JP5088044B2 - Engine control device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an engine control device including a variable valve operating device, and more specifically, a variable valve operating device that opens and closes an engine valve via a link mechanism linked to a cam shaft. TECHNICAL FIELD OF THE INVENTION

  Various variable valve gears configured to variably control the valve lift characteristics (lift amount or opening / closing timing) of an intake valve or exhaust valve of an engine have been proposed, and some have already been put into practical use.

  In response to the demand for higher engine performance and higher output in recent years, a variable valve gear has been developed that can be continuously changed in addition to the lift amount of engine valves such as intake valves. ing. This variable valve operating apparatus has a link mechanism having a plurality of cams, and this link mechanism operates in conjunction with the cam shaft, thereby opening and closing the engine valve. According to this, it is possible to realize a valve lift characteristic that is more suitable for the operating conditions of the engine. However, this has a complicated structure and more sliding parts than a general variable valve operating device represented by VTC, etc., and slides due to deterioration of the state of lubricating oil (the lubricating state of the sliding parts). There is a high possibility that the parts will be worn or deteriorated.

The following technique is known as a function guarantee for the lubrication failure of the variable valve operating device. The temperature of the lubricating oil supplied to the variable valve system is detected, and when the detected temperature exceeds the specified temperature, the supply of hydraulic oil to the variable valve system is stopped and the valve lift characteristics are switched. It is prohibited (Patent Document 1).
Japanese Patent Laid-Open No. 08-177432 (paragraph number 0006)

  In order to avoid lubrication failure due to a decrease in viscosity against excessive rises in the temperature of the lubricating oil, the above technology prohibits switching of the valve lift characteristics, lowers the engine output, and further increases the temperature of the lubricating oil. It prevents the rise. However, the above technique is intended for a variable valve apparatus having a relatively simple structure, and is not intended for a variable valve apparatus having a link mechanism. In addition, when there is a risk of poor lubrication, switching of the valve lift characteristics is uniformly prohibited, and even if the variable valve device can be operated as much as possible within a range that can ensure lubrication performance. Absent.

  The present invention, in an engine configured to include a variable valve device having a link mechanism linked to a camshaft, maintains a good lubrication state of a sliding portion in the link mechanism, and prevents poor lubrication of the variable valve device. The objective is to achieve both functional security and improved engine performance.

The present invention provides an engine control apparatus.
According to the present invention, in an engine having a variable valve gear that opens and closes an engine valve via a link mechanism linked to a camshaft, a lubrication state of a sliding portion in the link mechanism is detected and detected by the lubrication state detection means. When the sliding part is in a state where the desired lubrication performance cannot be obtained, the operating range of the variable valve device is reduced to limit its operation. belongs to.
The means for detecting the lubrication state determines whether or not the lift amount of the engine valve by the variable valve operating device is larger than a predetermined upper limit lift amount according to the temperature of the lubricating oil supplied to the sliding portion. The restricting means restricts the lift amount of the engine valve to the upper limit lift amount or less when the lift amount of the engine valve is larger than the upper limit lift amount, and the operation area restricting means restricts the maximum lift amount of the engine valve to the lubricating oil. An engine control device that limits the lift amount to a lower value as the temperature increases.
The operating region limiting means limits the maximum lift amount of the engine valve by the variable valve operating device when the engine speed is equal to or lower than the rotation speed set as the rotation speed on the low rotation side,
The operating region limiting means is an engine control device that limits the maximum lift amount of the engine valve to a lower lift amount as the engine speed is lower.
Furthermore, the engine speed detecting means for detecting the engine speed, and the engine speed detected by the engine speed detecting means is higher than a predetermined limit speed corresponding to the temperature of the lubricating oil supplied to the sliding portion. An engine speed reduction means for lowering the engine speed, and the limit speed is set to a smaller value as the lubricating oil temperature is higher.

  According to the present invention, since the operation of the variable valve operating apparatus is limited based on the detection result of the lubrication state, it is possible to prevent poor lubrication in the sliding portion and maintain the good lubrication state. .

