JP2011202547A - Control device of internal combustion engine, and internal combustion engine equipped with the control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine and a control device of the same, which fulfills low fuel consumption, low harmful gas and comfortability at a higher level.SOLUTION: The control device 50 selects, for an engine 1, either one operation mode of: a heat creation mode of setting one rotation of a crankshaft as one period and repeating one cycle comprising a second intake stroke in which, with downward movement of a piston in a state that an exhaust valve is closed, an intake valve is opened to take air in a combustion chamber and then the intake valve is closed, a second combustion stroke in which the intake valve and the exhaust valve are closed and a combustion chamber ignition plug generates a spark to combust a mixture in the combustion chamber, and a second exhaust stroke in which the intake valve is closed and with upward movement of the piston, the exhaust valve is opened to exhaust combustion gas in the combustion engine; and a power mode of generating torque on the crankshaft, namely in which the engine operates as a so-called four stroke cycle engine, and performs control for operating the engine in the selected mode.

Description

  The present invention relates to an internal combustion engine control device and an internal combustion engine equipped with the control device, and more particularly to an internal combustion engine that can be warmed up in a short time after starting.

  The internal combustion engine is a technique that was invented about 100 years ago to extract thermal energy obtained by chemical reaction of fuel as kinetic energy. In the internal combustion engine, for example, gasoline, light oil, ethanol or the like is used as the fuel. When gasoline is used as the fuel, a known Otto cycle is employed as the operating cycle of the internal combustion engine. Since the birth of the internal combustion engine, the technology aimed at increasing the efficiency of the Otto cycle, in other words, the positive work during the Otto cycle, that is, the area of the hatched portion on the PV diagram shown in FIG. A number of techniques aimed at expanding have been invented (see, for example, Patent Document 1).

JP-A-8-296447

Although the thermal efficiency of the engine has improved dramatically since the birth of the internal combustion engine (hereinafter referred to as the engine), the engine still has the following problems.
(1) During cold start, the temperature of the engine body, cooling water, and lubricating oil is low, and it takes time to increase the temperature to a stable temperature. For this reason, until the engine temperature stabilizes, the frictional force of the engine (for example, the sliding contact portion between the piston and cylinder, etc.) is large, the fuel is not sufficiently evaporated, and a good air-fuel mixture is not formed. It becomes stable and fuel consumption worsens. In addition, the operation of the exhaust gas purification system, for example, the function of the catalyst becomes unstable, and it becomes difficult to reduce harmful components in the exhaust gas.
(2) When the engine is used as a motor for a car, the heat generated by the engine is used as a heat source for heating the car cabin, but the heating performance at the cold start is low, that is, the cabin temperature is a comfortable temperature. It takes time to reach
(3) There is a case where an engine which is a prime mover is driven intermittently in a car. For example, there are an idling stop system that temporarily stops the engine when the automobile is stopped, and a hybrid system that uses other types of prime movers having different operating principles in addition to the engine. In these systems, it is difficult to obtain a heat source for heating while the engine is stopped.

  The present invention has been made in view of the above circumstances, and a purpose thereof is a control device capable of realizing low fuel consumption, low harmful gas, and comfort on an internal combustion engine at a higher level, and the control. An object of the present invention is to provide an internal combustion engine provided with the device.

  In order to achieve the above-described object, a control device for an internal combustion engine according to claim 1 of the present invention includes a cylinder, a piston that reciprocates within the cylinder, and a kinetic energy that is coupled to the piston and is reciprocated by the piston. A power output unit for outputting the air, a cylinder and a piston, a combustion chamber in which a mixture of fuel and air burns, and a combustion chamber provided in the combustion chamber for generating a spark for burning the mixture Between the spark plug, the intake valve provided between the intake port for introducing air into the combustion chamber and the combustion chamber, and the exhaust port for discharging the combustion gas generated by combustion of the air-fuel mixture in the combustion chamber and the combustion chamber The exhaust valve is closed, and the exhaust valve is closed, and the intake valve is opened as the piston descends, and intake to the combustion chamber is performed, and the intake valve is based on the piston becoming the bottom dead center. Close The air stroke and the intake stroke are performed, the intake valve and the exhaust valve are closed, the compression stroke in which the gas in the combustion chamber is compressed, and the compression stroke is performed, and the intake valve and the exhaust valve are The combustion chamber ignition plug generates a spark, and a combustion stroke for burning the air-fuel mixture compressed in the compression stroke is performed following the combustion stroke, and the intake valve is closed. In the internal combustion engine in which the exhaust valve is opened as the piston rises and the exhaust stroke in which the combustion gas in the combustion chamber is exhausted, the exhaust valve is closed, and the intake valve is opened and the combustion chamber is opened as the piston descends The intake valve is closed and the intake valve is closed, followed by the second intake stroke and the second intake stroke, the intake valve and the exhaust valve are closed, and the combustion chamber ignition plug generates a spark to cause combustion. Burning the air-fuel mixture in the room The second combustion stroke is performed, and the second combustion stroke is performed following the second combustion stroke, the intake valve is closed, and the exhaust valve is opened and the combustion gas in the combustion chamber is exhausted as the piston rises. And a control device that controls the internal combustion engine. The control device includes one cycle including a first intake step, a first compression step, a first combustion stroke, and a first exhaust step, and two rotations of the crankshaft as one cycle. Select one of the power mode to be repeatedly executed and the heat generation mode to repeatedly execute one cycle consisting of the second intake process, the second combustion stroke, and the second exhaust process with one rotation of the crankshaft as one cycle. The mode selection unit, the power control execution unit that controls the internal combustion engine to operate in the power mode when the power mode is selected by the mode selection unit, and the heat selection mode is selected by the mode selection unit. And a heat generation control execution unit that controls the internal combustion engine to operate in the heat generation mode.

