JP2016070144A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, for simply suppressing the flapping of components of a winding transmission mechanism at starting the internal combustion engine.SOLUTION: The control device controls the internal combustion engine to which auxiliary equipment is attached while being connected via the winding transmission mechanism. When the wearing degrees of ignition plugs of the internal combustion engine are relatively high, the control device controls a delay time period after starting the operation of a motor to start the internal combustion engine but before starting the injection of fuel in the internal combustion engine, to be set longer than when the wearing degrees of the ignition plugs of the internal combustion engine are relatively low.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a control device for controlling an internal combustion engine accompanied by an auxiliary machine connected via a winding transmission mechanism.

  An internal combustion engine mounted on a vehicle includes a generator (which may also serve as an electric motor for supplying driving force to the crankshaft or the axle of the internal combustion engine) that is driven by the internal combustion engine, and refrigerant compression for an air conditioner Auxiliary equipment such as compressors and water pumps are attached. The auxiliary machine and the internal combustion engine are usually connected by a winding transmission mechanism having a belt (or chain) and a pulley (or sprocket) as elements.

  By the way, when the spark plug installed in the cylinder of the internal combustion engine is worn out due to deterioration over time or the like, the ignition and combustion of the fuel tends to become unstable. For this reason, the magnitude of the output torque and the rotational speed of the internal combustion engine during cranking may fluctuate so as to vibrate.

  Along with this, the tension of the belt wound around the crankshaft side pulley and the accessory side pulley also fluctuates greatly, and the belt and the tensioner that applies tension to the belt may flutter, resulting in abnormal noise. It can cause problems. Also, the possibility of damage to the tensioner due to the flapping of the tensioner cannot be completely denied. Further, slippage may occur between the belt and the pulley due to fluctuations in belt tension. The above problem becomes apparent when a pendulum type auto tensioner (double arm tensioner; see Patent Document 1 below) in which tension pulleys are arranged on both sides of a pulley provided in a generator / motor is employed.

  As a measure for avoiding the problem described in the previous stage, it is conceivable to use an electric tensioner (see, for example, Patent Document 2 below). However, the electric tensioner has a complicated mechanism, increases cost, and increases weight.

Japanese Patent Application No. 2014-131234 JP 2003-343307 A

  An object of the present invention is to easily suppress flapping of components of a winding transmission mechanism at the start of an internal combustion engine.

  In order to solve the above problems, a control device for an internal combustion engine according to the present invention has a configuration as described below. That is, the control device for an internal combustion engine according to the present invention is a control device for controlling an internal combustion engine accompanied by an auxiliary machine connected via a winding transmission mechanism, and operates an electric motor for starting the internal combustion engine. A delay period between the start and the start of fuel injection in the internal combustion engine is set longer when the degree of wear of the spark plug is relatively high than when the degree of wear of the spark plug is relatively low, or After starting the operation of the electric motor for starting the internal combustion engine, fuel injection into the cylinder of the internal combustion engine is not started until the rotational speed of the internal combustion engine reaches a threshold value, and the degree of wear of the spark plug is relatively high The threshold value is set to a higher value than when the spark plug wear level is relatively low.

  With such a configuration, when the degree of wear of the spark plug is relatively high, the temperature in the combustion chamber of the cylinder can be raised during the delay period when the internal combustion engine is started. Accordingly, the ignition and combustibility after the start of fuel injection can be improved, and as a result, fluctuations in the rotational speed and fluctuations in the tension of the belt (or chain) of the winding transmission mechanism accompanying this rotational speed fluctuation. Can be suppressed. That is, fluttering of the tensioner and belt and generation of noise can be suppressed.

  In the present invention, the delay period until the start of fuel injection in the internal combustion engine is set longer when the degree of wear of the spark plug is relatively high than when the degree of wear of the spark plug is relatively low. “Yes” means that when the degree of wear of the spark plug is in the first range, the first delay period is set, and when the degree of wear of the spark plug is in the second range higher than the first range. Is a concept including both a mode in which a second delay period longer than the first delay period is set and a mode in which the delay period is gradually set longer as the degree of wear of the spark plug increases.