  Further, according to the present invention, since the operation region is reduced when the operation is restricted, the variable valve operating device can be operated (change the valve lift characteristics) within a range in which the lubrication performance can be secured. The engine performance can be improved while preventing the lubrication failure of the variable valve operating apparatus.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows the configuration of an engine (hereinafter simply referred to as “engine”) 1 according to an embodiment of the present invention.

  An electronically controlled throttle valve 102 is installed in the intake passage 101, whereby the amount of air taken into the engine 1 can be controlled. In the present embodiment, the intake air amount is mainly controlled by changing a valve lift characteristic of an intake valve 104, which will be described later, and the throttle valve 102 controls intake pressure, which is a precondition for control by changing the valve lift characteristic. To adopt. The intake passage 101 is provided with an injector 103 for supplying fuel. The injector 103 injects an amount of fuel necessary to achieve a predetermined equivalence ratio under a controlled intake air amount. A poppet type intake valve 104 is installed in the port portion 101a of the intake passage. The intake valve 104 is driven by a variable valve operating device (hereinafter referred to as “intake valve operating device”) 105 disposed above the intake valve 104, and during the open period, a mixture of intake air and fuel is introduced into the cylinder. The The intake valve operating device 105 can continuously change the lift amount and opening / closing timing of the intake valve 104.

  In the engine body, a spark plug 106 is installed on the cylinder head H so as to face the substantially upper center of the combustion chamber. The spark plug 106 ignites the air-fuel mixture introduced into the cylinder.

  After combustion, the generated exhaust gas is sent out to the exhaust passage 107. A poppet type exhaust valve 108 is installed in the port portion 107a of the exhaust passage. The exhaust valve 108 is driven by another valve gear 109 disposed above the exhaust valve 108, and exhaust gas is delivered during the open period. In this embodiment, unlike the intake valve 104, the valve lift characteristic of the exhaust valve 108 is constant. However, a configuration similar to that of the intake valve device 105 or other known variable valve device is used. It may be adopted that the valve lift characteristics can be changed.

  The operations of the intake valve operating device 105, the throttle valve 102, and the like are controlled by an engine control unit (hereinafter referred to as “ECU”) 201 configured as an electronic control unit. The ECU 201 has a crank angle for generating a signal from the accelerator sensor 211 for detecting the amount of depression of the accelerator pedal by the driver (hereinafter referred to as “accelerator operation amount”) and a signal for each unit crank angle and reference crank angle. A signal from the sensor 212 (the ECU 201 calculates the engine speed NE based on the signal) is input. In addition to these signals, the ECU 201 has a signal from the coolant temperature sensor 213 for detecting the temperature of the engine coolant, and a lubricant temperature for detecting the temperature of the engine oil (hereinafter referred to as “lubricant”). A signal from the sensor 214 and a signal from the key switch 215 are input. The ECU 201 executes a predetermined calculation related to engine control based on various input signals and outputs a command signal to the intake valve operating device 105 and the like. The ECU 201 is connected to an information display device (hereinafter referred to as “indicator”) 251 provided on the control panel of the driver's seat, and a control unit 301 of the automatic transmission. Command signals are sent to these devices. It is configured to allow output.

FIG. 2 shows the configuration of the intake valve operating device 105.
The intake valve operating device 105 includes a device A for changing the lift amount and opening / closing period (operating angle) of the intake valve 104 as an engine valve (hereinafter referred to as “operating angle changing device”) A, a center angle changing device B, Consists of The center angle changing device B is for changing the phase related to the crank angle of the opening / closing period (operating angle).

  A drive shaft (corresponding to a “cam shaft”) 151 is disposed above the intake valve 104 so as to extend in the cylinder row direction. A drive cam 152 is attached to the drive shaft 151 so as to be relatively rotatable. Yes. The drive cam 152 contacts the lifter 141 of the intake valve 104 and drives the intake valve 104 in the opening direction via the lifter 141. The operating angle change device A changes the lift amount and the opening / closing period (operating angle) of the intake valve 104 by changing the attitude of a link mechanism, which will be described later, connecting the drive shaft 151 and the drive cam 152. On the other hand, the center angle changing device B changes the phase of the open / close period (operating angle) by changing the phase of the drive shaft 151 with respect to a crankshaft or cam sprocket (not shown).

