JP2733856B2 - Interlocking control device for internal combustion engine and transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an interlocking control device for an internal combustion engine and a transmission, and more particularly, to an internal combustion engine having a valve operating mechanism capable of switching a valve operating state of an intake valve or an exhaust valve. The present invention relates to an interlocking control device in a vehicle equipped with a.

(Problems to be Solved by the Related Art and the Invention) In a vehicle equipped with an automatic transmission (AT), it is generally performed to change the shift characteristics of the automatic transmission by selecting traveling conditions. For example, it has been conventionally performed to prepare required patterns such as a normal pattern and a sports pattern as shift patterns of a transmission and to use these patterns properly.

In the engine output control of a vehicle, the output of an internal combustion engine with a supercharger can be varied by varying the supercharging pressure of the supercharger, and such output control is also known.

However, the above control is basically performed independently, and when performed without mutual relation, it is not always possible to secure and maintain appropriate engine output control and shift control in accordance with running conditions. Can't expect. That is, regarding the change of the shift characteristics of the automatic transmission, only the shift characteristics of the automatic transmission are changed, and therefore, the output characteristics of the engine do not change at all. In such a case, the engine output characteristics are often not optimal for the running conditions. Also, in the above-described engine output control, the output is not changed by changing the supercharging pressure, but by changing the basic characteristic itself of the engine specification.

Some internal combustion engines have a variable valve operating mechanism that can change the characteristics of an intake valve or an exhaust valve system. The valve operating mechanism is set to a low-speed switching state suitable for the low engine speed range and automatically switches to a high-speed switching state when the engine speed becomes high, so that the valve operating mechanism is high in a wide range from a low speed range to a high speed range. The applicant can switch the valve operation state so that the output can be drawn out, and the present applicant previously sets at least one of the intake valve and the exhaust valve to the low-speed valve timing (low-speed V /
T) and high-speed valve timing (high-speed V
/ T), and proposes valve timing switching control that switches the valve timing to set the optimal valve timing according to the operating conditions (Japanese Patent Application No. 63-63).
No. 192239), but in engine and transmission control, further improvement of fuel efficiency is expected if gear control is combined properly with engine output control based on such a variable V / T mechanism. it can.

The present invention has been made in view of the above points,
An object of the present invention is to provide an improved engine output characteristic control and an optimal shift control that can be performed in accordance with running conditions in controlling an internal combustion engine and a transmission of a vehicle, thereby improving fuel efficiency. An object of the present invention is to provide an interlocking control device for an internal combustion engine and a transmission.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a low-speed switching state suitable for a low-speed region and a high-speed switching state suitable for a high-speed region in at least one of an intake valve and an exhaust valve. An interlocking control device for an internal combustion engine having a valve operating mechanism capable of switching between at least two states and a transmission used in a vehicle equipped with the engine, wherein the transmission determines a shift characteristic of the transmission. Characteristic determining means, valve operating mechanism control means for controlling a switching state of the valve operating mechanism, and interlocking control means for controlling the other of the shift characteristic determining means and the valve operating mechanism control means in accordance with one of the states. The shift characteristic determining means includes an economy mode in which automatic shifting is set with emphasis on fuel efficiency, and a high engine speed as compared with the economy mode in which power performance is emphasized. In an interlocking control apparatus for an internal combustion engine and a transmission that switches the shift characteristics to a power mode set to perform automatic shifting at a high speed or a vehicle speed, the valve operating mechanism control means includes: A low-speed switching state holding state in which the switching from the switching state to the high-speed switching state is prohibited and the low-speed switching state is maintained, and a switching permission in which the switching from the low-speed switching state to the high-speed switching state is allowed in the case of the power mode. It is characterized in that the state is switched and controlled.

Note that switching of the valve operation state in this specification refers to switching of the valve timing or both of the valve timing and the valve lift.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a control device to which the present invention is applied. In FIG. 1, reference numeral 1 denotes a DOHC in-line four-cylinder engine in which each cylinder is provided with a pair of an intake valve and an exhaust valve.

In the middle of the intake pipe 2 of the engine 1, a throttle body 3
And a throttle valve 3 ′ is disposed therein. Throttle valve 3 'has throttle valve opening (θ _TH )
A sensor 4 is connected, and outputs an electric signal corresponding to the opening of the throttle valve 3 ′ and supplies it to an electronic control unit (hereinafter referred to as “ECU”) 5.

The fuel injection valve 6 is provided for each cylinder between the engine 1 and the throttle valve 3 'and slightly upstream of the intake valve (not shown) of the intake pipe 2. Each injection valve is connected to a fuel pump (not shown). And is electrically connected to ECU5
The valve opening time of fuel injection is controlled by a signal from the ECU 5.

An ignition plug 22 provided for each cylinder of the engine 1 is connected to the ECU 5 via a drive circuit 21, and the ECU 5 controls the ignition timing θig of the ignition plug 22.

An electromagnetic valve 23 for performing valve timing switching control described later is connected to the output side of the ECU 5, and the opening and closing operation of the electromagnetic valve 23 is controlled by the ECU 5.

On the other hand, an intake pipe absolute pressure (P _BA ) sensor 8 is provided immediately downstream of the throttle valve 3 ′ via a pipe 7. The absolute pressure signal converted into an electric signal by the absolute pressure sensor 8 is supplied to the ECU 5. Supplied to Further, the downstream mounted an intake air temperature (T _A) sensor 9 is supplied to the ECU5 outputs an electric signal indicative of the sensed intake air temperature T _A.