  Further, in the present invention, “when the degree of wear of the spark plug is relatively high, the threshold value is set to a higher value than when the degree of wear of the spark plug is relatively low” means that the degree of wear of the spark plug is first. If it is in the range of 1, the first threshold is set, and if the degree of wear of the spark plug is in the second range higher than the first range, the second threshold is higher than the first threshold. And a mode in which the threshold is gradually set to a higher value as the degree of wear of the spark plug increases.

  According to the present invention, flapping of the components of the winding transmission mechanism at the start of the internal combustion engine can be easily suppressed.

1 is a schematic configuration diagram of an internal combustion engine in a first embodiment of the present invention. The schematic diagram of the connection aspect of the internal combustion engine and ISG in the embodiment. The figure which shows the electric circuit for controlling the various electric loads mounted in the vehicle. FIG. 2 is an overall schematic front view of the internal combustion engine in the same embodiment. FIG. 2 is an overall schematic plan view of the internal combustion engine in the same embodiment. The figure which looked at the pendulum type auto tensioner in the same embodiment from the direction of a rotation axis. XX sectional drawing of FIG. The flowchart which shows the control procedure of the embodiment roughly. The flowchart which shows roughly the control procedure of 2nd embodiment of this invention.

  A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment. A vehicle internal combustion engine 100 shown in FIG. 1 is a spark ignition type four-stroke engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  As shown in FIG. 2, the internal combustion engine 100 according to the present embodiment is accompanied by a starter motor (cell motor) 140, an ISG (Integrated Starter Generator), a compressor 130, and other auxiliary machines.

  The starter motor 140 is an electric motor dedicated to cranking that mainly drives the crankshaft 10 of the internal combustion engine 100 during cold start. The starter motor 140 has a pinion gear 141 on its output shaft, and the pinion gear 141 rotates on the crankshaft 10 by meshing with a ring gear 104 fixed to the crankshaft 10 that is the output shaft of the internal combustion engine 100. Transmits driving force. The pinion gear 141 is separated from the ring gear 104 except when the internal combustion engine 100 is being cranked by the starter motor 140.

  The ISG 110 has a function as an electric motor that drives the crankshaft 10 and thus an axle (and driving wheels) of the vehicle, and a function as a generator that receives power from the crankshaft 10 and generates electric power.

  The ISG 110 is, for example, an inner-rotor type AC synchronous machine, and includes a rotor (rotor) having both permanent magnets and a rotor coil (excitation (field) winding) 116, and a three-phase AC facing the outer peripheral surface of the rotor. A stator (stator) including a stator coil (stator winding) 115 is used as an element. The rotor is fixed to the outer periphery of the rotor shaft 111.

  The ISG 110 is connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the first winding transmission mechanism 201. The first winding transmission mechanism 201 includes an ISG pulley (or sprocket) 112, a first belt (or chain) 113, and a first crank pulley 101. The ISG pulley 112 and the first crank pulley 101 are fixed to the rotor shaft 111 and the crankshaft 10, respectively. The ISG pulley 112 and the first belt 113 wound around the first crank pulley 101 transmit a rotational driving force between the crankshaft 10 and the rotor shaft 111 (bidirectionally).

  The ISG 110 supplies power from the in-vehicle power storage device 61 mainly at the time of restarting the internal combustion engine 100 that has been idle-stopped or at the time of motor assist that increases the driving force to be supplied to the axle (particularly during acceleration or climbing). In response, the crankshaft 10 is driven to rotate. The power storage device 61 includes a battery and / or a capacitor. In turn, when power is generated by being rotationally driven by the crankshaft 10, the power storage device 61 is charged with the generated power. When the vehicle decelerates, regenerative braking is performed by the ISG 110, and the kinetic energy of the vehicle can be recovered as electric energy.