  In the above configuration, when the power mode is selected, the internal combustion engine operates as a normal four-stroke cycle engine. During the operation of a normal four-stroke cycle engine, fuel energy, that is, heat energy generated by combustion, is converted into pressure, further converted into motive power, and used for traveling of an automobile. And, it is transmitted to the engine body through the inner wall of the exhaust port and contributes to the temperature rise of the internal combustion engine body. On the other hand, when the heat generation mode is selected, the internal combustion engine is operated again while the crankshaft of the internal combustion engine makes one revolution, in other words, the piston descends from the top dead center and rises past the bottom dead center. During the period up to the top dead center, an operation is performed with intake, combustion, and exhaust as one cycle. This is an operation as a so-called two-stroke cycle engine in which one cycle is completed by one rotation of the crankshaft of the internal combustion engine. However, in the heat generation mode of the internal combustion engine according to claim 1 of the present invention, the air-fuel mixture sucked into the combustion chamber by the lowering of the piston is emitted by the combustion chamber ignition plug when the piston reaches the vicinity of the bottom dead center. The combustion gas is ignited by the spark and burns, and the combustion gas flows out from the combustion chamber to the exhaust port by opening the exhaust valve as the piston rises. Thus, in the heat generation mode of the internal combustion engine according to claim 1 of the present invention, there is no compression process in a two-stroke cycle as a power generation cycle, and the air-fuel mixture sucked into the combustion chamber is hardly compressed. It is ignited and burned by the energy of the spark. In combustion in such a heat generation mode, the combustion gas generated in the second combustion stroke is hardly accompanied by a pressure increase, in other words, it is not converted into pressure to generate power, but simply increases the temperature of the intake air. The temperature is transmitted to the internal combustion engine body through the combustion chamber wall and the exhaust port inner wall, and the temperature of the internal combustion engine body rises. That is, in the heat generation mode of the internal combustion engine according to claim 1 of the present invention, most of the energy of the fuel is converted into heat, which is used for increasing the temperature of the engine body. Further, when operating in the power mode, that is, when operating as a four-stroke cycle engine, combustion is performed once per two rotations of the crankshaft, whereas when operating in the heat generation mode, one rotation of the crankshaft is performed. One combustion is performed. Therefore, in the heat generation mode of the internal combustion engine according to claim 1 of the present invention, combustion is performed twice as frequently as in the power mode, in other words, heat is generated, so that the unit time transmitted to the main body of the internal combustion engine The amount of heat per hit can be increased.

  In summary, in the internal combustion engine according to claim 1 of the present invention, by performing the heat creation mode operation, most of the thermal energy of the fuel can be contributed to the temperature rise of the internal combustion engine body. The internal combustion engine body temperature can be raised in a short time. As a result, if the heat generation mode operation is performed when starting the cold engine, the internal combustion engine body temperature can be raised in a short time to increase the cabin temperature in a short time, and the operation of exhaust gas purification equipment such as a catalyst can be shortened. It becomes possible to make it stable in time. As described above, it is possible to provide a control device for an internal combustion engine that can achieve low fuel consumption, low harmful gas, and comfort on a higher level.

  An internal combustion engine according to a second aspect of the present invention includes a cylinder, a piston that reciprocates in the cylinder, a power output unit that is coupled to the piston and outputs kinetic energy due to the reciprocating motion of the piston, and a cylinder And a piston, and a combustion chamber in which a mixture of fuel and air burns, a combustion chamber spark plug provided in the combustion chamber for generating a spark for burning the mixture, and introducing air into the combustion chamber An intake valve provided between the intake port and the combustion chamber, an exhaust valve provided between the exhaust port for discharging the combustion gas generated by the combustion of the air-fuel mixture in the combustion chamber, and the exhaust port; And an exhaust port ignition plug that generates a spark for burning the air-fuel mixture, the exhaust valve is closed, and the intake valve opens as the piston descends, and intake into the combustion chamber is performed. An intake stroke that closes the intake valve based on the bottom dead center, and a compression stroke that is performed subsequent to the intake stroke, the intake valve and the exhaust valve are closed, and the gas in the combustion chamber is compressed, The combustion stroke is performed following the compression stroke, the intake valve and the exhaust valve are closed, and the combustion chamber ignition plug generates a spark, thereby burning the air-fuel mixture compressed in the compression stroke, In the internal combustion engine in which the intake valve is closed following the combustion stroke, the exhaust valve is opened as the piston rises and the exhaust gas is exhausted from the combustion chamber, the exhaust valve is closed. As the piston descends, the intake valve opens, intake into the combustion chamber is performed, the intake valve closes after the second intake stroke, and the second intake stroke is performed. The combustion gas in the open combustion chamber The third exhaust stroke is performed, and the third exhaust stroke is performed following the third exhaust stroke, the intake valve is closed, and the exhaust port ignition plug generates a spark to burn the air-fuel mixture in the exhaust port. And a control device that controls the internal combustion engine. The internal combustion engine performs one cycle including an intake process, a compression process, a combustion process, and an exhaust process, and performs two rotations of the crankshaft that is a power output unit. A power mode that is repeatedly executed as a cycle and a heat generation mode that repeatedly executes one cycle consisting of the second intake step, the third exhaust step, and the third combustion stroke as one cycle of one rotation of the crankshaft can be executed. The control device includes a mode selection unit that selects one of the power mode and the heat generation mode, and a power control that controls the internal combustion engine when the power mode is selected by the mode selection unit. And a heat generation control execution unit that controls the internal combustion engine when the heat generation mode is selected by the mode selection unit.

  The control apparatus for an internal combustion engine according to claim 2 of the present invention is similar to the control apparatus for an internal combustion engine according to claim 1 of the present invention described above. In the heat generation mode, the air-fuel mixture does not ignite in the combustion chamber, that is, no spark is generated in the combustion chamber ignition plug, and the air-fuel mixture flows out to the exhaust port. A spark is generated and the mixture is ignited.

  In this case, the air-fuel mixture sucked into the combustion chamber flows out from the exhaust valve to the exhaust port without being compressed as the piston rises, and is ignited and combusted by the exhaust port spark plug there. In such heat generation mode combustion, the combustion gas generated in the third combustion stroke is not accompanied by an increase in pressure, in other words, does not contribute to power generation, but is simply used for increasing the temperature of the intake air, The temperature is transmitted to the internal combustion engine body through the inner wall of the port, and the temperature of the internal combustion engine body rises. Therefore, in the heat generation mode of the internal combustion engine according to claim 2 of the present invention, as in the case of the heat generation mode of the internal combustion engine according to claim 1 of the present invention, most of the thermal energy possessed by the fuel is reduced. This is used to increase the temperature of the internal combustion engine body.