Here, the operation of the operating angle changing device A will be described with reference to FIG.
The operating angle changing device A includes an eccentric cam 153 fixed to the drive shaft 151, a ring-shaped link 154 that is fitted around the eccentric cam 153 so as to be relatively rotatable, and a control shaft 155 that is arranged in parallel with the drive shaft 151. A rocking cam 156 fixed to the control shaft 155, a rocker arm 157 externally fitted to the rocking cam 156 so as to be relatively rotatable, and connected to a ring-shaped link 154 at one end, and the rocker arm 157 as a drive cam. 152 and a rod-shaped link 158 connected to 152. The control shaft 155 rotates when an actuator 161 (FIG. 1) such as a step motor drives the gear 162.

  The operation of the operating angle changing device A is as follows. When the drive shaft 151 rotates in conjunction with the crankshaft, this rotational motion is converted into a reciprocating motion of the ring-shaped link 154 by the eccentric cam 153, and the rocker arm 157 swings. The rocking movement of the rocker arm 157 is performed around the rocking cam 156. When the rocker arm 157 swings, the rod-shaped link 158 follows and the drive cam 152 swings. Further, when the control shaft 155 is rotated by the actuator 161, the center of the swing cam 156 is displaced, and thereby the swing center of the rocker arm 157 is displaced, and the lift amount and the opening / closing period (operation angle) of the intake valve 104 are displaced. ) Changes continuously.

  Here, the operating angle changing device A has a complicated structure and a large number of sliding portions as compared with the conventional general variable valve operating device, and wear or deterioration of the sliding portions occurs due to deterioration of the state of the lubricating oil. Probability is high. Specifically, when the temperature of the lubricating oil in the sliding portion rises excessively due to the influence of environmental conditions such as the air temperature or the operating conditions of the engine 1, the viscosity of the lubricating oil decreases, and the intended lubricating performance is reduced. It cannot be obtained. In such a state, if the operating angle changing device A is operated in the large lift region when the engine 1 is rotating at a low speed, an amount (or pressure) of lubricating oil that can compensate for the decrease in viscosity is provided to the eccentric cam 153. Although a large driving torque is input even though it is not supplied, there is a possibility that wear may occur due to metal touch between the eccentric cam 153 and the ring-shaped link 154. On the other hand, if the operating angle changing device A is operated in a small lift region when the engine 1 is rotating at a high speed, the rocking cam 156 is slid on the rocking cam 156 by a small rocking motion of the rocker arm 157 at high speed. Since uniform supply of the lubricating oil to the entire part is hindered, there is a possibility that the sliding part may be worn. In response to these problems, the present embodiment detects the lubrication state of the sliding portion in the intake valve operating device 105 (specifically, the operating angle changing device A), and the intake valve operating device 105 based on the detection result. By restricting the operation of this, the acceleration of wear and deterioration of the sliding portion is avoided. In the present embodiment, control relating to the operation restriction of the intake valve operating device 105 is performed by the ECU 201 as part of engine control. It should be noted that “detection” regarding the lubrication state of the sliding portion includes indirect detection and substantial detection by estimation or the like.

Hereinafter, the operation of the ECU 201 will be described.
4 and 5 show the configuration of the ECU 201 in functional blocks, FIG. 4 shows the configuration of the variable valve lift control unit of the ECU 201, and FIG. 5 shows the configuration of the throttle control unit.

  In FIG. 4, the target torque calculation unit B101 calculates a target torque TRQtg of the engine 1 based on the accelerator operation amount APO and the engine speed NE. Under normal conditions, the target lift amount LFTtg of the intake valve 104, the target opening TVOtg of the throttle valve 102, and the like are calculated based on the target torque TRQtg, and each actuator such as the intake valve operating device 105 is controlled.

