JP2008069720A - Warm-up control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a warm-up control device for an internal combustion engine capable of suppressing an increase of fuel consumption and emission when a temperature difference occurs between cylinder groups. <P>SOLUTION: In the warm-up control device, the internal combustion engine 1 is equipped with a water temperature sensor 64 capable of detecting the temperature of a first cylinder group 11 arranged on a first bank 16 and the temperature of a second cylinder group 12 arranged on a second bank 17 based on the water temperature of the first bank 16 and the water temperature of the second bank 17. Further, an ECU 70 of the internal combustion engine 1 is provided with a start control portion 75 for performing such start control as to start only the cylinder group 10 higher in temperature when the temperatures of the cylinder groups 10 detected by the water temperature sensor 64 are different from each other. Thus, when the temperature of the first cylinder group 11 is different from that of the second cylinder group 12 at the time of starting the internal combustion engine 1, only the cylinder group 10 higher in temperature is started first. As a result, it is possible to suppress an increase of fuel consumption and emission when the temperature difference occurs between the cylinder groups 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a warm-up control device for an internal combustion engine. In particular, the present invention relates to a warm-up control device for an internal combustion engine having a plurality of cylinder groups.

  In some conventional internal combustion engines, cylinder resting control is performed during operation of the internal combustion engine for the purpose of improving fuel consumption. That is, the fuel supplied to some cylinders is stopped during the operation of the internal combustion engine to reduce the fuel injection amount. Further, in conventional internal combustion engines, in order to purify exhaust gas exhausted, many internal combustion engines are provided with a catalyst that serves as purification means in the path of exhaust gas exhausted from the internal combustion engine. However, since this catalyst has a limited temperature range in which exhaust gas can be purified, when the temperature of the catalyst is low, such as when starting an internal combustion engine, and the catalyst is not activated, the exhaust gas is efficiently removed. It may be difficult to purify. For this reason, some conventional internal combustion engines ensure the exhaust gas purification performance immediately after the internal combustion engine is started.

  For example, in the cylinder resting control device of the multi-cylinder engine described in Patent Document 1, when the cooling water temperature at the time of starting the engine is equal to or higher than a predetermined temperature, the particular cylinder is subjected to the resting control until a predetermined time elapses immediately after the engine starts. is doing. As a result, it is possible to suppress excessive cylinder resting control when the water temperature is low, and when the cooling water temperature is equal to or higher than the predetermined temperature, the cylinder resting control is executed for a predetermined time immediately after the engine is started. The amount of fuel consumed can be reduced, and the exhaust gas discharged from the engine can be reduced. As a result, it is possible to suppress the deterioration of the emission when the catalyst is not activated.

JP 2003-148185 A

  However, in an internal combustion engine having a plurality of cylinders, there may be a temperature difference between the cylinders. In particular, in a so-called V-type internal combustion engine in which cylinders are provided in two directions when viewed from the crankshaft, such a temperature difference is likely to occur between cylinder groups provided in two banks. . As described above, when a temperature difference occurs between the cylinder groups, in the cylinder group having the lower temperature, since the temperature of the lubricating oil is low and the viscosity is high, the mechanical loss increases, and the fuel consumption may be deteriorated. Further, in the cylinder group having the lower temperature, the fuel vaporization rate is low, so that the combustion state is bad and the emission state may be deteriorated. For this reason, in order to maintain good combustion, it is necessary to supply an air-fuel mixture with a large amount of fuel, that is, an air-fuel mixture that is close to richness, which may deteriorate fuel consumption.

  The present invention has been made in view of the above, and provides a warm-up control device for an internal combustion engine that can suppress deterioration of fuel consumption and emission when a temperature difference occurs between cylinder groups. With the goal.

  In order to solve the above-described problems and achieve the object, a warm-up control device for an internal combustion engine according to the present invention is provided for each cylinder group that is a part of a plurality of cylinders of the internal combustion engine. A temperature detecting means capable of detecting a temperature, and a part of the cylinder group which can be started at the time of starting the internal combustion engine; and the temperature of the cylinder group detected by the temperature detecting means is different between the cylinder groups. Start control means for performing start control, which is control for starting only the cylinder group having a higher temperature when there is a fuel.

  In the present invention, the temperature of the cylinder group is detected for each cylinder group by the temperature detection means, and when there is a temperature difference between the cylinder groups, only the cylinder group having the higher temperature when the internal combustion engine is started is started by the start control means. It is starting. The cylinder group with the higher temperature has a lower mechanical loss because the temperature of the lubricating oil is higher and the viscosity of the lubricating oil is lower. For this reason, deterioration of fuel consumption can be suppressed. Further, in the cylinder group having a higher temperature, the fuel is easily vaporized, so that a good combustion state can be obtained. Thereby, generation | occurrence | production of an emission can be suppressed. As a result, it is possible to suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  In the internal combustion engine warm-up control device according to the present invention, the start control means may be configured such that when the temperature of the cylinder group detected by the temperature detection means has a temperature difference of a predetermined value or less between the cylinder groups. The cylinder group that has not been started is started.

  In this invention, after starting only the cylinder group having the higher temperature when starting the internal combustion engine, when the temperature difference between the cylinder groups becomes a predetermined value or less, the unstarted cylinder group is started. In other words, the cylinder group with the higher temperature is started, and the heat generated during operation of this cylinder group is transferred to the cylinder group with the lower temperature, the temperature of this cylinder group rises, and the higher temperature When the temperature difference from the cylinder group becomes a predetermined value or less, the cylinder group having the lower temperature is started. As described above, since the cylinder group with the lower temperature is started after the temperature rises, the deterioration of the fuel consumption and the emission can be suppressed similarly to the start of the cylinder group with the higher temperature. As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  Further, in the warm-up control device for an internal combustion engine according to the present invention, when the temperature of the cylinder group detected by the temperature detection means has a difference between the cylinder groups, the start control means The start control is performed when the temperature of the cylinder group is equal to or lower than a predetermined temperature.

  In the present invention, since the start control is performed when the temperature of the cylinder group having the lower temperature is equal to or lower than a predetermined value, it is possible to more reliably suppress deterioration of fuel consumption and emission. In other words, even if there is a temperature difference between the cylinder groups, if the temperature of the lower cylinder group is higher than the predetermined temperature, the viscosity of the lubricant is low due to the high temperature of the lubricating oil, and the fuel is vaporized. It is easy. For this reason, even if the start control is not performed, the fuel consumption is unlikely to deteriorate and the emission may not easily occur. Therefore, when there is a temperature difference between the cylinder groups, the start control is performed when the temperature of the lower cylinder group is equal to or lower than a predetermined temperature, so that deterioration of fuel consumption and emission can be more reliably suppressed. In addition, when the temperature of the cylinder group having the lower temperature is higher than a predetermined temperature, the start control is not performed, so that good startability can be obtained. As a result, it is possible to ensure startability while more reliably suppressing deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  The warm-up control device for an internal combustion engine according to the present invention includes a temperature detection unit capable of detecting a temperature of the cylinder group for each cylinder group that is a part of a plurality of cylinders of the internal combustion engine, and the internal combustion engine When the temperature of the cylinder group detected by the temperature detection means during operation of the engine is different between the cylinder groups, warm-up control is performed that is a control for increasing the temperature of the lower cylinder group. And a control means.

  In the present invention, the temperature of the cylinder group is detected for each cylinder group by the temperature detection means, and when there is a temperature difference between the cylinder groups, the warm-up control means increases the temperature of the lower cylinder group by the warm-up control means. The machine is being controlled. The cylinder group having the lower temperature tends to have a large mechanical loss because the temperature of the lubricating oil is low and the viscosity of the lubricating oil is high. Further, in a cylinder group having a low temperature, the fuel is difficult to vaporize, and it may be difficult to obtain a good combustion state. For this reason, the cylinder group with the lower temperature is likely to deteriorate in fuel efficiency and may easily generate emissions. Occurrence can be suppressed. As a result, it is possible to suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  In the internal combustion engine warm-up control device according to the present invention, when the temperature of the cylinder group detected by the temperature detection means has a temperature difference of a predetermined value or less between the cylinder groups. The warm-up control is terminated.

  In the present invention, after the warm-up control is started, the warm-up control is terminated when the temperature difference between the cylinder groups becomes a predetermined value or less. In other words, when the temperature of the lower cylinder group rises due to the warm-up control and the temperature difference from the higher cylinder group falls below a predetermined value, the warm-up control is terminated. Yes. As described above, since the warm-up control is performed until the temperature of the cylinder group having the lower temperature rises, it is possible to suppress the deterioration of the fuel consumption and the emission due to the low temperature of the cylinder group. As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  In the warm-up control device for an internal combustion engine according to the present invention, the warm-up control means adjusts at least one of valve timing, ignition timing, fuel injection amount, and fuel injection timing of the cylinder group having a lower temperature. Thus, the warm-up control is performed.

  In the present invention, since the warm-up control is performed by at least one of the valve timing, the ignition timing, the fuel injection amount, and the fuel injection timing, the temperature of the cylinder group having the lower temperature can be more reliably increased. As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  Further, in the warm-up control device for an internal combustion engine according to the present invention, the warm-up control means has a lower temperature when the temperature of the cylinder group detected by the temperature detection means is different between the cylinder groups. The warm-up control is performed when the temperature of the cylinder group is equal to or lower than a predetermined temperature.

  In this invention, since the warm-up control is performed when the temperature of the cylinder group having the lower temperature is equal to or lower than a predetermined temperature, it is possible to more reliably suppress the deterioration of fuel consumption and emission. That is, as in the above-described start control, when there is a temperature difference between the cylinder groups, the warm-up control is performed more reliably when the temperature of the cylinder group having the lower temperature is equal to or lower than a predetermined temperature, thereby improving the fuel consumption. Deterioration of emissions can be suppressed, and when the temperature of the lower cylinder group is higher than a predetermined temperature, the warm-up control is not performed, so that a stable operating state can be obtained. As a result, it is possible to ensure stability during operation of the internal combustion engine while more reliably suppressing deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  In the warm-up control device for an internal combustion engine according to the present invention, the internal combustion engine is connected to an electric motor that can output together with the output of the internal combustion engine, and further, a torque difference occurs between the cylinder groups. If there is, vibration suppression control means for performing vibration suppression control by the electric motor is provided.

  In the present invention, when a torque difference is generated between the cylinder groups, the vibration suppression control is performed by the electric motor, so that stable output can be performed. That is, during start-up control or warm-up control, the cylinder group with the lower temperature is deactivated and only the cylinder group with the higher temperature is operated, so there is a possibility that a torque difference may occur between the cylinder groups. For this reason, there is a risk that vibration will occur at the time of output due to this torque difference.For example, during operation of the internal combustion engine during start-up control or warm-up control, at the time of output of the cylinder of the cylinder group with the lower temperature By increasing the torque of the electric motor and outputting them together, it is possible to equalize the torque at the time of output. Thereby, the vibration resulting from the torque difference between the cylinder groups at the time of internal combustion engine operation can be suppressed. As a result, a part of the cylinder group is deactivated to suppress vibration in the case of suppressing deterioration of fuel consumption and emission due to a temperature difference between the cylinder groups and ensuring stability during operation of the internal combustion engine. it can.

  The warm-up control device for an internal combustion engine according to the present invention has an effect that it is possible to suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups.