  Therefore, even with the control apparatus for an internal combustion engine according to claim 2 of the present invention, most of the thermal energy of the fuel can be contributed to the temperature increase of the internal combustion engine body by performing the heat generation mode operation. The internal combustion engine body temperature can be raised in a short time. As a result, if the heat generation mode operation is performed when starting the cold internal combustion engine, the internal combustion engine body temperature can be raised in a short time to increase the cabin temperature in a short time and the operation of exhaust gas purification equipment such as a catalyst can be performed. It becomes possible to make it stable in a short time. As described above, it is possible to provide a control device for an internal combustion engine that can achieve low fuel consumption, low harmful gas, and comfort on a higher level.

  A control device for an internal combustion engine according to claim 3 of the present invention is the control device for an internal combustion engine according to claim 1 or 2, wherein the internal combustion engine has a plurality of cylinders. It is characterized by being.

  In the heat generation mode, the fuel supplied to the cylinder does not become power even if it is burned, that is, the cylinder operating in the heat generation mode does not generate the rotational force of the crankshaft. For this reason, in order to operate the internal combustion engine in the heat generation mode, it is necessary to supply a rotational force to the crankshaft by some power. If the internal combustion engine has a plurality of cylinders, some of the plurality of cylinders are operated in a heat generation mode, and the remaining cylinders are operated in a power mode, so that the internal combustion engine is rotated by itself and heated. Creation mode operation can be executed.

  According to a fourth aspect of the present invention, there is provided an internal combustion engine control device comprising: an exhaust port connected to an exhaust port and an outlet side of the exhaust port in the internal combustion engine according to any one of the first to third aspects. A heat exchanger provided in at least one of the heat exchangers, and the heat exchanger heats between the fluid introduced into the heat exchanger from the outside of the exhaust port and the combustion gas generated by combustion of the air-fuel mixture. It is characterized by exchange.

  According to the above-described configuration, in addition to transmitting the heat of the combustion gas generated by the combustion of the air-fuel mixture to the internal combustion engine body through the wall surface of the exhaust port and contributing to the internal combustion engine body temperature increase, Heat can be transferred to the fluid via the heat exchanger to increase the fluid temperature. Therefore, this fluid can be used to raise the temperature of an arbitrary place by moving it to a desired place away from the engine body and dissipating heat there. In this case, as in the control device for an internal combustion engine according to claim 5 of the present invention, if the fluid is configured to be cooling water of the internal combustion engine, it is not necessary to newly prepare the fluid, It can be used to increase the temperature of the place.

  An internal combustion engine according to claim 6 of the present invention is characterized by including the control device for an internal combustion engine according to any one of claims 1 to 5 described above.

  In such an internal combustion engine, by performing the heat generation mode operation, most of the thermal energy of the fuel can be contributed to the temperature rise of the internal combustion engine body, so the internal combustion engine body temperature is raised in a short time. It becomes possible. As a result, if the heat generation mode operation is performed when starting the cold engine, the internal combustion engine body temperature can be raised in a short time to increase the cabin temperature in a short time, and the operation of exhaust gas purification equipment such as a catalyst can be shortened. It becomes possible to make it stable in time. As described above, it is possible to provide an internal combustion engine that can achieve low fuel consumption, low harmful gas, and comfort on a higher level.

It is sectional drawing which shows typically the planar structure around the combustion chamber of the engine which is an internal combustion engine by one Embodiment of this invention. It is the II-II sectional view taken on the line in FIG. It is a block diagram which shows the structural example about the control apparatus which controls the engine by one Embodiment of this invention. FIG. 4 is an operation diagram showing changes in combustion chamber pressure and the like when a power mode is selected, (a) is a timing chart showing changes in combustion chamber pressure accompanying rotation of the crankshaft, and (b) is a crank chart. It is a timing chart which shows transition of an intake valve lift and an exhaust valve lift accompanying rotation of a shaft. FIG. 6 is an operation diagram showing a transition of the combustion chamber pressure and the like when the heat generation mode is selected, (a) is a timing chart showing a transition of the combustion chamber pressure accompanying the rotation of the crankshaft, and (b) is a timing chart. It is a timing chart which shows transition of intake valve lift and exhaust valve lift accompanying rotation of a crankshaft. FIG. 3 is an operation diagram showing transition of states of an engine piston, an intake valve, an exhaust valve, and the like when a heat creation mode is selected for the engine according to the first embodiment of the present invention. It is a PV diagram in case the power mode is selected about the engine by one Embodiment of this invention. It is a PV diagram when heat creation mode is selected about an engine by one embodiment of the present invention. (A) is a schematic diagram showing the breakdown of various losses when the power mode is selected, and (b) shows the breakdown of various losses when the heat generation mode is selected for the engine according to the embodiment of the present invention. It is a schematic diagram. (A) is a schematic diagram which shows transition of the engine main body temperature in the prior art after engine starting, a cooling water temperature, and lubricating oil temperature. (B) is a schematic diagram showing changes in engine body temperature, cooling water temperature, and lubricating oil temperature after engine start according to the first embodiment of the present invention. It is sectional drawing explaining the structure around the combustion chamber in the modification of the engine by one Embodiment of this invention. This corresponds to FIG.

  Hereinafter, an embodiment of an internal combustion engine and a control device thereof according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view schematically showing a planar structure around a combustion chamber 12 of an engine 1 which is an internal combustion engine. 2 is a cross-sectional view taken along the line II-II in FIG. 1 and is a cross-sectional view schematically showing a side structure of the engine 1. First, the structure of the engine 1 will be described with reference to FIGS. 1 and 2. In the present embodiment, engine 1 is embodied as an internal combustion engine mounted as a prime mover on a vehicle (not shown).

  The engine 1 has a plurality of cylinders, for example, four cylinders. The engine 1 has the same structure as a conventional internal combustion engine as an internal combustion engine that realizes a so-called Otto cycle (power output mode described later). However, each cylinder constituting the engine 1 has a valve drive mechanism 40 and a heat exchanger 80, which will be described later, and is a new cycle different from the Otto cycle and is a characteristic operation of the present invention. It is configured as an internal combustion engine that can also be operated.

  This will be described in detail below. As shown in FIG. 2, the engine 1 includes a cylinder head 10 and a cylinder block 20.

