JP4748078B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine that injects fuel into a cylinder in which a piston reciprocates, and more particularly to cooling thereof.

  In a general internal combustion engine cooling structure, a water jacket through which cooling water flows is formed inside the cylinder head and inside the cylinder block, and a cooling channel through which cooling oil flows is formed in the piston. According to the following Non-Patent Document 1, a majority of the heat generated by combustion and transferred to the piston is transferred to the oil passing through the cooling channel and released from the cooling channel outlet to the outside of the piston. The remaining heat transferred to the piston is transferred to the cylinder liner through the piston ring and piston skirt, and released to the cooling water flowing in the water jacket. Further, the heat generated by the combustion and transmitted to the lower surface of the cylinder head is released to the cooling water flowing in the water jacket inside the cylinder head. The heat released to the cooling water is released into the atmosphere by the radiator. The heat transmitted to the oil is also released into the atmosphere through the oil pan and oil cooler.

  In order to reduce the cooling loss, a ceramic heat shield internal combustion engine in which the combustion chamber wall surface is coated with ceramic has been proposed, and the related technology is disclosed in Non-Patent Document 2 below.

  In addition, an internal combustion engine in which a two-fluid injection device for injecting fuel and water into the combustion chamber from the same injection valve is disposed in a cylinder head has been proposed. Is disclosed. In Patent Document 1, water injected mainly to suppress combustion control (NOx and soot) is injected from the cylinder head side toward a combustion chamber wall high temperature portion such as an exhaust valve, so that the combustion chamber wall surface The thermal stress is reduced.

Japanese Patent Laid-Open No. 7-150966 Edited by the Engine Technology Editorial Committee, “Automotive Engine Element Technology I, All Evolving Technologies”, First Edition, Sankai-do Co., Ltd., May 15, 2006, p.62 Keio Sekiyama and two others, "Observation of high-temperature combustion in ceramic thermal insulation diesel engine", Proceedings of the Society of Automotive Engineers of Japan, January 1994, Vol 25, No. 1, p. Tatsuo Takaishi and five others, “Research and development of smokeless diesel engines using water-based stratified injection,” [online], JPEC (Oil Institute for Petroleum Industry Activation), [October 2, 2006 search], Internet, < URL: http://www.pecj.or.jp/japanese/report/2005report/05P315.pdf>

  In the cooling structure for a general internal combustion engine described above, about 1/3 of the heat generated by combustion is released from the combustion chamber wall surface such as the piston top surface as a cooling loss through the refrigerant, and the thermal efficiency is low. In particular, on the piston top surface, the transfer of heat generated by combustion becomes large, and heat is easily released from the piston top surface as a cooling loss through the refrigerant. If the combustion chamber wall surface is a heat insulating wall, there is no cooling loss to the wall surface, and ideal thermal efficiency can be obtained.

  In view of this, in a ceramic heat insulation type internal combustion engine, cooling loss is reduced by insulating the ceramic wall. However, in this case, there is a disadvantage that heat is accumulated in the ceramic wall and the temperature of the combustion chamber wall becomes high.

  Also, in an internal combustion engine that injects water from the cylinder head toward the combustion chamber wall, when water is injected toward the piston top surface to cool the piston top surface, the injected water reaches the piston top surface. In the process of proceeding through the high-temperature in-cylinder gas before starting, most of the water is evaporated by receiving heat from the in-cylinder gas. Therefore, in order to cool the piston top surface, in addition to the amount of water that reaches the piston top surface and cools, it is necessary to inject an extra amount of water that evaporates and is lost in the middle.

  An object of this invention is to provide the internal combustion engine which can reduce a cooling loss and can improve thermal efficiency.

  The internal combustion engine according to the present invention employs the following means in order to achieve the above-described object.

  An internal combustion engine according to the present invention is an internal combustion engine that injects fuel into a cylinder in which a piston reciprocates, and inside the piston, a coolant flow path to which a coolant is supplied, and a cooling in the coolant flow path A coolant delivery port for delivering the liquid to the piston top surface, and a delivery adjusting valve that allows or blocks communication between the coolant flow channel and the coolant delivery port. When the fuel is burned in the cylinder, the coolant supply means for supplying the coolant is driven to connect the coolant flow path and the coolant discharge port so that the coolant in the coolant flow path is communicated. And a delivery adjusting valve driving means for delivering the gas from the coolant delivery port to the piston top surface.

  According to the present invention, when the fuel is burned in the cylinder, the coolant in the coolant channel is sent to the piston top surface from the coolant delivery port provided in the piston, so that the water film is formed on the piston top surface. Form. And the heat transfer from the high-temperature combustion gas in a cylinder to the piston top surface can be reduced using this water film and the water vapor | steam which a water film evaporates as a heat insulation layer. Therefore, the temperature rise of the piston top surface can be suppressed, and the cooling loss from the piston top surface can be reduced. As a result, the thermal efficiency of the internal combustion engine can be improved.

  In one aspect of the present invention, the delivery adjustment valve is a valve that allows communication between the coolant flow path and the coolant delivery port according to an increase in the pressure of the coolant in the coolant flow path, and a delivery adjustment valve driving means. Is disposed on the cylinder head facing the piston in the cylinder axial direction, and is movable on the piston facing the movable member in the cylinder axial direction. Pressure adjustment by pressurizing the coolant in the coolant flow path by being pressed by the movable member, and moving the movable member to the pressure member side, and pressing the pressure member by the movable member to adjust delivery It is preferable to include a movable member driving means for driving the valve to communicate the coolant flow path and the coolant delivery port. Thereby, the delivery adjusting valve provided in the piston can be driven from the cylinder head side.

  In one aspect of the present invention, the movable member driving means adjusts at least one of a period during which the movable member is moved to the pressure member side and a moving amount of the movable member to the pressure member side. It is preferable to adjust at least one of the cooling liquid delivery period and the delivery amount from the liquid delivery outlet. Thereby, heat transfer from the high-temperature combustion gas in the cylinder to the piston top surface can be adjusted.

  In one aspect of the present invention, it is preferable that the movable member driving means moves the movable member to the pressure member side so that the movable member presses the pressure member when the piston is positioned near the compression top dead center. It is. As a result, the coolant can be sent to the top surface of the piston when the piston is positioned near the compression top dead center.