  The target lift amount calculation unit B102 calculates a target lift amount LFTtg of the intake valve 104 based on the target torque TRQtg and the engine speed NE. The target lift amount LFTtg is calculated as a lift amount having a larger value as the target torque TRQtg is larger and the engine speed NE is lower, by searching from a calculation map set with a tendency as shown in FIG. The In FIG. 7, a solid line A indicates the maximum lift amount in the operating region of the intake valve operating device 105 (specifically, the operating angle changing device A) determined by the engine speed NE and the lift amount LFT of the intake valve 104. The solid line B indicates the minimum lift amount in this operating region. The intake valve operating device 105 is controlled within a range of an operation region surrounded by the solid lines A and B in a normal state.

  The upper limit lift amount calculation unit B103 calculates the upper limit lift amount Lmax of the intake valve 104 based on the temperature Toil of the lubricating oil supplied to the intake valve operating device 105. The upper limit lift amount Lmax is provided to limit the lift amount LFT of the intake valve 104 according to the lubrication state of the sliding portion, separately from the maximum lift amount indicated by the solid line A (FIG. 7). As shown in FIG. 10, the upper limit lift amount Lmax is calculated as a smaller lift amount as the lubricating oil temperature Toil is higher. The temperature Toil of the lubricating oil is preferably the temperature of the lubricating oil at the sliding portion for detecting the lubrication state. However, in this embodiment, for convenience, the temperature at the main gallery detected by the lubricating oil temperature sensor 214 is used. to substitute. In the present embodiment, the sliding portion to be detected is a sliding portion in the eccentric cam 153 or the swing cam 156. It is also possible to estimate the temperature at the sliding portion of the eccentric cam 153 or the like from the detected temperature Toil at the main gallery in consideration of the operating conditions of the engine 1 or the like.

  The target lift amount selection unit B104 compares the target lift amount LFTtg calculated based on the target torque TRQtg with the upper limit lift amount Lmax calculated based on the lubricating oil temperature Toil, and determines the smaller lift amount. This is selected, and this is set to the final target lift amount LFTtg.

  In FIG. 5, the target limit torque calculating unit B201 calculates the target limit torque TRQrs based on the target lift amount LFTtg (= LFTtg0) calculated by the target lift amount calculating unit B102 and the engine speed NE. The target limit torque TRQrs is calculated by inverse conversion from the calculation map shown in FIG.

  The target torque selector B202 compares the target torque TRQtg (= TRQtg0) calculated by the target torque calculator B101 with the target limit torque TRQrs calculated by the target limit torque calculator B201, and the smaller target torque. Is output to the target throttle opening calculation unit B203 as the final target torque TRQtg.

The target throttle opening calculator B203 calculates the target opening TVOtg of the throttle valve 102 based on the target torque TRQtg and the engine speed NE.
Hereinafter, the operation of the ECU 201 will be described with reference to flowcharts.

FIG. 12 is a flowchart of a basic routine of variable valve lift control according to this embodiment.
In S101, the accelerator operation amount APO, the engine speed NE, and the like are read as operating conditions of the engine 1.

In S102, the target torque TRQtg of the engine 1 is calculated based on the read APO, NE, etc. (target torque calculation unit B101).
In S103, the target lift amount LFTtg of the intake valve 104 is calculated based on the calculated TRQtg and the engine speed NE (target lift amount calculation unit B102). The target lift amount LFTtg is calculated by a search from the calculation map shown in FIG.

  In S104, the temperature Toil of the lubricating oil supplied to the sliding part is detected. In the present embodiment, the temperature Toil of the lubricating oil is substituted with the temperature at the main gallery detected by the lubricating oil temperature sensor 214.

  In S105, an upper limit lift amount Lmax of the intake valve 104 is calculated based on the detected Toil (upper limit lift amount calculation unit B103). The upper limit lift amount Lmax is calculated as a lift amount with a smaller value in accordance with the temperature Toil of the lubricating oil, the higher this is (FIG. 10).

In S106, it is determined whether or not the automatic transmission is performing a speed change operation. Only when the shift operation is not being performed, the routine proceeds to S107, and when the shift operation is being performed, this routine is terminated.
In S107, the operation of the intake valve operating device 105 is limited according to the routine shown in FIG.