The engine water temperature (Tw) sensor 10 mounted on the main body of the engine 1 is composed of a thermistor or the like, detects the engine water temperature (cooling water temperature) Tw, outputs a corresponding temperature signal, and supplies it to the ECU 5. The engine speed (Ne) sensor 11 and the cylinder discrimination (CYL) sensor 12 are mounted around the camshaft or the crankshaft of the engine 1. Engine speed sensor 11
Outputs a pulse (hereinafter referred to as a “TDC signal pulse”) at a predetermined crank angle position every time the crankshaft of the engine 1 rotates 180 degrees, and the cylinder discriminating sensor 12 outputs a signal pulse at a predetermined crank angle position of a specific cylinder. Output
Each of these signal pulses is supplied to the ECU 5.

The three-way catalyst 14 is disposed in the exhaust pipe 13 of the engine 1 and purifies components such as HC, CO, and NOx in the exhaust gas. O ₂ sensor 15 as an exhaust gas concentration detector outputs a three-way catalyst 14 is mounted on the upstream side of the signal corresponding to the detected value by detecting the oxygen concentration in the exhaust gas in the exhaust pipe 13 ECU 5 To supply.

An output shaft of the engine 1 has an automatic transmission 19 described later.
Is connected.

As is well known, the control of the automatic transmission 19 can be performed by a hydraulic control device that controls the clutch unit and a solenoid valve that operates the hydraulic control device for the transmission.
U5 outputs a shift signal, that is, a shift signal to the solenoid valve for operation as a control signal based on a shift map determined by an engine load and a vehicle speed or an engine speed as described later, and the transmission hydraulic control device By driving the automatic transmission 19 in accordance with the operation of the solenoid valve, the shift speed (shift speed) is selected. The driving force of the engine 1 is
The power is transmitted to the drive wheels (not shown) of the vehicle via the output shaft of the automatic transmission 19.

The ECU 5 further includes a vehicle speed sensor 16, a gear position sensor 17 for detecting a shift position of the automatic transmission, and a hydraulic pressure sensor 18 for detecting a hydraulic pressure in an oil supply passage (48 in FIG. 2B) of the engine 1 described later. They are connected, and the detection signals of these sensors are supplied to the ECU 5.

The ECU 5 shapes input signal waveforms from various sensors, corrects a voltage level to a predetermined level, and converts an analog signal value to a digital signal value. The input circuit 5a has a function of a central processing unit (hereinafter referred to as a “CPU”). 5b, a storage means 5c for storing various calculation programs executed by the CPU 5b, calculation results, and the like, an output circuit 5d for supplying drive signals to the fuel injection valve 6, the drive circuit 21, and the solenoid valve 23, and the like. .

Based on the various engine parameter signals described above, the CPU 5b determines various engine operation states such as a feedback control operation area and an open loop control operation area corresponding to the oxygen concentration in the exhaust gas, and determines the next according to the engine operation state. Based on the equation (1), a fuel injection time _TOUT of the fuel injection valve 6 synchronized with the TDC signal pulse is calculated.

T _OUT = Ti × K ₁ + K ₂ (1) where Ti is the basic fuel amount, specifically the engine speed
This is a basic fuel injection time determined according to Ne and the intake pipe absolute pressure _PBA. The Ti map for determining the Ti value includes a low-speed valve timing (Ti _L map) and a high-speed valve timing (Ti _L map). two maps of Ti _H map) is stored in the memory means 5c.

K ₁ and K ₂ are other correction coefficients and correction variable computed according to various engine parameter signals, so that the fuel consumption characteristic according to engine operating conditions, the optimization of various properties such as the engine acceleration characteristics can be achieved Is determined to be a predetermined value.

CPU5b further absolute intake pipe and engine rotational speed Ne pressure P _BA
The ignition timing θig is determined accordingly. Similar to the Ti map, two maps for the low-speed valve timing (θig _L map) and for the high-speed valve timing (θig _H map) are stored in the storage means 5c as the θig map for determining the ignition timing. .

The CPU 5b controls the opening and closing of the solenoid valve 23 by outputting a valve timing switching instruction signal by a method shown in FIG.

The CPU 5b outputs a signal for driving the fuel injection valve 6, the drive circuit 21, and the solenoid valve 23 via the output circuit 5d based on the result calculated and determined as described above.

Further, in this embodiment, the CPU 5b shifts based on the value of the parameter signal supplied from the throttle valve opening (θ _TH ) sensor 4 as the engine load parameter and the value of the parameter signal supplied from the vehicle speed sensor 16. The gear is determined, and the automatic transmission 19 is controlled.

Further, in the present embodiment, the transmission used is an automatic transmission, and the valve timing is switched in two modes: a low-speed valve timing suitable for a low rotation region and a high-speed valve timing suitable for a high rotation region. The switching of the shift mode combined with the engine output control based on the valve timing is performed in a so-called economy mode (FIG. 5 (A)) in which the shift is performed at a relatively low vehicle speed, and a shift at a relatively high vehicle speed. To the so-called power mode (FIG. 5 (B)) which is set so as to perform.

The economy mode is a mode in which fuel efficiency is emphasized, and the power mode is a mode in which power performance is emphasized. The switching means for determining such shift characteristics of the automatic transmission 19 which emphasizes fuel efficiency and power performance is based on a shift lever. Specifically, for example, switching is performed by selecting a D range and an S (sports) range having different shift characteristics in a shift range. Note that a switch can be used instead of the shift lever for the switching means. For example, the economy mode and the power mode can be switched by switching the switch in the D range.