  In one aspect of the present invention, it is preferable that the movable member driving means includes a feeding cam mechanism for converting a rotational movement accompanying the rotation of the crankshaft into a movement of the movable member in the cylinder axial direction. As a result, the delivery adjusting valve can be driven using the rotation of the crankshaft.

  In one embodiment of the present invention, it is preferable that the movable member is disposed at a position closer to the exhaust valve than to the intake valve.

  In one aspect of the present invention, the piston has a coolant receiving port that receives the coolant supplied to the coolant channel, and a receiving adjustment valve that opens and closes the coolant receiving port facing the cylinder head in the cylinder axial direction. Preferably, the coolant supply means is a means for driving the reception adjusting valve from the cylinder head side to open the coolant reception port and supplying the coolant to the coolant flow path.

  In one aspect of the present invention, the coolant supply means is a coolant supply nozzle disposed in the cylinder head so as to face the piston in the cylinder axial direction, and includes a coolant discharge port for discharging the coolant, and a cylinder axis. The coolant supply nozzle provided with a discharge adjustment valve that opens the coolant discharge port by moving to the reception adjustment valve side in the direction and moving the coolant supply nozzle to the piston side. With the nozzle drive means that contacts the piston and the coolant supply nozzle in contact with the piston, the discharge adjustment valve is moved to the reception adjustment valve side, and the reception adjustment valve is driven by the discharge adjustment valve to cool the coolant. It is preferable to include a discharge adjusting valve driving unit that opens the receiving port to supply the cooling liquid from the cooling liquid discharge port to the cooling liquid flow path through the cooling liquid receiving port. Thus, the coolant can be supplied from the cylinder head side to the coolant flow path provided in the piston.

  In one aspect of the present invention, it is preferable that the nozzle driving means moves the coolant supply nozzle toward the piston so that the coolant supply nozzle contacts the piston when the piston is positioned near the intake top dead center. is there. Thus, the coolant can be supplied to the coolant flow path when the piston is positioned near the intake top dead center.

  In one aspect of the present invention, it is preferable that the nozzle driving means includes a supply cam mechanism for converting the rotational movement accompanying the rotation of the crankshaft into the movement of the coolant supply nozzle in the cylinder axial direction. Thereby, the coolant supply nozzle can be moved to the piston side by utilizing the rotation of the crankshaft.

  In one aspect of the present invention, it is preferable that the coolant supply nozzle is disposed at a position closer to the intake valve than to the exhaust valve. This can avoid exposing the coolant supply nozzle to high heat.

  In one aspect of the present invention, it is preferable that a recess is formed in the central portion of the piston top surface, and the coolant flow path is provided around the recess. In this aspect, the coolant supply outlet can form a water film in a region where heat transfer from the combustion gas in the cylinder is increased by sending the coolant to the edge of the recess on the piston top surface. Further, in this aspect, the coolant delivery port can also form a water film in a region where heat transfer from the combustion gas in the cylinder is increased by sending the coolant outside the recess on the piston top surface. it can.

  In one aspect of the present invention, it is preferable to include a boiling determination unit that determines whether or not the coolant in the coolant channel is boiling. In this aspect, when it is determined by the boiling determination means that the coolant in the coolant channel is boiling, the fuel injection amount into the cylinder is decreased or the fuel injection into the cylinder is stopped. Thus, the temperature of the coolant in the coolant channel can be lowered. Further, in this aspect, when the boiling determination means determines that the coolant in the coolant channel is boiling, the coolant can also be increased by increasing the amount of coolant sent from the coolant outlet. The temperature of the coolant in the flow path can be lowered. Further, in this aspect, the boiling determination unit is configured to detect the inside of the cooling fluid channel based on the pressure change of the cooling fluid in the cooling fluid supply unit when the cooling fluid is supplied from the cooling fluid supply unit to the cooling fluid channel. It is preferable to determine whether or not the coolant is boiling.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1 and 2 are diagrams showing a schematic configuration of an internal combustion engine according to an embodiment of the present invention, and show a case where the present invention is applied to a compression self-ignition internal combustion engine such as a diesel engine. FIG. 1 shows an outline of an internal configuration viewed from a direction orthogonal to the axial direction of the cylinder 11, and FIG. 2 shows an outline of an internal configuration viewed from the upper side of the cylinder 11 in the axial direction. The internal combustion engine (engine) includes a cylinder block 9 and a cylinder head 10, and a cylinder 11 is formed by the cylinder block 9 and the cylinder head 10. A piston 12 that reciprocates along the axial direction is accommodated in the cylinder 11. A space surrounded by the top surface 12 a of the piston 12, the inner wall of the cylinder block 9, and the lower surface 10 a of the cylinder head 10 forms a combustion chamber 13. A fuel injection valve 14 that directly injects fuel into the cylinder 11 (inside the combustion chamber 13) is disposed in the cylinder head 10 so as to face the combustion chamber 13. For example, when fuel is injected from the fuel injection valve 14 into the combustion chamber 13 when the piston 12 is positioned near the compression top dead center, the fuel in the combustion chamber 13 is self-ignited and burns. The fuel injection control here is performed by an electronic control device (not shown). A recess 12b (piston cavity) is formed at the center of the piston top surface 12a facing the combustion chamber 13. 1 and 2, the tip of the fuel injection valve 14 in which the injection hole is formed is disposed so as to face the substantially central portion in the combustion chamber 13, and the fuel spray 15 is directed from the injection hole of the fuel injection valve 14 to the recess 12b. The example which erupts radially toward is shown.