  Embodiments of a warm-up control device for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic diagram of an internal combustion engine provided with a warm-up control device for an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a schematic view taken along the line AA in FIG. The internal combustion engine 1 shown in the figure is provided with a warm-up control device 5 according to Embodiment 1 of the present invention, and the internal combustion engine 1 has a plurality of cylinders 8. Each cylinder 8 has a cylinder head 21 and a cylinder block 22 in which a combustion chamber 35 is formed. A crankcase 23 is located on the opposite side of the cylinder block 22 from the cylinder head 21 side. Among these, inside the cylinder block 22, a piston 30 is provided so as to be capable of reciprocating in the cylinder 8. A crankshaft 32 as a shaft is provided. The crankshaft 32 is provided in the crankcase 23, has a rotation shaft in a direction orthogonal to the direction of reciprocation of the piston 30, and is formed to be rotatable around the rotation shaft. The piston 30 and the crankshaft 32 provided in this way are connected by a connecting rod 31. As a result, the crankshaft 32 can rotate with the reciprocating motion of the piston 30.

  Further, the internal combustion engine 1 has a starter motor 68 for starting the internal combustion engine 1 by transmitting rotation to the crankshaft 32 via a flywheel (not shown) connected to the crankshaft 32 at the time of starting. Is provided.

  The plurality of cylinders 8 are formed with the cylinders 8 facing in two directions when viewed from the crankshaft 32. The internal combustion engine 1 having the cylinders 8 formed in this way is a so-called V-type internal combustion engine 1. It has become. In this V-type internal combustion engine 1, four cylinders 8 form one set to form a bank 15, and two banks 15 are provided. That is, the internal combustion engine 1 has eight cylinders 8. Of the two banks 15, one bank 15 is a first bank 16 and the other bank 15 is a second bank 17. As described above, among the cylinders 8 provided in the first bank 16 and the second bank 17, the cylinders 8 provided in the first bank 16 constitute the first cylinder group 11, and the cylinders 8 provided in the second bank 17. Is the second cylinder group 12. That is, the first cylinder group 11 includes a part of the plurality of cylinders 8 included in the internal combustion engine 1, and the second cylinder group 12 includes the first cylinder 8 included in the internal combustion engine 1. The cylinders 8 other than the cylinder group 11 are provided.

  The cylinder 8 formed in this manner will be described in detail. The cylinder block 22 is formed with a cooling water passage 25 through which cooling water that circulates through the internal combustion engine 1 during operation and cools the internal combustion engine 1 passes. Each of the first bank 16 and the second bank 17 is provided with a water temperature sensor 64 that is a temperature detecting means capable of detecting the temperature of the cooling water flowing through the cooling water passage 25. The water temperature sensor 64 is provided separately in the first bank 16 and the second bank 17, and is formed in the second bank 17 and the temperature of the cooling water flowing through the cooling water passage 25 formed in the first bank 16. The temperature of the cooling water flowing through the cooling water channel 25 can be detected separately. Since the water temperature sensor 64 is provided in this way, the temperature of the first cylinder group 11 is detected via this water temperature by detecting the water temperature of the cooling water flowing through the cooling water passage 25 formed in the first bank 16. By detecting the temperature of the cooling water flowing through the cooling water passage 25 formed in the second bank 17, the temperature of the second cylinder group 12 can be detected via this water temperature. That is, the water temperature sensor 64 is provided for each cylinder group 10 so that the temperature of the cylinder group 10 can be detected.

  The cylinder head 21 is fixed to an end of the cylinder block 22 on the side of the direction in which the piston 30 in the cylinder block 22 faces the top dead center via a gasket (not shown). The cylinder head 21 is provided with an ignition plug 37, an intake valve 45, and an exhaust valve 46. The spark plug 37, the intake valve 45, and the exhaust valve 46 are provided in each cylinder 8 of the plurality of cylinders 8. In addition, an intake passage 41 and an exhaust passage 42 are connected to the combustion chamber 35, an intake valve 45 is provided on the intake passage 41 side, and an exhaust valve 46 is provided on the exhaust passage 42 side. .

  Specifically, the intake valve 45 and the exhaust valve 46 provided in the cylinder head 21 are each provided with a retainer 51 on the opposite side of the intake valve 45 and the exhaust valve 46 from the combustion chamber 35 side. Covered. Further, a valve spring 53 is provided between the retainer 51 and the cylinder head 21, and the intake valve 45 and the exhaust valve 46 have a biasing force in a direction to close the intake passage 41 or the exhaust passage 42 by the valve spring 53. Is given. A cam 55 is provided on the opposite side of the valve lifter 52 from the combustion chamber 35 side. The cam 55 is provided on a camshaft 56 that rotates in conjunction with the rotation of the crankshaft 32, and the cam 55 also rotates as the camshaft 56 rotates. Further, the cam 55 has a portion away from the rotation center of the camshaft 56, and the distance from the rotation center of the camshaft 56 to the outer peripheral surface 57 of the cam 55 is not constant. The cam 55 formed in this manner is in contact with the valve lifter 52, and the valve spring 53 applies a biasing force to the valve lifter 52 via the retainer 51. Thereby, the valve lifter 52 is pressed against the cam 55 by the valve spring 53.

  By providing the intake valve 45 and the exhaust valve 46 in this way, reciprocating motion is possible. Among these, the intake valve 45 is provided so as to communicate or block the intake passage 41 and the combustion chamber 35 by reciprocating, and the exhaust valve 46 is provided so as to reciprocate. And the combustion chamber 35 are provided to communicate or block.

  The ignition plug 37 is provided between the intake valve 45 and the exhaust valve 46, and further includes an ignition unit 38 that discharges when a high voltage is applied. The ignition unit 38 is disposed in the combustion chamber 35. It is provided so that it may be located in. The intake passage 41 is provided with an injector 60 which is a fuel supply means for injecting fuel used during operation of the internal combustion engine 1 into the intake passage 41.

  Further, the intake passage 41 and the exhaust passage 42 connected to the combustion chamber 35 are branched corresponding to a plurality of cylinders 8 provided. Specifically, the intake passage 41 branches into an intake passage 41 connected to the cylinder 8 of the first bank 16 and an intake passage 41 connected to the cylinder 8 of the second bank 17. Further, it branches corresponding to each cylinder 8 and is connected to each cylinder 8. The injector 60 provided in the intake passage 41 is provided at a portion branched in the intake passage 41 corresponding to each cylinder 8. That is, the injector 60 is provided for each cylinder 8.

  Further, in the intake passage 41 formed in this way, a portion where the intake passage 41 is connected to the cylinder 8 of the first bank 16 and a cylinder of the second bank 17 in the flow direction of the air flowing through the intake passage 41. A throttle valve 61 capable of adjusting the flow rate of the air flowing in the intake passage 41 is provided on the upstream side of the portion connected to 8.

  The exhaust passage 42 is connected to each cylinder 8 in the same manner as the intake passage 41. That is, the exhaust passage 42 is branched into a plurality of portions corresponding to the respective cylinders 8 similarly to the intake passage 41, and the branched exhaust passages 42 are connected to the respective cylinders 8. Further, in this exhaust passage 42, the exhaust passages 42 connected to the cylinders 8 included in the first bank 16 are gathered into one, and the exhaust passages 42 connected to the cylinders 8 included in the second bank 17 are combined into one. Are gathered.

  Further, the spark plug 37 provided in the cylinder head 21 is connected to an ignition circuit 63 that controls the discharge of the ignition unit 38 included in the spark plug 37. The ignition circuit 63, the water temperature sensor 64, the injector 60, and the starter motor 68 are connected to an ECU (Electronic Control Unit) 70 that controls each part of a vehicle (not shown) on which the internal combustion engine 1 is mounted. The ECU 70 can be controlled.

  The ECU 70 is provided with a processing unit 71, a storage unit 79, and an input / output unit 80, which are connected to each other and can exchange signals with each other. The water temperature sensor 64, the injector 60, the ignition circuit 63, and the starter motor 68 connected to the ECU 70 are connected to the input / output unit 80. The input / output unit 80 is connected to the water temperature sensor 64 and the like. Input / output signals. The storage unit 79 stores a computer program for controlling the warm-up control device 5 for the internal combustion engine 1 according to the present invention. The storage unit 79 is a hard disk device, a magneto-optical disk device, a non-volatile memory such as a flash memory (a storage medium that can be read only such as a CD-ROM), or a RAM (Random Access Memory). A volatile memory or a combination thereof can be used.

  The processing unit 71 includes a memory and a CPU (Central Processing Unit), and at least a water temperature acquisition unit 72 that is a temperature acquisition unit that acquires the coolant temperature as the temperature of the cylinder group 10, and the internal combustion engine 1. The starting temperature difference calculating means calculates the difference between the water temperature of the first bank 16 that is the temperature of the first cylinder group 11 and the water temperature of the second bank 17 that is the temperature of the second cylinder group 12 at the time of starting. An hour water temperature difference calculating unit 73 and a starting temperature difference determining means for determining whether the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 at the time of starting the internal combustion engine 1 is equal to or greater than a predetermined value. When the internal combustion engine 1 is started, only the first cylinder group 11 or the second cylinder group 12 can be started, and the water temperature of the bank 15 detected by the water temperature sensor 64, that is, the cylinder group 10 temperature When there is a difference between the cylinder groups 10, a start control unit 75 that is a start control unit that performs start control, which is a control for starting only the cylinder group 10 having a higher temperature, and the water temperature of the first bank 16 during the start control. And a water temperature difference calculating unit 76 for starting control that is a temperature difference calculating means for starting control for calculating a difference between the water temperature of the first bank 16 and the water temperature of the second bank 17, And a start-control-time water temperature difference determination unit 77 that is a start-control-time temperature difference determination unit that determines whether the water temperature difference is equal to or less than a predetermined value.

  Control of the injector 60 and the like included in the warm-up control device 5 of the internal combustion engine 1 is performed by the processing unit 71 using the computer program and the processing unit 71 based on the detection results of sensors provided in each part of the vehicle such as the water temperature sensor 64. The control is performed by reading into a memory incorporated in the memory and calculating and operating the injector 60 or the like according to the result of the calculation. At that time, the processing unit 71 appropriately stores a numerical value in the middle of the calculation in the storage unit 79 and takes out the stored numerical value to execute the calculation. In addition, when controlling the warm-up control device 5 of the internal combustion engine 1 in this way, it may be controlled by dedicated hardware different from the ECU 70 instead of the computer program.

  The warm-up control device 5 for the internal combustion engine 1 according to the first embodiment is configured as described above, and the operation thereof will be described below. During the operation of the internal combustion engine 1, the piston 30 repeats reciprocating motion in the cylinder block 22, and this cycle is repeated with the intake stroke, the compression stroke, the combustion stroke, and the exhaust stroke as one cycle. The reciprocating motion of the piston 30 is transmitted to the crankshaft 32 by the connecting rod 31, and the reciprocating motion is converted into rotational motion by the action of the connecting rod 31 and the crankshaft 32, and the crankshaft 32 rotates. When the crankshaft 32 rotates, the camshaft 56 rotates in conjunction with this rotation, and the cam 55 rotates as the camshaft 56 rotates.

