JP2005264864A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set the appropriate quantity of fuel injection (supply quantity) and ignition timing according to actual valve timing. <P>SOLUTION: This control device for an internal combustion engine provided with a variable valve timing mechanism for changing the opening/closing timing of an intake valve or an exhaust valve of the engine, is provided with an opening/closing timing detecting means capable of detecting the opening/closing timing at optional timing. Actual valve timing (actual rotation phase θdet) is detected by the opening/closing timing detecting means (S14), and when starting the engine, starting fuel injection control and starting ignition timing control for correcting the fuel injection quantity (supply quantity) and ignition timing according to the detected valve timing are carried out (S15-17). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for an internal combustion engine provided with a variable valve timing mechanism that changes an opening / closing timing (valve timing) of an intake valve or an exhaust valve.

As a control device for an internal combustion engine provided with a variable valve timing mechanism for changing the valve timing of an intake valve or an exhaust valve of the internal combustion engine, there is one disclosed in Patent Document 1. This includes a crank angle sensor that outputs a crank angle signal at the reference rotational position of the crankshaft, and a cam sensor that outputs a cam signal at the reference rotational position of the camshaft, and the crank sensor based on the deviation angle of the reference rotational position. The rotational phase (that is, valve timing) of the camshaft with respect to the shaft is detected.
JP 2000-297686 A

By the way, in the above-described conventional configuration, the valve timing is detected at every constant crank angle (camshaft rotation cycle). Therefore, the valve timing (rotation phase) is low at the time of low rotation such as when the engine is started. There is a problem that the detection cycle becomes long, and the difference between the detected valve timing and the actual valve timing becomes large.
The cylinder filling air amount and the blown back gas amount (internal EGR) change according to the valve timing. In the above-described conventional type, an appropriate fuel supply amount and ignition timing corresponding to this change are set. There was room for improvement in this respect.

  The present invention has been made paying attention to such problems. By setting the fuel supply amount and the ignition timing in consideration of the valve timing, it is possible to improve the emission and the combustion stability particularly at a low rotation speed. With the goal.

For this reason, the control apparatus for an internal combustion engine according to the present invention includes an opening / closing timing detection means capable of detecting the opening / closing timing of the intake valve or the exhaust valve of the engine at an arbitrary timing, and based on the opening / closing timing detected by the opening / closing timing detection means. Correct at least one of the fuel supply amount and the ignition timing.
In this way, it is possible to set the optimal fuel supply amount and ignition timing according to the actual valve timing in consideration of the cylinder charge air amount and the blowback gas amount that change as the valve timing is changed. Thereby, it is possible to improve the emission and combustion stability especially at the time of low rotation.

Here, the correction of the fuel supply amount and the ignition timing may be performed in a low rotation region where the engine rotation speed is a predetermined rotation speed or less. This makes it possible to prevent an increase in control load by performing correction only within the minimum necessary range.
If the variable valve timing mechanism that changes the opening / closing timing of the intake valve or exhaust valve of the engine is configured to change the opening / closing timing by changing the rotational phase of the camshaft relative to the crankshaft of the engine, for example, Opening / closing timing detecting means capable of detecting the timing at an arbitrary timing includes first rotating position detecting means for detecting the rotating position of the crankshaft, second rotating position detecting means for detecting the rotating position of the camshaft, Rotation phase detection means for detecting a rotation phase of the camshaft relative to the crankshaft based on output signals of the one rotation position detection means and the second rotation position detection means, and at least the second rotation position detection means, To output different signals depending on the rotational position of the camshaft That.

  In this case, since the output signal of the second rotational position detecting means corresponds to the rotational position of the camshaft on a one-to-one basis, the rotational position of the camshaft can be arbitrarily set based on the output signal of the second rotational position detecting means. It can be obtained instantly at the timing. As a result, the rotational phase of the camshaft relative to the crankshaft can be detected regardless of the rotational period of the camshaft. Timing can be detected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an internal combustion engine for a vehicle in the embodiment. In FIG. 1, an electronic control throttle 104 that opens and closes a throttle valve 103 b by a throttle motor 103 a is interposed in an intake pipe 102 of the internal combustion engine 101, and the combustion chamber is connected via the electronic control throttle 104 and the intake valve 105. Air is inhaled into 106.

Each combustion chamber of the engine is provided with a spark plug 133, which ignites sparks to ignite and burn the air-fuel mixture. The combustion exhaust is discharged from the combustion chamber 106 through the exhaust valve 107, purified by the front catalyst 108 and the rear catalyst 109, and then released into the atmosphere.
The intake valve 105 and the exhaust valve 107 are driven to open and close by cams provided on the intake side camshaft 134 and the exhaust side camshaft 110, respectively. The intake side camshaft 134 includes a variable valve timing mechanism (VTC) 113. Is provided.