The shift pattern is stored in the storage means 5c, and the combination with the valve timing control is performed in such a manner that the above-mentioned fuel economy-oriented pattern is interlocked with the switching of the shift mode in an operation state in which the valve timing is maintained at the low valve timing. In addition, a valve having a pattern emphasizing power performance is combined with an operating state that allows switching between low-speed valve timing and high-speed valve timing. That is, in the case of an AT car, for example, based on the range by the shift lever, the valve timing can be fixed at the low speed valve timing in the D range and can be switched between the low speed valve timing and the high speed valve timing in the S range.

In this example, switching between the high-speed valve timing and the low-speed valve timing is performed by selecting a rocker arm and a cam as described below.

FIG. 2 shows an intake valve-side valve train 30 for driving the intake valve 40 of each cylinder of the engine 1. A valve train of basically the same configuration is provided on the exhaust valve side. The valve gear 30 is moved halfway from a crankshaft (not shown) of the engine 1.
A camshaft 31 rotatably driven at a speed ratio of, a high-speed camshaft 34 and low-speed cams 32 and 33 provided on the camshaft 31 corresponding to each cylinder, respectively,
And a first drive rocker arm 36, a second drive rocker arm 37, and a free rocker arm 38 pivotally supported by the rocker shaft 35 corresponding to each cylinder, respectively. Each rocker arm
And a connection switching mechanism 39 provided between each of 36, 37, and 38.

In FIG. 2 (b), a connection switching mechanism 39 includes a first switching pin 41 capable of connecting the first drive rocker arm 36 and the free rocker arm 38, and a second switching pin 41 capable of connecting the free rocker arm 38 and the second drive rocker arm 37. A second switching pin 42, a regulating pin 43 for regulating movement of the first and second switching pins 41 and 42,
A return spring 44 for biasing each of the pins 41 to 43 toward the connection release side.

The first drive rocker arm 36 has a bottomed first guide hole 45 opened to the free rocker arm 38 side in parallel with the rocker shaft 35, and a first switching pin 41 slides in the first guide hole 45. The hydraulic chamber 46 is movably fitted between the one end of the first switching pin 41 and the closed end of the first guide hole 45. Further, a passage 47 communicating with the hydraulic chamber 46 is formed in the first drive rocker arm 36, and an oil supply passage 48 is formed in the rocker shaft 35.
The oil supply passage 48 is always in communication with the hydraulic chamber 46 via the passage 47 irrespective of the swinging state of the first drive rocker arm 36.

A guide hole 49 corresponding to the first guide hole 45 is formed in the free rocker arm 38 in parallel with the rocker shaft 35 between both side surfaces, and one end of the first switch pin 41 is abutted on the other end. The second switching pin 42 is slidably fitted in the guide hole 49.

A second guide hole 50 having a bottom corresponding to the guide hole 49 is formed in the second drive rocker arm 37 so as to open toward the free rocker arm 38 and is formed in parallel with the rocker shaft 35.
The disc-shaped regulating pin 43 that contacts the other end of the switching pin 42 is the second
It is slidably fitted in the guide hole 50. In addition, a guide cylinder 51 is fitted into the closed end of the second guide hole 50, and a shaft portion 52 slidably fitted in the guide cylinder 51 is coaxially and integrally protruded from the regulating pin 42. You. The return spring 44 is inserted between the guide cylinder 51 and the regulating pin 43, and the pins 41, 42, and 43 are urged toward the hydraulic chamber 46 by the return spring 44.

In the connection switching mechanism 39, the first switching pin 41 is fitted in the guide hole 49 and the second switching pin 42 is fitted in the second guide hole 50 by increasing the hydraulic pressure in the hydraulic chamber 46,
Each rocker arm 36, 38, 37 is connected. When the oil pressure in the hydraulic chamber 46 decreases, the contact surface of the first switching pin 41 with the second switching pin 42 returns to a position corresponding to between the first drive rocker arm 36 and the free rocker arm 38 by the spring force of the return spring 44, Since the contact surface of the second switching pin 42 with the regulating pin 43 returns to a position corresponding to between the free rocker arm 38 and the second drive rocker arm 37, the connected state of each rocker arm 36, 38, 37 is released.

The oil supply passage 48 in the rocker shaft 35 is connected to the oil pump 25 via the switching valve 24, and the switching operation of the switching valve 24 causes the oil pressure in the oil supply passage 48, and thus the hydraulic chamber of the connection switching mechanism 39 to be changed. The oil pressure in 46 is switched between high and low. The switching valve 24 is connected to the solenoid valve 23, and the switching operation of the switching valve 24 is controlled by the ECU 5 via the solenoid valve 23.

Intake side valve train of engine 1 configured as described above
30 works as follows. Note that the exhaust-side valve gear operates in the same manner.

When a valve opening command signal is output from the ECU 5 to the solenoid valve 23, the solenoid valve 23 opens, the switching valve 24 opens, and the oil pressure in the oil supply passage 48 increases. As a result, the connection switching mechanism 39
Is activated and each rocker arm 36, 38, 37 is connected,
The rocker arms 36, 38, and 37 are integrally operated by the high-speed cam 34, and the pair of intake valves 40 are opened and closed at a high-speed valve timing in which the valve opening period and the lift amount are relatively large.

On the other hand, when a valve closing command signal is output from the ECU 5 to the solenoid valve 23, the solenoid valve 23 and the switching valve 24 close and the oil supply passage 48
Oil pressure drops. As a result, the connection switching mechanism 39 operates in the opposite direction to the above, the connection state of each rocker arm 36, 38, 37 is released, and the corresponding rocker arms 36, 37 are operated by the low speed cams 32, 33, respectively, and a pair of The intake valve 40 operates at a low valve timing in which the valve opening period and the lift amount are relatively small.