  Since the cam 55 has a portion away from the rotation center of the cam shaft 56 in the cam 55, when the cam 55 rotates, this portion is connected to the intake valve 45 and the exhaust via the valve lifter 52 and the retainer 51. The valve 46 is pushed away from the camshaft 56. This portion pushes the intake valve 45 and the exhaust valve 46 at predetermined intervals as the cam 55 rotates, whereby the intake valve 45 and the exhaust valve 46 reciprocate, and the intake passage 41 and the exhaust passage 42 The communication with and disconnection from the cylinder 8 or the combustion chamber 35 is repeated.

  During the operation of the internal combustion engine 1, the intake valve 45 and the exhaust valve 46 reciprocate in this way, and the intake passage 41, the exhaust passage 42 and the combustion chamber 35 are repeatedly connected and disconnected to perform intake and exhaust. Repeat the four steps. The outline of each stroke is as follows. In the intake stroke, fuel is injected from the injector 60 to generate a mixture of fuel and air in the intake passage 41, and the mixture is sucked into the cylinder 8 when the intake valve 45 is opened. . In the compression stroke, both the intake valve 45 and the exhaust valve 46 are closed. In this state, the piston 30 moves in the direction of the top dead center, thereby compressing the air-fuel mixture in the cylinder 8.

  Further, in the combustion stroke, a high voltage current is applied to the ignition plug 37 by the ignition circuit 63 and arc discharge is generated in the ignition part 38 of the ignition plug 37, whereby the compressed air-fuel mixture is ignited. As a result, the fuel in the compressed air-fuel mixture burns, so that the piston 30 moves in the direction of the bottom dead center due to the pressure during combustion, and is connected to the piston 30 via the connecting rod 31 as the piston 30 moves. The crankshaft 32 is rotated. Further, in the exhaust stroke, the piston 30 moves in the direction of the top dead center while the intake valve 45 is closed and the exhaust valve 46 is opened, so that the exhaust gas after combustion of fuel is discharged from the cylinder 8 into the exhaust passage. It flows in the direction of 42 and is exhausted.

  The internal combustion engine 1 is operated by repeating these strokes. However, since fuel burns in the combustion stroke, heat is generated during the combustion of the fuel in the combustion stroke. The heat generated in this combustion stroke is transmitted to each part such as the cylinder block 22 and is also transmitted to the cooling water in the cooling water passage 25. The cooling water in the cooling water passage 25 circulates through each part of the internal combustion engine 1 while exchanging heat during operation of the internal combustion engine 1. In addition, a radiator (not shown) as a heat radiating means is provided in the cooling water path, and the cooling water radiates heat when passing through the radiator. For this reason, the cooling water dissipates heat when passing through the radiator, and absorbs heat when heat is exchanged in each part of the internal combustion engine 1. That is, the cooling water radiates heat generated during operation of the internal combustion engine 1 by the radiator.

  When the internal combustion engine 1 operating in this way is started, the starter motor 68 is started. Specifically, when the starter motor 68 is operated, rotation is transmitted from the starter motor 68 to the crankshaft 32, and the crankshaft 32 is rotated by this rotation. When the crankshaft 32 rotates, this rotation is transmitted to the piston 30 by the connecting rod 31, whereby the piston 30 reciprocates and the above steps are repeated, and the internal combustion engine 1 is started.

  As a result, the internal combustion engine 1 starts, but at the time of starting the internal combustion engine 1, the coolant temperature in the cooling water passage 25 formed in the first bank 16 and the cooling in the cooling water passage 25 formed in the second bank 17. The water temperature is acquired by a water temperature acquisition unit 72 included in the processing unit 71 of the ECU 70. The water temperature of the first bank 16 and the water temperature of the second bank 17 acquired by the water temperature acquisition unit 72 are calculated by the water temperature difference calculation unit 73 at the start of the ECU 70, and whether or not the water temperature difference is equal to or greater than a predetermined value. The ECU 70 determines the start time water temperature difference determination unit 74. If the water temperature difference is greater than or equal to the predetermined value as a result of this determination, the start control unit 75 of the ECU 70 determines only the bank 15 with the higher water temperature out of the first bank 16 and the second bank 17 when starting the internal combustion engine 1. Start.

  FIG. 3 is a diagram showing the relationship between the fuel temperature and the amount of port wet. Here, the relationship between the temperature of the fuel and the amount of port wet, that is, the amount of fuel adhering to the intake passage 41 at the time of fuel injection will be described. Generally, the fuel tends to evaporate as the temperature increases, and the temperature It becomes difficult to evaporate as it gets lower. For this reason, when fuel is injected into the intake passage 41, the fuel easily evaporates as the temperature increases, so the amount of port wet decreases, and the fuel becomes difficult to evaporate as the temperature decreases. The amount of port wet increases. This is because the vapor pressure of the fuel increases as the temperature increases, and the vapor pressure decreases as the temperature decreases. That is, since the fuel easily evaporates as the vapor pressure increases, the port wet amount decreases, and as the vapor pressure decreases, it becomes difficult to evaporate, so the amount of fuel that does not evaporate increases in the intake passage 41, The amount of port wet increases.

  FIG. 4 is a graph showing the relationship between ethanol temperature and vapor pressure. FIG. 5 is a diagram showing the relationship between the temperature of ethanol and the amount of port wet. The relationship between temperature and vapor pressure will be described using ethanol, which is an example of the fuel used to operate the internal combustion engine 1. As shown in FIG. 4, ethanol increases in vapor pressure as the temperature increases. The vapor pressure rises steeply when it exceeds 78 ° C. For this reason, as for the relationship between the temperature of ethanol and the amount of port wets, as shown in FIG. 5, the amount of port wets changes a lot around 78 degreeC. That is, when the temperature of ethanol exceeds 78 ° C., the amount of port wet decreases significantly, and when the temperature falls below 78 ° C., the amount of port wet increases significantly.

  Since the fuel used for the operation of the internal combustion engine 1 has such characteristics, when the internal combustion engine 1 is started, the fuel used for the determination to start only one of the first bank 16 and the second bank 17 is used. The value is determined based on the relationship between this temperature and the amount of port wet. That is, when the temperature of the fuel is low and the amount of port wet is large, the amount of fuel supplied into the cylinder 8 is greatly reduced, so that it is difficult to start the cylinder 8 when the internal combustion engine 1 is started. There is a risk. For this reason, the predetermined value used for the determination includes a temperature region where the water temperature of the bank 15 having the lower temperature out of the water temperature of the first bank 16 and the water temperature of the second bank 17 includes a large amount of port wet. It is desirable to be determined based on the water temperature difference between both banks 15.

  In this way, a predetermined value used for the determination of starting only one bank 15 at the time of starting the internal combustion engine 1 is determined, and only one of the first bank 16 and the second bank 17 is started. When the internal combustion engine 1 is operated, the heat of the bank 15 having the higher water temperature is transferred to the bank 15 having the lower water temperature by the cooling water circulating through the internal combustion engine 1 and the components constituting the internal combustion engine 1 such as the cylinder block 22. Communicated. As a result, the temperature of the bank 15 with the lower water temperature rises, so that the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 becomes small. In the start control water temperature difference calculation unit 76 of the ECU 70, the water temperature difference at the start control is calculated, and the start control water temperature difference determination unit 77 of the ECU 70 determines whether the calculated water temperature difference is equal to or less than a predetermined value. As a result of this determination, when the water temperature difference is equal to or smaller than the predetermined value, the bank 15 having the lower water temperature is also started. Thereby, the first bank 16 and the second bank 17 are started.

  In this way, the water temperature difference determining unit 77 during the start control determines whether the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 during the start control is equal to or less than a predetermined value. It is desirable that the predetermined value used in the above is determined by the same method as the predetermined value used for determining the water temperature difference between the banks when the internal combustion engine 1 is started. In other words, the predetermined value used for determining whether to start the bank 15 with the lower water temperature during start control is the water temperature of the bank 15 with the lower temperature of the water temperature of the first bank 16 and the water temperature of the second bank 17. However, it is desirable to be determined based on the water temperature difference between both banks 15 that includes a temperature region in which the amount of port wet is reduced.

  FIG. 6 is a flowchart showing a processing procedure of the warm-up control device for the internal combustion engine according to the first embodiment of the present invention. Next, a control method of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, that is, a processing procedure of the warm-up control device 5 will be described. This processing procedure is executed when the internal combustion engine 1 is started. When the internal combustion engine 1 is started, first, the water temperatures of the first bank 16 and the second bank 17 are acquired (step ST101). The water temperature of the first bank 16 and the second bank 17 is determined by the water temperature sensor 64 provided in the first bank 16 and the second bank 17. And the water temperature of the cooling water in the cooling water channel 25 formed in the 2nd bank 17 is detected, and the detected water temperature is acquired by the water temperature acquisition part 72 which the process part 71 of ECU70 has.

  Next, the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is calculated (step ST102). This calculation is performed by a starting water temperature difference calculation unit 73 included in the processing unit 71 of the ECU 70. Specifically, the water temperature of the first bank 16 and the water temperature of the second bank 17 acquired by the water temperature acquisition unit 72 are transmitted to the start time water temperature difference calculation unit 73, and both the banks 15 The water temperature difference is calculated.

  Next, it is determined whether the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is equal to or greater than a predetermined value (step ST103). In this determination, the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 calculated by the starting water temperature difference calculating unit 73 is transmitted to the starting water temperature difference determining unit 74 included in the processing unit 71 of the ECU 70. Whether the water temperature difference is equal to or greater than a predetermined value is determined by the starting water temperature difference determination unit 74. If it is determined by this determination that the water temperature difference between both banks 15 is smaller than the predetermined value, the processing procedure is exited. A predetermined value used for determining the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is stored in advance in the storage unit 79 of the ECU 70.

  If the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is determined to be greater than or equal to a predetermined value as determined by the start water temperature difference determination unit 74, the first bank 16 and the second bank 17 Of these, only the bank 15 having the higher water temperature, that is, the high water temperature side bank is started (step ST104). That is, when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 at the time of starting the internal combustion engine 1 is equal to or greater than a predetermined value, start control, which is control for starting only the high water temperature side bank, This is performed by a start control unit 75 included in the processing unit 71 of the ECU 70. Here, the water temperature of the first bank 16 detected by the water temperature sensor 64 is the temperature of the first cylinder group 11, and the water temperature of the second bank 17 is also the temperature of the second cylinder group 12. Thus, the temperature of the first cylinder group 11 and the second cylinder group 12 can be detected. Therefore, in other words, when the temperature of the cylinder group 10 detected by the water temperature sensor 64 is different between the cylinder groups 10, the start control unit 75 of the ECU 70 controls to start only the cylinder group 10 having the higher temperature. The starting control is performed.

  Specifically, this start control is performed by the start control unit 75 in a state where the starter motor 68 is operated, the crankshaft 32 is rotated, and the piston 30 is reciprocating, and the cylinder group provided in the bank 15 on the high water temperature side. The fuel is injected only from the injector 60 provided in the intake passage 41 of 10. Thereby, only the cylinders 8 included in the cylinder group 10 provided in the high water temperature side bank perform the above-mentioned respective strokes during the operation of the internal combustion engine 1 and start. In this case, in the bank 15 having the lower water temperature of the first bank 16 and the second bank 17, that is, the cylinder 8 included in the cylinder group 10 provided in the low water temperature side bank, the above-described strokes are not performed and the crankshaft is not performed. The piston 30 only reciprocates in the cylinder 8 with the rotation of 32. That is, the low water temperature side bank is suspended. The starter motor 68 may be operated at a stage prior to step ST104, or may be operated at step ST104.