The VTC 113 is a mechanism that changes the opening / closing timing of the intake valve 105 by changing the rotational phase of the intake camshaft 134 with respect to the crankshaft 120, and details thereof will be described later.
In the present embodiment, the VTC 113 is provided only on the intake valve 105 side, but the VTC 113 may be provided on the exhaust valve 107 side instead of the intake valve 105 side or together with the intake valve 105 side.

In addition, an electromagnetic fuel injection valve 131 is provided in the intake port 130 of each cylinder. When the fuel injection valve 131 is driven to open by an injection pulse signal from an engine control unit (ECU) 114, a predetermined value is set. The fuel adjusted to the pressure is injected and supplied toward the intake valve 105.
The ECU 114 incorporating the microcomputer receives output signals from various sensors, and controls the electronic control throttle 104, the VTC 113, and the fuel injection valve 131 by arithmetic processing based on the signals.

  Examples of the various sensors include an accelerator opening sensor APS116 for detecting the accelerator opening, an air flow meter 115 for detecting the intake air amount Qa of the engine 101, and a reference crank angle signal at a reference rotational position at every crank angle of 180 ° from the crankshaft 120. A crank angle sensor 117 that extracts a unit angle signal POS for each unit crank angle, extracts a REF, a throttle sensor 118 that detects an opening TVO of the throttle valve 103b, a water temperature sensor 119 that detects a cooling water temperature Tw of the engine 101, an intake side A cam sensor 132 that extracts a cam signal CAM at a reference rotational position for each cam angle 90 ° (crank angle 180 °) from the cam shaft 134, a pressure sensor 135 that detects the combustion pressure in the combustion chamber 106, and a voltage sensor that detects the battery voltage Vb 136 etc. are provided . The engine speed Ne is calculated based on the cycle of the reference crank angle signal REF or the number of unit angle signals POS generated per unit time. Although not shown, the ECU 114 also receives operation signals such as an idle switch and a start switch.

  Next, the configuration of the VTC 113 will be described with reference to FIGS. As shown in FIG. 2, the VTC 113 according to the present embodiment is assembled to the intake side camshaft (hereinafter simply referred to as a camshaft) 134 and a front end portion of the camshaft 134 so as to be relatively rotatable as necessary. And a drive ring 303 (drive rotator) having a timing sprocket 302 linked to the crankshaft 120 via a chain (not shown) on the outer periphery, and a front side of the drive ring 303 and the camshaft 134 (in FIG. 2) An assembly angle operation mechanism 304 for operating an assembly angle between the camshaft 134 and the drive ring 303 and a further front side of the assembly angle operation mechanism 304. The operating force applying means 305 for driving, and the cylinder head and the head cover (not shown) of the internal combustion engine are attached to the front face of the head cover and assembled. And VTC cover outside view covering the front and periphery region of the operating mechanism 304 and the operation force imparting unit 305, and a. 3 (and FIG. 5) corresponds to the AA sectional view of FIG. 2, and FIG. 4 corresponds to the BB sectional view of FIG.

  The drive ring 303 is formed in a short shaft cylindrical shape having a step-like insertion hole 306, and the insertion hole 306 portion rotates to a driven shaft member 307 (driven rotating body) coupled to the front end portion of the camshaft 134. It is assembled as possible. As shown in FIG. 3, three radial grooves 308 (radial guides) having parallel side walls facing each other are provided on the front surface of the drive ring 303 (the surface opposite to the camshaft 134). It is formed so as to be along the substantially radial direction.

  In addition, as shown in FIG. 2, the driven shaft member 307 has an enlarged diameter portion formed on the outer periphery of the base that is abutted against the front end portion of the camshaft 134, and an outer peripheral surface on the front side of the enlarged diameter portion. The three levers 309 projecting radially are integrally formed, and are coupled to the camshaft 134 by bolts 310 penetrating the shaft core portion. The base end of each link 311 is pivotally connected to each lever 309 by a pin 312, and a columnar protrusion 313 slidably engaged with each radial groove 308 is integrally formed at the tip of each link 311. Is formed.

  Since each link 311 is connected to the driven shaft member 307 via the pin 312 in a state where the protruding portion 313 is engaged with the corresponding radial groove 308, the distal end side of the link 311 receives an external force and receives the radial groove. When displaced along 308, the drive ring 303 and the driven shaft member 307 are relatively rotated by a direction and an angle corresponding to the displacement of the protruding portion 313 by the action of the link 311.