FIG. 3 is a graph showing the characteristics of the engine output by the valve timing control according to the present invention. The engine speed Ne and the engine output (PS) when the valve timing is controlled to the low valve timing and the high valve timing, respectively. Is shown.

The engine speed _NPL is the engine speed at which peak power is obtained at low speed valve timing (V / T), and the engine speed _NPH is the engine speed at which peak power is obtained at high speed valve timing (V / T). is there. In the figure,
As described above, for example, economy mode or D
In the case of the range, as described later, the valve timing is fixed and held at a low-speed valve timing exhibiting a solid line output characteristic. That is, a low-speed valve timing holding state in which the switching from the low-speed valve timing to the high-speed valve timing is prohibited. In addition, in the case of the power mode emphasizing the power performance or the S range, the low-speed valve timing and the high-speed valve timing switching control is performed, that is, the switching is allowed to switch between the low-speed valve timing and the high-speed valve timing. In this case, The characteristic of the engine output is switched between that of the solid line and that of the high-speed valve timing exhibiting the output characteristic of the broken line according to the operating state.

Here, as shown in the figure, the rotation speed of the power peak changes at the low-speed valve timing and the high-speed valve timing. This interlocking control utilizes such low speed valve timing and high speed valve timing output characteristics of the variable valve timing engine.

The basics of the control are, as an engine output and transmission characteristic control device, a selection means for selecting running conditions, a change means for changing the engine output in accordance with the selection, and a vehicle with an automatic transmission (AT) as in this embodiment. With respect to (1), a configuration having a change means for changing the shift characteristics is adopted.

That is, in the interlocking control in the case of an AT vehicle, the engine output control based on the engine output characteristics generated at each valve timing and valve lift amount of the variable V / T engine that makes the valve timing and valve lift amount variable, and A gear shift control of the automatic transmission is performed in combination with the output control. By selecting a travel condition, an optimal engine output characteristic and an optimal gear shift characteristic for the travel condition are obtained. It is intended to reduce the fuel consumption rate under running conditions that do not require the above, and to obtain optimum fuel efficiency performance under any running conditions.

In order to improve fuel efficiency by giving optimum engine output characteristics and optimum shift characteristics (AT vehicle) according to driving conditions, the output characteristics of the low-speed valve timing and high-speed valve timing shown in FIG. In conjunction with the switching, the combination of the low-speed valve timing fixed control and the switching control between the low-speed valve timing and the high-speed valve timing is performed, whereby the optimal shift characteristics and engine output characteristics for the driving conditions are obtained, and the optimal Fuel economy performance can be obtained.

Hereinafter, vehicles with automatic transmissions, that is, automatic vehicles (AT)
The case will be described more specifically with reference to FIGS. 4 and 5.

FIG. 4 is a diagram showing a program for switching control of valve timing including the fixed low-speed valve timing interlocking with the switching of the shift mode and the interlocking control of the low-speed valve timing and the high-speed valve timing switching using the above-described configuration. It is a flowchart.

In this program example, an example is shown in which the present invention is applied to a case where the shift characteristics are changed between the D range and the S range in an automatic vehicle. This program is executed every time a TDC signal pulse is generated.

First, in step S1, it is determined whether or not signals are normally input from the various sensors to the ECU 5, or whether or not an abnormality has already occurred in another control system, that is, whether or not fail-safe should be performed.

Specifically, an intake pipe absolute pressure (P _BA ) sensor 8, a cylinder discrimination (CYL) sensor 12, an engine speed (TDC) sensor 11,
Abnormal output from the engine water temperature sensor 10 and vehicle speed sensor 16, abnormal ignition timing control signal output and abnormal fuel injection control output, abnormal current flowing through the valve timing control solenoid valve 23, valve timing control solenoid valve 23 Abnormal change such that a normal oil pressure change in an outlet port (not shown) in the switching valve 24 and communicating with the oil supply passage 48 cannot be confirmed by the oil pressure switch in the oil pressure sensor 18 even after a lapse of a predetermined time according to the opening and closing of the valve Is detected and it is determined that the engine is in the operating state to be fail-safe. Note that a cylinder discrimination (CYL) sensor and T
When one of the DC sensors has an abnormality, the other output is used in place of the one output.

When the answer to step S1 is affirmative (Yes), that is, when fail-safe is to be performed, the process proceeds to step S33 described below, and negative (No)
If so, the process proceeds to step S2 and subsequent steps.

Steps S2 to S10 are steps for determining whether or not the engine output can be reduced. One of these steps is to fix the low fuel valve timing with good fuel economy in economy mode and D range, and to compare the low valve timing and high valve timing in power mode with emphasis on power performance and S range. A step of determining the mode of the transmission for performing the switching control is included.

First, in step S2, it is determined whether or not the engine is being started based on the engine speed Ne or the like. Step S3 is a step of determining whether or not the remaining time t _ST of the delay timer has become 0, and a predetermined time (for example, 5 seconds) while starting t _ST.
(Step S4), and the timekeeping operation is started after starting.