  In the cylinder head 10, corresponding to each cylinder 21, an intake port 11 that is an air passage for introducing air from the outside to the combustion chamber 12, and an intake port 11 that is disposed facing the intake port 11, fuel is supplied into the intake port 11. A fuel injection valve 14 for injecting and forming a mixture of air and fuel in the intake port 11; and a combustion chamber 12 in which the mixture of air and fuel introduced through the intake port 11 is combusted; An exhaust port 13 is formed through which combustion gas generated by combustion of the air-fuel mixture in the combustion chamber 12 is discharged. Here, when the assembly of the engine 1 is completed, the combustion chamber 12 includes a side wall of a cylinder 21 formed in the cylinder block 20 and a top surface of a piston 30 disposed so as to be capable of reciprocating in the cylinder 21. The cylinder head 10 is formed as a space surrounded by the surfaces of the piston 30 facing the top surface of the piston 30 and the surfaces of the intake valve 17 and the exhaust valve 18 facing the top surface of the piston 30. Therefore, the combustion chamber 12 volume changes in response to a change in the relative positional relationship between the piston 30 and the cylinder 21, that is, a change in the rotational angle position of the crankshaft 32 of the engine 1.

  An intake passage (not shown) is connected to the side opposite to the combustion chamber 12 of the intake port 11, that is, to the left side in FIG. An intake air temperature sensor (not shown) that detects the temperature of air in the intake air passage and an air flow meter (not shown) that detects the amount of air flowing through the intake air passage toward the intake port 11 are disposed in the intake air passage. On the other hand, an exhaust pipe 16 is connected to the side of the exhaust port 13 opposite to the combustion chamber 12, that is, to the right side in FIG. 2, as shown in FIG. As shown in FIG. 2, a heat exchanger 70 is disposed in the exhaust pipe 16. The heat exchanger 70 performs heat exchange between the cooling water of the engine 1 that is a fluid introduced from the outside of the exhaust pipe 16 into the heat exchanger 70 and the exhaust gas flowing through the exhaust pipe 16. . Specifically, the heat exchanger 70 is formed in a tubular shape from a metal as a good heat conductor, such as copper or aluminum alloy, and flows around the heat exchanger 70 and cooling water flowing inside the heat exchanger 70. Exhaust gas exchanges heat through the tube wall of the heat exchanger 70. Usually, since the exhaust gas temperature is higher than the cooling water temperature, when the exhaust gas flows around the outer periphery of the heat exchanger 70, the heat of the exhaust gas is transmitted to the cooling water via the heat exchanger 70, and the cooling water temperature is increased. Rises. The exhaust pipe 16 is provided with an oxygen concentration sensor (not shown) that detects the oxygen concentration in the exhaust gas flowing through the exhaust pipe 16. The control device 50 to be described later calculates the oxygen content in the exhaust gas based on the detection signal of the oxygen concentration sensor, and further in the air-fuel mixture formed in the intake port 11 based on the oxygen content. The weight ratio of air and fuel, that is, the air-fuel ratio is calculated. The control device 50 described later controls the fuel injection amount so that the calculated air-fuel ratio becomes an appropriate value. A catalyst device (not shown) for purifying exhaust gas is disposed downstream of the exhaust pipe 16, that is, on the right side in FIG.

  Control of the fuel injection valve 14 disposed in the intake port 11 of the cylinder head 10, that is, control of the fuel injection timing and the amount of injected fuel, is determined by a control device 50 described later. The control device 50 includes an output value of the air flow meter provided in the engine 1, an output value of the intake air temperature sensor, an air-fuel ratio calculated based on an output value of the oxygen concentration sensor, an output value of a cooling water temperature sensor described later, It is determined based on information about an operation mode (information about which mode of the power mode and the heat generation mode is selected) described later. In the present embodiment, the fuel injection valve 14 is disposed in the intake port 11 and fuel is injected and supplied to the intake air in the intake port 11, but the cylinder side wall of the cylinder block 20, the cylinder head 10, etc. It is good also as a structure which is arrange | positioned and supplies a fuel directly in the combustion chamber 12. FIG.

  As shown in FIG. 2, a combustion chamber ignition plug 15 is disposed in the cylinder head 10 so as to face the combustion chamber 12. The combustion chamber ignition plug 15 generates a spark between the electrodes protruding into the combustion chamber 12 when a high voltage is applied, and ignites and burns the air-fuel mixture introduced from the intake port 11 by the energy of the spark. belongs to. The timing for generating a spark in the combustion chamber ignition plug 15, in other words, the timing for igniting the air-fuel mixture is determined by the control device 50.

  An intake valve 17 is disposed between the intake port 11 of the cylinder head 10 and the combustion chamber 12. The intake valve 17 is driven by a known valve drive mechanism 40 such as a direct acting type or a rocker arm type, for example, and the intake port 11 and the combustion chamber 12 can be in either a communication state or a cutoff state.

  An exhaust valve 18 is disposed between the combustion chamber 12 and the exhaust port 13 of the cylinder head 10. Similarly to the intake valve 17, the exhaust valve 18 is also driven by a known valve driving mechanism 40 such as a direct acting type or a rocker arm type, and the combustion chamber 12 and the exhaust port 13 are either in a communication state or a cutoff state. You can also.

  The cylinder head 10 and the cylinder block 20 are formed with a water jacket W that is a flow path of cooling water for cooling the engine. The cylinder block 20 is provided with a cooling water temperature sensor 62 for detecting the temperature of the cooling water flowing in the water jacket W as shown in FIG. In the engine 1, when the fuel / air mixture burns in the combustion chamber 12, a part of the heat generated by the combustion is transferred to the cooling water in the water jacket W via the wall surface of the cylinder 21 and the wall surface of the cylinder head 1. As a result, the cooling water temperature rises.

  The piston 30 is fitted in the cylinder 21 so as to be capable of reciprocating in the cylinder 21, and is coupled to a crankshaft 32, which is a power output unit, via a connecting rod 31. With such a structure, the reciprocating motion of the piston 30 is converted into the rotational motion of the crankshaft 32. In the engine 1, the power generated by the engine 1 is output to be usable as the rotational torque of the crankshaft 32.

  The engine 1 according to the embodiment of the present invention having the above-described structure includes a power mode for mainly converting the combustion energy of the fuel into the torque of the crankshaft 32, and heat for increasing the coolant temperature mainly by the fuel combustion energy. Two modes of operation are possible: a heat creation mode that converts to energy. The control of the operation of the engine 1 including switching between these two operation modes is performed by the control device 50. Hereinafter, the configuration and operation of the control device 50 will be described.