  Next, the water temperatures of the first bank 16 and the second bank 17 in the state where the start control is performed in this way are acquired (step ST105). The acquisition of the water temperature is performed by the water temperature sensor 64 in a state where the start control is performed, that is, only the high water temperature side bank is started, as in the case of acquiring the water temperature when starting the internal combustion engine 1 (step ST101). The detected water temperatures of the first bank 16 and the second bank 17 are acquired by the water temperature acquisition unit 72 of the ECU 70.

  Next, the water temperature difference between the banks 15 at the start control time is calculated (step ST106). This calculation is performed by the water temperature difference calculation unit 76 at the time of start control which the processing unit 71 of the ECU 70 has. Specifically, as in the case of calculating the water temperature difference at the start of the internal combustion engine 1 (step ST102), the water temperature difference in the first bank 16 and the water temperature in the second bank 17 acquired by the water temperature acquisition unit 72 is the water temperature difference at the start control time. The temperature is transmitted to the calculation unit 76, and the water temperature difference calculation unit 76 at the start control calculates the water temperature difference between both banks 15.

  Next, it is determined whether the water temperature difference between the banks 15 at the start control is equal to or less than a predetermined value (step ST107). In this determination, the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 calculated by the water temperature difference calculating unit 76 at the start control time is transferred to the water temperature difference determining unit 77 at the start control time which the processing unit 71 of the ECU 70 has. The start control time water temperature difference determination unit 77 determines whether or not this water temperature difference is equal to or less than a predetermined value. If it is determined by this determination that the water temperature difference between both banks 15 is greater than the predetermined value, the process returns to step ST105, and the water temperatures of the first bank 16 and the second bank 17 at the time of start control are acquired again. . Note that the predetermined value used for determining the water temperature difference between the banks 15 during the start control is stored in advance in the storage unit 79 of the ECU 70.

  If it is determined by the water temperature difference determining unit 77 during the start control that the water temperature difference between the banks 15 during the start control is equal to or less than a predetermined value, the low water temperature side bank is started (step ST108). The low water temperature side bank is started by the start control unit 75 of the ECU 70. That is, when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 at the time of start control becomes equal to or less than a predetermined value, the start control unit 75 provides the cylinder group 10 that has been stopped. Start the low water temperature bank. In other words, the start control unit 75 starts the unstarted cylinder group 10 when the temperature of the cylinder group 10 detected by the water temperature sensor 64 becomes a temperature difference of a predetermined value or less between the cylinder groups 10.

  In the cylinder group 10 provided in the low water temperature side bank, the unstarted cylinder group 10 is started in accordance with the start of the cylinder 8 included in the cylinder group 10 provided in the high water temperature side bank. Because of the reciprocating motion, fuel is injected from the injector 60 provided in the intake passage 41 of the cylinder group 10. As a result, the cylinder 8 included in the cylinder group 10 provided in the low water temperature side bank performs the above-described stroke during the operation of the internal combustion engine 1 and starts. As a result, the first cylinder group 11 included in the first bank 16 and the second cylinder group 12 included in the second bank 17 are started together.

  The warm-up control device 5 for the internal combustion engine 1 described above detects the temperature of the cooling water flowing through the cooling water passage 25 provided in the first bank 16 and the second bank 17 by the water temperature sensor 64, and the cylinder is connected via this water temperature. When the temperature of the cylinder group 10 is detected for each group 10, and there is a temperature difference between the cylinder groups 10, only the cylinder group 10 with the higher temperature is started by the start control unit 75 when the internal combustion engine 1 is started. Yes. The cylinder group 10 having the higher temperature has a low mechanical loss because the temperature of the lubricating oil is high and the viscosity of the lubricating oil is low. For this reason, when the internal combustion engine 1 is started, the deterioration of fuel consumption can be suppressed by starting only the cylinder group 10 having the higher temperature. Further, in the cylinder group 10 having the higher temperature, the fuel is easily vaporized, so that a good combustion state can be obtained. Thereby, generation | occurrence | production of an emission can be suppressed. As a result, it is possible to suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  Further, when only the cylinder group 10 having the higher temperature is started when the internal combustion engine 1 is started, and the temperature difference between the cylinder groups 10 becomes a predetermined value or less, the unstarted cylinder group 10 is started. Yes. That is, the cylinder group 10 with the higher temperature is started, and heat generated during operation of the cylinder group 10 is transmitted to the cylinder group 10 with the lower temperature, and the temperature of the cylinder group 10 with the lower temperature increases. Then, when the temperature difference with the higher temperature cylinder group 10 becomes a predetermined value or less, the lower temperature cylinder group 10 is started. As described above, since the cylinder group 10 with the lower temperature is started after the temperature rises, the deterioration of the fuel consumption and the emission can be suppressed similarly to the start of the cylinder group 10 with the higher temperature. . As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  The warm-up control device 90 for the internal combustion engine 1 according to the second embodiment has substantially the same configuration as the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, but performs warm-up control during the operation of the internal combustion engine 1. There is a feature in the point to do. Since other configurations are the same as those of the first embodiment, the description thereof is omitted and the same reference numerals are given. FIG. 7 is a schematic diagram of an internal combustion engine provided with a warm-up control device for an internal combustion engine according to Embodiment 2 of the present invention. The warm-up control device 90 of the internal combustion engine 1 shown in the figure is similar to the warm-up control device 5 of the internal combustion engine 1 according to the first embodiment, and the first bank 16 having the first cylinder group 11 and the second cylinder group. And a second bank 17 having 12. The first bank 16 and the second bank 17 are formed with cooling water passages 25 through which cooling water flows. The first bank 16 and the second bank 17 detect the temperature of the cooling water, respectively. A water temperature sensor 64 is provided.

  The camshaft 56 of the internal combustion engine 1 is connected to a valve timing control unit 95 that is a valve timing control means, and the valve timing control unit 95 causes a relative rotation angle to the rotation angle position of the crankshaft 32. It is provided so that the position can be changed. As a result, the cam 55 provided on the camshaft 56 can also change the rotation angle position relative to the rotation angle position of the crankshaft 32. Therefore, the opening / closing timing of the intake valve 45 and the exhaust valve 46 formed by the cam 55 with respect to the rotational angle position of the crankshaft 32 also changes, and the position of the piston 30 that reciprocates in conjunction with the crankshaft 32. The timing of opening and closing the intake valve 45 and the exhaust valve 46, that is, the valve timing can be changed.

  Further, the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment includes the ECU 100 as in the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. The unit 79 and the input / output unit 80 are included. Among these, the processing unit 71 is the temperature of the first cylinder group 11 during normal operation of the internal combustion engine 1 and the water temperature acquisition unit 72 that is a temperature acquisition unit that acquires the coolant temperature as at least the temperature of the cylinder group 10. A normal operation water temperature difference calculating unit 101 which is a normal operation temperature difference calculating means for calculating a difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 which is the temperature of the second cylinder group 12; A normal operation water temperature difference determination unit 102 which is a normal operation temperature difference determination means for determining whether the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 during a normal operation is greater than or equal to a predetermined value; When the internal combustion engine 1 is operating, more specifically, when the water temperature of the bank 15 detected by the water temperature sensor 64 during normal operation of the internal combustion engine 1, that is, when the temperature of the cylinder group 10 is different between the cylinder groups 10, the temperature is lower. Increase the temperature of the cylinder group 10 Warm-up control unit 103, which is a warm-up control means for performing warm-up control, and a warm-up control time for calculating the difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 during the warm-up control. A warm-up control water temperature difference calculation unit 104 that is a temperature difference calculation means and a warm-up that determines whether the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 during the warm-up control is equal to or less than a predetermined value. And a warm-up control water temperature difference determination unit 105 which is a machine control temperature difference determination means. A valve timing control unit 95 that controls the valve timing of the intake valve 45 and the exhaust valve 46 is connected to the ECU 100.

  The normal operation of the internal combustion engine 1 here refers to an operation state in a state where the warm-up operation is completed after the internal combustion engine 1 is started.

  The warm-up control device 90 for the internal combustion engine 1 according to the second embodiment is configured as described above, and the operation thereof will be described below. In the internal combustion engine 1, as in the internal combustion engine 1 provided with the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, each cylinder 8 performs an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke in one cycle. Then, this cycle is repeated for operation. At that time, the water temperature acquisition unit 72 included in the processing unit 71 of the ECU 90 acquires the water temperature of the first bank 16 and the water temperature of the second bank 17 during normal operation of the internal combustion engine 1.

  The water temperature difference of the first bank 16 and the water temperature of the second bank 17 acquired by the water temperature acquisition unit 72 is calculated by the water temperature difference calculation unit 101 during normal operation of the ECU 100, and is this water temperature difference equal to or greater than a predetermined value? Is determined by the normal operation water temperature difference determination unit 102 of the ECU 100. If it is determined that the water temperature difference is equal to or greater than a predetermined value, the warm-up control unit 103 of the ECU 100 performs warm-up control. That is, the warm-up control unit 103 operates the bank 15 having the lower water temperature among the first bank 16 and the second bank 17 under the warm-up condition.

  The predetermined value used for determining whether to perform warm-up control is the predetermined value used for determining whether to perform start-up control when the internal combustion engine 1 is started in the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. It is desirable to decide in the same way. That is, during normal operation of the internal combustion engine 1, the predetermined value used for determining whether the bank 15 with the lower water temperature is operated under the warm-up condition is the temperature between the water temperature of the first bank 16 and the water temperature of the second bank 17. It is desirable that the water temperature of the lower bank 15 is determined based on the water temperature difference between the banks 15 that includes the temperature region where the amount of port wet is large.

  Further, the warm-up condition is an operation state in which the temperature of the cylinder group 10 can be raised, and in the warm-up control performed by the warm-up control unit 103, the cylinder group 10 provided in the bank 15 having the lower water temperature. By adjusting at least one of valve timing, ignition timing, fuel injection amount, and fuel injection timing, the cylinder group 10 is operated under warm-up conditions.

  Each of these adjustment methods will be described in detail. When the warm-up control is performed by adjusting the valve timing, the intake valve 45 of the cylinder 8 included in the cylinder group 10 provided in the bank 15 having the lower water temperature. The valve timing is delayed for both valve opening and closing than during normal operation. Thus, by delaying the timing of opening the intake valve 45, the pump loss during the intake stroke can be increased and the flow rate of the air-fuel mixture flowing into the cylinder 8 can be increased, so the flow energy is changed to heat. be able to. In addition, by delaying the closing timing of the intake valve 45 and closing it when the piston 30 is located near the bottom dead center, more air-fuel mixture can be sucked, so that the actual compression ratio can be increased. Thereby, combustion temperature can be made high.

  Further, when the warm-up control is performed by adjusting the valve timing, the timing for opening the intake valve 45 may be advanced. By advancing the valve opening timing of the intake valve 45, the overlap with the valve opening state of the exhaust valve 46 can be lengthened and the internal EGR can be increased, so that the combustion temperature can be increased. By adjusting the valve timing as described above, the temperature of the cylinder 8 can be raised.