  The compressor 130 for compressing the refrigerant of the air conditioner is also connected to one end side of the crankshaft 10 of the internal combustion engine 100 via the second winding transmission mechanism 202, similarly to the ISG 110. The second winding transmission mechanism 202 includes a second crank pulley 102, a second belt (or chain) 134, and a compressor pulley (or sprocket) 133. The compressor pulley 133 and the second crank pulley 102 are fixed to the input shaft 132 and the crankshaft 10 of the compressor 130, respectively. A rotational driving force is transmitted from the crankshaft 10 to the input shaft 132 by the second belt 134 wound around the compressor pulley 133 and the second crank pulley 102. A magnet clutch 131 that can be connected and disconnected is provided between the main body of the compressor 130 and the input shaft 132, and the clutch 131 is disconnected when the air conditioner is not operated.

  A transmission 120 that connects the internal combustion engine 100 and the axle is installed on the other end side of the crankshaft 10.

  Various electric loads are mounted on the vehicle. Specific examples of electrical loads include air conditioner blowers, rear glass defoggers, audio equipment, car navigation systems, lighting (headlamps, taillights, stoplights (brakelights), foglights, turn signals (turns) Signal lamp)), a radiator fan for cooling the cooling water of the internal combustion engine 100, an electric power steering device, and the like.

  FIG. 3 shows an electric circuit for controlling the electric load. As already described, the magnet clutch 131 is interposed between the crankshaft 10 of the internal combustion engine 100 and the refrigerant compression compressor 130. When operating the air conditioner, the magnet clutch 131 is energized to engage the clutch 131. When the air conditioner is not operated, the magnet clutch 131 is not energized and the clutch 131 is disconnected. Energization and disconnection of the magnet clutch 131 is performed by ON / OFF of the relay switch 62.

  The motor 63 that rotationally drives the blower for blower and the heating wire heater 65 laid on the rear glass as a defogger operate by receiving power supply from the power storage device 61 (or ISG 110). The energization and the interruption of the motor 63 and the heater 65 are performed by turning on / off the relay switch 64 or firing / switching the semiconductor switching element (power device represented by a power transistor, power MOSFET, etc.). Do by arc extinguishing.

  The same applies to audio devices, car navigation systems, illumination lamps, motors that rotate the radiator fan, and other electrical loads.

  Here, an outline of the basic structure of the internal combustion engine 100 of the present embodiment will be described based on FIGS. 4 and 5. In the following description, the front / rear / left / right terms are used to specify the direction. The front / rear direction is the direction of the crank axis L1, and the left / right direction is a direction orthogonal to the cylinder axis L2 and the crank axis L1. The front view is a state seen from the direction of the crank axis L1. In the internal combustion engine 100 of the present embodiment, the cylinder axis L2 is slightly inclined (slant) with respect to the vertical line L3, but in the figure, the cylinder axis L2 is in a vertical posture for convenience. it's shown.

  The basic configuration of the internal combustion engine 100 is the same as the conventional one. That is, as main elements, a cylinder block 1a, a cylinder head 1b fixed to the upper surface of the cylinder block 1a, and a front cover (chain cover, chain case) 1d fixed to a number of bolts 1c on one end face thereof are provided. A head cover 1e is fixed to the upper surface of the cylinder head 1b, and an oil pan 1f is fixed to the lower surface of the cylinder block 1a.

  One end of the crankshaft 10 projects outward from the outer surface of the front cover 1d (one end surface of the engine body), while the ISG 110 is disposed on the left side of the engine body in front view, and the compressor 130 is disposed on the right side. doing. In addition, a water pump 150 is disposed in a portion of the front cover 1d that is substantially in the middle of the upper and lower sides and on the left side when viewed from the front.

  The ISG 110 is fixed to the cylinder block 1a and the front cover 1d via an upper bracket B1, a first lower bracket (not shown) and a second lower bracket (not shown), and the compressor 130 is connected to the cylinder block 1a via a bracket (not shown). (Or / and the front cover 1d). The water pump 150 also serves as a pump housing for the front cover 1d, and the water pump 150 is configured by fixing the pump cover 1g (see FIG. 4) to the front cover 1d.