  In S201, it is determined whether or not the target lift amount LFTtg is equal to or less than the upper limit lift amount Lmax (target lift amount selection unit B104). When it is less than or equal to the upper limit lift amount Lmax, the process proceeds to S204, and when it is greater than Lmax, the process proceeds to S202.

  In S202, the upper limit lift amount Lmax is set to the final target lift amount TRQtg. Accordingly, the intake valve operating device 105 (specifically, the operating angle changing device A) is controlled based on the limited target lift amount TRQtg (= Lmax).

  In S203, a command signal for limiting the shift to the low speed stage is output to the control unit 301 of the automatic transmission. In this embodiment, the kickdown operation of the automatic transmission is prohibited.

  In S204, it is determined whether or not the engine speed NE is equal to or lower than a predetermined limit speed NElmt. If it is equal to or less than the limit rotational speed NElmt, this routine is terminated. If it is higher than NElmt, the routine proceeds to S111. The limit rotational speed NElmt is calculated as a rotational speed having a smaller value as the lubricating oil temperature Toil is higher, as shown in FIG.

  In S205, the engine speed NE is reduced to a limit speed NElmt or less. In the present embodiment, the control for reducing the engine speed is performed by stopping the fuel supply to some cylinders. Specifically, in the fuel cut control performed as part of the engine control, the upper limit number of revolutions for fuel cut that is set in order to prevent the engine 1 from over-rotation is decreased from the normal time. The engine torque itself may be reduced by reducing the opening of the throttle valve 102 and reducing the intake air amount.

  In conjunction with the process of S202, the display means such as the indicator 251 provided in the passenger compartment is operated to allow the driver to recognize that the operation of the intake valve operating device 105 is limited and the engine torque is reduced. May be. Further, by driving the radiator fan in conjunction with the operation restriction of the intake valve operating device 105 (or increasing its output), it is possible to reduce the temperature Toil of the lubricating oil and promote the recovery of the lubrication state.

  Furthermore, when the control related to the operation restriction of the intake valve operating device 105 is started by the process of S201, this control may be continued until the key switch 215 is subsequently turned off and the engine 1 is stopped. It is expected that the driver will depress the accelerator pedal deeper than usual due to the reduction in engine torque accompanying the operation restriction. This is because if it is released, the drivability may deteriorate due to a sudden increase in engine torque.

  In the present embodiment, the “link mechanism” of the intake valve operating device 105 (specifically, the operating angle changing device A) is constituted by the eccentric cam 153, the ring-shaped link 154, the swing cam 156, the rocker arm 157, and the rod-shaped link 158. Is configured. Further, the function as the “lubrication state detecting means” is realized by the process of S201 in the flowchart shown in FIG. 13, and the function as the “operating region limiting means” is realized by the process of S202. Further, in the ECU 201, the target torque calculation unit B101 is “target torque calculation unit”, the target lift amount calculation unit B102 is “target lift amount setting unit”, and the target throttle opening calculation unit B203 is “target opening setting unit”. ”And“ target limit opening setting means ”, the target limit torque calculation unit B201 corresponds to“ target limit torque calculation means ”, and the crank angle sensor 212 corresponds to“ engine speed detection means ”. Further, the function as the “engine speed reduction means” by the process of S205 in the flowchart shown in FIG. 13 and the function as the “shift limiting means” by the process of S203 are “restricted” by the process of S106 in the flowchart shown in FIG. The function as “prohibiting means” is realized.