  Further, when warm-up control is performed by adjusting the ignition timing, for example, the ignition timing is set to an ignition timing suitable for warm-up, for example, the ignition timing is advanced from the normal operation, that is, advanced. Thereby, combustion temperature can be made high and the temperature of a cylinder can be raised.

  Further, when warm-up control is performed by adjusting the fuel injection amount, the fuel injection amount injected from the injector 60 is made larger than that during normal operation. That is, when the temperature of the cylinder 8 is low, the fuel injected from the injector 60 into the intake passage 41 does not evaporate and may adhere to the intake passage 41 and not be supplied to the cylinder 8, so warm-up control is performed. In this case, the fuel injection amount is increased so that the fuel is supplied into the cylinder 8 more reliably. As a result, the fuel is supplied into the cylinder 8 and combusted in the cylinder 8, so that the temperature of the cylinder 8 can be raised.

  Further, when the warm-up control is performed by adjusting the fuel injection timing, the injection timing of the fuel injected from the injector 60 is made earlier than that during normal operation. Thus, after the fuel is injected, the time until the fuel is supplied to the cylinder 8 and combusted becomes longer, so the time for the fuel injected from the injector 60 to evaporate can be ensured more reliably. Therefore, the injected fuel can be burned in the cylinder 8 more reliably, and the temperature of the cylinder 8 can be raised.

  As described above, by performing warm-up control when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 is equal to or greater than a predetermined value, the cylinder group 10 provided in the bank 15 having the lower water temperature. Temperature rises. As a result, the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 is reduced, but this water temperature difference is calculated by the water temperature difference calculating unit 104 during the warm-up control of the ECU 100, and the calculated water temperature difference is predetermined. Whether the temperature is equal to or less than the value is determined by the water temperature difference determination unit 105 during ECU 100 warm-up control. If it is determined that the water temperature difference is equal to or smaller than the predetermined value, the bank 15 having the lower water temperature is set to the normal operation. As a result, both the first bank 16 and the second bank 17 are in normal operation.

  The warm-up control water temperature difference determination unit 105 determines whether the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 during the warm-up control is equal to or less than a predetermined value. The predetermined value used for this determination is the same as the predetermined value used for determining whether to start the bank 15 with the lower water temperature during the start-up control of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. It is desirable to decide. That is, during warm-up control, the predetermined value used to determine whether the bank 15 with the lower water temperature is operated in normal operation is the lower one of the water temperature of the first bank 16 and the water temperature of the second bank 17. It is desirable that the water temperature of the bank 15 is determined based on the water temperature difference between the banks 15 that includes a temperature region in which the amount of port wet is reduced.

  FIG. 8 is a flowchart showing a processing procedure of the warm-up control device for an internal combustion engine according to the second embodiment of the present invention. Next, a control method of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment, that is, a processing procedure of the warm-up control device 90 will be described. This processing procedure is executed during the normal operation of the internal combustion engine 1. First, during the normal operation of the internal combustion engine 1, the water temperatures of the first bank 16 and the second bank 17 are acquired (step ST201). The water temperature of the first bank 16 and the second bank 17 is determined by the water temperature sensor 64 provided in the first bank 16 and the second bank 17, and the coolant temperature in the cooling water passage 25 formed in the first bank 16. And the water temperature of the cooling water in the cooling water channel 25 formed in the 2nd bank 17 is detected, and the detected water temperature is acquired by the water temperature acquisition part 72 which the process part 71 of ECU100 has.

  Next, the water temperature difference between the banks 15 during normal operation of the internal combustion engine 1 is calculated (step ST202). This calculation is performed by the normal operation water temperature difference calculation unit 101 included in the processing unit 71 of the ECU 100. Specifically, the water temperature of the first bank 16 and the water temperature of the second bank 17 acquired by the water temperature acquisition unit 72 are transmitted to the normal operation water temperature difference calculation unit 101, and the normal operation water temperature difference calculation unit 101 The water temperature difference of the bank 15 is calculated.

  Next, it is determined whether the water temperature difference between the banks 15 during normal operation of the internal combustion engine 1 is equal to or greater than a predetermined value (step ST203). In this determination, the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 calculated by the normal operation water temperature difference calculation unit 101 is transferred to the normal operation water temperature difference determination unit 102 included in the processing unit 71 of the ECU 100. The normal operation water temperature difference determination unit 102 determines whether the water temperature difference is greater than or equal to a predetermined value. If it is determined by this determination that the water temperature difference between both banks 15 is smaller than the predetermined value, the processing procedure is exited. A predetermined value used for determining a water temperature difference between the banks 15 during normal operation of the internal combustion engine 1 is stored in advance in the storage unit 79 of the ECU 100.

  If it is determined by the normal operation water temperature difference determination unit 102 that the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is greater than or equal to a predetermined value, the first bank 16 and the second bank 17 Of these, the bank 15 having the lower water temperature, that is, the low water temperature side bank is operated under warm-up conditions (step ST204). That is, when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 during normal operation of the internal combustion engine 1 is equal to or greater than a predetermined value, the low water temperature side bank is operated under warm-up conditions, Warm-up control, which is control for increasing the temperature of the side bank, is performed by the warm-up control unit 103 included in the processing unit 71 of the ECU 100. Here, the water temperature of the first bank 16 detected by the water temperature sensor 64 is the temperature of the first cylinder group 11, and the water temperature of the second bank 17 is also the temperature of the second cylinder group 12. Thus, the temperature of the first cylinder group 11 and the second cylinder group 12 can be detected. Therefore, in other words, the warm-up control unit 103 of the ECU 100 increases the temperature of the lower cylinder group 10 when the temperature of the cylinder group 10 detected by the water temperature sensor 64 is different between the cylinder groups 10. The warm-up control is performed.

  In this warm-up control, at least one of the valve timing, ignition timing, fuel injection amount, and fuel injection timing of each cylinder 8 included in the cylinder group 10 provided in the low water temperature side bank by the warm-up control unit 103 is as described above. This is done by adjusting to Among these, when adjusting the valve timing, the valve timing is adjusted by transmitting a control signal from the warm-up control unit 103 to the valve timing control unit 95 via the input / output unit 80 of the ECU 100. When adjusting the ignition timing, the ignition timing is adjusted by transmitting a control signal from the warm-up control unit 103 to the ignition circuit 63 via the input / output unit 80. When adjusting the fuel injection amount and the fuel injection timing, the control signal is transmitted from the warm-up control unit 103 to the injector 60 via the input / output unit 80 to adjust the fuel injection amount and the fuel injection timing. . By these, the temperature of the cylinder group 10 provided in the low water temperature side bank is raised.

  Next, the water temperatures of the first bank 16 and the second bank 17 in the state where the warm-up control is performed in this way are acquired (step ST205). This water temperature is acquired in a state where warm-up control is performed, that is, in a state where the low water temperature side bank is operated under a warm-up condition, as in the case where the water temperature is acquired during normal operation of the internal combustion engine 1 (step ST201). Thus, the water temperature of the first bank 16 and the second bank 17 detected by the water temperature sensor 64 is acquired by the water temperature acquisition unit 72 of the ECU 100.

  Next, the water temperature difference between the banks 15 during the warm-up control is calculated (step ST206). This calculation is performed by the warm-up control water temperature difference calculation unit 104 included in the processing unit 71 of the ECU 100. Specifically, as in the case of calculating the water temperature difference during normal operation of the internal combustion engine 1 (step ST202), the water temperature of the first bank 16 and the water temperature of the second bank 17 acquired by the water temperature acquisition unit 72 are during warm-up control. The water temperature difference calculation unit 104 transmits the difference, and the warm-up control water temperature difference calculation unit 104 calculates the water temperature difference between both banks 15.

  Next, it is determined whether the water temperature difference between the banks 15 during the warm-up control is equal to or less than a predetermined value (step ST207). In this determination, the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 calculated by the water temperature difference calculating unit 104 during the warm-up control is the water temperature difference determining unit during the warm-up control that the processing unit 71 of the ECU 100 has. The warm-up control water temperature difference determination unit 105 determines whether the water temperature difference is equal to or less than a predetermined value. If it is determined by this determination that the water temperature difference between both banks 15 is greater than the predetermined value, the process returns to step ST205, and the water temperatures of the first bank 16 and the second bank 17 during warm-up control are acquired again. To do. The predetermined value used for determining the water temperature difference between the banks 15 during the warm-up control is stored in advance in the storage unit 79 of the ECU 100.

  If the water temperature difference between the banks 15 during the warm-up control is determined to be equal to or less than a predetermined value as determined by the water temperature difference determining unit 105 during the warm-up control, the low water temperature side bank is operated in the normal operation ( Step ST208). That is, the low water temperature side bank is operated under the warm-up condition during the warm-up control by the warm-up control unit 103 of the ECU 100, but the water temperature difference between the banks 15 during the warm-up control is not more than a predetermined value. And the warm-up control water temperature difference determination unit 105 determines that the normal operation is performed. In other words, the warm-up control unit 103 ends the warm-up control when the temperature of the cylinder group 10 detected by the water temperature sensor 64 becomes a temperature difference of a predetermined value or less between the cylinder groups 10.

  As described above, when the warm-up control is finished and the low water temperature side bank is operated in the normal operation, the warm-up control unit 103 of the ECU 100 normally sets the valve timing of the cylinder group 10 provided in the low water temperature side bank. The operation conditions, i.e., the valve timing suitable for normal operation, are returned to normal operation. Accordingly, the first cylinder group 11 included in the first bank 16 and the second cylinder group 12 included in the second bank 17 are both operated in a normal operation.

  The above-described warm-up control device 90 for the internal combustion engine 1 detects the water temperature of the cooling water flowing through the cooling water passage 25 provided in the first bank 16 and the second bank 17 by the water temperature sensor 64, and the cylinder via this water temperature. When the temperature of the cylinder group 10 is detected for each group 10 and there is a temperature difference between the cylinder groups 10, the temperature of the cylinder group 10 with the lower temperature during normal operation of the internal combustion engine 1 by the warm-up control unit 103. The warm-up control that raises the In the cylinder group 10 having the lower temperature, the temperature of the lubricating oil is low and the viscosity of the lubricating oil is high, so that the mechanical loss is likely to increase. Further, in the cylinder group 10 having a low temperature, since it is difficult for the fuel to vaporize, it may be difficult to obtain a good combustion state. For this reason, the cylinder group 10 having a lower temperature is likely to deteriorate in fuel efficiency and may easily generate emissions. Therefore, by increasing the temperature of the cylinder group 10 by the warm-up control, the fuel efficiency is deteriorated. Generation of emissions can be suppressed. As a result, it is possible to suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  Also, during normal operation of the internal combustion engine 1, when the temperature difference between the cylinder groups 10 becomes a predetermined value or less after starting the warm-up control by operating the cylinder group 10 having the lower temperature under the warm-up condition. The warm-up control is terminated. That is, by performing warm-up control and operating the lower temperature cylinder group 10 under the warm-up condition, the temperature of the cylinder group 10 rises, and the temperature difference from the higher temperature cylinder group 10 is a predetermined value. The warm-up control is terminated when the following occurs. As described above, since the warm-up control is performed until the temperature of the cylinder group 10 having the lower temperature rises, it is possible to suppress deterioration of fuel consumption and emission due to the low temperature of the cylinder group 10. As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  Further, since the warm-up control is performed by at least one of the valve timing, the ignition timing, the fuel injection amount, and the fuel injection timing, the temperature of the cylinder group 10 having the lower temperature can be more reliably increased. As a result, it is possible to more reliably suppress deterioration of fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  The warm-up control device 110 for the internal combustion engine 1 according to the third embodiment has substantially the same configuration as the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, but a motor generator 111 is connected to the internal combustion engine 1. There is a feature in that. Since other configurations are the same as those of the first embodiment, the description thereof is omitted and the same reference numerals are given. FIG. 9 is a schematic view of an internal combustion engine provided with a warm-up control device for an internal combustion engine according to Embodiment 3 of the present invention. The warm-up control device 110 for the internal combustion engine 1 shown in the figure has substantially the same configuration as the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, and the warm-up of the internal combustion engine 1 according to the first embodiment. A motor generator 111 that is an electric motor that can output together with the output of the internal combustion engine 1 is added to the control device 5. The internal combustion engine 1 and the motor generator 111 are connected to a power split device 112, and the power split device 112 is further connected to a speed reducer 113. For this reason, the motor generator 111 of the internal combustion engine 1 is connected via the power split device 112. The power split device 112 is provided so as to distribute the output of the internal combustion engine 1 to the motor generator 111 and the speed reducer 113 and to transmit the output from the motor generator 111 to the speed reducer 113. Further, the motor generator 111 is connected to a motor generator operating unit 115 provided so that the motor generator 111 can be operated.