  In the present embodiment, an annular water channel (cooling liquid flow path) 22 to which cooling water (cooling liquid) is supplied is formed in the piston 12 so as to surround the recess 12b. A configuration for supplying cooling water to the water channel 22 will be described later. Further, inside the piston 12, the plurality of cooling water outlets 24 for sending the cooling water in the water channel 22 to the piston top surface 12a and the communication between the water channel 22 and the plurality of cooling water outlets 24 are allowed. Or the delivery adjustment valve 26 which interrupts | blocks is provided. 1 and 2 show an example in which an annular slide valve that is movable in the circumferential direction of the cylinder is provided as the delivery adjusting valve 26. A pressure receiving plunger 27 is connected to the delivery adjusting valve (slide valve) 26, and an urging force by a spring 28 and a pressing force by cooling water in the water channel 22 act on the pressure receiving plunger 27 in opposite directions. To do. When the pressure of the cooling water in the water channel 22 decreases and the urging force of the spring 28 exceeds the pressing force of the cooling water in the water channel 22, the slide valve 26 is moved in the cylinder circumferential direction as shown in FIG. By energizing to one side (counterclockwise in the figure), communication between the water channel 22 and the cooling water delivery port 24 is blocked. On the other hand, when the pressure of the cooling water in the water channel 22 rises and the pressing force by the cooling water in the water channel 22 exceeds the urging force of the spring 28, the slide valve 26 moves in the cylinder circumferential direction as shown in FIG. The water channel 22 and the coolant outlet 24 are allowed to communicate with each other by rotating to the other side (clockwise in the figure). As described above, the delivery adjustment valve 26 allows the communication between the water channel 22 and the cooling water outlet 24 according to the increase in the pressure of the cooling water in the water channel 22, and reduces the pressure of the cooling water in the water channel 22. Accordingly, the communication between the water channel 22 and the coolant outlet 24 is blocked.

  Next, a configuration example for driving the delivery adjusting valve 26 will be described. As shown in FIG. 4, the push rod 32 is disposed on the cylinder head 10 so as to face the piston 12 in the cylinder axial direction, and is slidable along the cylinder axial direction with respect to the cylinder head 10. The push rod 32 is provided with a gas seal ring 33 for preventing the gas in the combustion chamber 13 from flowing out. The oil chamber cylinder 36 is fixed to the cylinder head 10 on one side in the cylinder axial direction (the upper side in FIG. 4) from the push rod 32, and the push rod 32 is moved toward the oil chamber cylinder 36 by the elastic force of the spring 35. The urging force is acting. Further, an actuator 38 that is slidable along the cylinder axial direction with respect to the oil chamber cylinder 36 is disposed on one side of the push rod 32 in the cylinder axial direction. As a result, an urging force to one side in the cylinder axial direction is applied.

  An oil chamber 37 is formed by a space surrounded by the push rod 32, the actuator 38, and the oil chamber cylinder 36. The check valve 46 allows the oil flow from the oil inlet 36a to the oil chamber 37 and blocks the oil flow from the oil chamber 37 to the oil inlet 36a. The check valve 46 blocks the oil flow when the oil pressure in the oil chamber 37 increases. The control valve 48 allows or blocks communication between the oil chamber 37 and the oil outlet 36b. When the control valve 48 is closed, the oil outflow from the oil chamber 37 to the oil outlet 36b is blocked, and when the control valve 48 is open, the oil outflow from the oil chamber 37 to the oil outlet 36b. Is acceptable. The opening / closing control of the control valve 48 here is performed by an electronic control device (not shown).

  The rocker arm 41 is connected to the actuator 38 and supported so as to be swingable around the arm shaft 42. The roller 43 is rotatably supported by the rocker arm 41, and the sending cam 44 is in contact with the roller 43. The rotation shaft of the delivery cam 44 is integral with the rotation shaft of the exhaust cam (not shown), and the delivery cam 44 rotates in conjunction with the rotation of the crankshaft (not shown), while the crankshaft rotates twice. The cam 44 makes one rotation. In conjunction with the rotation of the delivery cam 44, the rocker arm 41 swings around the arm shaft 42, and the actuator 38 moves along the cylinder axis direction. When the control valve 48 is closed, the movement of the actuator 38 in the cylinder axial direction is transmitted to the push rod 32 by the oil pressure in the oil chamber 37, and the push rod 32 moves along the cylinder axial direction. Thus, the rotational motion of the delivery cam 44 accompanying the rotation of the crankshaft is converted into the motion of the push rod 32 in the cylinder axis direction.

  On the other hand, a plunger 34 is disposed on the piston 12 so as to face the push rod 32 in the cylinder axial direction. The plunger 34 is slidable along the cylinder axis direction with respect to the piston 12. The push rod 32 is moved to the plunger 34 side (the other side in the cylinder axial direction, the lower side in FIG. 4) by the rotation of the delivery cam 44, and the plunger 34 is pressed by the push rod 32. Cooling water is pressurized by the plunger 34. When the cooling water in the water channel 22 is pressurized, the delivery regulating valve 26 is driven to connect the water channel 22 and the cooling water delivery port 24, so that the cooling water in the water channel 22 is cooled. 24 is sent out to the piston top surface 12a. On the other hand, when the push rod 32 moves to the cylinder head 10 side (one side in the cylinder axis direction), the pressurization of the cooling water by the plunger 34 ends, and the pressure of the cooling water in the water channel 22 decreases, The communication between the channel 22 and the cooling water outlet 24 is cut off, and the cooling water delivery from the cooling water outlet 24 is stopped. Thus, by pressing the plunger 34 with the push rod 32, the delivery adjusting valve 26 provided in the piston 12 can be driven from the cylinder head 10 side. Furthermore, the delivery adjusting valve 26 can be driven by utilizing the rotation of the crankshaft.

  When the heat generated by the combustion of the fuel in the combustion chamber 13 is transmitted to the wall surface of the combustion chamber 13 such as the piston top surface 12a, the heat efficiency is lowered by being released as a cooling loss through the refrigerant. If the wall surface of the combustion chamber 13 such as the piston top surface 12a is a heat insulating wall, there is no cooling loss to this wall surface, and ideal thermal efficiency is obtained.