Hereinafter, effects obtained by the present embodiment will be described.
In the present embodiment, when the lubrication state of the sliding portion in the intake valve operating device 105 (specifically, the operating angle changing device A) is detected and a good lubrication state cannot be obtained, the temperature Toil of the lubricating oil is set. The corresponding upper lift amount Lmax is set as the target lift amount LFTtg. Thereby, the operation region of the intake valve operating device 105 is substantially reduced, the operation in a state where poor lubrication may occur can be avoided, and the intake valve operating device 105 can be operated while maintaining a good lubrication state. it can. In particular, in this embodiment, the restriction by the upper limit lift amount Lmax is adopted, so that the operation in the large lift region at the time of low rotation of the engine 1 is avoided, and the metal touch due to the input of a large driving torque to the eccentric cam 153. Can be prevented and wear of the eccentric cam 153 can be suppressed. Furthermore, the lubrication state of the sliding portion can be easily detected by comparing the target lift amount LFTtg with the upper limit lift amount Lmax. It is also possible to detect the temperature state of the sliding portion based on the temperature of the lubricating oil at the main gallery and limit the target lift amount LFTtg based on the detection result.

  In the present embodiment, the upper limit lift amount Lmax of the intake valve 104 is calculated based on the lubricating oil temperature Toil, and the higher the lubricating oil temperature Toil, the smaller the lift amount is set. Thereby, the actual lubrication state of the sliding portion is reflected in the limit of the target lift amount LFTtg, and the limit can be appropriately executed. FIG. 7 shows a change in the upper limit lift amount Lmax according to the temperature Toil of the lubricating oil. The upper limit lift amount Lmaxl is switched to a smaller value Lmaxh as the lubricating oil temperature Toil increases, and the operating range of the intake valve operating device 105 is reduced.

  In the present embodiment, the upper limit lift amount Lmax is set as a constant lift amount for each lubricating oil temperature Toil regardless of the engine speed NE (FIG. 7). However, the upper limit lift amount Lmax is equal to the engine speed NE. It can be changed accordingly. FIG. 9 shows the setting of the upper limit lift amount Lmax in this case. The upper limit lift amount Lmax is changed according to the temperature Toil of the lubricating oil, and the engine speed NE is equal to or lower than the low speed side rotational speed (corresponding to “second rotational speed”) NE2 (NE2l, NE2h). In some cases, the lift amount is set to a smaller value as the engine speed NE is lower. Thereby, the large lift operation of the intake valve operating device 105 at the time of low rotation can be avoided more effectively, and the wear of the eccentric cam 153 can be suppressed.

  Further, in the present embodiment, when the engine speed NE is higher than the predetermined limit speed NElmt, the engine speed NE is decreased and limited to the limit speed NElmt or less. Accordingly, excessive high-speed vibration of the rocker arm 157 centering on the swing cam 156 can be avoided, and wear due to the lubricant not spreading over the entire sliding portion can be prevented. Further, the higher the lubricating oil temperature Toil, the lower the limiting rotational speed NElmt is set to a smaller rotational speed, thereby reflecting the state of the lubricating oil and preventing wear more effectively.

In the present embodiment, with respect to the lift amount LFT, the operation of the intake valve operating device 105 is limited only by the upper limit lift amount Lmax of the intake valve 104. Not limited to this, by using the lower limit lift amount Lmin of the intake valve 104 together with the upper limit lift amount Lmax, it is possible to more actively prevent the swing cam 156 from being worn by minute vibrations at high speed. As shown in FIG. 8, the engine speed NE is equal to or higher than the engine speed NE1 (NE1l, NE1h) equal to or higher than the engine speed NE1 on the high rotation side (corresponding to the "first engine speed"). The lift amount Lmin is set as a larger lift amount as the engine speed NE is higher. When the target lift amount LFTtg calculated based on the operating conditions of the engine 1 is smaller than the minimum lift amount Lmin, this minimum lift amount Lmin is set as the final target lift amount LFTtg, and the intake valve operating device 105 Limit operation. The upper limit lift amount Lmax may be a constant lift amount for each lubricating oil temperature Toil (FIG. 7) or may be changed according to the engine speed NE (FIG. 9).

  Furthermore, when the operation of the intake valve operating device 105 is restricted, good lubrication can be obtained by restricting the shift to the low speed stage by the automatic transmission (in this embodiment, the kickdown operation of the automatic transmission). It is possible to avoid high-speed vibration of the rocker arm 157 in the absence, and to prevent the rocking cam 156 from being worn.