  Further, the warm-up control device 110 for the internal combustion engine 1 according to the third embodiment includes a main ECU 120 having the same configuration as the ECU 70 included in the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. That is. The main ECU 120 includes a processing unit 71, a storage unit 79, and an input / output unit 80. Among these, the processing unit 71 includes at least a water temperature acquisition unit 72, a start time water temperature difference calculation unit 73, a start time water temperature difference determination unit 74, a start control unit 75, a start control time water temperature difference calculation unit 76, and a start. And a control-time water temperature difference determination unit 77. Further, the processing unit 71 is an operating state acquisition unit that acquires the torques of both banks 15 during the operation of the internal combustion engine 1 as the operation states of the first bank 16 and the second bank 17 during the operation of the internal combustion engine 1. The acquisition unit 121, the torque difference calculation unit 122 that is a driving state difference calculation unit that calculates the difference between the torque of the first bank 16 and the torque of the second bank 17, and the torque of the first bank 16 and the second bank 17 A torque difference determination unit 123 that is an operation state difference determination unit that determines whether the torque difference from the torque is equal to or greater than a predetermined value, and a motor generator control unit 124 that controls the operation of the motor generator 111. Yes.

  Further, the warm-up control device 110 for the internal combustion engine 1 according to the third embodiment is provided with a motor ECU 130 that performs substantial control of the motor generator 111. The motor ECU 130 is connected to the main ECU 120, and has a processing unit 131, a storage unit 135, and an input / output unit 136, similar to the main ECU 120. Further, the processing unit 71 performs vibration damping control by the motor generator 111 at least when a torque difference is generated between the first bank 16 and the second bank 17 of the internal combustion engine 1, that is, between the cylinder groups 10. It has a vibration suppression control unit 132 which is a vibration suppression control means to perform. The motor generator operating unit 115 is connected to the motor ECU 130, and the motor ECU 130 substantially controls the motor generator 111 via the motor generator operating unit 115.

  The warm-up control device 110 for the internal combustion engine 1 according to the third embodiment is configured as described above, and the operation thereof will be described below. In the internal combustion engine 1, as in the internal combustion engine 1 provided with the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, each cylinder 8 performs an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke in one cycle. Then, this cycle is repeated for operation. When there is a predetermined temperature difference between the cylinder groups 10 when the internal combustion engine 1 is started, start control is performed.

  When the start control is performed in this way, only one of the first bank 16 and the second bank 17 is started, so that a torque difference is generated between both banks 15. For this reason, when the start control is performed, the torque acquisition unit 121 of the main ECU 120 acquires the torque of the first bank 16 and the second bank 17, and the torque difference calculation unit 122 of the main ECU 120 acquires the torques of both banks 15. Calculate the torque difference. Further, it is determined by the torque difference determination unit 123 of the main ECU 120 whether the torque difference is equal to or greater than a predetermined value. .

  The torque difference determination unit 123 determines whether the torque difference between the first bank 16 and the second bank 17 at the start control is equal to or less than a predetermined value as described above. The predetermined value used for this determination is It is desirable that the vibration at the time of output from the internal combustion engine 1 is determined based on a torque difference that exceeds an allowable range during operation of the internal combustion engine 1.

  FIG. 10 is a flowchart showing a processing procedure of the warm-up control device for an internal combustion engine according to the third embodiment of the present invention. Next, a control method of the warm-up control device 110 for the internal combustion engine 1 according to the third embodiment, that is, a processing procedure of the warm-up control device 110 will be described. This processing procedure is executed during the start-up control by performing the same processing procedure as the processing procedure in the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. When starting control of the internal combustion engine 1 is performed and only one of the first bank 16 and the second bank 17 is started, first, the first bank 16 and the second bank 17 Both torques are acquired (step ST301). The torques of the first bank 16 and the second bank 17 are calculated for use in other controls during the operation of the internal combustion engine 1, and are processed by the processing unit of the main ECU 120. Obtained by the torque obtaining unit 121 included in 71. Specifically, this torque is a map stored in advance in the storage unit 79 based on the rotational speed of the crankshaft 32 (see FIG. 1), the intake air amount, the fuel supply amount, the ignition timing, and the like during the operation of the internal combustion engine 1. Etc., and the torque due to the operation of the first cylinder group 11 included in the first bank 16 and the torque due to the operation of the second cylinder group 12 included in the second bank 17 are calculated separately. The torque acquisition unit 121 acquires the torque of the first bank 16 and the torque of the second bank 17 calculated in this way.

  Next, the torque difference between the banks 15 is calculated (step ST302). This calculation is performed by the torque difference calculation unit 122 included in the processing unit 71 of the main ECU 120. Specifically, the torque of the first bank 16 and the torque of the second bank 17 acquired by the torque acquisition unit 121 are transmitted to the torque difference calculation unit 122, and the torque difference calculation unit 122 calculates the torque difference between both banks 15. calculate.

  Next, it is determined whether the torque difference between the banks 15 is greater than or equal to a predetermined value (step ST303). In this determination, the torque difference between the torque of the first bank 16 and the torque of the second bank 17 calculated by the torque difference calculation unit 122 is transmitted to the torque difference determination unit 123 included in the processing unit 71 of the main ECU 120. The torque difference determination unit 123 determines whether the difference is greater than or equal to a predetermined value. If it is determined by this determination that the torque difference between both banks 15 is smaller than the predetermined value, the processing procedure is exited. The predetermined value used for determining the torque difference between the banks 15 is stored in advance in the storage unit 79 of the main ECU 120.

  When the torque difference determination unit 123 determines that the torque difference between the banks 15 is greater than or equal to a predetermined value, the vibration suppression control is a control that suppresses vibration caused by torque imbalance between the banks 15. (Step ST304). In this vibration suppression control, when the torque difference between the torque of the first bank 16 and the torque of the second bank 17 is equal to or greater than a predetermined value, the motor generator control unit 124 included in the processing unit 71 of the main ECU 120 controls the motor ECU 130. A control signal for performing vibration suppression control is transmitted.

  Receiving this signal, the motor ECU 130 performs vibration suppression control by the vibration suppression control unit 132 included in the processing unit 131 of the motor ECU 130. When this damping control is performed, the torque of the motor generator 111 during the combustion stroke of the cylinder 8 of the cylinder group 10 provided in the bank 15 having the smaller torque of the first bank 16 and the second bank 17. The control signal is transmitted from the vibration suppression control unit 132 to the motor generator operation unit 115 so that the frequency increases.

  Specifically, when the motor generator 111 is stopped, the motor generator 111 is operated only during the combustion stroke of the cylinder 8 included in the cylinder group 10 provided in the bank 15 having the smaller torque. Further, when the internal combustion engine 1 and the motor generator 111 are used in combination, the current flowing through the motor generator 111 is increased during the combustion stroke of the cylinder 8 included in the cylinder group 10 provided in the bank 15 having the smaller torque. Thus, the torque of the motor generator 111 is increased. As a result, when output from the internal combustion engine 1 to the speed reducer 113 via the power split device 112, the torque of the motor generator 111 increases during the combustion stroke of the bank 15 having the smaller torque. The motor generator 111 can supplement the output to the speed reducer 113 during the period when the torque of the motor is small. Therefore, since the internal combustion engine 1 and the motor generator 111 output to the speed reducer 113 in a well-balanced manner via the power split device 112, vibration during output is suppressed.

  Since the warm-up control device 110 for the internal combustion engine 1 described above performs vibration suppression control with the motor generator 111 when a torque difference occurs between the cylinder groups 10, stable output can be performed. That is, during start control of the internal combustion engine 1, the cylinder group 10 with the lower temperature is deactivated and only the cylinder group 10 with the higher temperature is operated, so there is a possibility that a torque difference occurs between the cylinder groups 10. For this reason, there is a possibility that vibration is generated at the time of output due to this torque difference, but at the time of output of the cylinder 8 included in the cylinder group 10 having the lower temperature during operation of the internal combustion engine 1 during start-up control, that is, combustion By increasing the torque of the motor generator 111 during the stroke and outputting the output of the internal combustion engine 1 and the output of the motor generator 111 together, it is possible to equalize the torque at the time of output. Thereby, the vibration resulting from the torque difference between the cylinder groups 10 at the time of internal combustion engine 1 driving | operation can be suppressed. As a result, a part of the cylinder group 10 is deactivated to suppress vibrations in the case of suppressing the deterioration of fuel consumption and emission due to the temperature difference between the cylinder groups 10 and ensuring the stability during the operation of the internal combustion engine 1. can do.

  FIG. 11 is a schematic view of an internal combustion engine provided with a modification of the warm-up control device for an internal combustion engine according to the first embodiment of the present invention. Note that the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment determines that only one of the banks 15 is started based only on the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17. However, when this determination is made, the determination may be made including the absolute water temperature. For example, as shown in FIG. 11, in the processing unit 71 of the ECU 70, the water temperature of the bank 15 having the lower water temperature is equal to or lower than a predetermined temperature, that is, equal to or lower than a reference temperature that is a reference temperature for performing start control. A reference temperature determination unit 140 that is a reference temperature determination unit that determines whether or not may be provided.

  In this way, when the reference temperature determination unit 140 is provided in the ECU 70, it is determined whether the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 is equal to or greater than a predetermined value. After the determination by the unit 74, the reference temperature determination unit 140 further determines whether the water temperature in the low water temperature side bank is equal to or lower than the reference temperature. When it is determined by this determination that the water temperature in the low water temperature side bank is equal to or lower than the reference temperature, the start control unit 75 of the ECU 70 is the internal combustion engine as in the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. When the engine 1 is started, only the bank 15 having the higher water temperature among the first bank 16 and the second bank 17 is started.