  Therefore, in the present embodiment, as shown in FIGS. 5 to 7, when fuel is burned in the cylinder 11, the feed adjustment valve 26 is driven by the push rod 32 so that the water channel 22 and the cooling water delivery port 24 are connected. By communicating, the cooling water in the water channel 22 is sent out from the cooling water delivery port 24 to the wall surface of the combustion chamber 13 such as the piston top surface 12a. Here, for example, the movement of the push rod 32 toward the plunger 34 is started from the end of the compression stroke. As shown in FIG. 6, the cooling water flowing out from the cooling water delivery port 24 forms a water film 16 on the wall surface of the combustion chamber 13 such as the piston top surface 12a. By using the water film 16 and the water vapor layer 17 formed by evaporation of the water film 16 as a heat insulating layer, heat transfer from the high-temperature combustion gas 19 in the combustion chamber 13 to the wall surface of the combustion chamber 13 is reduced. Cooling loss from the wall surface of the combustion chamber 13 is reduced. Further, the combustion temperature is lowered by the water vapor layer 17 to suppress generation of nitrogen oxide (NOx). As shown in FIG. 8, the water film 16 here is preferably formed in a region where the flame 18 collides violently and heat transfer to the combustion chamber 13 wall surface increases. For example, it is preferable that the cooling water delivery port 24 feeds the cooling water to a region including the extension line of the fuel spray 15 injected from the fuel injection valve 14 to form the water film 16.

  Further, when the piston 12 starts to descend, the high-temperature combustion gas 19 in the combustion chamber 13 flows out to the squish area 13a above the piston 12 as shown in FIG. At that time, the flow rate is increased because the outflow rate of the combustion gas 19 to the squish area 13a is extremely high. Therefore, the edge (lip portion) 12c of the recess 12b in the piston top surface 12a or the recess in the piston top surface 12a. The heat flux to the region 12d outside the portion 12b (region facing the squish area 13a) and the region 10b facing the squish area 13a on the cylinder head lower surface 10a increases. Therefore, as shown in FIGS. 6 and 7, the cooling water delivery port 24 preferably feeds the cooling water to the edge 12 c of the recess 12 b on the piston top surface 12 a to form the water film 16. In addition, as shown in FIGS. 6 and 7, the cooling water delivery port 24 preferably forms the water film 16 by sending the cooling water to the region 12 d outside the recess 12 b on the piston top surface 12 a. Furthermore, as shown in FIGS. 6 and 7, the cooling water sent to the piston top surface 12a (region 12d outside the recess 12b) is not only the piston top surface 12a but also the cylinder head lower surface 10a (squish area 13a). The water film 16 and the water vapor layer 17 are also formed by reaching the facing region 10b).

  Further, in the internal combustion engine that forms a swirl flow in the cylinder 11, as shown in FIG. 8, the flame 18 that accompanies combustion is caused to flow downstream by the swirl flow. Therefore, as shown in FIG. 8, the cooling water delivery port 24 can send the cooling water to the region downstream of the swirl from the extension line of the fuel spray 15 injected from the fuel injection valve 14 to form the water film 16. preferable. Moreover, the cooling water sent out to the combustion chamber 13 wall surface (piston top surface 12a and cylinder head lower surface 10a) is transmitted to the combustion chamber 13 wall surface by the swirl flow and flows downstream on the swirl. Therefore, as shown in FIGS. 2 and 8, the cooling water delivery port 24 is preferably formed to be inclined toward the downstream side of the swirl with respect to the cylinder radial direction. As a result, a region where the water film 16 and the water vapor layer 17 (heat insulating layer) are formed on the piston top surface 12a and the cylinder head lower surface 10a can be widened, and the piston top surface 12a and the piston top surface 12a Heat transfer to the cylinder head lower surface 10a can be reduced more effectively. In addition, since a well-known technique is applicable about the specific structure for forming a swirl flow in the cylinder 11, description is abbreviate | omitted here.

  In the current water-cooled internal combustion engine, as shown in FIG. 9, heat is transferred from the high-temperature combustion gas to the metal wall (combustion chamber wall), and heat is transferred from the metal wall to the cooling water. In this case, the heat transfer coefficient αw from the metal wall to the cooling water is larger than the heat transfer coefficient αg between the combustion gas and the metal wall, in other words, the heat flow path is composed of the combustion gas and the metal. The cooling water is wider from the metal wall than between the walls. Therefore, the heat flux, that is, the cooling loss from the wall surface of the combustion chamber is limited by the heat transfer coefficient αg between the combustion gas and the metal wall.

  Further, in a ceramic heat insulation type internal combustion engine, by using a highly heat-resistant ceramic instead of a metal wall, it can withstand a state without water cooling and heat is cut off. Looking at the heat flux in this case, as shown in FIG. 9, the heat transfer coefficient αg between the combustion gas and the ceramic wall does not change much even if the material is changed from metal to ceramic. The heat flux is limited by decreasing the heat transfer coefficient αw to the heat flux. However, in this case, since heat is accumulated in the ceramic wall, the temperature of the ceramic wall rises. Therefore, the intake air temperature rises due to the heat received from the ceramic wall, and becomes a temperature about 250 ° C. higher than that of a general water-cooled internal combustion engine, for example, at the compression top dead center. The fuel spray injected into the high-temperature atmosphere has a reduced ignition delay period, and diffusion combustion proceeds without forming a sufficient premixed gas. Therefore, the peak of the initial heat generation rate is low, the isobaric combustion ratio is reduced, and the thermal efficiency is lowered. Further, since the gas temperature during the combustion period is greatly increased as compared with the water-cooled internal combustion engine, NOx increases. Further, since the intake air receives heat from the wall surface of the combustion chamber and expands, the volumetric efficiency of the intake air decreases. As a result, soot emissions increase due to lack of air. As described above, even if heat is shielded by the ceramic wall in the compression self-ignition internal combustion engine, the thermal efficiency cannot be improved and the exhaust emission increases.

  On the other hand, in this embodiment, as shown in FIGS. 7 and 9, a heat insulating layer composed of a water film 16 and a water vapor layer 17 is provided between the metal wall (piston top surface 12 a and cylinder head lower surface 10 a) and the combustion gas 19. The heat transfer coefficient αg from the combustion gas 19 in the combustion chamber 13 to the metal wall (combustion chamber 13 wall surface) can be reduced by forming and confining the heat in the combustion chamber 13 by this heat insulating layer. Therefore, the amount of heat transmitted to the combustion chamber 13 wall surface (piston top surface 12a and cylinder head lower surface 10a) can be reduced, so that the temperature rise of the combustion chamber 13 wall surface can be suppressed and heat is released from the combustion chamber 13 wall surface to the outside. This can reduce the cooling loss caused. As a result, the thermal efficiency of the internal combustion engine can be improved, and the fuel consumption can be improved.