  The control device 50 is mainly composed of a microcomputer, and executes various control programs stored in a built-in ROM. As shown in FIG. 3, the control device 50 includes a mode selection unit 51, a power control execution unit 52, and a heat creation control execution unit 53 from the functional viewpoint.

  As shown in FIG. 3, an external ignition switch 60, a heating switch 61, a cooling water temperature sensor 62, and various sensors are connected to the control device 50 so as to be able to input electric signals therefrom. Among these, the ignition switch 60 is a known switch for instructing the engine 1 to start, and is provided at a position where the driver in the vehicle can operate. The heating switch 61 is a switch for requesting the engine 1 to operate in the heat creation mode, and is provided at a position where the driver in the vehicle compartment can operate, like the ignition switch 60. The various sensors are the intake air temperature sensor, the oxygen concentration sensor, the air flow meter, the accelerator sensor for detecting the depression amount of the accelerator pedal operated when the driver controls the speed of the vehicle, and the like.

  As shown in FIG. 3, the fuel injection valve 14, the combustion chamber ignition plug 15, and the valve drive mechanism 40 that are various devices to be controlled by the control device 50 are connected to the control device 50.

  The fuel injection valve 14 injects fuel during the period when the drive signal is output from the control device 50. Therefore, the fuel injection amount is controlled by the drive signal output time, and the fuel injection timing is controlled by the drive signal output timing.

  The combustion chamber ignition plug 15 generates a discharge spark when a drive signal is output from the control device 50. The ignition timing is controlled by the timing at which the control device 50 outputs the drive signal.

  The valve driving mechanism 40 performs an opening / closing operation of the intake valve 17 and an opening / closing operation of the exhaust valve 18, and a known electric valve timing variable mechanism or hydraulic valve timing variable mechanism is used.

  The control device 50 receives signals from the ignition switch 60, the heating switch 61, the coolant temperature sensor 62, and various sensors, and based on them, the mode selection unit 51 selects either the power mode or the heat generation mode, The fuel injection valve 14, the combustion chamber ignition plug 15, and the valve drive mechanism 40 are driven so as to execute the selected operation mode under optimum conditions.

  Control of the engine 1 in the control device 50 will be described. When the ignition switch 60 is turned on by the driver's operation, the control device 50 starts control of the engine 1. When the control is started, first, the mode selection unit 51 determines whether to execute the power mode or the heat generation mode. When the mode selection unit 51 selects the power mode, the power control execution unit 52 subsequently executes the power mode operation control of the engine 1. When the mode selection unit 51 selects the heat generation mode, the heat generation control execution unit 52 subsequently executes the heat generation mode operation control of the engine 1.

  The mode selection unit 51 first determines whether the heating switch 61 is ON or OFF. When it is determined that the heating switch 61 is OFF, the mode selection unit 51 selects the power mode as the operation mode of the engine 1 and causes the power control execution unit 52 to execute control of the engine 1. When it is determined that the heating switch 61 is ON, the mode selection unit 51 subsequently calculates the cooling water temperature based on the detection signal of the cooling water temperature sensor 62, and the calculated cooling water temperature is a predetermined temperature (for example, , 60 ° C.). When the coolant temperature is less than 60 ° C., the mode selection unit 51 selects the heat creation mode as the operation mode of the engine 1 and causes the heat creation control execution unit 53 to execute control of the engine 1. On the other hand, when the calculated coolant temperature is 60 ° C. or higher, the mode selection unit 51 selects the power mode as the operation mode of the engine 1 and causes the power control execution unit 52 to execute control of the engine 1.

  Even when the heat generation mode is selected as the determination result of the mode selection unit 51 and the engine 1 is controlled by the heat generation control execution unit 53, the heating switch 61 is operated to be turned off or the cooling water When the temperature is 60 ° C. or higher, mode selection unit 51 selects a power mode as the operation mode of engine 1 and causes power control execution unit 52 to execute control of engine 1.

  To summarize the above, the control device 50 of the engine 1 according to the embodiment of the present invention performs the heat generation control execution unit 53 only when the heating switch 61 is in the ON state and the cooling water temperature is less than 60 ° C. The heat generation mode operation is executed, and when both of these two conditions are not satisfied and when either one is not satisfied, the power control execution unit 52 executes the power mode operation.

  Next, the operation of the engine 1 in the power mode executed by the power control execution unit 52 and the operation of the engine 1 in the heat generation mode executed by the heat generation control execution unit 53 will be described.

  First, the operation of the engine 1 in the power mode executed by the power control execution unit 52 will be described. In the power mode, the engine 1 is controlled to operate as a known four-stroke cycle engine. That is, in the 4-stroke cycle engine, as shown in FIGS. 4 (a) and 4 (b), the exhaust valve 18 is closed (the valve lift is 0), and the piston 30 is lowered from the top dead center. When the intake valve 17 is opened (the valve lift is increased), the air-fuel mixture is sucked into the combustion chamber 12 from the intake port 11, and the intake valve 17 is closed when the piston 30 reaches bottom dead center. "Stroke" and "compression stroke" performed after the "intake stroke", the piston 30 ascends from the bottom dead center while the intake valve 17 and the exhaust valve 18 are closed, and the air-fuel mixture in the combustion chamber is compressed. , Following the “compression stroke”, with the intake valve 17 and the exhaust valve 18 being closed, a voltage is applied to the combustion chamber ignition plug 15 to generate a spark to ignite and burn the compressed air-fuel mixture. Increase the pressure in the combustion chamber 12 This is performed following the “combustion stroke” in which the piston 30 is lowered from the top dead center by a sudden pressure increase, and the “combustion stroke”. The intake valve 17 is closed and the piston 30 is exhausted as it rises from the bottom dead center. One cycle consisting of four strokes of “exhaust stroke” in which the valve 18 is opened and the combustion gas in the combustion chamber 12 is discharged to the exhaust port 13 is taken as 2 revolutions of the crankshaft 32 of the engine 1, that is, 720 degrees of the crank angle is 1 It is executed repeatedly as a cycle. In the four-stroke cycle engine, a sudden pressure increase in the “combustion stroke” is applied to the piston 30 to lower the piston 30 to generate torque on the crankshaft 32. Further, part of the heat of the high-temperature combustion gas generated by the “combustion stroke” is transmitted to the cooling water in the water jacket W via the wall surface of the cylinder 21 and the lower surface of the cylinder head, and the cooling water temperature rises. Thereby, the cylinder wall surface 21 temperature and the cylinder head lower surface temperature are maintained at appropriate temperatures. Thus, in the four-stroke cycle engine, heat is transferred to the cooling water in the water jacket W once for every two rotations of the crankshaft 32 of the engine 1.