  FIG. 12 is a flowchart showing a processing procedure in a modification of the warm-up control device for an internal combustion engine according to the first embodiment of the present invention. Next, a control method in a modification of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, that is, a processing procedure of the warm-up control device 5 will be described. The processing procedure in the modified example of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment is substantially the same as the processing procedure of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. In the processing procedure of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, the determination as to whether the water temperature in the low water temperature side bank is equal to or lower than the reference temperature is added.

  That is, when the internal combustion engine 1 is started, the water temperatures of the first bank 16 and the second bank 17 are acquired by the water temperature sensors 64 provided in the first bank 16 and the second bank 17 and the water temperature acquisition unit 72 of the ECU 70. (Step ST401) From the acquired water temperature, the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is calculated by the start time water temperature difference calculation unit 73 of the ECU 70 (Step ST402). Next, the starting water temperature difference determination unit 74 of the ECU 70 determines whether or not the water temperature difference between the banks 15 at the time of starting the internal combustion engine 1 is greater than or equal to a predetermined value (step ST403). If it is determined by this determination that the water temperature difference between both banks 15 is smaller than the predetermined value, the processing procedure is exited.

  If the water temperature difference between the banks 15 at the start of the internal combustion engine 1 is determined to be greater than or equal to a predetermined value as determined by the start water temperature difference determination unit 74, the bank 15 on the low water temperature side next has the reference temperature. It is determined whether it is the following (step ST404). In this determination, the water temperature acquired by the water temperature acquisition unit 72 is transmitted to the reference temperature determination unit 140 included in the processing unit 71 of the ECU 70, and the reference temperature determination unit 140 determines the water temperature of the first bank 16 and the second bank 17. It is determined whether the water temperature in the low water temperature side bank which is the lower bank 15 is equal to or higher than the reference temperature. If it is determined by this determination that the water temperature in the low water temperature side bank is higher than the reference temperature, the processing procedure is exited. The reference temperature used for determining the water temperature of the low water temperature side bank is stored in advance in the storage unit 79 of the ECU 70.

  Based on the determination at the starting water temperature difference determining unit 74, it is determined that the water temperature difference between the banks 15 at the time of starting the internal combustion engine 1 is greater than or equal to a predetermined value, and further, according to the determination at the reference temperature determining unit 140, the low water temperature side bank When it is determined that the water temperature is equal to or lower than the reference temperature, only the high water temperature side bank which is the bank 15 having the higher water temperature among the first bank 16 and the second bank 17 is started (step ST405). That is, when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 at the start of the internal combustion engine 1 is equal to or greater than a predetermined value, and when the water temperature in the low water temperature side bank is equal to or lower than the reference temperature. The start control which is a control for starting only the high water temperature side bank is performed by the start control unit 75 included in the processing unit 71 of the ECU 70. Here, the water temperature of the first bank 16 detected by the water temperature sensor 64 is the temperature of the first cylinder group 11, and the water temperature of the second bank 17 is also the temperature of the second cylinder group 12. Thus, the temperature of the first cylinder group 11 and the second cylinder group 12 can be detected. Therefore, in other words, the start control unit 75 of the ECU 70 is configured such that the temperature of the cylinder group 10 detected by the water temperature sensor 64 is different between the cylinder groups 10, and the temperature of the cylinder group 10 with the lower temperature is further increased. Start control is performed when the temperature is lower than a predetermined temperature.

  Next, the water temperatures of the first bank 16 and the second bank 17 in the state in which the start control is performed in this way are acquired by the water temperature acquisition unit 72 of the ECU 70 (step ST406), and between the banks 15 during the start control. The water temperature difference is calculated by the start temperature control water temperature difference calculation unit 76 of the ECU 70 (step ST407).

  Next, whether or not the water temperature difference between the banks 15 during the start control is equal to or less than a predetermined value is determined by the start control time water temperature difference determining unit 77 of the ECU 70 (step ST408). If it is determined by this determination that the water temperature difference between both banks 15 is greater than the predetermined value, the process returns to step ST406, and the water temperatures between the first bank 16 and the second bank 17 at the time of start control are acquired again. . When the water temperature difference between the banks 15 at the time of start control is determined to be equal to or less than a predetermined value as determined by the water temperature difference determination unit 77 at the start control, the start control unit 75 of the ECU 70 sets the low water temperature side bank. Start (step ST409). As a result, the first cylinder group 11 included in the first bank 16 and the second cylinder group 12 included in the second bank 17 are started together.

  In the modification of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment, the low water temperature side bank is equal to or lower than the reference temperature, that is, the cylinder group 10 provided in the first bank 16 and the cylinder provided in the second bank 17. Since the start control is performed when the temperature of the cylinder group 10 having the lower temperature among the groups 10 is equal to or lower than the reference temperature, it is possible to more reliably suppress deterioration of fuel consumption and emission. In other words, even if there is a temperature difference between the cylinder groups 10, if the temperature of the lower cylinder group 10 is higher than the reference temperature, the viscosity of the lubricant is low due to the high temperature of the lubricating oil, and the fuel is not gas. It is easy to change. For this reason, even if the start control is not performed, the fuel consumption is unlikely to deteriorate and the emission may not easily occur. Therefore, when there is a temperature difference between the cylinder groups 10, start control is performed when the temperature of the lower cylinder group 10 is equal to or lower than the reference temperature, thereby more reliably suppressing deterioration of fuel consumption and emission. In addition, when the temperature of the cylinder group 10 having the lower temperature is higher than the reference temperature, the start control is not performed, so that good startability can be obtained. As a result, it is possible to ensure startability while more reliably suppressing deterioration in fuel consumption and emission when a temperature difference occurs between the cylinder groups 10.

  FIG. 13 is a schematic diagram of an internal combustion engine provided with a modification of the warm-up control device for an internal combustion engine according to the second embodiment of the present invention. Further, the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment also determines whether or not to perform the warm-up control, similarly to the modified example of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment. At this time, the determination may be made including the absolute water temperature. For example, as shown in FIG. 13, the processing unit 71 of the ECU 100 allows the water temperature of the bank 15 with the lower water temperature to be equal to or lower than a predetermined temperature, that is, equal to or lower than a reference temperature that is a reference temperature for performing warm-up control. You may provide the reference temperature determination part 140 which is the reference temperature determination means which determines whether there exists.

  As described above, when the reference temperature determination unit 140 is provided in the ECU 100, it is determined whether the water temperature difference between the water temperature in the first bank 16 and the water temperature in the second bank 17 is equal to or greater than a predetermined value. After the determination by the determination unit 102, the reference temperature determination unit 140 further determines whether the water temperature in the low water temperature side bank is equal to or lower than the reference temperature. When it is determined by this determination that the water temperature in the low water temperature side bank is equal to or lower than the reference temperature, the warm-up control unit 103 of the ECU 100 is similar to the warm-up control device 90 of the internal combustion engine 1 according to the second embodiment. During normal operation of the internal combustion engine 1, the bank 15 having the lower water temperature of the first bank 16 and the second bank 17 is operated under warm-up conditions.

  FIG. 14 is a flowchart showing a processing procedure in a modification of the warm-up control device for an internal combustion engine according to the second embodiment of the present invention. Next, a control method in a modification of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment, that is, a processing procedure of the warm-up control device 90 will be described. The processing procedure in the modification of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment is substantially the same as the processing procedure of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment. In the processing procedure of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment, a determination is made as to whether the water temperature in the low water temperature side bank is equal to or lower than the reference temperature.

  That is, first, during normal operation of the internal combustion engine 1, the water temperatures of the first bank 16 and the second bank 17 are acquired by the water temperature sensors 64 provided in the first bank 16 and the second bank 17 and the water temperature acquisition unit 72 of the ECU 100. (Step ST501) Then, the water temperature difference between the banks 15 during the normal operation of the internal combustion engine 1 is calculated by the normal operation water temperature difference calculation unit 101 of the ECU 100 from the acquired water temperature (Step ST502). Next, the normal operation water temperature difference determination unit 102 of the ECU 100 determines whether or not the water temperature difference between the banks 15 during the normal operation of the internal combustion engine 1 is greater than or equal to a predetermined value (step ST503). If it is determined by this determination that the water temperature difference between both banks 15 is smaller than the predetermined value, the processing procedure is exited.

  If it is determined by the normal operation water temperature difference determination unit 102 that the water temperature difference between the banks 15 during the normal operation of the internal combustion engine 1 is greater than or equal to a predetermined value, the reference temperature determination unit 140 of the ECU 100 is next. Thus, it is determined whether the bank 15 on the low water temperature side is below the reference temperature (step ST504). If it is determined by this determination that the water temperature in the low water temperature side bank is higher than the reference temperature, the processing procedure is exited. The reference temperature used for determining the water temperature of the low water temperature side bank is stored in advance in the storage unit 79 of the ECU 100.

  Based on the determination in the normal operation water temperature difference determination unit 102, it is determined that the water temperature difference between the banks 15 during the normal operation of the internal combustion engine 1 is equal to or greater than a predetermined value. When it is determined that the water temperature of the bank is equal to or lower than the reference temperature, the low water temperature side bank is operated under warm air conditions (step ST505). That is, when the water temperature difference between the water temperature of the first bank 16 and the water temperature of the second bank 17 during the normal operation of the internal combustion engine 1 is equal to or greater than a predetermined value, and when the water temperature of the low water temperature side bank is equal to or lower than the reference temperature. The warm-up control that is the control for operating the low water temperature side bank under the warm-up condition is performed by the warm-up control unit 103 included in the processing unit 71 of the ECU 100.

  Here, the water temperature of the first bank 16 detected by the water temperature sensor 64 is the temperature of the first cylinder group 11, and the water temperature of the second bank 17 is also the temperature of the second cylinder group 12. Thus, the temperature of the first cylinder group 11 and the second cylinder group 12 can be detected. Therefore, in other words, the warm-up control unit 103 of the ECU 100 is configured so that the temperature of the cylinder group 10 detected by the water temperature sensor 64 is different between the cylinder groups 10, and the temperature of the cylinder group 10 with the lower temperature is further decreased. When the temperature is below a predetermined temperature, warm-up control is performed.

  Next, the water temperature of the first bank 16 and the second bank 17 in the state where the warm-up control is performed in this way is acquired by the water temperature acquisition unit 72 of the ECU 100 (step ST506), and the bank 15 at the time of the warm-up control is acquired. The water temperature difference between them is calculated by the water temperature difference calculating unit 104 during the warm-up control of the ECU 100 (step ST507).

  Next, the warm-up control water temperature difference determination unit 105 of the ECU 100 determines whether the water temperature difference between the banks 15 during the warm-up control is equal to or smaller than a predetermined value (step ST508). If it is determined by this determination that the water temperature difference between both banks 15 is greater than the predetermined value, the process returns to step ST506, and the water temperatures of the first bank 16 and the second bank 17 during warm-up control are acquired again. To do. If it is determined by the warm-up control water temperature difference determination unit 105 that the water temperature difference between the banks 15 during the warm-up control is equal to or less than a predetermined value, the warm-up control unit 103 of the ECU 100 determines the low water temperature. The side bank is operated in normal operation (step ST509). As a result, the first cylinder group 11 included in the first bank 16 and the second cylinder group 12 included in the second bank 17 are both operated in a normal operation.