In step S5, the engine coolant temperature Tw is set to a predetermined set temperature Tw.
Step S6 for determining whether or not the vehicle speed V is lower than ₁ (for example, 60 ° C.), that is, whether or not the warm-up is completed, is for determining whether or not the vehicle speed V is lower than the extremely low vehicle speed V ₁ (for example, 8 km / 5 km with hysteresis). Step S7 is a step of determining the transmission mode described above, that is, a step of determining whether or not the vehicle is in the economy mode or the D range. Step S8 is a step in which the vehicle equipped with the engine is a manual vehicle (MT).
Step S9 is an automatic vehicle (A
The step of the shift lever is determined whether or not it is the parking (P) range or the neutral (N) range if the T), S10 is a step of Ne, it is determined whether or not the lower limit value Ne ₁ or more, During fail-safe (answer of step S1 is affirmative (Yes)), during start-up (answer of step S2 is affirmative (Y
es)) and after the start, before the set time t _{ST of the} delay timer elapses (the answer in step S3 is negative (No)), during warm-up, that is, when the water temperature is low (the answer in step S5 is affirmative (Yes)), when the vehicle is stopped, or when the vehicle is slowing down Medium (answer of step S6 is affirmative (Yes)), economy mode,
When the engine is in the D range, that is, when fuel efficiency is emphasized (FIG. 5 (A)) (the answer to step S7 is affirmative (Yes)),
When in the P, N range (the answer in step S9 is affirmative (Ye
s)), and when Ne <Ne ₁ (the answer to step S10 is negative (No)), the solenoid valve 23 is closed and the valve timing is held at the low-speed valve timing as described later.

Thus, for example, when the engine coolant temperature Tw is lower operating conditions than the predetermined temperature Tw _1, the valve timing will be fixed to low speed valve timing, and as shown in FIG. 5 (A), the shift pattern is the fuel consumption In economy mode where emphasis is placed, in conjunction with switching the shift mode,
The valve timing is fixed to the low-speed valve timing of the engine output characteristic as shown in FIG.

That is, if the answer to step S7 is affirmative (Yes), the low-speed valve timing fixing control is executed and maintained through the processing of steps S31 and S30 described later (the answer to step S31 is negative (No), affirmative ( The same applies to both cases of Yes).

An example of the shift map shown in FIG. 5 shows an example in which the shift characteristics are determined by the throttle valve opening θ _TH and the vehicle speed V as shown. In the maps of FIGS. 5A and 5B, the economy mode and the power mode
The latter power mode shift pattern in FIG.
As shown in the figure, the points are shifted so that the automatic transmission is performed at a higher vehicle speed side than the former. That is, the vehicle speed line is shifted to the high vehicle speed line.

In the case of the economy mode, the upshift is performed as soon as possible, and the fuel consumption performance can be increased as compared with the power mode.
On the other hand, in the case of the power mode, power performance is emphasized,
The purpose is to enable the vehicle to be towed at the lowest possible speed, that is, to run at the first speed when the driver thinks that the vehicle is running fast. Therefore, if the economy mode is adopted (selected) by associating these with the valve timing control, it means that fuel economy is important,
As described above, the valve timing is fixed at the low speed valve timing. That is, if the high-speed valve timing is used, this consumes a large amount of fuel and lowers the fuel consumption. Therefore, the switching to this is prohibited and the low-speed valve timing is fixed.

When the shift characteristic is set to the power mode, that is, when the driver desires acceleration or the like (the answer of steps S7 and S9 is negative (No)), as described later, it is possible to respond to this. The switching between the low-speed valve timing and the high-speed valve timing can be performed, that is, the switching is permitted.

As described above, the output characteristics of the low-speed valve timing and the high-speed valve timing at the variable valve timing are used in conjunction with the switching of the shift mode. Switching is performed in two modes, and by combining these with the engine output control, optimal shift characteristics and engine output characteristics for running conditions can be obtained, and optimal fuel economy performance can be obtained.

In the example of FIG. 5, the shift is performed based on the shift characteristic determined by the throttle valve opening as the engine load parameter and the vehicle speed as one of the other parameters. As an example, the engine speed may be applied. In this case, the shift characteristic may be such that the shift is performed at a relatively low and high engine speed for each shift pattern according to the above example.

Returning to FIG. 4, the answer is negative (N
o), that is, when it is determined that the power mode is in the S range and the process proceeds to step S10 via steps S8 and S9, if it is determined that Ne ≧ Ne ₁ is satisfied in step S10, the process proceeds to step S11. in searching and Ti _L map and Ti _H map, (hereinafter referred to as Ti _H) currently in Ne, Ti _L map Ti value corresponding to P _BA (hereinafter referred to as Ti _L) and Ti _H map of Ti value And then read out the _TVT according to Ne from the _TVT table set according to the AT car and the MT car in step S12,
In step S13, T _VT is compared with T _{OUT of the} previous loop to determine whether or not T _OUT ≧ T _VT holds, that is, whether or not the vehicle is in a high load state for enriching the air-fuel mixture. The answer is negative (N
o), that is, when T _OUT <T _VT holds, step S14
Proceed to Ne performs discrimination of whether or not the upper limit value Ne ₂ or more. The answer to step S14 is negative (No), ie if Ne <Ne ₂ is satisfied, the process proceeds to step S15, and compares the Ti _L and Ti _H obtained in the step S11. As a result, when Ti _L > Ti _H holds, it is determined whether or not the timer value t _VTOFF of the delay timer set in step S16 to be described later is zero (step S17), and if this answer is affirmative (Yes), Step S18
Sends a command to close the solenoid valve 23, that is, a command to switch to low-speed bub timing. When any of T _OUT ≧ T _VT , Ne ≧ Ne ₂ , and Ti _L ≦ Ti _H is satisfied in each of the steps S13, S14, and S15, the timer value of the solenoid valve opening delay timer is set to t. _VTOFF (for example, 3 seconds) is set and started (step S16), and in step S19, a command to open the solenoid valve 23, that is, a command to switch to the high-speed bub timing is issued.