  In addition, a housing hole 314 that opens to the front side in the axial direction is formed at the tip of each link 311, and the housing hole 314 has a spherical protrusion 316 a that engages with a spiral groove 315 (spiral guide) described later. An engagement pin 316 (rolling member) and a coil spring 317 that biases the engagement pin 316 forward (spiral groove 315 side) are accommodated. In this embodiment, a movable guide portion that is displaceable in the radial direction is configured by the protruding portion 313 at the tip of the link 311, the engagement pin 316, the coil spring 317, and the like.

  On the other hand, an intermediate rotating body 318 having a disk-like flange wall 318 a is rotatably supported via a bearing 331 in front of the protruding position of the lever 309 of the driven shaft member 307. The aforementioned spiral groove 315 having a semicircular cross section is formed on the rear surface side of the flange wall 318a of the intermediate rotating body 318, and the engagement pin 316 at the tip of each link 311 can freely roll in the spiral groove 315. Is engaged with the guide. The spiral of the spiral groove 315 is formed so as to gradually reduce the diameter along the rotation direction of the drive ring 303. Accordingly, in the state where the engagement pin 316 at the tip of each link 311 is engaged with the spiral groove 315, when the intermediate rotating body 318 rotates relative to the drive ring 303 in the delay direction, the tip of the link 311 becomes the radial groove 308. When the intermediate rotating body 318 is relatively displaced in the advancing direction, it is guided radially by the spiral shape of the spiral groove 315 and conversely moves in the radial direction.

  The assembly angle operation mechanism 304 of this embodiment is constituted by the radial groove 308, the link 311, the protrusion 313, the engagement pin 316, the lever 309, the intermediate rotating body 318, the spiral groove 315, etc. of the drive ring 303 described above. Has been. When the relative turning operation force with respect to the camshaft 134 is input from the operation force applying means 305 to the intermediate rotating body 318, the assembly angle operation mechanism 304 receives the operation force from the spiral groove 315 and the engagement pin 316. The distal end of the link 311 is displaced in the radial direction through the engaging portion, and at this time, relative rotational force is transmitted to the drive link 303 and the driven shaft member 307 by the action of the link 311 and the lever 309.

  On the other hand, the operating force applying means 305 includes a spring 319 that urges the intermediate rotator 318 in the rotation direction of the drive ring 303 and a braking mechanism that urges the intermediate rotator 318 in the direction opposite to the rotation direction of the drive ring 303. The intermediate rotating body 318 relative to the drive ring 303 by appropriately controlling the braking force of the hysteresis brake 320 according to the operating state of the internal combustion engine, or Is configured to maintain the rotational position of both.

The spring spring 319 has an outer peripheral end coupled to a cylindrical member 321 integrally attached to the drive ring 303, while an inner peripheral end is coupled to a cylindrical base of the intermediate rotating body 318, and the whole is intermediate. The rotating body 318 is disposed in the space on the front side of the flange wall 318a.
On the other hand, the hysteresis brake 320 is in a state in which the rotation is restricted by a bottomed cylindrical hysteresis ring 323 attached to the front end portion of the intermediate rotating body 318 via a retainer plate 322 and a VTC cover (not shown) which is a non-rotating member. And a coil yoke 325 which is a magnetic induction member for guiding the magnetism of the electromagnetic coil 324. The electromagnetic coil 324 is energized by the ECU 114 according to the operating state of the engine. To be controlled. Specifically, the ECU 114 controls the energization amount for the electromagnetic coil 324 based on a duty control signal on which a dither signal is superimposed.

As shown in FIG. 6, the hysteresis ring 323 is formed of a hysteresis material (semi-hard material) having a characteristic (magnetic hysteresis characteristic) in which magnetic flux force changes with a phase lag with respect to a change in an external magnetic field. The cylindrical wall 323a is subjected to a braking action by the coil yoke 325.
The entire coil yoke 325 is formed in a substantially cylindrical shape so as to surround the electromagnetic coil 325, and the inner peripheral surface thereof is rotatably supported by the distal end portion of the driven shaft member 307 via the bearing 328. A pair of circumferential facing surfaces 326 and 327 are formed on the rear surface side (intermediate rotating body 318 side) of the coil yoke 315 so that the magnetic input / output portions face each other with a cylindrical gap.