  And since the amount of heat transmitted to the wall surface of the combustion chamber 13 can be reduced, the amount of heat released to the atmosphere via the cooling water in the water jacket can also be reduced. As a result, the radiator can be reduced in size, and the engine can be reduced in size and weight. Similarly, since the amount of heat released to the atmosphere via the oil in the cooling channel can be reduced, the oil cooler can be downsized or omitted, and the thermal deterioration of the oil can be weakened.

  Moreover, in this embodiment, the combustion temperature of the flame in the combustion chamber 13 can be lowered | hung because the cooling water sent out from the cooling water delivery port 24 evaporates. As a result, generation of nitrogen oxide (NOx) can be suppressed. Although EGR (exhaust gas recirculation) is used to suppress NOx, there is a time delay in the process in which the exhaust gas leaves the combustion chamber and is supplied again to the combustion chamber via the exhaust pipe → EGR cooler → intake pipe. In addition, the NOx suppression effect decreases during transient operation. On the other hand, in this embodiment, since water can be directly supplied into the combustion chamber 13 immediately before the combustion period without causing a time delay, the generation of NOx can be sufficiently suppressed even during transient operation. .

  In addition, when the cooling water is jetted from the cylinder head side toward the piston top surface to form a water film, the jetted cooling water travels through the high-temperature in-cylinder gas before reaching the piston top surface. Most of the water evaporates by receiving heat from the in-cylinder gas. Therefore, in order to form a water film on the piston top surface, in addition to the amount of water reaching the piston top surface, it is necessary to inject an extra amount of water lost by evaporation in the middle.

  On the other hand, in this embodiment, since cooling water is supplied from the inside of the piston 12 to the piston top surface 12a forming the water film 16, the cooling water passes through the high-temperature in-cylinder gas and evaporates wastefully. Can be suppressed. When the cooling water is supplied to the cylinder head lower surface 10a (region 10b facing the squish area 13a), the cooling water passes through the high-temperature in-cylinder gas. Since the distance between the surface 12a (region 12d outside the recess 12b) and the cylinder head lower surface 10a (region 10b facing the squish area 13a) is very short, the cooling lost by evaporation before reaching the cylinder head lower surface 10a The amount of water is small. Moreover, if it is liquids (incompressible fluid), such as water, it will be comparatively easy to send out into the combustion chamber 13 after compression. Unlike gas (compressible fluid), liquid has almost no change in density, so it is easy to increase the pressure and less mechanical work is required.

  Further, in the present embodiment, one or more of a period during which the push rod 32 is moved toward the plunger 34 and a movement amount of the push rod 32 toward the plunger 34 by driving control of the push rod 32 (delivery adjustment valve 26). , And any one or more of the cooling water delivery period and delivery amount from the cooling water delivery port 24 can be controlled. This makes it possible to control the amount of heat transferred from the high-temperature combustion gas 19 in the combustion chamber 13 to the combustion chamber 13 wall surface (piston top surface 12a and cylinder head lower surface 10a). Hereinafter, a specific example of the control of the cooling water delivery period and the delivery amount from the cooling water delivery port 24 will be described with reference to FIGS.

  10 to 13 show the relationship between the tip of the push rod 32 and the position of the piston top surface 12a (the lower surface 10a of the cylinder head 10 is 0) with respect to the crank angle (time). 10 to 13, the push rod 32 starts to move toward the piston top surface 12a (plunger 34) at time t0. Then, from time t1 when the tip of the push rod 32 hits the piston top surface 12a (upper end of the plunger 34), the delivery adjusting valve 26 is driven to start the cooling water outflow from the cooling water outlet 24, and the tip of the push rod 32 is moved to the plunger 34. The cooling water outflow from the cooling water outlet 24 is completed at a time t2 when the valve is pushed to the deepest position, in other words, at a time t2 when the distance between the tip position of the push rod 32 and the position of the piston top surface 12a becomes maximum. Here, the period from time t0 to time t2 is a period during which the push rod 32 moves to the plunger 34 side. The period from time t1 to time t2 is a period during which the push rod 32 presses the plunger 34, and is a period during which the cooling water is sent from the cooling water delivery port 24. Further, the distance between the tip position of the push rod 32 and the position of the piston top surface 12a at time t2 corresponds to the amount of cooling water delivered from the cooling water delivery port 24.

  In the example shown in FIG. 10, the control valve 48 is kept closed. Furthermore, the timing t0 when the push rod 32 starts to be fed, and the timing t1 when the push rod 32 hits the plunger 34 are before the compression top dead center TDC, and the timing t2 when the push rod 32 is fed are maximized. The profile of the delivery cam 44 is set so as to coincide with the dead point TDC.

  In the example shown in FIG. 11, as compared with the example shown in FIG. 10, the control valve 48 is switched from the open state to the closed state at time t0 before the compression top dead center TDC. When the control valve 48 is in the open state (before time t0), even if the delivery cam 44 drives the actuator 38, the oil in the oil chamber 37 flows out to the oil outlet 36b through the control valve 48. Thus, since the motion of the actuator 38 is not transmitted to the push rod 32, the push rod 32 is not driven. Then, after the control valve 48 is switched to the closed state (after time t0), the push rod 32 is fed out. In the example shown in FIG. 11, compared with the example shown in FIG. 10, the delivery start time t <b> 1 of the push rod 32 is delayed, and therefore the delivery start time t <b> 1 of the coolant is delayed. Thus, the amount of cooling water delivered is reduced.

  In the example shown in FIG. 12, as compared with the example shown in FIG. 10, the control valve 48 is switched from the closed state to the open state at time t2 before the compression top dead center TDC. After the control valve 48 is switched to the open state (after time t2), the oil in the oil chamber 37 flows out through the control valve 48 to the oil outlet 36b, so that the push rod 32 moves toward the cylinder head 10. Return, cooling water delivery stops. In the example shown in FIG. 12, the cooling water delivery end time t2 is earlier than in the example shown in FIG. 10, so that the cooling water delivery period is shortened and the cooling water delivery amount is reduced.