When the valve closing command is issued in step S18, it is determined in step S20 whether or not the hydraulic switch in the hydraulic sensor 18 is turned on, that is, whether or not the oil pressure in the oil supply passage 48 has become low. When the answer is affirmative (Yes), that is, when the hydraulic switch is turned on, it is determined in step S22 whether or not the remaining time t _LVT of the low speed valve timing switching delay timer has become zero. The answer to step S22 is affirmative (Yes), that is, t _LVT
When = 0, the remaining time t _HVT of the high-speed valve timing switching delay timer is set to a set time (for example, 0.1 second) in step S24, and then the Ti map and ignition used in the fuel injection control routine are set in step S26. A process of selecting a Ti _L map and a low-speed valve timing ignition timing map (θig _L map) is performed as a timing map, and a process of setting the rev limiter value N _HFC to a low-speed valve timing value N _HFC1 is performed in a subsequent step S28. .

On the other hand, when the valve opening command is issued in step S19, it is determined in step S21 whether or not the hydraulic switch in the hydraulic sensor 18 has been turned off, that is, whether or not the hydraulic pressure in the oil supply passage 48 has become high. When the answer is affirmative (Yes), that is, when the hydraulic switch is turned off, it is determined in step S23 whether the remaining time t _HVT of the high-speed valve timing switching delay timer has become 0. When the answer to step S23 is affirmative (Yes), that is, when t _HVT = 0, at step S25, the remaining time t _LVT of the low-speed valve timing switching delay timer is set to a set time (for example, 0.2 seconds), and then step S27 in performs processing of selecting the respective Ti _H map and the high-speed valve timing for ignition timing map (? ig _H map) as Ti map and ignition timing map for use in injection control routine of the fuel, followed by the high-speed valve the N _HFC in step S29 A process for _setting the value for the timing _NHFC2 is performed.

By the way, both switching delay timers t _HVT and t _LVT described above
Is set in accordance with the response delay time from when the solenoid valve 23 is opened and closed to when the switching valve 24 is switched, the oil pressure in the oil supply passage 48 changes, and the switching operation of the connection switching mechanism 39 of all cylinders is completed. When the solenoid valve 23 is switched from open to closed, until the hydraulic switch in the hydraulic sensor 18 is turned on,
The program proceeds in the order of S20 → S23 → S25 → S27 → S29.After turning on, the sequence proceeds in the order of S20 → S22 → S27 → S29 until the connection switching mechanism 39 of all cylinders is switched to the low-speed valve timing side. Even if a valve closing command is issued due to a failure of the switching valve 23 or the switching valve 24, the switching valve 24 does not switch to the closing side, and when the hydraulic switch in the hydraulic sensor 18 does not turn on for a long time, the same as S20 → The process proceeds in the order of S23 → S25 → S27 → S29, and as long as the connection switching mechanism 39 of all the cylinders is not switched to the low-speed valve timing side, the fuel injection control is maintained at the high-speed valve timing. When switching the solenoid valve 23 from the closed state to the open state, in the same manner as described above, unless the connection switching mechanism 39 of all the cylinders is switched to the high-speed valve timing side, the fuel injection control is adapted to the low-speed valve timing. Will be maintained.

On the other hand, the answer in step S2 is affirmative (Yes), or the answer in step S3 is negative (No), or the steps S5 and S6
If the answer is affirmative (Yes), that is, during start-up and before the elapse of the set time after start-up, during warm-up, that is, at low water temperature, during stoppage, or during slow-speed running, the routine proceeds to step S30, and the valve closing command of the solenoid valve 23 is issued. And the process proceeds from step S30 in the order of S24 → S26 → S28.

When the engine water temperature is low and thus the viscosity of the engine oil is high in the internal combustion engine that can be switched between the low-speed valve timing and the high-speed valve timing as described above, for example, since the friction of each part of the engine such as a bearing is high, the low rotation region The valve timing is controlled to be fixed at a low speed suitable for the engine, thereby protecting the engine.

As already mentioned, the economy mode in the determination in step S7, if the D-range, Further, N in the discrimination at step S9, if the P range, select the Ti _H maps the last loop proceeds to step S31 It is also determined whether or not Ne <Ne ₁ is satisfied in step S10, and the process proceeds to step S31. The answer in step S31 is affirmative (Ye
s), that is, when the previous loop Ti _H map is selected, the timer value t _VTOFF of the solenoid valve opening delay timer is _used.
The by zero (step S32), the process proceeds to step S18, when the answer to step S31 is negative (No), i.e. when not in use the last time Ti _H map, connection switching mechanism 39 of all cylinders fast in other words When it is not switched to the valve timing side, the process proceeds in the order of S30 → S24 → S26 → S28 in the same manner as described above, and the fuel injection control suitable for the low-speed valve timing is performed regardless of the hydraulic switch in the hydraulic pressure sensor 18. This is a countermeasure when the hydraulic switch in the hydraulic sensor 18 is kept off due to disconnection or the like.

By the way, the above-mentioned N _HFC1 is set higher than Ne ₂ , and usually, the valve timing is switched to the high-speed valve timing before Ne rises to N _HFC1, and the value of N _HFC becomes N
_{Since the mode} is switched to _HFC2 , the fuel cut at _NHFC1 is not performed. On the other hand, from step S2 to S9 to step S3
In the operating state proceeding to 0, since Ne by racing and the like are held in the low-speed valve timing even exceed the Ne _2, the fuel cut at the N _HFC1 performed. Further, even if the low-speed valve timing is switched to the high-speed valve timing, the fuel cut by the _{NHFC 1} is performed until t _HVT becomes 0, that is, until the coupling mechanism 39 is actually switched to the high-speed valve timing.