  As described above, the ISG 110 receives power from the crankshaft 10 via the first winding transmission mechanism 201 including the ISG pulley 112, the first crank pulley 101, and the first belt 113. The compressor 130 also receives power from the crankshaft 10 through the second winding transmission mechanism 202 including the compressor pulley 133, the second crank pulley 102, and the second belt 134 as described above. On the other hand, the water pump 150 receives power from the crankshaft 10 via the third winding transmission mechanism 203 including the pump pulley 152, the third crank pulley 103, and the third belt 153. The pump pulley 152 is fixed to an input shaft 151 that is a rotating shaft. The third crank pulley 103 is fixed to the crankshaft 10. Power is transmitted from the crankshaft 10 to the water pump 150 via a third belt 153 wound around the pump pulley 152 and the third crank pulley 103.

  The first crank pulley 101 and the second crank pulley 102 have substantially the same diameter, and the ISG pulley 112 has an outer diameter that is substantially half that of the first crank pulley 101. Therefore, when functioning as a generator, the ISG pulley 112 is driven at a rotational speed several times the rotational speed of the crankshaft 10, and when the ISG 110 functions as a motor, the crankshaft 10 is equal to the number of ISG pulleys 112. It is driven at a rotational speed of 1.

  The upper and lower portions 113a and 113b of the first belt 113 sandwiching the ISG pulley 112 are sandwiched by two upper and lower tension pulleys 161a and 161b in a pendulum type auto tensioner 160 described later.

  In this case, in order for the autotensioner 160 to function, the first belt 113 needs to spread as it moves away from the ISG pulley 112. Therefore, in order to ensure the spread angle of the first belt 113, the front cover 1d Among them, an idle pulley 169 is attached to the upper side of the water pump 150. Therefore, the water pump 150 is disposed in an area surrounded by the first belt 113. Further, the idle pulley 169 is disposed on the side closer to the ISG 110 than the cylinder axis L2 in a front view.

  Note that the first belt 113 can be wound around the compressor pulley 133 as indicated by a one-dot chain line in FIG. In this case, of course, the second belt 134 is not used.

  As shown in FIGS. 6 and 7, the auto tensioner 160 has a disk-like base 162 on which the ISG pulley 112 is loosely fitted, and two arms 163 on which the tension pulleys 161 a and 161 b are rotatably held. The two arms 163 are rotatably connected to the base 162 so that the tension pulleys 161a and 161b can move far and away, and the two arms 163 are attached in a direction to approach each other by a substantially C-shaped spring 164. It is fast. The two arms 163 are attached to the base 162 so as to turn around the base of the base 162 while turning around the base.

  Accordingly, the two tension pulleys 161 a and 161 b can rotate around the axis 162 a of the base 162 together with the spring 164, and can move independently of each other by deforming the spring 164. A plurality (three) of cylindrical foot portions 165 are provided on the side of the base 162 opposite to the tension pulleys 161a and 161b, and the foot portions 165 are fixed to the outer surface of the ISG 110 with bolts (not shown). ing. The foot 165 is fixed to a top bracket plate 166 indicated by a one-dot chain line in FIG. The top bracket plate 166 is connected to the rear bracket plate 167 and the reinforcing rod 168.

In the present embodiment, the auto tensioner 160 is set such that the axis 162a of the base 162 is separated from the front cover 1e by a slight dimension E from the axis 112a of the ISG pulley 112 in a front view.
The ECU 0 is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like. The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle of the crankshaft 10 and the engine speed, and an accelerator pedal. From an accelerator opening signal c output from a sensor that detects the amount of depression of the engine or the opening of the throttle valve 32 as an accelerator opening (so-called required load), a sensor (shift position switch) for knowing the range of the shift lever An output shift range signal d, an intake air temperature / intake pressure signal e output from a sensor for detecting intake air temperature and intake air pressure in the intake passage 3 (particularly, the surge tank 33), and a cooling water temperature of the internal combustion engine 100 are detected. The coolant temperature signal f output from the sensor, the brake pedal being depressed, or the brake pedal A brake signal g output from a sensor (such as a brake switch or a master cylinder pressure sensor) that detects the amount of depression, a terminal voltage and a terminal current of the power storage device 61 (in particular, a battery voltage or a battery current), and the like. A voltage / current signal h, a travel distance signal l output from the odometer, an operation request signal m regarding whether or not to operate each of the air conditioner and various electric loads, and the like are input.