  Next, the operation of the engine 1 during the heat generation mode executed by the heat generation control execution unit 53 will be described. In the heat generation mode, the engine 1 has the exhaust valve 18 closed (valve lift is 0) and the piston 30 is at the top dead center, as shown in FIGS. 5 (a), 5 (b), and 6. As the valve descends, the intake valve 17 opens (the valve lift increases), and a mixture of air and fuel is sucked into the combustion chamber 12 from the intake port 11 and before the piston 30 reaches bottom dead center. The combustion chamber ignition plug 15 is performed before the piston 30 reaches the bottom dead center with the intake valve 17 and the exhaust valve 18 closed while the “second intake stroke” and the “second intake stroke” are closed. This is performed following the “second combustion stroke” and the “second combustion stroke” in which a voltage is applied to the gas to generate sparks and ignite and burn the air-fuel mixture in the combustion chamber 12, and the intake valve 17 is closed. As the piston 30 rises from the bottom dead center, the exhaust valve 18 One cycle consisting of three strokes of the “second exhaust stroke” for discharging the combustion gas in the open combustion chamber 12 to the exhaust port 13 is made one rotation of the crankshaft 32 of the engine 1, that is, 360 degrees of the crank angle. Is executed repeatedly. In terms of operating with one rotation of the crankshaft 32 of the engine 1 as one cycle, the operation of the engine 1 in the heat generation mode can be said to be the operation of a so-called two-stroke cycle engine. In a normal two-stroke cycle engine, a scavenging process is performed in which the combustion gas and the air-fuel mixture are exchanged in the vicinity of the bottom dead center of the piston. After the scavenging stroke, the air-fuel mixture is compressed as the piston rises, and the piston approaches the top dead center. The mixture is ignited and burned. Due to the combustion of the air-fuel mixture, the pressure in the combustion chamber rapidly increases, and this pressure acts on the piston to generate torque on the crankshaft. That is, power is generated. In contrast, in the heat creation mode of the engine 1 according to the embodiment of the present invention, a spark is applied to the combustion chamber spark plug 15 at the end of the second intake stroke, that is, without compressing the air-fuel mixture. Since the air-fuel mixture is ignited and combustion is started, the pressure in the combustion chamber 12 gradually increases as shown in FIG. 5A, and the maximum pressure is much higher than the maximum pressure in the power mode. The pressure is very low. For this reason, in the heat generation mode, most of the combustion energy of the fuel is converted into heat, and no torque is generated on the crankshaft 32. In other words, in order to continuously execute the heat generation mode, it is necessary to rotate the crankshaft 32 using some means. Therefore, in the engine 1 according to the embodiment of the present invention, the heat generation mode is executed by two cylinders out of the four cylinders, and the power mode operation described above is executed by two cylinders. The torque required to execute the heat generation mode operation is generated. During the heat generation mode operation, the heat of the combustion gas generated by burning the fuel is transmitted to the cooling water in the water jacket W through the wall surface of the cylinder 21 and the lower surface of the cylinder head. Further, the high-temperature combustion gas flows out to the exhaust pipe 16 and flows around the heat exchanger 70, thereby being transmitted to the cooling water flowing in the heat exchanger 70. Thereby, the temperature of cooling water rises.

  In this way, in the heat generation mode, the air-fuel mixture is ignited and burned without being compressed, so that the time during which the combustion gas contacts the cylinder 21 wall surface and transfers heat becomes longer than in the power mode. In addition, the cycle in which the combustion stroke is performed is two revolutions of the crankshaft 32 in the power mode, whereas it is as short as one revolution of the crankshaft 32 in the heat generation mode. As a result, the amount of heat transferred to the cooling water per unit time is significantly greater in the heat creation mode than in the power mode.

  The effects obtained by the engine 1 of the present embodiment described above will be described with reference to an indicator diagram of the engine. The indicator diagram is a graph showing the relationship between the pressure in the combustion chamber and the stroke volume during one cycle of the engine, where the vertical axis represents the pressure in the combustion chamber and the horizontal axis represents the stroke volume as the combustion chamber volume. FIG. 8 shows an indicator diagram in the power generation mode, and FIG. 8 shows an indicator diagram in the heat generation mode.

  When the power mode is selected, the engine 1 executes the Otto cycle by the conventional four-stroke cycle engine, and therefore can perform “positive work”, that is, the hatched portion in FIG. The engine 1 generates engine output by converting this "positive work" into crankshaft torque. The “positive work” is larger as the area of the hatched portion in FIG. 7 is larger.

  On the other hand, when the heat generation mode is selected, the engine 1 executes a new cycle different from the Otto cycle in the power mode. In the new cycle of the heat generation mode, the engine 1 generates almost no “positive work” as shown in FIG. 8, and therefore no torque is generated on the crankshaft 32 in the engine 1. . In other words, most of the energy of the fuel is converted into heat and further transmitted to the cooling water through the wall surface of the combustion chamber 12 and the heat exchanger 70, thereby contributing to an increase in the cooling water temperature.

  Next, the effects obtained by the engine 1 of the present embodiment described above will be described with reference to the engine heat bill graph. The engine heat balance graph shows the amount of heat generated by the complete combustion of the fuel as 100%, and shows how much it is distributed as a bar graph. FIG. 9B shows a heat account when the mode is selected, and FIG. 9B shows a heat account when the heat creation mode is selected.

  When the engine 1 is operated in the power mode, the amount of heat generated by the complete combustion of the fuel, as shown in FIG. Exhaust loss released to the engine, the amount of heat transferred to the engine cooling water and the cooling loss that is the amount of heat radiated from the outer surface of the engine 1 into the air, the pump loss consumed to suck and compress the air, and the crankshaft 32 is allocated to available net work as torque on. When the engine 1 is operated in the power mode, the amount of heat that contributes to the heating of the vehicle and the temperature rise of each part of the engine is mainly the cooling loss, but as is apparent from FIG. Occupies a small percentage, which is expected to reduce the heating capacity of the vehicle. As the engine's inherent performance, it is important that the ratio of net work is high, but there is a possibility that sufficient heating capacity cannot be obtained.