When the answer to the step S1 is affirmative (Yes), that is, when the fail-safe operation is being performed, a valve closing command for the solenoid valve 23 is issued (step S33), and fail-safe processing is executed (step S34). Proceed to end the present control program. Here, in the fail-safe processing, the fixed control may be performed at the same low-speed valve timing as when the engine water temperature is low as described above.

In the above description, switching of the shift mode, which is one element of the interlocking control, and control of the valve timing, which is another element, control the latter in accordance with the former. But it is possible. That is, in the above example, under the condition that the valve timing is fixed to the low-speed valve timing (low water temperature, valve timing fail-safe, etc.), even if the power mode is selected, from the viewpoint of the fuel efficiency performance, Linkage control for forcibly setting the mode to the economy mode, that is, the mode may be automatically switched to the economy mode. The interlocking control according to the present invention does not prevent application in such an aspect.

 Next, another embodiment of the present invention will be described.

In the above embodiment, the case of the interlocking control of the AT car has been described. However, the manual car (M) using a manual transmission as the transmission is described.
The same applies to T).

In the case of an MT vehicle, a selection switch (SEL SW) is provided as a means for making the engine output variable according to the running conditions. The driving condition selection switch (SEL SW) is a switch that can be manually operated by a driver as a mode switch, and the switching state (switching position) of the switch (SEL SW) is, for example, variable in the above-described embodiment. In the case of an example of a vehicle equipped with an engine with a valve timing mechanism, two types of control can be provided in accordance with two control modes: a mode in which low-speed valve timing is fixed and a mode in which low-speed valve timing and high-speed valve timing can be switched. Condition selection switch (SE
L SW), these control modes are switched.

In other words, the selection switch (SEL SW) is either one that the driver himself or herself fixes the valve timing to the low-speed valve timing or that the valve timing can be switched between low and high valve timing. Is used to select whether or not to use.
If the driver selects one of the above by himself, for example, if the switching position of the driving condition selection switch (SEL SW) is set to the mode of the low speed valve timing fixed side, in such a state, it corresponds to the above-mentioned economy mode focusing on fuel efficiency. When the position is set to the mode on the side where the low-speed valve timing and the high-speed valve timing can be switched, this corresponds to the power mode in which the power performance is emphasized.

The modes that can be selected are not limited to the types of economy and power as described above, and as will be described later, for example, economy (fuel efficiency is emphasized), normal (fuel efficiency is emphasized and power performance is emphasized) according to the characteristics of the engine with the variable valve timing mechanism to be applied. , And power (emphasis on power performance).

In this embodiment, the driving condition selection switch (SE
L SW) is provided separately, and the economy mode and power mode are selectable modes for varying the engine output.
LSW) switching by the driver, fixed low-speed valve timing when the economy mode is selected by the driver and low-speed valve timing and high-speed valve timing control when the power mode is selected when the power mode is selected. And That is, similarly to the above, the output characteristics of the low-speed valve timing and the high-speed valve timing (FIG. 3) are used, and the low-speed valve timing is fixed (the economy mode side), Is switched (power mode side).

Interlocking control in the case of MT vehicles focuses on the following points.

That is, when the selection switch (SEL SW) is switched to the economy mode switching state by the driver, the low-speed valve timing is fixed, but the engine output characteristic at the valve timing when fixed in this manner. Is shown by a solid line in FIG. 3, and in this characteristic, the power is quickly lost as the engine speed Ne increases. Therefore, when the driver changes gears by manual shift, the driver performs the shift operation earlier.

When the selection switch (SEL SW) is set to the switching state on the power mode side, that is, when the valve timing is low and high switching is permitted, the output characteristic of the engine at that time is the third as described above. The solid line in the figure (slow V / T),
Since it is indicated by the broken line (high-speed V / T), it is possible to operate the engine so as to rotate it to a higher speed. (Even when shifting, the driver thinks that he must shift again. The engine speed will also change.)

In other words, the driver operates the driving condition selection switch (SEL S
Depending on which of the switching states W) is set, the criterion changes as to whether or not the driver himself or herself can take the manner of maneuvering to shift earlier in a shift change (driving) The driver is manually shifting gears, but regarding valve timing, a switch (SEL SW)
Fixed (low speed V / T) or switchable state (low speed V / T, high speed)
V / T) mode is not determined, and accordingly, the recognition point at which the driver himself / herself needs to change gears changes at the same time, and consequently the conditions for manual shift also change).

As will be described more specifically below, the interlocking control device in the case of the MT vehicle is such that the automatic transmission 19 is changed to a manual transmission in FIG. The switching state signal is supplied from the SEL SW), and the ECU 5 can detect and monitor the switching state.

The monitoring of the selection switch (SEL SW) and the determination of the switching state are performed by the determination step S7 in the program of FIG.
Can be performed by replacing this with the one for determining the switching state of the selection switch (SEL SW), and according to the result of the determination, proceed to step S31 or lower (fixed at low speed V / T) or via step S8. Or go to step S10
/ T, high-speed V / T control).

In the above, when each switching state is selected, the interlocking control device enables the driver to adopt the following maneuvering method.

Now, if the driver wants to drive quickly by acceleration, etc., and has switched the driving condition selection switch (SEL SW) to the power mode side of the low-speed V / T and high-speed V / T control, such a state is assumed. In the case of, the engine speed Ne that the driver feels to shift is higher than in the case where the characteristics of the engine output are fixed to those of the solid line (low speed V / T) in FIG. In this case, the power performance is emphasized. When the driver knows that the engine speed does not increase anymore even if the driver depresses the accelerator pedal, the driver performs an upshift. In this case, the output characteristic is as shown in FIG. Since the valve timing can be switched between the low-speed valve timing exhibiting the output characteristics of the solid line and the high-speed valve timing exhibiting the output characteristics of the broken line, the valve shift is performed at a higher rotational speed compared to when the valve timing is fixed to the solid line. As a result, the vehicle can be pulled even at the highest possible rotational speed, so that it is possible to respond to driving that emphasizes power performance.