  The operation request signal m is manually issued from an operation switch (or control panel) for each air conditioner or electric load, which is manually operated by a driver or passenger who desires to operate the air conditioner and various electric loads. It may be a control signal or an automatic control signal issued from an auto air conditioner ECU that controls the auto air conditioner system.

  From the output interface of the ECU 0, the ignition signal i is sent to the igniter of the spark plug 12, the fuel injection signal j is sent to the injector 11, the opening operation signal k is sent to the throttle valve 32, and this is sent to the controller 114 of the ISG 110. Control signal n for control, switch 62 on the electric circuit for energizing the magnet clutch 131, clutch engagement signal o for the switch 64, 66 on the electric circuit for energizing the motor 63, heater 65 and other electric loads Switch ON signals p, q and the like.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 100. The ECU 0 acquires various information a, b, c, d, e, f, g, h, l, m required for operation control of the internal combustion engine 100 via the input interface, and opens the required throttle valve 32. Various operating parameters such as fuel injection amount commensurate with the amount of intake air (fresh air amount) charged into the cylinder 1, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, etc. decide. The ECU 0 applies various control signals i, j, k, n, o, p, q corresponding to the operation parameters via the output interface.

  In addition, the ECU 0 inputs the control signal r to the starter motor 140 when the internal combustion engine 100 is started, particularly during cold start, and engages the pinion gear 141 with the ring gear 104 to crank the internal combustion engine 100.

  In addition, the predetermined distance in the memory of the ECU 0 stores the travel distance when the spark plug 12 was last replaced (0 km is stored at the time of shipment), and the difference from the current travel distance indicated by the travel distance signal l is: The travel distance from the time when the spark plug 12 was replaced last time to the present is obtained.

  Therefore, in the present embodiment, when cranking the internal combustion engine 100, the ECU 0 performs the following control. Specifically, a delay period control program is stored in a predetermined area of the memory of the ECU 0, and the processor performs the following control by executing the delay period control program. That is, a delay period from the start of starter motor 140 to start internal combustion engine 100 to the start of fuel injection is set. This delay period is set longer when the degree of wear of the spark plug 12 is relatively small than when the degree of wear of the spark plug 12 is relatively small, with the degree of wear of the spark plug 12 indicated by the travel distance as a parameter. To do. More specifically, the length of the delay period is, for example, travel from the time when the spark plug 12 was replaced last time to the present, in order from the one corresponding to the case where the degree of wear of the spark plug 12 is low (the travel distance is short). The first length corresponding to the case where the distance (hereinafter referred to as the travel distance after replacement) is less than 5000 km, the second length corresponding to the case in which the travel distance after the replacement is 5000 km or more and less than 10,000 km, and travel after the replacement. The third length corresponding to the case where the distance is equal to or greater than 10,000 km and less than 15000 km, and the fourth length corresponding to the case where the travel distance after replacement is equal to or greater than 15000 km are set. Of these first to fourth lengths, the first length is the shortest, and the second length, the third length, and the fourth length become longer in the following order. The reason for setting the length of the delay period in this way is that the spark plug 12 is considered to deteriorate as the travel distance after replacement becomes longer. Note that the number of stages of the length of the delay period may be arbitrarily set, and the range of the travel distance after replacement corresponding to each stage may be arbitrarily set. Further, the delay period may be set to gradually increase as the travel distance after replacement increases. Note that cylinder discrimination is performed in parallel during the delay period.