In addition, as shown in FIG. 7, a plurality of concavities and convexities are continuously formed along the circumferential direction on both facing surfaces 326 and 327 of the coil yoke 325, and the convex portions 326 a and 327 a are magnetic poles among these concavities and convexities. (Magnetic field generator).
And the convex part 326a of one opposing surface 326 and the convex part 327a of the other opposing surface 327 are alternately arrange | positioned in the circumferential direction, and the convex parts 326a and 327a which the opposing surfaces 326 and 327 mutually adjoin are all the circumferential direction. It is shifted to. Therefore, a magnetic field having an inclination in the circumferential direction as shown in FIG. 7 is generated by the excitation of the electromagnetic coil 24 between the adjacent convex portions 326a and 327a of the opposing surfaces 326 and 327. A cylindrical wall 323a of the hysteresis ring 323 is interposed in a non-contact state in the gap between the opposing surfaces 326 and 327.

Here, the operating principle of the hysteresis brake 320 will be described with reference to FIG. 8A shows a state where a magnetic field is first applied to the hysteresis ring 323 (hysteresis material), and FIG. 8B shows a state where the hysteresis ring 323 is displaced (rotated) from the state of FIG. 8A. Indicates.
In the state of FIG. 8A, the direction of the magnetic field between the opposing surfaces 326 and 327 of the coil yoke 325 (the direction of the magnetic field from the convex portion 327a of the opposing surface 27 toward the convex portion 327a of the other opposing surface 326). A magnetic flux flows in the hysteresis ring 323 along the line.

  When the hysteresis ring 323 receives the external force F from this state and moves to the state shown in FIG. 8B, the hysteresis ring 323 is displaced in the external magnetic field. At this time, the magnetic flux inside the hysteresis ring 323 is The direction of the magnetic flux inside the hysteresis ring 323 has a phase delay, and the direction of the magnetic field between the opposing surfaces 326 and 327 is shifted (tilted). Accordingly, the flow of magnetic flux (magnetic lines) entering the hysteresis ring 323 from the convex portion 327a of the opposing surface 327 and the flow of magnetic flux (magnetic lines) from the hysteresis ring 323 toward the convex portion 326a of the other opposing surface 326 are distorted. An attractive force that corrects the distortion of the magnetic flux acts between the opposing surfaces 326 and 327 and the hysteresis ring 323, and the attractive force acts as a drag force F ′ that brakes the hysteresis ring 323.

  When the hysteresis ring 323 is displaced in the magnetic field between the opposing surfaces 326 and 327 as described above, the hysteresis brake 320 generates a braking force due to a deviation between the direction of the magnetic flux inside the hysteresis ring 323 and the direction of the magnetic field. However, the braking force depends on the strength of the magnetic field, that is, the magnitude of the excitation current of the electromagnetic coil 324, regardless of the rotational speed of the hysteresis ring 323 (relative speed between the opposed surfaces 326 and 327 and the hysteresis ring 323). It becomes a constant value approximately proportional to.

  FIG. 9 shows test results obtained by examining the relationship between the rotational speed and the braking torque in the hysteresis brake 320 by changing the excitation current to a to d (a <b <c <d). As is apparent from the test results, the hysteresis brake 320 is not affected by the rotational speed unlike a brake using an eddy current, for example, and can always obtain a braking force according to the excitation current value. .

  The VTC 113 according to the present embodiment is configured as described above. When the excitation of the electromagnetic coil 324 of the hysteresis brake 320 is turned off, the intermediate rotating body 318 is engineed against the drive ring 303 by the force of the mainspring spring 319. It is rotated to the maximum in the direction of rotation (see FIG. 3). Thereby, the rotational phase of the camshaft 134 with respect to the crankshaft 120 is maintained on the most retarded angle side where the valve timing is most delayed (the valve timing of the intake valve 105 is the most retarded timing).

  When the ECU 114 issues a command to change the rotational phase to the most advanced angle side from this state, the excitation of the electromagnetic coil 324 of the hysteresis brake 320 is turned on, and the braking force that resists the force of the mainspring spring 319. Is applied to the intermediate rotating body 318. As a result, the intermediate rotating body 318 rotates and moves with respect to the drive ring 303, whereby the engaging pin 316 at the tip of the link 311 is guided to the spiral groove 315, and the tip of the link 311 moves along the radial groove 308. As shown in FIG. 5, the assembly angle of the drive ring 303 and the driven shaft member 307 is changed to the most advanced angle side by the action of the link 311. As a result, the rotational phase is changed to the most advanced angle side where the valve timing is most advanced (the valve timing of the intake valve 105 is the most advanced angle timing).

  On the other hand, when the ECU 114 emits the rotational phase from this state (the most advanced angle side) to the most retarded angle side, the excitation of the electromagnetic coil 324 of the hysteresis brake 320 is turned off, and the spring spring 319 is again activated. The intermediate rotating body 318 is rotationally moved in the returning direction by the force. Then, the link 311 swings in the direction opposite to the above by the guide of the engaging pin 316 by the spiral groove 315, and the assembly angle of the drive ring 303 and the driven shaft member 307 is caused by the action of the link 311 as shown in FIG. Is again changed to the most retarded angle side.