  In the example shown in FIG. 13, the profile of the delivery cam 44 is set so that the full lift amount of the push rod 32 (actuator 38) is large and the inclination of the lift section becomes steep compared to the example shown in FIG. Yes. Cooling water starts to be delivered by the push rod 32 hitting the plunger 34 at the timing t1 before the compression top dead center TDC, and the push rod 32 continues to press the plunger 34 even after the compression top dead center TDC, thereby cooling. Water delivery continues. Then, at the time t2 after the compression top dead center TDC, the distance between the tip end position of the push rod 32 and the position of the piston top surface 12a is maximized, and the cooling water delivery ends. In the example shown in FIG. 13, compared with the example shown in FIG. 10, the cooling water delivery end time t <b> 2 is delayed, the cooling water delivery period becomes longer, and the push rod 32 feed amount increases to reduce the cooling time. The amount of water delivered increases. During high-load operation of the internal combustion engine, the combustion period becomes longer, and the combustion chamber 13 is exposed to the high-temperature combustion gas 19 until 20 ° after the compression top dead center TDC. Therefore, during high load operation of the internal combustion engine, in order to reduce the heat transfer from the combustion gas 19 to the wall surface of the combustion chamber 13, the cooling water continues to be sent after the compression top dead center TDC as shown in FIG. Increase the amount of cooling water delivered. As shown in FIG. 13, by switching the control valve 48 from the closed state to the open state at the cooling water delivery end timing t2, the push rod 32 is quickly moved toward the cylinder head 10 after the cooling water delivery is finished. Can be returned to. Further, by performing opening / closing control of the control valve 48 as in the examples shown in FIGS. 11 and 12, the cooling water delivery period can be shortened, and the cooling water delivery amount can be reduced.

  As described above, the push cam 32 is moved toward the plunger 34 side by the delivery cam 44 so that the push rod 32 presses the plunger 34 when the piston 12 is positioned near the compression top dead center TDC. Furthermore, by controlling the opening and closing of the control valve 48, the drive control of the push rod 32 (delivery adjustment valve 26) can be performed, and any one of the delivery period and delivery amount of the cooling water from the cooling water delivery port 24 can be performed. More than one can be controlled. However, in the present embodiment, the period during which the push rod 32 is moved toward the plunger 34 and the plunger of the push rod 32 can also be changed by changing the profile of the delivery cam 44 by switching the delivery cam 44 that drives the push rod 32. Any one or more of the movement amounts to the 34 side can be changed, and any one or more of the cooling water delivery period and the delivery amount from the cooling water delivery port 24 can be changed. In addition, about the specific structure for switching the delivery cam 44, since the well-known technique of a variable valve timing mechanism is applicable, description is abbreviate | omitted here.

  Next, a configuration example for supplying cooling water to the water channel 22 will be described. As for the supply of cooling water to the water channel 22, the oil supply method to the piston pin widely used in the current internal combustion engine, that is, the flow path is provided inside each component by the route of crankshaft to connecting rod to piston pin. It is possible to apply the method of providing and sending out oil to the supply of cooling water. However, in this case, it is inevitable that the cooling water leaks from the respective bearing components, and when the crankshaft or the like is lubricated with oil, the cooling water is likely to be mixed with the oil. In order to use this method, it is necessary to add an oil / water separator or lubricate the crankshaft with water. Therefore, in this embodiment, it is preferable to supply cooling water to the water channel 22 from the cylinder head 10 side. Hereinafter, an example of the configuration will be described.

  As shown in FIG. 14, the piston 12 has a cooling water inlet 54 that receives the cooling water supplied to the water channel 22, and a receiving adjustment valve 56 that opens and closes the cooling water inlet 54 in the cylinder axial direction. It is provided facing the head 10. A biasing force to the cylinder head 10 side (one side in the cylinder axial direction) is applied to the receiving adjustment valve 56 by the elastic force of the spring 55. When the receiving adjustment valve 56 is in contact with the seat portion provided in the piston 12 by the urging force of the spring 55, the cooling water receiving port 54 is closed.

  On the other hand, the cylinder head 10 is provided with a water supply nozzle 62 facing the piston 12 in the cylinder axial direction. The water supply nozzle 62 is slidable along the cylinder axis direction with respect to the cylinder head 10. The oil chamber cylinder 66 is fixed to the cylinder head 10 on one side in the cylinder axial direction from the water supply nozzle 62, and the water supply nozzle 62 is biased toward the oil chamber cylinder 66 by the elastic force of the spring 65. It works. Further, an actuator 68 slidable along the cylinder axial direction with respect to the oil chamber cylinder 66 is disposed on one side of the water supply nozzle 62 in the cylinder axial direction. A biasing force is applied to one side in the cylinder axis direction by the force.

  An oil chamber 67 is formed by a space surrounded by the water supply nozzle 62, the actuator 68, and the oil chamber cylinder 66. The check valve 76 allows the oil flow from the oil inlet 66a to the oil chamber 67 and blocks the oil flow from the oil chamber 67 to the oil inlet 66a. The open / close control valve 78 allows or blocks communication between the oil chamber 67 and the oil outlet 66b. When the open / close control valve 78 is closed, the oil flow from the oil chamber 67 to the oil outlet 66b is blocked, and when the open / close control valve 78 is open, the oil from the oil chamber 67 to the oil outlet 66b is blocked. Spillage is allowed. The opening / closing control of the opening / closing control valve 78 here is performed by an electronic control device (not shown). Further, a pressure control valve 79 is provided in parallel with the open / close control valve 78 between the oil chamber 67 and the oil outlet 66b. When the pressure of the oil in the oil chamber 67 is higher than the set pressure, the pressure control valve 79 is opened even when the open / close control valve 78 is closed, so that the oil can flow out from the oil chamber 67 to the oil outlet 66b. Is done. As a result, the pressure of the oil in the oil chamber 67 is kept below the set pressure.