  Further, when the automatic transmission is performing a speed change operation, it is possible to protect the automatic transmission from a shock input due to a sudden change in the engine torque by prohibiting the restriction on the operation of the intake valve operating device 105.

  The operation restriction of the intake valve operating device 105 is not limited to the method based on the comparison between the target lift amount LFTtg and the upper limit lift amount Lmax, and the intake valve operating device 105 and the throttle valve 102 are controlled by using the target torque TRQtg as a reference. It is also possible to configure each control in an integrated manner.

  FIG. 6 shows the configuration of the control system in this case. The target limit torque calculation unit B303 calculates the target limit torque TRQrs by inverse conversion of the upper limit lift amount Lmax (set based on the lubricating oil temperature Toil), and the target torque selection unit B304 calculates the target torque TRQtg. The smaller TRQrs are compared with each other, and the smaller one is set as the final target torque TRQtg. Based on the set TRQtg and the engine speed NE, the target lift amount LFTtg of the intake valve 104 is calculated (target lift amount calculation unit B305), and the target opening degree TVOtg of the throttle valve 102 is calculated (target throttle opening degree). Calculation unit B306).

  Further, when restricting the operation of the intake valve operating device 105, in addition to limiting the shift to the low speed stage by the automatic transmission, the variable valve operating device (specifically, the operation angle change) that is the target of the operation restriction. The pressure of the lubricating oil supplied to the device A) may be increased. As a result, an effect of restoring the lubrication state of the sliding portion is obtained, and wear of the sliding portion can be surely avoided. The flowchart shown in FIG. 14 shows the contents of the processing related to the operation restriction in this case.

In FIG. 14, steps that perform the same processing as in the flowchart shown in FIG.
When it is determined in S201 that the target lift amount LFTtg is larger than the upper limit lift amount Lmax, the upper limit lift amount Lmax is set to the target lift amount LFTtg in S202, and in S203, automatic shift is performed as a shift restriction for the automatic transmission. Prohibit the machine from kicking down. In S301, it is determined whether or not the temperature Toil of the lubricating oil is equal to or lower than the predetermined temperature Toil1, and the process proceeds to S302 only when the temperature exceeds the predetermined temperature Toil1. In S302, the central angle changing device B (corresponding to “second variable valve operating device”) as another variable valve operating device other than the target of operation restriction is stopped and supplied to the operating angle changing device A. Increase lubricant pressure. The discharge amount of the oil pump may be increased. A function as “pressure increasing means” is realized by the processing of S301 and S302. Here, the predetermined temperature Toil1 used as a criterion for the determination of increasing the pressure of the lubricating oil is set as the upper limit of the temperature at which the function can be guaranteed by limiting the maximum lift amount of the intake valve 104 (FIG. 10). The increase in the pressure of the lubricating oil may be performed when it can be determined from the lubricating oil temperature Toil and the operating conditions of the engine 1 that the temperature of the lubricating oil in the sliding portion may further increase. . When the process of S301 is omitted and the operation of the intake valve operating device 105 is limited, the other variable valve operating device may always be stopped regardless of the temperature Toil of the lubricating oil.

Configuration of engine according to one embodiment of the present invention Configuration of variable valve operating apparatus (intake valve operating apparatus) according to the same embodiment Configuration of operating angle changing device of intake valve operating device Configuration of variable valve lift control section of engine control unit Configuration of throttle control section of engine control unit Configuration of modified engine control unit Calculation map for target lift amount setting Relationship between engine speed and lower limit lift amount according to another embodiment of the present invention Relationship between engine speed and upper limit lift amount according to the embodiment Table data trend of upper lift amount Table data for limit speed Flow chart of basic routine of variable valve lift control Flowchart of processing related to operation restriction in the same routine The flowchart of the example of a change of the process regarding an operation restriction same as the above

