed line Q101 when the first stream waveform 601 is used, and an injection quantity and an injection quantity fluctuation are indicated by a fine dashed line Q102 when the second stream waveform 602 (or the stream waveform 603) is used.

[0134] In a control method of the fuel injection device 101 according to the fifth embodiment, the control device 150 can set an injection quantity of the injected fuel (injection pulse width) to a larger value until the valve 214 comes back into contact with the valve seat 218 after the valve 214 has been separated from the valve seat 218, because the fuel pressure is higher.

[0135] As in Fig.As shown in Figure 12, a fluid force due to the fuel pressure acting on the valve 214 is increased when the pressure of the fuel supplied to the fuel injection device 101 is high. Therefore, the slope of a characteristic curve of the injection quantity becomes small, as with an injection quantity of 1201, and the injection pulse width for the valve 214 to reach its maximum altitude position becomes large. Accordingly, the injection pulse width 714, in which a ratio between the injection quantity fluctuations in the first flow waveform 601 and the second flow waveform 602 (or flow waveform 603) is switched, is increased up to an injection pulse width of 1202. Furthermore, even with the same displacement of the valve 214, the amount of fuel injected is greater the higher the fuel pressure.

[0136] Therefore, in the present embodiment, the CPU 501 sets a larger value for the injection quantity (or injection pulse width) from the opening to the closing of valve 214 when the fuel pressure is higher, with the set value being used to switch between the first current waveform 601 and the second current waveform 602. Thus, it is possible to stably reduce the injection quantity fluctuation even when the fuel pressure changes. In other words, in the present embodiment, the robustness (resistance to disturbances) of the fuel injection control can be ensured when the fuel pressure changes.

[0137] If the fuel pressure is increased, and thus the fluid force acting on the valve 214 is increased, the speed of the mover 202 can also be reduced, and the collision speed, should the mover 202 collide with the solid core 207, can be reduced. In this case, even if the time t66 at which the maximum current Ipeak of the first current waveform 601 is stopped is delayed, the limiting of the valve 214 after the valve 214 has reached its maximum height position can be suppressed. Therefore, the current can be controlled such that the time at which the maximum current Ipeak is stopped is delayed when the fuel pressure is higher. That is, the CPU 501 performs control such that the time at which the voltage applied to the electromagnet 205 is switched to less than 0 V (reverse polarity) by the first current control is delayed when the fuel pressure is higher.

[0138] As such, the point in time at which the maximum current Ipeak is stopped is changed according to the fuel pressure, so that it is possible to achieve both the stability so that the valve 214 reaches the maximum altitude position, and the reduction of the injection quantity variation by reducing the limit of the valve 214. <andere>

[0139] Furthermore, the present invention is not limited to the embodiments described above, and various other applications and modifications can be made without departing from the scope of the present invention as described in the claims.

[0140] In the embodiments described above, the configurations of the fuel injection system 1 and the control device 150, for example, are described in detail and specifically to clearly explain the present invention, and the present invention is not necessarily limited to including all described constituent elements. Furthermore, a part of the configuration of one embodiment can be replaced by a constituent element of another embodiment. Furthermore, a constituent element of one embodiment can be added to a configuration of another embodiment. In addition, a part of the configuration of each embodiment can be subjected to the addition, deletion, or replacement of other constituent elements.

[0141] For example, in each of the first to fifth embodiments described above, the fuel injection device 101 is configured to have an internal structure in which the mover 202, attracted by the magnetic force, collides with the solid core 207, but the present invention is not limited to this configuration. A movable section (e.g., the mover 202, the valve 214, or the like) that is pulled upward in the valve opening direction by the magnetic force can collide (come into contact) with any solid area arranged or formed within the fuel injection device 101. The solid core 207 is an example of such a solid area. Alternatively, the fuel injection device 101 can be configured such that the intermediate element 220 (gap-forming element) is not used.Even in these configurations, which are similar to the configurations of the first to fifth embodiments described above, the injection quantity fluctuation can be suppressed if the current waveform of the drive current supplied to the electromagnet 205 is appropriately adjusted according to the injection quantity (or the injection pulse width).

[0142] Furthermore, each of the aforementioned configurations, functions, processing units, and the like can be implemented in hardware by designing some or all of them, for example, as an integrated circuit. Additionally, each of the aforementioned components, functions, and the like can be implemented in software, where a processor interprets and executes a program to implement the respective functions. Information about programs, tables, files, and the like for implementing the respective functions can be stored in a recording device such as semiconductor memory, a hard disk drive or solid-state drive (SSD), or a magnetic or optical recording medium.

[0143] Furthermore, the above embodiments describe control lines or information lines that are deemed necessary for explanation, but it is not absolutely necessary to describe the control lines or information lines in the product completely. In practice, it can be assumed that almost all components are interconnected. List of reference signs 103 101,101A-101D Fuel injection device Drive circuit 104 ECU 107 Fuel chamber 108 cylinders 150 control device 202 movers 205 Electromagnet 207 solid core 214 Valve 218 Valve seat 219 Injection hole 501 CPU 501MB storage 601 first current waveform 602 second current waveform 610 Current (holding current) 714 Injection pulse width (set value)< / andere>