  Note that the rotational phase (of the camshaft 134 with respect to the crankshaft) changed by the VTC 113 is not limited to the two phases of the most retarded angle and the most advanced angle described above, but can be arbitrarily set by controlling the braking force of the hysteresis brake 320. The phase can also be maintained by the balance between the force of the mainspring spring 319 and the braking force of the hysteresis brake 320.

In the present embodiment, as shown in FIG. 10, a rotating body 401 that rotates together with the intake camshaft 134 and an electromagnetic gap sensor 402 that is disposed in the vicinity of the outer periphery of the rotating body 401 are provided.
The rotating body 401 is fixed to the intake camshaft 134 directly or indirectly through another member, and the outer periphery thereof has a circumferential distance from the center of the intake camshaft 134 as shown in FIG. It is formed to change gradually. The gap sensor 402 outputs to the ECU 114 a signal (voltage) corresponding to the gap Gp between the intake camshaft 134 and the outer periphery of the rotating body 401 that changes with rotation. In addition, as long as the rotating body 401 is provided so as to rotate together with the intake side camshaft 134, the fixing method and the fixing position are not limited, and the gap sensor 402 is configured to have a gap Gp with the outer periphery of the rotating body 401. Any system may be used as long as a signal corresponding to the signal can be output continuously.

  Here, as shown in FIG. 11, the output from the gap sensor 402 is in a substantially direct relationship with the gap with the outer periphery of the rotating body 401, and the rotation angle of the intake camshaft 134 is the gap. Since there is a one-to-one correspondence, the output of the gap sensor 402 and the rotation angle (cam angle) of the intake camshaft 134 are substantially directly proportional as shown in FIG. Therefore, the ECU 114 can instantaneously detect the rotation angle of the intake side camshaft 134 based on the output signal from the gap sensor 402.

  That is, in the present embodiment, (1) based on the output signals of the crank angle sensor 117 and the cam sensor 132, the rotation phase of the intake camshaft 134 relative to the crankshaft 120 (intake air) for each rotation cycle of the intake camshaft 134. (The valve timing of the valve 105) can be detected (hereinafter referred to as detection by the first rotational phase detection means), and (2) based on the output signals of the crank angle sensor 117 and the gap sensor 402, continuously at an arbitrary timing. It is possible to detect the rotational phase (valve timing of the intake valve 105) (hereinafter referred to as detection by the second rotational phase detection means).

  Specifically, the first rotation phase detection means detects (calculates) the rotation phase by counting the unit angle signal POS from the generation of the reference crank angle signal REF to the generation of the cam signal CAM, and performs the second rotation. The phase detection means detects the rotation angle of the intake camshaft 134 detected based on the output signal of the gap sensor 402, and the unit angle signal POS from the generation of the reference crank angle signal REF to the detection of the rotation angle of the intake camshaft 134. The rotational phase is detected (calculated) from the rotational angle of the crankshaft 120 detected by counting.

  Thus, by providing two rotational phase detection means, for example, at the time of high rotation, the first rotational phase detection means detects the rotational phase of the intake camshaft 134 with respect to the crankshaft 120 stably and accurately while rotating. At the time of low rotation when the phase detection period is longer, the rotation phase is detected by appropriately selecting the first and second rotation phase detection means, such as detecting the rotation phase by the second rotation phase detection means. can do.

Here, in the present embodiment, valve timing control, fuel supply amount (fuel injection amount) control, and ignition timing control executed by the ECU 114 will be described.
FIG. 13 is a flowchart showing the main routine. This flow is started when the key switch is turned on, and is executed every predetermined time (for example, 10 ms).
In S11, engine operating conditions such as the engine speed Ne, the coolant temperature Tw, and the engine load (target volume efficiency set in a separate routine) are read.

In S12, the start time determination flag FLGST is set. Specifically, this setting is performed according to the flowchart shown in FIG.
In S13, a target rotation phase θtg is set. Specifically, this setting is performed according to the flowchart shown in FIG.
In S14, the actual rotational phase θdet is detected. Such detection is performed by the first rotation phase detection means or the second rotation phase detection means. As described above, the actual rotational phase may be detected by the second rotational phase detection means at the time of low rotation below the predetermined rotational speed, and the actual rotational phase may be detected by the first rotational phase detection means otherwise. .

  In S15, it is determined whether or not the start time determination flag FLGST is set. If the start time determination flag is set (if FLGST = 1), the process proceeds to S16 and S17 to execute start time fuel injection control (see FIGS. 16 and 17) and start time point fire timing control (see FIG. 18). ). On the other hand, if the start time determination flag is not set (if FLGST = 0), the process proceeds to S18 and S19, and the normal time fuel injection control and the normal time point fire timing control are executed.