Further, when the driver has switched the traveling condition selection switch (SEL SW) to the switching state on the economy mode side instead of the switching state described above, the following occurs.

That is, the selection in this case is focused on fuel economy, but at the time of the selection, the low-speed valve timing is fixed (the processing of step S31 and subsequent steps is executed). Therefore, the engine output characteristic is as shown by the solid line in FIG. In this case, the peak power decreases, and the driver shifts earlier and earlier as compared to the case where the power performance is emphasized.

In this case, regarding the recognition of the shift, the timing of the engine speed can be easily recognized by listening to the sound of the engine speed or watching the tachometer. In this way, the driver knows the operating state at that time by the change in the sound of the engine speed, the indication of the pointer of the tachometer, etc., and the traveling condition selection switch (SEL SW) is switched to the above-mentioned economy mode side switching state. In this case, the driver himself / herself performs the shift operation earlier and earlier, so that the fuel efficiency can be improved.

As described above, this interlocking control can be applied to the MT vehicle, and by interlocking with the driving condition selection switch (SEL SW),
The optimum engine output characteristics for the driving conditions are obtained, and the best fuel efficiency is obtained.

In the above, the example of the engine output control shown in FIG. 3 has been described, but the present invention is not limited to this.

For example, if there are three types of valve timings (low speed, medium speed, high speed V / T, etc.), in the case of an MT vehicle, there are three selection modes.

Furthermore, supercharger (turbocharger, supercharger), variable intake (line switching, resonance supercharging), variable compression,
Further, by combining with a high-speed V / T mechanism, multi-stage output control can be performed.

In addition, control with further improved fuel efficiency can also be performed by combining with a valve stop, A / F leaning, a shift indicator, and the like.

(Effects of the Invention) According to the present invention, at least one of the valve operating states of the intake valve and the exhaust valve is switched to at least two states of a low-speed switching state suitable for a low rotation area and a high-speed switching state suitable for a high rotation area. An interlocking control device for an internal combustion engine having a switchable valve operating mechanism and a transmission used in a vehicle equipped with the engine, wherein a shift characteristic determining means for determining a shift characteristic of the transmission; A valve operating mechanism control means for controlling a switching state of the mechanism; and an interlocking control means for controlling one of the shift characteristic determining means and the valve operating mechanism control means in accordance with one of the states. Means are
An economy mode in which automatic shifting is performed with an emphasis on fuel efficiency performance, and a power mode in which automatic shifting is performed at a high engine speed or a high vehicle speed compared to the economy mode with emphasis on power performance. In the interlocking control device for an internal combustion engine and a transmission that switches the shift characteristics, the valve operating mechanism control means prohibits switching from the low speed switching state to the high speed switching state in the economy mode to switch the low speed switching state. In the case of the power mode, the switching control is performed to switch between the low-speed switching state holding state to be held and the switching allowable state in which the switching from the low-speed switching state to the high-speed switching state is performed. Optimal shift control can be performed, and fuel efficiency can be improved. That is, in the power mode, fuel consumption can be suppressed while emphasizing power performance, and in the economy mode, fuel efficiency can be further enhanced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle control device to which an interlocking control device for an internal combustion engine and an automatic transmission according to an embodiment of the present invention is applied, and FIG. 2 is a diagram showing an engine valve gear and its control system. FIG. 3 is a diagram showing an example of the characteristic of the engine output by the valve timing control. FIG. 4 is a diagram including the interlocking control of the low speed valve timing fixed and the low speed valve timing and the high speed valve timing switching interlocked with the shift mode switching. FIG. 5 is a flowchart showing an example of a program for switching control of the valve timing. FIG. 5 is a diagram showing an example of each shift pattern in the economy mode and the power mode. 1 ... internal combustion engine, 4 ... throttle valve opening sensor,
5 ... Electronic control unit (ECU), 6 ... Fuel injection valve, 11 ... Engine speed sensor, 16 ... Vehicle speed sensor, 19 ... Automatic transmission, 23 ... Solenoid valve, 24 ... Switching valve,
30: Valve operating device, 40: Intake valve or exhaust valve.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication // F16H 59:74

Claims (1)

(57) [Claims] 1. A valve operating mechanism capable of switching at least one of an intake valve and an exhaust valve between at least two states of a low-speed switching state suitable for a low rotation region and a high-speed switching state suitable for a high rotation region. A transmission characteristic determining means for determining a transmission characteristic of the transmission; and controlling a switching state of the valve operating mechanism. Valve operation mechanism control means, and interlocking control means for controlling one of the shift characteristic determination means and the valve operation mechanism control means in accordance with one of the states. The economy mode is set so that automatic shifting is performed with emphasis, and the automatic shifting is performed at high engine speed or high vehicle speed as compared with the economy mode while emphasizing power performance. An interlocking control device for an internal combustion engine and a transmission that switches the shift characteristic to a power mode, wherein the valve operating mechanism control means inhibits switching from the low speed switching state to the high speed switching state in the economy mode. An internal combustion engine that performs switching control between a low-speed switching state holding state for maintaining a low-speed switching state and a switching permission state for allowing switching from the low-speed switching state to the high-speed switching state in the case of the power mode. Transmission interlocking control device.