  Hereinafter, a procedure of processing executed by the ECU 0 by the delay period control program of the present embodiment will be described with reference to FIG. 8 which is a flowchart. When the start of the starter motor 140 (step S1), the ECU 0 detects the travel distance after replacement, which is a parameter indicating the degree of wear of the spark plug 12 (step S2), and based on the degree of wear of the spark plug 12, In other words, the delay period is determined using the travel distance after replacement as a parameter (step S3). Then, fuel is not injected until the delay period elapses from the start of operation of the starter motor 140 (step S4). After the delay period elapses (step S4), fuel injection is started (step S5). ).

  By performing the control in this manner, when the degree of wear of the spark plug 12 is large, the delay period can be set long, and the temperature in the combustion chamber of the cylinder 1 can be raised during the delay period. Accordingly, the ignition and combustibility after the start of fuel injection can be improved, and thereby the fluctuation of the rotational speed of the internal combustion engine 100 and the fluctuation of the tension of the first belt 113 due to the fluctuation of the rotational speed can be reduced. Can be suppressed. That is, the pendulum type auto tensioner 160 and the first belt 113 fluttering due to a large fluctuation in the tension of the first belt 113, the generation of noise, and the gap between the first belt 113 and the pulleys 101 and 112. The slippage can be easily suppressed without using a special member or mechanism.

  Next, a second embodiment of the present invention will be described. Since the internal combustion engine in the second embodiment has the same configuration as that of the first embodiment described above, detailed description thereof is omitted. In the following description, the same names and symbols are assigned to the portions corresponding to those in the first embodiment described above.

  In the present embodiment, the ECU 0 performs the following control when starting the internal combustion engine 100, instead of the control by the delay period control program in the first embodiment. Specifically, a threshold setting program is stored in a predetermined area of the memory of the ECU 0, and the processor performs the following control by executing this threshold setting program. That is, after starting the starter motor 140 to start the internal combustion engine 100, fuel injection is not started until the rotational speed of the internal combustion engine 100 reaches a threshold value. This threshold value is set to a higher value when the degree of wear of the spark plug 12 is relatively small than when the degree of wear of the spark plug 12 is relatively small, with the degree of wear of the spark plug 12 indicated by the travel distance as a parameter. Set. More specifically, for example, the threshold value of the rotational speed of the internal combustion engine 100 corresponds to the case where the degree of wear is low (when the travel distance is short), for example, the travel distance from when the spark plug 12 was last replaced to the present. The first threshold corresponding to the case where the travel distance after replacement is less than 5000 km, the second threshold corresponding to the case where the travel distance after replacement is not less than 5000 km and less than 10,000 km, and the travel distance after replacement is 10,000 km. The third threshold value corresponding to the case where the distance is less than 15000 km and the fourth threshold value corresponding to the case where the travel distance after replacement is 15000 km or more are set. The first to fourth threshold values are the lowest at the first threshold value, and are increased in the order of the second threshold value, the third threshold value, and the fourth threshold value. The reason for setting the threshold in this way is that the spark plug 12 is considered to deteriorate as the travel distance after replacement becomes longer. In addition, when the threshold value of the rotational speed of the internal combustion engine 100 becomes high, the starter motor 140 is kept constant in order to keep the time from when the starter motor 140 starts operating until the rotational speed of the internal combustion engine 100 reaches the threshold value. The output of is increased to increase. Note that the number of threshold levels may be set arbitrarily, and the range of the travel distance after replacement corresponding to each level may be set arbitrarily. Further, the threshold value of the rotational speed of the internal combustion engine 100 may be set to gradually increase as the travel distance after replacement becomes longer.

  Hereinafter, a procedure of processing executed by the ECU 0 by the threshold setting program of the present embodiment will be described with reference to FIG. 9 which is a flowchart. When the start of the starter motor 140 (step S11), the ECU 0 detects the travel distance after replacement, which is a parameter indicating the degree of wear of the spark plug 12 (step S12), and based on the degree of wear of the spark plug 12, In other words, the threshold value of the rotational speed of the internal combustion engine 100 is determined using the travel distance after replacement as a parameter (step S13). Then, fuel is not injected until the rotational speed of the internal combustion engine 100 exceeds the threshold (step S14), and when the rotational speed of the internal combustion engine 100 exceeds the threshold (step S14), fuel injection is started (step S14). S15).