Claims

[1] Control device (150) for a vehicle for controlling a fuel injection device (101, 101A-101D) comprising a valve (214) that comes into contact with and is separated from a valve seat (218), a mover (202) that actuates the valve (214), an electromagnet (205) that generates a magnetic attraction force to attract the mover (202) to form a space for introducing a fuel between the valve seat (218) and the valve (214), and a solid core (207) that attracts the mover (202) by the magnetic attraction force, wherein the control device (150) comprises a control unit that performs: a first current control for the electromagnet (205) by a first current waveform (601) by switching a polarity of a voltage applied to the electromagnet (205) before the mover (202) or the valve (214) collides with a fixed area to a polarity that is reversed to the polarity of the voltage applied before the mover (202) or the valve (214) collides with the fixed area, when an injection quantity of the fuel that is injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is a set value or more; and a second current control for the electromagnet (205) by a second current waveform (602), such that a current greater than a holding current (610) that keeps the mover (202) or the valve (214) in a state of contact with the fixed area flows to the electromagnet (205) until the mover (202) or the valve (214) collides with the fixed area when the amount of fuel injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is less than the set value. [2] Control device (150) for a vehicle according to claim 1, wherein the control unit performs the second current control by reducing a voltage applied to the electromagnet (205) after the collision of the mover (202) or the valve (214) to a set voltage at which the holding current (610) flows. [3] Control device (150) for a vehicle according to claim 2, wherein one polarity of the set voltage in the second current control is the same as the polarity of the voltage before the reversal in the first current control. [4] Control device (150) for a vehicle according to claim 1, wherein the control unit controls the voltage applied to the electromagnet (205) during the first current control such that a current reaches a maximum current before the mover (202) or the valve (214) collides with the fixed area, and the current decreases from the maximum current before the mover (202) or the valve (214) collides with the fixed area. [5] Control device (150) for a vehicle according to claim 1, wherein the control unit controls the voltage applied to the electromagnet (205) during the second current control such that a current reaches a maximum current before the mover (202) or the valve (214) collides with the fixed area, and the maximum current is maintained even after the mover (202) or the valve (214) collides with the fixed area. [6] Control device (150) for a vehicle according to claim 1, wherein the control unit performs each of the first current control and the second current control for the electromagnet (205) at least once during a combustion cycle. [7] Control device (150) for a vehicle according to claim 6, wherein the control unit performs the first current control during a first injection and the second current control during a subsequent injection during an intake stroke. [8] Control device (150) for a vehicle according to claim 7, wherein the control unit performs the second current control in a compression stroke. [9] Control device (150) for a vehicle according to claim 1, wherein in a case where two or more injections are carried out during a combustion cycle, when the injection quantity of the fuel injected by the fuel injection device (101, 101A-101D) at any given time is equal to or less than a set threshold value, the control unit performs a control such that the number of times the second current control is performed is greater than the number of times the first current control is performed. [10] Control device (150) for a vehicle according to claim 1, wherein the set value of the injection quantity of the injected fuel until the valve (214) makes renewed contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is greater the higher the fuel pressure is. [11] Control device (150) for a vehicle according to claim 1, wherein the control unit performs a control such that the time at which the polarity of the voltage applied to the electromagnets (205) is reversed by the first current control is delayed when a fuel pressure is higher. [12] Control device (150) for a vehicle according to claim 1, wherein in a case where a half-stroke control initiating a movement of the mover (202) or the valve (214) in a valve closing direction is performed before the mover (202) or the valve (214) collides with the fixed area, the control unit performs the first current control. [13] Control device (150) for a vehicle according to claim 1, wherein the injection quantity of the injected fuel is determined as a function of an injection pulse width (714) of the fuel injection device (101, 101A-101D) which injects the fuel introduced into the space. [14] Control device (150) for a vehicle according to one of claims 1 to 13, wherein the fixed area is the solid core (207). [15] Fuel injection control method for a vehicle for controlling a fuel injection device (101, 101A-101D) comprising a valve (214) that comes into contact with and is separated from a valve seat (218), a mover (202) that actuates the valve (214), an electromagnet (205) that generates a magnetic attraction force to attract the mover (202) to form a space for introducing a fuel between the valve seat (218) and the valve (214), and a solid core (207) that attracts the mover (202) by the magnetic attraction force, wherein the fuel injection control method comprises the following operations to be performed: a first current control for the electromagnet (205) by a first current waveform (601) by switching a polarity of a voltage applied to the electromagnet (205) before the mover (202) or the valve (214) collides with a fixed area to a polarity that is reversed to the polarity of the voltage applied before the mover (202) or the valve (214) collides with the fixed area, when an injection quantity of the fuel that is injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is a set value or more; and a second current control for the electromagnet (205) by a second current waveform (602), such that a current greater than a holding current (610) that keeps the mover (202) or the valve (214) in a state of contact with the fixed area flows to the electromagnet (205) until the mover (202) or the valve (214) collides with the fixed area when the amount of fuel injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is less than the set value. [16] A program for controlling the fuel injection of a vehicle, which allows a computer to perform processes: a first current control for an electromagnet (205) by means of a first current waveform (601) by switching a polarity of a voltage applied to the electromagnet (205) before a mover (202) or a valve (214) collides with a fixed area to a polarity that is reversed to the polarity of the voltage applied before the mover (202) or the valve (214) collides with the fixed area, when an injection quantity of the fuel that is injected until the valve (214) comes back into contact with a valve seat (218) after the valve (214) has been separated from the valve seat (218) is a set value or more; and a second current control for the electromagnet (205) by a second current waveform (602), such that a current greater than a holding current (610), which keeps the mover (202) or the valve (214) in a state of contact with the fixed area, flows to the electromagnet (205) until the mover (202) or the valve (214) collides with the fixed area when the amount of fuel injected until the valve (214) comes back into contact with the valve seat (218) after the valve (214) has been separated from the valve seat (218) is less than the set value, wherein the computer is included in a control device (150) for a vehicle for controlling a fuel injection device (101, 101A-101D) comprising the valve (214) which comes into contact with and is separated from the valve seat (218), the mover (202) which drives the valve (214), the electromagnet (205) which generates a magnetic attraction force to attract the mover (202) to form a space for introducing a fuel between the valve seat (218) and the valve (214), and a solid core (207) which attracts the mover (202) by the magnetic attraction force.

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