  On the other hand, as is apparent from the indicator diagram of FIG. 8, in the heat account in the case of operating in the heat generation mode, there is no pump loss and no net work, and the ratio of exhaust loss and cooling loss is much higher by that amount. Has increased. In the heat generation mode operation, the amount of heat in the exhaust is recovered by the heat exchanger 70 as the temperature rise of the cooling water. Accordingly, during the heat generation mode operation, the ratio of the amount of heat generated by the complete combustion of the fuel contributing to the heating of the passenger compartment and the temperature of each part of the engine is significantly greater than in the power mode. Thereby, heating capability can be increased by implementing heat creation mode.

  Next, the effect of the present invention will be described with reference to data obtained by measuring changes in the coolant temperature, the lubricating oil temperature, and the engine body temperature after starting the engine when the engine is started in cold weather. FIG. 10A is a graph showing changes in the coolant temperature, the lubricating oil temperature, and the engine main body temperature after starting the engine in a conventional engine (only the power mode operation in the engine 1 according to the embodiment of the present invention is performed). FIG. 10B shows the transition of the coolant temperature, the lubricating oil temperature, and the engine body temperature when the engine 1 according to this embodiment performs the heat generation mode operation that is a feature of the present invention after the engine is started. It is a graph to show.

  As shown in FIG. 10 (a), when a conventional engine, that is, an engine that is operated in an Otto cycle, is cold-started, the time required from the cold start to the completion of warm-up is approximately “10 minutes”. That ’s it. On the other hand, as shown in FIG. 10B, when the engine 1 of the present embodiment is cold started, the time required from the cold start to the completion of warm-up is approximately “1 minute. "It was about. Here, in the engine 1 of the present embodiment, immediately after the engine is started, the condition for selecting the “heat generation mode” in the mode selection unit 51 of the control device 50 is satisfied, and the “heat generation mode” is executed. Is done. However, when the cooling water temperature rises as the operation time elapses and the cooling water temperature becomes 60 ° C. or higher in the case of the engine 1 of the present embodiment, the mode selection unit 51 of the control device 50 selects the “heat creation mode”. The mode selection unit 51 selects the “power mode”. Therefore, after that time, the engine 1 is operated in the “power mode”. However, the amount of heat transferred to the cooling water during “power mode” operation is sufficient to maintain the cooling water temperature, the lubricating oil temperature, and the engine body temperature at their respective predetermined temperatures.

  From these things, it turns out that the engine 1 of this Embodiment can be warmed up early compared with the conventional Otto cycle type internal combustion engine. Therefore, in the conventional Otto cycle type internal combustion engine, (1) the frictional force of the internal combustion engine is large, the fuel is not sufficiently evaporated and a good air-fuel mixture is not formed, resulting in unstable combustion, poor fuel consumption, and harmful Issues such as large gas emissions, (2) when the internal combustion engine is mounted on an automobile, slow heating at cold start, and (3) the effects of low fuel consumption technology are not fully demonstrated before the engine stage However, since the engine 1 of the present embodiment can be warmed up early, low fuel consumption, low harmful gas, and comfort can be established at a higher level.

  The internal combustion engine and the control device according to the present invention are not limited to the configurations exemplified in the above-described embodiments, and various modifications are made without departing from the spirit of the present invention. It is possible. In other words, for example, the following embodiment can be implemented by appropriately changing the above embodiment.

  In the above embodiment, as shown in FIG. 2, the heat exchanger 70 is disposed in the exhaust pipe 16, but the installation location of the heat exchanger 70 is not limited to the exhaust pipe 16, and the exhaust port 13 may be used. Alternatively, it may be installed over both the exhaust port 13 and the exhaust pipe 16. Further, the heat exchanger 70 may not be provided.

  In the above embodiment, the air-fuel mixture is ignited by the combustion chamber ignition plug 15 in the second combustion stroke in the heat generation mode. However, the present invention is not limited to this, and as shown in FIG. The exhaust port ignition plug 19 is installed facing the engine, and during operation in the heat generation mode, a voltage is applied to the exhaust port ignition plug 19 to generate a spark to ignite and burn the air-fuel mixture in the exhaust port 13. In the power mode operation, the mixture in the combustion chamber 12 may be ignited by the combustion chamber ignition plug 15 without operating the exhaust port ignition plug 19.

  Further, in the above embodiment, during the heat generation mode operation, the heat generation mode is executed by two cylinders out of the four cylinders, and the power mode operation described above is executed by two cylinders. Although the torque necessary for executing the heat generation mode operation is generated by two cylinders, it is not necessary to limit to such a configuration. The distribution of the number of cylinders that are operated in the heat generation mode and the number of cylinders that are operated in the power mode in order to generate the torque necessary to execute the heat generation mode operation may be changed as appropriate. In the above-described embodiment, the engine 1 is described as a four-air engine. However, the number of cylinders of the engine to which the present invention is applied is not limited to four, and may be any number. Furthermore, it is not necessary to limit the prime mover for generating the torque necessary for executing the heat generation mode operation to the engine 1, and a prime mover different from the engine 1, for example, an electric motor included in the vehicle may be used. . In this case, the electric motor may be a starter motor for starting the engine 1 or a motor for driving the vehicle.

  Moreover, in the said embodiment, the heating switch 61 is an ON state as conditions when the control apparatus 50 starts control of the engine 1 and the mode selection part 51 selects either a heat creation mode or a motive power mode. And only when the cooling water temperature is less than 60 ° C, the heat generation control execution unit 53 executes the heat generation mode operation, and when both of these two conditions are not satisfied, and when either one is not satisfied The power control execution unit 52 executes the power mode operation, but it is not necessary to limit to such a configuration. Other conditions may be added or replaced. For example, the heating switch 61 may be omitted and the determination may be made based only on the coolant temperature. Or it is good also as a structure which performs heat creation mode, when a cooling water temperature is less than 60 degreeC and the vehicle is not drive | working. Here, the detection of “the vehicle is not running” is, for example, at least one of the fact that an accelerator pedal sensor (not shown) is not depressed and the running speed of the vehicle is zero. When you do, you should do.