  By performing the control in this way, when the degree of wear of the spark plug 12 is large, the threshold value for the rotational speed of the internal combustion engine 100 for starting fuel injection is set to a high value, and this rotational speed reaches the threshold value. Until the temperature of the cylinder 1 can be raised. Accordingly, the ignition and combustibility after the start of fuel injection can be improved, and thereby the fluctuation of the rotational speed of the internal combustion engine 100 and the fluctuation of the tension of the first belt 113 due to the fluctuation of the rotational speed can be reduced. Can be suppressed. That is, the elements constituting the pendulum type auto tensioner 160 and the fluctuation of the first belt 113 itself, the generation of noise, and the first belt 113 and the pulley 101 due to the great fluctuation of the tension of the first belt 113. , 112 can be easily suppressed without using a special member or mechanism.

  Further, when the temperature of the internal combustion engine 100 is relatively low, in other words, when the rotation speed threshold value is high, the output of the starter motor 140 is increased to increase combustion instability and misfire. The influence of the rotational speed fluctuation when it occurs can be made relatively small.

  The present invention is not limited to the embodiment described above.

  For example, in the first embodiment and the second embodiment described above, the travel distance from the time when the ignition plug was replaced last time to the present as the parameter indicating the degree of wear of the ignition plug of the internal combustion engine is used. Time integration or integration of the total number of ignitions up to the present after the replacement, the total engine speed up to the present after the previous replacement of the spark plug, and the required load and speed up to the present after the previous replacement of the spark plug Other parameters such as values may be used. This is because it is considered that the degree of wear of the spark plug is large when these parameters are also large.

  Further, in the first embodiment and the second embodiment described above, mention is made of the effect of suppressing fluctuations in the tension of the first belt that mainly constitutes the winding transmission mechanism between the internal combustion engine and the auxiliary ISG. However, according to the present invention, the effect of suppressing fluctuations in the tension of the belt (or chain) constituting the winding transmission mechanism between the internal combustion engine and other auxiliary machines can be obtained in the same manner.

  Furthermore, in the second embodiment described above, the output of the starter motor is increased when the degree of wear of the spark plug is relatively high. However, the output of the starter motor is constant regardless of the degree of wear of the spark plug. Good. In that case, the length of the delay period from the start of the operation of the electric motor for starting the internal combustion engine to the start of fuel injection in the internal combustion engine varies relatively depending on the degree of wear of the spark plug. .

  And this invention may be applied to what the tensioner for adjusting the tension | tensile_strength of the belt which comprises a winding transmission mechanism is other than the pendulum type auto tensioner in 1st embodiment mentioned above and 2nd embodiment. An example of a tensioner other than a pendulum type auto tensioner is one that imparts an urging force to an auxiliary machine.

  In addition, various changes may be made without departing from the spirit of the present invention.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 11 ... Injector 12 ... Spark plug 100 ... Internal combustion engine 110 ... Auxiliary machine (ISG)
140: Electric motor (starter motor)
160 ... Auto tensioner 201 ... Wound transmission mechanism b ... Crank angle signal l ... Driving distance signal

Claims (2)

A control device for controlling an internal combustion engine accompanied by an auxiliary machine connected via a winding transmission mechanism,
After starting the operation of the electric motor for starting the internal combustion engine, a delay period from the start of fuel injection in the internal combustion engine is set to a degree of wear of the spark plug when the degree of wear of the spark plug is relatively high. A control device for an internal combustion engine that is set longer than a relatively low case. A control device for controlling an internal combustion engine accompanied by an auxiliary machine connected via a winding transmission mechanism,
After starting the operation of the electric motor for starting the internal combustion engine, do not start fuel injection into the cylinders of the internal combustion engine until the rotational speed of the internal combustion engine reaches a threshold value,
A control device for an internal combustion engine, wherein the threshold value is set to a higher value when the degree of wear of the spark plug is relatively high than when the degree of wear of the spark plug is relatively low.

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