FIG. 14 is a flowchart showing the setting of the start time determination flag FLGST, which is executed in S12 of FIG.
In S21, it is determined whether or not the start switch is ON. If the start switch is ON, the process proceeds to S22, and if it is OFF, the process proceeds to S24. Instead of the start switch ON / OFF determination, the start motor ON / OFF determination may be used.

In S22, it is determined whether or not the engine rotational speed Ne is equal to or lower than a predetermined rotational speed Ns (for example, 500 rpm). If Ne ≦ Ns, the process proceeds to S23, and if Ne> Ns1, the process proceeds to S24.
In S23, the starting time determination flag FLGST is set to 1 (set).
In S24, the starting determination flag FLGST is set to 0 (released).

FIG. 15 is a flowchart showing the setting of the target rotation phase θtg (target closing timing TGIVC of the intake valve), and is executed in S13 of FIG.
In S31, it is determined whether or not the engine is rotating. If the engine is rotating, the process proceeds to S32. If the engine is not rotating, this flow is terminated without setting the target rotation phase θtg.
In S32, it is determined whether or not a start time setting flag is set. If the start time determination flag is set (if FLGST = 1), the process proceeds to S33, and if not set (if FLGST = 0), the process proceeds to S34.

  In S33, based on the cooling water temperature Tw, a table as shown in the figure is searched to set the starting target rotational phase θtg1 (TGIVC). This starting target rotational phase θtg1 (TGIVC) is set on the more advanced side than the most retarded position so that the optimum valve timing (starting valve timing) for engine starting is obtained, and the coolant temperature Tw is The lower the value, the more advanced it is set. This is because when the temperature is low, the closing timing (IVC) of the intake valve 105 is advanced to approach the intake bottom dead center to increase the effective compression ratio to ensure startability, while at the time of high temperature, the closing timing of the intake valve 105 is secured. The vibration is reduced by moving (IVC) away from the intake bottom dead center.

In S34, based on the engine rotational speed Ne and the engine load (target volume efficiency ηV), a normal target rotational phase θtg2 (TGIVC) is set with reference to a map as shown in the figure. Note that the map to be referred to by the cooling water temperature Tw may be switched in consideration of a change in valve timing required according to the cooling water temperature Tw.
As a result, the start target rotation phase θtg1 is set at the start, and the VTC 113 is controlled so that the actual rotation phase θdet detected at the second rotation phase coincides with the start target rotation phase θtg1. The hour target rotational phase θtg2 is set, and the VTC 113 is controlled so that the actual rotational phase θdet detected by the first rotational phase detecting means or the second rotational phase detecting means coincides with the normal target rotational phase θtg2. In this control, for example, the feedback operation amount U is calculated by PID control based on the deviation Er between the set target rotation phase θtg1 or θtg2 and the detected actual rotation phase θdet, and the calculated feedback operation amount U is supplied to the VTC 113. This is done by outputting.

16 and 17 are flowcharts showing the setting of the starting fuel injection amount (drive pulse width) TIst, which is executed in S16 of FIG.
In S41, based on the coolant temperature Tw, a table as shown in the figure is searched to set the starting basic fuel injection amount TIst0. The starting basic fuel injection amount TIst0 is set as the fuel injection amount when the valve timing becomes the starting timing, and is set to be larger (larger) as the cooling water temperature Tw is lower. This is because the fuel vaporization is poor and the wall flow rate increases at low temperatures, so that the injection amount is increased in consideration of this.

  In S42, a rotation correction coefficient KHOSNe (<1.0) for correcting the starting basic fuel injection amount TIst0 is calculated. Such calculation is performed by searching a table as shown in the figure based on the engine speed Ne. The rotation correction coefficient KHOSNE is set to a smaller value as the engine speed is higher. This is because when the engine rotational speed Ne increases with the throttle opening kept constant, the volumetric efficiency also decreases, so the injection amount is reduced on the high rotation side.

  In S43, a correction amount (VTC correction amount of fuel injection amount) THOSVTC corresponding to the valve timing of the fuel injection amount is calculated. Since the valve timing correction amount THOSVTC is different from the target valve timing (target rotation phase) θtg and the actual valve timing (actual rotation phase), a “deviation” of the effective compression ratio (cylinder charge air amount) occurs. It is calculated as a fuel amount to be corrected according to this “deviation”, and specifically, is calculated according to the flowchart shown in FIG.