  The rocker arm 71 is connected to the actuator 68 and is supported so as to be swingable around the arm shaft 72. The roller 73 is rotatably supported by the rocker arm 71, and the supply cam 74 is in contact with the roller 73. The rotation axis of the supply cam 74 is integral with the rotation axis of the intake cam (not shown). The supply cam 74 rotates in conjunction with the rotation of the crankshaft, while the crankshaft rotates twice. Rotates once. In conjunction with the rotation of the supply cam 74, the rocker arm 71 swings around the arm shaft 72, and the actuator 68 moves along the cylinder axis direction. When the open / close control valve 78 is closed, the movement of the actuator 68 in the cylinder axial direction is transmitted to the water supply nozzle 62 by the oil pressure in the oil chamber 67, and the water supply nozzle 62 moves along the cylinder axial direction. In this way, the rotational movement of the supply cam 74 accompanying the rotation of the crankshaft is converted into the movement of the water supply nozzle 62 in the cylinder axis direction.

  The water supply nozzle 62 has a pressurizing chamber 83 to which cooling water (high pressure water) is supplied from a cooling water supply source (not shown), a cooling water discharge port 84 for discharging the cooling water supplied to the pressurizing chamber 83, A discharge adjusting valve 86 that opens and closes the cooling water discharge port 84 by facing the receiving adjustment valve 56 in the cylinder axial direction and sliding along the cylinder axial direction is provided. A biasing force to the pressurizing chamber 83 side (one side in the cylinder axial direction) acts on the discharge adjusting valve 86 due to the elastic force of the spring 85, and the acceptance adjusting valve 56 by the pressure of the cooling water in the pressurizing chamber 83. A pressing force to the side (the other side in the cylinder axial direction) acts. The discharge adjustment valve 86 here is an open valve that opens the cooling water discharge port 84 by moving to the reception adjustment valve 56 side and closes the cooling water discharge port 84 by moving to the pressurizing chamber 83 side. The opening / closing control valve 88 allows or blocks communication between the cooling water supply source and the pressurizing chamber 83. When closing the open / close control valve 88, the supply of cooling water from the cooling water supply source to the pressurizing chamber 83 is shut off, so that the urging force of the spring 85 increases the pressing force of the cooling water in the pressurizing chamber 83. Around, the discharge regulating valve 86 closes the cooling water discharge port 84. On the other hand, when the opening / closing control valve 88 is opened, the supply of cooling water from the cooling water supply source to the pressurizing chamber 83 is allowed, so that the pressing force of the cooling water in the pressurizing chamber 83 is applied by the spring 85. The discharge adjustment valve 86 moves to the reception adjustment valve 56 side and opens the cooling water discharge port 84. The opening / closing control of the opening / closing control valve 88 here is performed by an electronic control device (not shown). When cooling water is supplied to the pressurizing chamber 83 from the cooling water supply source, leakage of the cooling water is prevented by the water seal rings 91 and 92 provided in the water supply nozzle 62.

  15 to 19 show the cooling water supply process. First, at the end of the exhaust stroke, as shown in FIG. 15, the water supply nozzle 62 is moved to the piston 12 side (the other side in the cylinder axial direction) by the rotation of the supply cam 74, and the water supply nozzle 62 is moved to the lowest point. Feed it out. Here, the open / close control valve 78 is closed, and the movement of the water supply nozzle 62 follows the movement of the supply cam 74. Thereafter, the piston 12 rises at a faster speed while the water supply nozzle 62 is rising and catches up with the water supply nozzle 62, so that the water supply nozzle 62 and the piston 12 are docked (contacted) as shown in FIG. ) At this time, when the oil chamber 67 is pushed by the water supply nozzle 62 and the pressure of the oil in the oil chamber 67 exceeds the set pressure, the pressure control valve 79 is opened and the oil in the oil chamber 67 flows out. Can reduce the impact of docking. Thereafter, at the time when the piston 12 is positioned near the intake top dead center, the tip of the water supply nozzle 62 contacts the piston top surface 12a with a constant oil pressure. At that time, a seal between the water supply nozzle 62 and the piston 12 is secured by a seal washer 93 provided at the tip of the water supply nozzle 62.

  When the open / close control valve 88 is switched from the closed state to the open state while the water supply nozzle 62 is in contact with the piston 12, the discharge adjustment valve 86 adjusts the reception by the pressure of the cooling water supplied to the pressurizing chamber 83. Move to the valve 56 side. As a result, as shown in FIG. 17, the cooling water discharge port 84 is opened, and the discharge adjustment valve 86 presses the reception adjustment valve 56 so that the reception adjustment valve 56 is separated from the seat portion provided in the piston 12. The cooling water inlet 54 opens. Therefore, the cooling water in the pressurizing chamber 83 is supplied to the water channel 22 through the cooling water discharge port 84 and the cooling water receiving port 54. In this way, the discharge adjusting valve 86 drives the receiving adjustment valve 56 from the cylinder head 10 side to open the cooling water receiving port 54, whereby the cooling water is supplied from the cooling water discharging port 84 to the water channel 22 through the cooling water receiving port 54. Can be supplied. When the open / close control valve 88 is switched from the open state to the closed state, the discharge adjusting valve 86 moves to the pressurizing chamber 83 side, whereby the cooling water discharge port 84 and the cooling water receiving port 54 are closed, and water is supplied from the water supply nozzle 62. The supply of cooling water to the channel 22 is stopped. Thereafter, the piston 12 stops rising at the top dead center and turns downward, and the water supply nozzle 62 continues to rise, so that the water supply nozzle 62 moves away from the piston 12 as shown in FIG. Then, as shown in FIG. 19, the water supply nozzle 62 is stored in the cylinder head 10. The actuator 68 rises according to the rotation of the supply cam 74, and the oil pressure in the oil chamber 67 decreases along the way, so that oil is supplied to the oil chamber 67 via the check valve 76.

  FIG. 20 shows an arrangement example of the push rod 32 and the water supply nozzle 62. In the example shown in FIG. 20, the push rod 32 is disposed between the two exhaust valves EX, and the water supply nozzle 62 is disposed between the two intake valves IN. That is, the push rod 32 is disposed at a position closer to the exhaust valve EX than the intake valve IN, and the water supply nozzle 62 is disposed at a position closer to the intake valve IN than the exhaust valve EX. The region between the exhaust valves EX becomes hotter than the region between the intake valves IN due to the exhaust gas passing through the exhaust port during the exhaust stroke. Therefore, in order to prevent the water supply nozzle 62 that supplies the cooling water to the water channel 22 from being exposed to high heat, the water supply nozzle 62 is disposed in a region between the intake valves IN. On the other hand, since the push rod 32 that drives the delivery adjusting valve 26 does not cause a problem even if it is exposed to high heat, the push rod 32 is disposed in a region between the exhaust valves EX.