  In the modification of the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment, the low water temperature side bank is equal to or lower than the reference temperature, that is, the cylinder group 10 provided in the first bank 16 and the cylinder provided in the second bank 17. Since the warm-up control is performed when the temperature of the cylinder group 10 having the lower temperature among the groups 10 is equal to or lower than the reference temperature, it is possible to more reliably suppress deterioration of fuel consumption and emission. That is, in the case where there is a temperature difference between the cylinder groups 10 as in the start-up control in the modified example of the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment described above, the cylinder group 10 with the lower temperature is selected. By performing warm-up control when the temperature is lower than the reference temperature, it is possible to more reliably suppress the deterioration of fuel consumption and emission, and when the temperature of the lower temperature cylinder group 10 is higher than the reference temperature. Therefore, since the warm-up control is not performed, a stable operation state can be obtained. As a result, it is possible to ensure the stability during the operation of the internal combustion engine 1 while suppressing the deterioration of the fuel consumption and the emission when the temperature difference occurs between the cylinder groups 10 more reliably.

  In the warm-up control device 110 for the internal combustion engine 1 according to the third embodiment, the internal combustion engine 1 including the warm-up control device 5 for the internal combustion engine 1 according to the first embodiment is connected to the motor generator 111 and controlled by the motor generator 111. Although the vibration control is performed, the motor generator 111 may be connected to the internal combustion engine 1 including the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment. Even in the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment, when warm-up control is performed, there is a possibility that a torque difference occurs between the bank 15 operating under the warm-up condition and the other bank 15. For this reason, the vibration caused by the torque difference between the cylinder groups 10 during operation of the internal combustion engine 1 can be suppressed by performing the vibration suppression control by the motor generator 111. As a result, a part of the cylinder group 10 is deactivated to suppress vibrations in the case of suppressing the deterioration of fuel consumption and emission due to the temperature difference between the cylinder groups 10 and ensuring the stability during the operation of the internal combustion engine 1. can do.

  The internal combustion engine 1 including the warm-up control devices 5, 90, 110 of the internal combustion engine 1 is provided with a starter motor 68, and is started by the starter motor 68 when the internal combustion engine 1 is started. The internal combustion engine 1 may be started by means other than the starter motor 68. For example, since the internal combustion engine 1 including the warm-up control device 110 for the internal combustion engine 1 according to the third embodiment is connected to the motor generator 111, the motor generator 111 may be used to start the internal combustion engine 1. In the case of the internal combustion engine 1 connected to the motor generator 111 in this manner, even when the internal combustion engine 1 is not started, when the motor generator 111 is operating, the rotation of the motor generator 111 causes the internal combustion engine 1 to rotate. The crankshaft 32 rotates and the piston 30 reciprocates. Therefore, when the internal combustion engine 1 in this state is started, fuel is injected from the injector 60 to supply the fuel into the cylinder 8, and the spark plug 37 is discharged to ignite the fuel in the cylinder 8. The internal combustion engine 1 can be started.

  Further, in this way, in the internal combustion engine 1 to which the motor generator 111 is connected, even when the internal combustion engine 1 is not started, the motor generator 111 is operated to drive a vehicle on which the internal combustion engine 1 is mounted. it can. For this reason, there is a possibility that a temperature difference occurs between the first bank 16 and the second bank 17 when the traveling wind during traveling strikes the internal combustion engine 1. That is, among the first bank 16 and the second bank 17, the temperature of the bank 15 that is easily hit by the traveling wind at the time of traveling of the vehicle tends to be low, so that a temperature difference is easily generated between the banks 15. Accordingly, in the internal combustion engine 1 to which the motor generator 111 is thus connected, that is, the hybrid internal combustion engine 1, the start control of the warm-up control device 5 of the internal combustion engine 1 according to the first embodiment and the internal combustion engine according to the second embodiment. By performing the warm-up control of the warm-up control device 90 of the engine 1, the temperature difference between the banks 15 at the time of start-up and operation of the internal combustion engine 1 where a temperature difference tends to occur between the banks 15 can be reduced. As a result, in the internal combustion engine 1 in which a temperature difference is likely to occur between the banks 15, that is, between the cylinder groups 10, it is possible to suppress deterioration in fuel consumption and emission due to temperature differences between the cylinder groups 10.

  In the above-described warm-up control devices 5, 90, and 110 for the internal combustion engine 1, the intake valve 45 and the exhaust valve 46 open and close the intake passage 41 and the exhaust passage 42 using a cam 55 provided on the camshaft 56. Although it is possible, the intake valve 45 and the exhaust valve 46 may have other configurations. For example, the intake valve 45 and the exhaust valve 46 may be so-called electromagnetically driven valves (not shown) that operate by electrical control. By using electromagnetically driven valves for the intake valve 45 and the exhaust valve 46, the valve timing can be freely set. In particular, the warm-up control is performed by the warm-up control device 90 for the internal combustion engine 1 according to the second embodiment. In this case, the valve timing can be easily changed and the warm-up control can be easily performed.

  Further, in the internal combustion engine 1 provided with the warm-up control devices 5, 90, 110 of the internal combustion engine 1 described above, the injector 60 is provided in the intake passage 41, and fuel is injected into the cylinder 8 by port injection for injecting fuel into the intake passage 41. However, the injector 60 may be provided directly in the cylinder 8. That is, the internal combustion engine 1 may be an internal combustion engine 1 that supplies fuel by so-called in-cylinder injection, in which fuel is injected from the injector 60 into the cylinder 8. Even when fuel is supplied into the cylinder 8 by in-cylinder injection, there may be a temperature difference between the cylinder groups 10. In this case, the temperature between the cylinder groups 10 can be increased by performing the above-described start control and warm-up control. It is possible to suppress deterioration of fuel consumption and emission when a difference occurs.

  As described above, the warm-up control device for an internal combustion engine according to the present invention is useful for an internal combustion engine having a plurality of cylinder groups, and is particularly suitable for an internal combustion engine in which a temperature difference may occur in the cylinder groups. .

1 is a schematic view of an internal combustion engine provided with a warm-up control device for an internal combustion engine according to Embodiment 1 of the present invention. It is the schematic of the AA arrow of FIG. It is a figure which shows the relationship between the temperature of a fuel, and a port wet quantity. It is a figure which shows the relationship between the temperature of ethanol, and vapor pressure. It is a figure which shows the relationship between the temperature of ethanol, and the amount of port wets. It is a flowchart which shows the process sequence of the warm-up control apparatus of the internal combustion engine which concerns on Example 1 of this invention. It is the schematic of the internal combustion engine provided with the warm-up control apparatus of the internal combustion engine which concerns on Example 2 of this invention. It is a flowchart which shows the process sequence of the warm-up control apparatus of the internal combustion engine which concerns on Example 2 of this invention. It is the schematic of the internal combustion engine provided with the warm-up control apparatus of the internal combustion engine which concerns on Example 3 of this invention. It is a flowchart which shows the process sequence of the warm-up control apparatus of the internal combustion engine which concerns on Example 3 of this invention. It is the schematic of the internal combustion engine in which the modification of the warm-up control apparatus of the internal combustion engine which concerns on Example 1 of this invention was provided. It is a flowchart which shows the process sequence in the modification of the warm-up control apparatus of the internal combustion engine which concerns on Example 1 of this invention. It is the schematic of the internal combustion engine in which the modification of the warm-up control apparatus of the internal combustion engine which concerns on Example 2 of this invention was provided. It is a flowchart which shows the process sequence in the modification of the warming-up control apparatus of the internal combustion engine which concerns on Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 5, 90, 110 Warm-up control apparatus 8 Cylinder 10 Cylinder group 11 1st cylinder group 12 2nd cylinder group 15 Bank 16 1st bank 17 2nd bank 21 Cylinder head 22 Cylinder block 23 Crank case 25 Cooling water path 30 Piston 31 Connecting rod 32 Crankshaft 35 Combustion chamber 37 Spark plug 41 Intake passage 42 Exhaust passage 45 Intake valve 46 Exhaust valve 55 Cam 56 Camshaft 60 Injector 64 Water temperature sensor 68 Starter motor 70, 100 ECU
71, 131 Processing unit 72 Water temperature acquisition unit 73 Start-up water temperature difference calculation unit 74 Start-up water temperature difference determination unit 75 Start control unit 76 Start-up water temperature difference calculation unit 77 Start-up water temperature difference determination unit 79, 135 Storage unit 80, 136 I / O unit 95 Valve timing control unit 101 Normal operation water temperature difference calculation unit 102 Normal operation water temperature difference determination unit 103 Warm-up control unit 104 Warm-up control water temperature difference calculation unit 105 Warm-up control water temperature difference determination unit 111 Motor Generator 112 Power split device 113 Reducer 115 Motor generator operating unit 120 Main ECU
121 Torque Acquisition Unit 122 Torque Difference Calculation Unit 123 Torque Difference Determination Unit 124 Motor Generator Control Unit 130 Motor ECU
132 Vibration Suppression Control Unit 140 Reference Temperature Determination Unit

Claims (8)

A temperature detecting means capable of detecting the temperature of each cylinder group that is a part of a plurality of cylinders of the internal combustion engine;
When the internal combustion engine is started, only a part of the cylinder groups can be started, and when the temperature of the cylinder groups detected by the temperature detecting means is different between the cylinder groups, the higher one of the cylinder groups is provided. Start control means for performing start control, which is control for starting only the cylinder group;
A warm-up control device for an internal combustion engine, comprising:   The start control unit starts the unstarted cylinder group when the temperature of the cylinder group detected by the temperature detection unit becomes a temperature difference of a predetermined value or less between the cylinder groups. Item 2. A warm-up control device for an internal combustion engine according to Item 1.   When the temperature of the cylinder group detected by the temperature detection means has a difference between the cylinder groups, the start control means performs the start control when the temperature of the lower cylinder group is equal to or lower than a predetermined temperature. The warm-up control device for an internal combustion engine according to claim 1 or 2, wherein A temperature detecting means capable of detecting the temperature of each cylinder group that is a part of a plurality of cylinders of the internal combustion engine;
When the temperature of the cylinder group detected by the temperature detecting means during operation of the internal combustion engine is different between the cylinder groups, warm-up control is performed which is a control for increasing the temperature of the lower cylinder group. A warm-up control means;
A warm-up control device for an internal combustion engine, comprising:   The warm-up control unit ends the warm-up control when the temperature of the cylinder group detected by the temperature detection unit becomes a temperature difference of a predetermined value or less between the cylinder groups. 5. A warm-up control device for an internal combustion engine according to 4.   The warm-up control means performs the warm-up control by adjusting at least one of valve timing, ignition timing, fuel injection amount, and fuel injection timing of the cylinder group having a lower temperature. Item 6. The warm-up control device for an internal combustion engine according to Item 4 or 5.   When the temperature of the cylinder group detected by the temperature detection means is different between the cylinder groups, the warm-up control unit is configured to perform the warm-up control when the temperature of the lower cylinder group is equal to or lower than a predetermined temperature. The warm-up control device for an internal combustion engine according to any one of claims 4 to 6, wherein a machine control is performed. The internal combustion engine is connected to an electric motor that can output together with the output of the internal combustion engine,
Furthermore, when the torque difference between the said cylinder groups has arisen, it has the vibration suppression control means which performs the vibration suppression control by the said electric motor, The any one of Claims 1-7 characterized by the above-mentioned. A warm-up control device for an internal combustion engine.

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