In S44, the starting fuel injection amount TIst is calculated by the following equation. As a result, even when the valve timing does not reach the start timing at the start, an appropriate fuel injection amount (drive pulse width) corresponding to the actual valve timing is set and the fuel injection valve 131 is set. Is output.
TIst = TIst0 * KHOSNE + THOSVTC
Note that the normal fuel injection control executed in S18 of FIG. 13 is the same as that in the prior art, and the description thereof is omitted, but basically the engine operating state (engine speed Ne, engine load, etc.) is set. Based on this, a basic fuel injection amount Tbase is calculated with reference to a preset map. Next, the fuel injection amount (driving pulse width) Ti obtained by correcting the basic fuel injection amount Tibase according to the coolant temperature Tw or the like is output to the fuel injection valve 131.

FIG. 17 is a flowchart for calculating the VTC correction amount THOSVTC of the fuel injection amount, and is executed in S43 of FIG.
In S51 and S52, the target effective compression ratio TGVCYL and the actual effective compression ratio REVCYL are calculated. Such a calculation is performed by searching a table as shown in the figure based on the target rotation phase θtg1 at start (target closing timing TGIVC of the intake valve) and the actual rotation phase θdet (actual closing timing REIVC). The effective compression ratio becomes closer to 1.0 because the effective exhaust amount increases as the rotational phase is advanced (that is, the closing timing IVC of the intake valve 105 approaches the intake bottom dead center BDC). .

  In S53, the fuel injection amount (driving pulse width) correction amount is determined as the “deviation” between the target effective compression ratio TGVCYL and the actual effective compression ratio REVCYL, ie, the “deviation” of the fuel injection amount due to the “deviation” of the cylinder charge air amount. Calculated as THOSVTC. Specifically, as shown in the following equation, the shortage (ratio) of the actual effective compression ratio REVCYL with respect to the target effective compression ratio TGVCYL is calculated, and this is multiplied by a coefficient HKCONST # corresponding to the basic drive pulse.

THOSVTC = [(TGVCYL / REVCYL) −1] * HKCONST #
Thus, the VTC correction amount THOSVTC of the fuel injection amount is calculated (the fuel injection amount is corrected) until the actual rotation phase (actual valve timing) θdet reaches the starting target rotation phase (starting timing) θtg1. It will be.
FIG. 18 is a flowchart showing the setting of the start-time fire timing ADVst, which is executed in S17 of FIG.

In 61, the basic ignition timing ADVbase is set. Such setting is performed by referring to a preset map based on the engine speed Ne and the engine load (target ηv).
In S62, a correction amount (VTC correction amount of ignition timing) ADVvtc corresponding to the valve timing of the ignition timing is calculated. Such calculation is performed by searching a map as shown in the figure based on the engine rotational speed Ne and the actual rotational phase θdet. The map used here is: (a) The higher the actual rotational phase θdet (valve timing) is on the advance side, the more the internal EGR increases and the slower the combustion. This is set in advance in consideration of the fact that the larger the volumetric efficiency, the slower the ignition, and (c) the higher the engine speed Ne, the faster the ignition needs to be performed at the same volumetric efficiency.

In S63, the ignition timing ADVst at the start time is calculated by the following equation. Thereby, at the time of start-up, an appropriate ignition timing corresponding to the actual valve timing is set and output to the ignition coil (not shown) of the spark plug 133.
ADVst = ADVbase + ADVvtc
Before S62, a step is provided for determining whether or not the actual rotational phase θdet has reached the starting target rotational phase θtg1, and the actual rotational phase θdet is calculated similarly to the calculation of the VTC correction amount THOSVTC for correcting the fuel injection amount. The VTC correction amount ADVvtc for correcting the ignition timing only until the target rotational phase θtg1 at the time of start may be calculated.

Further, although the description of the normal ignition timing control executed in S19 of FIG. 13 is omitted, basically, based on the engine operation state (engine speed Ne, engine load, etc.) as in S61. The ignition timing ADV is calculated by referring to a preset map, and this is output to the ignition plug 133 (its ignition coil).
As described above, even when the engine is started, the actual valve timing can be detected when the fuel injection amount and ignition timing are set, and the fuel injection amount and ignition timing can be corrected according to the detected valve timing. The optimal fuel injection amount and ignition timing can be set in consideration of the cylinder filling air amount and the blowback gas amount. As a result, for example, when the valve timing is controlled to the optimum starting timing for starting, even when the starting timing is not reached, the emission is deteriorated or the combustion is unstable at the starting. Can be prevented.