1 engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 10 Cylinder head 11 Intake port 12 Combustion chamber 13 Exhaust port 14 Fuel injection valve 15 Combustion chamber ignition plug 16 Exhaust pipe 17 Intake valve 18 Exhaust valve 19 Exhaust port ignition plug 20 Cylinder block 21 Cylinder 30 Piston 31 Connecting rod 32 Crankshaft 40 Valve drive Mechanism 50 Control device 51 Mode selection unit 52 Power control execution unit 53 Heat generation control execution unit 60 Ignition switch 61 Heating switch 62 Coolant temperature sensor 70 Heat exchanger W Water jacket

Claims (6)

A cylinder,
A piston that reciprocates in the cylinder;
A crankshaft connected to the piston and outputting kinetic energy due to reciprocating motion of the piston to the outside as a rotational force;
Combustion chamber constituted by the cylinder and the piston, in which a mixture of fuel and air burns,
A combustion chamber spark plug provided in the combustion chamber for generating a spark for burning the air-fuel mixture;
An intake valve provided between an intake port for introducing air into the combustion chamber and the combustion chamber;
An exhaust valve provided between the combustion chamber and an exhaust port for discharging combustion gas generated by burning the air-fuel mixture in the combustion chamber;
The exhaust valve is closed, and as the piston descends, the intake valve opens to intake air into the combustion chamber, and the intake valve closes based on the piston becoming bottom dead center. The process,
A first compression stroke that is performed following the first intake stroke, the intake valve and the exhaust valve are closed, and the gas in the combustion chamber is compressed;
The mixing in the combustion chamber compressed in the compression stroke is performed following the first compression stroke, the intake valve and the exhaust valve are closed, and the combustion chamber ignition plug generates a spark. A first combustion stroke for burning qi,
The first combustion stroke is performed following the first combustion stroke, and the intake valve is closed, and the exhaust valve is opened as the piston rises, and the first exhaust stroke is performed in which the combustion gas in the combustion chamber is exhausted. In internal combustion engines,
The exhaust valve is closed, the intake valve is opened as the piston descends, intake into the combustion chamber is performed, and a second intake stroke in which the intake valve is closed;
The second combustion stroke is performed following the second intake stroke, the intake valve and the exhaust valve are closed, and the combustion chamber ignition plug generates a spark, thereby burning the air-fuel mixture in the combustion chamber. When,
A second exhaust stroke that is performed following the second combustion stroke, the intake valve is closed, the exhaust valve is opened and the combustion gas in the combustion chamber is exhausted as the piston rises,
A control device for controlling the internal combustion engine;
The control device is a power mode in which one cycle including the first intake step, the first compression step, the first combustion stroke, and the first exhaust step is repeatedly executed with two rotations of the crankshaft as one cycle And a heat generation mode in which one cycle consisting of the second intake step, the second combustion stroke, and the second exhaust step is repeatedly executed with one rotation of the crankshaft as one cycle. A power control execution unit that controls the internal combustion engine to operate in the power mode when the power mode is selected by the mode selection unit; and the heat generation mode by the mode selection unit. A heat generation control execution unit that controls the internal combustion engine to operate in the heat generation mode when the engine is selected. Location. A cylinder,
A piston that reciprocates in the cylinder;
A crankshaft connected to the piston and outputting kinetic energy due to reciprocating motion of the piston to the outside as a rotational force;
Combustion chamber constituted by the cylinder and the piston, in which a mixture of fuel and air burns,
A combustion chamber spark plug provided in the combustion chamber for generating a spark for burning the air-fuel mixture;
An intake valve provided between an intake port for introducing air into the combustion chamber and the combustion chamber;
An exhaust valve provided between the combustion chamber and an exhaust port for discharging combustion gas generated by burning the air-fuel mixture in the combustion chamber;
An exhaust port spark plug that is provided in the exhaust port and generates a spark for burning the air-fuel mixture;
The exhaust valve is closed, and as the piston descends, the intake valve opens to intake air into the combustion chamber, and the intake valve closes based on the piston becoming bottom dead center. The process,
A first compression stroke that is performed following the first intake stroke, the intake valve and the exhaust valve are closed, and the gas in the combustion chamber is compressed;
The mixing in the combustion chamber compressed in the compression stroke is performed following the first compression stroke, the intake valve and the exhaust valve are closed, and the combustion chamber ignition plug generates a spark. A first combustion stroke for burning qi,
The first combustion stroke is performed following the first combustion stroke, and the intake valve is closed, and the exhaust valve is opened as the piston rises, and the first exhaust stroke is performed in which the combustion gas in the combustion chamber is exhausted. In internal combustion engines,
The exhaust valve is closed, the intake valve is opened as the piston descends, intake into the combustion chamber is performed, and a second intake stroke in which the intake valve is closed;
A third exhaust stroke that is performed subsequent to the second intake stroke and in which the exhaust valve opens and exhausts the air-fuel mixture in the combustion chamber as the piston rises;
The third combustion stroke is performed following the third exhaust stroke, the intake valve is closed, and the exhaust port ignition plug generates a spark, thereby burning the air-fuel mixture in the exhaust port. Executed,
A control device for controlling the internal combustion engine;
The control device is a power mode in which one cycle including the first intake step, the first compression step, the first combustion stroke, and the first exhaust step is repeatedly executed with two rotations of the crankshaft as one cycle And a heat generation mode in which one cycle consisting of the second intake step, the third exhaust step, and the third combustion stroke is repeatedly executed with one rotation of the crankshaft as one cycle. A power control execution unit that controls the internal combustion engine to operate in the power mode when the power mode is selected by the mode selection unit; and the heat generation mode by the mode selection unit. A heat generation control execution unit that controls the internal combustion engine to operate in the heat generation mode when the engine is selected. Location. In the control device for an internal combustion engine according to any one of claims 1 and 2,
The internal combustion engine has a plurality of cylinders. The control apparatus for an internal combustion engine according to any one of claims 1 to 3,
A heat exchanger provided in at least one of the exhaust port and an exhaust pipe connected to an outlet side of the exhaust port;
The heat exchanger performs heat exchange between a fluid introduced into the heat exchanger from the outside of the exhaust port and a combustion gas generated by burning the air-fuel mixture. A control device for an internal combustion engine. The control apparatus for an internal combustion engine according to claim 4,
The control apparatus for an internal combustion engine, wherein the fluid is cooling water for the internal combustion engine.   An internal combustion engine comprising the control device for an internal combustion engine according to any one of claims 1 to 5.

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