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 101 ... Intake passage, 101a ... Intake port, 102 ... Throttle valve, 103 ... Injector, 104 ... Intake valve as "engine valve", 105 ... Intake valve operating device, 151 ... Drive shaft, 152 ... Drive cam 153, eccentric cam, 154, ring-shaped link, 155, control shaft, 156, rocking cam, 157, rocker arm, 158, rod-shaped link, 161, actuator, 162, gear, 106, spark plug, 107, exhaust. Passage, 107a ... exhaust port, 108 ... exhaust valve, 109 ... exhaust valve operating device, 201 ... control unit of engine 1, 211 ... accelerator sensor, 212 ... crank angle sensor, 213 ... cooling water temperature sensor, 214 ... lubricating oil temperature Sensors, 215, key switches, 251, information display device, 301, automatic transmission controller Over Ruyunitto, A ... "first variable valve system" operating angle changing device as, B ... center angle changing device as a "second variable valve operating device".

Claims (5)

An engine control device comprising a variable valve gear that opens and closes an engine valve via a link mechanism linked to a camshaft,
Lubrication state detection means for detecting the lubrication state of the sliding portion in the link mechanism;
When the lubrication state of the sliding portion detected by the lubrication state detection means is a state in which the desired lubrication performance cannot be obtained, the operation region of the variable valve operating device is reduced to limit the operation thereof. An operating area limiting means,
The lubrication state detection means determines whether the lift amount of the engine valve by the variable valve device is larger than a predetermined upper limit lift amount according to the temperature of the lubricating oil supplied to the sliding portion,
The operating region limiting means limits the lift amount of the engine valve to the upper limit lift amount or less when the lift amount of the engine valve is larger than the upper limit lift amount,
The operating region restricting means restricts the maximum lift amount of the engine valve to a smaller lift amount as the temperature of the lubricating oil is higher . An engine control device comprising a variable valve gear that opens and closes an engine valve via a link mechanism linked to a camshaft,
Lubrication state detection means for detecting the lubrication state of the sliding portion in the link mechanism;
When the lubrication state of the sliding portion detected by the lubrication state detection means is a state in which the desired lubrication performance cannot be obtained, the operation region of the variable valve operating device is reduced to limit the operation thereof. An operating area limiting means,
The operating region limiting means limits the maximum lift amount of the engine valve by the variable valve operating apparatus when the engine speed is equal to or lower than the rotational speed set as the low rotational speed,
The operating region limiting means limits the maximum lift amount of the engine valve to a lower lift amount as the engine speed is lower . An engine control device comprising a variable valve gear that opens and closes an engine valve via a link mechanism linked to a camshaft,
Lubrication state detection means for detecting the lubrication state of the sliding portion in the link mechanism;
When the lubrication state of the sliding portion detected by the lubrication state detection means is a state in which the desired lubrication performance cannot be obtained, the operation region of the variable valve operating device is reduced to limit the operation thereof. Working area limiting means;
An engine speed detecting means for detecting the engine speed;
When the engine speed detected by the engine speed detecting means is higher than a predetermined limit speed corresponding to the temperature of the lubricating oil supplied to the sliding portion, the engine speed is reduced to reduce the engine speed. Means,
The engine control device is configured such that the limit rotational speed is set to a smaller rotational speed as the temperature of the lubricating oil is higher . Target torque calculating means for calculating a target torque of the engine according to the accelerator operation amount;
Target lift amount setting means for setting a target lift amount of the engine valve based on the target torque calculated by the target torque calculation means;
Target opening setting means for setting a target opening of the throttle valve based on the calculated target torque;
At the time of operation restriction when the lift amount of the engine valve restricted by the operation region restriction means is set as a restriction lift amount, and the restriction lift amount is smaller than the target lift amount set by the target lift amount setting means, Target limit torque calculating means for calculating a target limit torque of the engine according to the limit lift amount;
And target limit opening setting means for setting a target limit opening of the throttle valve according to the target limit torque calculated by the target limit torque calculation means,
In the normal time, while controlling the throttle valve based on the target opening set by the target opening setting means,
3. The engine control device according to claim 1, wherein the throttle valve is controlled based on a target limit opening set by the target limit opening setting means when the operation is limited. The engine control device according to claim 3, wherein the engine speed reduction means reduces the engine speed by restricting the fuel supply to the engine or reducing the opening of the throttle valve.

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