  In the embodiment described above, the fuel injection amount and the ignition timing at the time of starting the engine are corrected according to the actual valve timing. However, the engine rotation speed Ne is not more than a predetermined rotation speed, not limited to at the time of engine startup. The fuel injection amount and ignition timing in the low rotation region may be corrected. In this case, in FIG. 14 (setting of the determination flag at start-up), S21 is deleted, and it is determined in S22 whether or not it is equal to or lower than a predetermined rotational speed Ns2 (> Ns). The determination flag may be set and canceled.

Further, although the intake valve 105 provided with the VTC 113 has been described, the present invention may be applied to the intake valve 105 provided with the VTC 113. Even in this case, the fuel injection amount and the ignition timing are set (corrected) in consideration of the cylinder filling air amount and the blowback gas amount (internal EGR) which change according to the valve timing.
Further, if the rotational phase of the intake camshaft 134 relative to the crankshaft 120 can be detected at an arbitrary timing, the second rotational phase detector is not limited to the above, and the cycle is shorter than the rotational cycle of the intake camshaft 134. A device that detects the rotational phase may be substituted.

Furthermore, although the electromagnetic VTC has been described above, the present invention may be applied to a hydraulic VTC (for example, one having a means for increasing the hydraulic pressure when the engine is started).
Here, technical ideas other than the claims that can be grasped from the above-described embodiment will be described together with the effects thereof (a) In the control device for an internal combustion engine according to any one of claims 1 to 3,
Based on the rotational phase detected by the opening / closing timing detection means when the engine is started, the rotational phase is controlled from a state in which the engine is stopped to a starting timing on the more advanced side, and the starting timing is reached. A control apparatus for an internal combustion engine, wherein the fuel supply amount or the ignition timing is corrected during

  Thereby, it is possible to prevent the deterioration of the emission and the instability of the combustion at the start while improving the startability.

1 is a system configuration diagram of an internal combustion engine according to an embodiment. It is sectional drawing which shows the variable valve timing mechanism (VTC) which concerns on embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. Sectional drawing which shows the operating state of the said VTC (equivalent to AA sectional drawing). It is a graph which shows the magnetic flux density-magnetic field characteristic of a hysteresis material. It is a partial expanded sectional view of FIG. FIG. 8 is a schematic diagram in which the component of FIG. 7 is developed linearly, and shows the flow of magnetic flux in the initial state (a) and when the hysteresis ring rotates (b). It is a graph which shows the brake torque-rotation speed characteristic of the said VTC. It is a figure explaining the rotary body 401 and the gap sensor 402 which comprise a 2nd rotation position detection means. It is a graph which shows the gap-output characteristic of a gap sensor. It is a graph which shows the output-cam angle (rotation position) characteristic of a gap sensor. 3 is a flowchart showing a main routine of valve timing control, fuel injection control, and ignition timing control according to the present embodiment. It is a flowchart which shows the setting of the starting time determination flag FLGST. It is a flowchart which shows the setting of target rotation phase (theta) tg. It is a flowchart which shows the setting of the fuel injection amount at the time of starting (drive pulse width) TIst. 6 is a flowchart for calculating a fuel injection amount VTC correction amount THOSVTC. It is a flowchart which shows the setting of ignition timing.

Explanation of symbols

      DESCRIPTION OF SYMBOLS 101 ... Internal combustion engine, 105 ... Intake valve, 113 ... VTC (variable valve timing mechanism), 114 ... ECU (engine control unit), Crank angle sensor ... 117, 120 ... Crank shaft, 131 ... Fuel injection valve, 132 ... Cam sensor, 133 ... Spark plug, 134 ... Intake side camshaft, 401 ... Rotating body, 402 ... Gap sensor

Claims (3)

In a control device for an internal combustion engine provided with a variable valve timing mechanism for changing the opening / closing timing of an intake valve or an exhaust valve of the engine,
An opening / closing timing detection means capable of detecting the opening / closing timing at an arbitrary timing;
A control apparatus for an internal combustion engine, wherein at least one of a fuel supply amount and an ignition timing is corrected based on an opening / closing timing detected by the opening / closing timing detecting means.   2. The control apparatus for an internal combustion engine according to claim 1, wherein the correction of the fuel supply amount or the ignition timing is performed in a low speed region where the engine speed is a predetermined speed or less. The variable valve timing mechanism is configured to change the opening / closing timing by changing the rotational phase of the camshaft with respect to the crankshaft of the engine,
The opening / closing timing detection means includes first rotation position detection means for detecting the rotation position of the crankshaft, second rotation position detection means for detecting the rotation position of the camshaft, the first rotation position detection means, and the Rotation phase detection means for detecting the rotation phase of the camshaft relative to the crankshaft based on the output signal of the second rotation position detection means,
3. The control device for an internal combustion engine according to claim 1, wherein at least the second rotational position detection means outputs a different signal according to the rotational position of the camshaft. 4.

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