  In addition, when the cooling water in the water channel 22 boils, the pressure of the water channel 22 becomes high and it becomes difficult to supply the cooling water to the water channel 22, or the plunger 34 presses the cooling water in the water channel 22. Even so, problems such as a decrease in the amount of cooling water delivered due to absorption by boiling steam occur. Therefore, in this embodiment, as shown in FIG. 21, in order to detect the presence or absence of boiling of the cooling water in the water channel 22, a cooling water supply source (not shown) and the water supply nozzle 62 (pressure chamber 83) are provided. A water pressure sensor 96 is provided in the water supply channel 94 to be connected, and the pressure of the cooling water in the water supply channel 94 is detected. When the electronic control device supplies the cooling water from the water supply nozzle 62 to the water channel 22, the electronic control device is based on the pressure change of the cooling water in the water supply passage 94 detected by the water pressure sensor 96. It is determined whether the cooling water inside is boiling.

  More specifically, if the cooling water in the water channel 22 does not boil, the pressure of the cooling water in the water channel 22 is lower than the pressure of the cooling water from the cooling water supply source. The pressure of the cooling water in the water supply flow path 94 (detected pressure of the water pressure sensor 96) is instant at the moment when the pressurizing chamber 83 is connected to the water channel 22 by opening the discharge regulating valve 86 and driving the receiving regulating valve 56. descend. On the other hand, when boiling occurs in the cooling water in the water channel 22 and the pressure is increased, the decrease in the detected pressure of the water pressure sensor 96 at the moment when the pressurizing chamber 83 is connected to the water channel 22 decreases. The electronic control unit determines that the cooling water in the water channel 22 is boiling when the decrease width of the detection pressure of the water pressure sensor 96 when the opening / closing control valve 88 is opened is equal to or less than a predetermined value.

  If the electronic control unit determines that the cooling water in the water channel 22 is boiling, the electronic control unit decreases the fuel injection amount into the cylinder 11 or the fuel injection into the cylinder 11 in the cycle immediately thereafter. Is stopped, the piston 12 is cooled, and the temperature of the cooling water in the water channel 22 is lowered. Thereby, boiling of the cooling water in the water channel 22 is suppressed. Further, when the electronic control unit determines that the cooling water in the water channel 22 is boiling, the push rod 32 so as to increase the amount of cooling water delivered from the cooling water delivery port 24 in the cycle immediately after that. Also by performing the drive control, the piston 12 can be cooled and the temperature in the water channel 22 can be lowered. Further, the pressure of the cooling water in the water channel 22 is set as high as possible so that boiling does not occur in the water channel 22. If a large amount of cooling water in the water channel 22 boils, the water channel 22 may be damaged, but the delivery adjustment valve 26 automatically opens when the pressure in the water channel 22 exceeds a certain value. Therefore, even if a large amount of boiling occurs in the water channel 22, the water channel 22 is not damaged by the steam.

  Next, another configuration example of this embodiment will be described. 22 and 23 show an example in which a plurality of needle valves that are movable along the cylinder axial direction are provided as the delivery adjusting valve 26. The urging force by the spring 28 and the pressing force by the cooling water in the water channel 22 act on the delivery adjusting valve (needle valve) 26 in opposite directions. When the pressure of the cooling water in the water channel 22 decreases and the urging force by the spring 28 exceeds the pressing force by the cooling water in the water channel 22, the needle valve 26 is moved in the cylinder axial direction as shown in FIG. By being urged to one side (the upper side in the figure) and coming into contact with the seat portion 23 provided on the piston 12, the communication between the water channel 22 and the cooling water delivery port 24 is blocked. On the other hand, when the pressure of the cooling water in the water channel 22 rises and the pressing force by the cooling water in the water channel 22 exceeds the urging force of the spring 28, as shown in FIG. The water channel 22 and the coolant outlet 24 are allowed to communicate with each other by moving to the other side (the lower side in the figure) in the cylinder axial direction. 22 and 23, similarly to the configuration examples shown in FIGS. 1 and 2, when the plunger 34 is pressed by the push rod 32, the delivery adjustment valve (needle valve) 26 is driven and the water channel 22. The cooling water delivery port 24 can be communicated.

  In the above description of the embodiment, the case where the present invention is applied to a diesel engine has been described. However, the present invention can also be applied to an internal combustion engine such as a direct injection gasoline engine.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

1 is a diagram showing a schematic configuration of an internal combustion engine according to an embodiment of the present invention. 1 is a diagram showing a schematic configuration of an internal combustion engine according to an embodiment of the present invention. 1 is a diagram showing a schematic configuration of an internal combustion engine according to an embodiment of the present invention. It is a figure which shows the structural example for driving a delivery adjustment valve. It is a figure explaining operation | movement of the internal combustion engine which concerns on embodiment of this invention. It is a figure explaining operation | movement of the internal combustion engine which concerns on embodiment of this invention. It is a figure explaining operation | movement of the internal combustion engine which concerns on embodiment of this invention. It is a figure explaining operation | movement of the internal combustion engine which concerns on embodiment of this invention. It is a figure explaining the effect of the internal combustion engine which concerns on embodiment of this invention. It is a figure explaining an example of control of the sending period and the sending amount of the cooling water from a cooling water sending outlet. It is a figure explaining an example of control of the sending period and the sending amount of the cooling water from a cooling water sending outlet. It is a figure explaining an example of control of the sending period and the sending amount of the cooling water from a cooling water sending outlet. It is a figure explaining an example of control of the sending period and the sending amount of the cooling water from a cooling water sending outlet. It is a figure which shows the structural example for supplying cooling water to a water channel. It is a figure explaining the operation | movement which supplies a cooling water to a water channel from a water supply nozzle. It is a figure explaining the operation | movement which supplies a cooling water to a water channel from a water supply nozzle. It is a figure explaining the operation | movement which supplies a cooling water to a water channel from a water supply nozzle. It is a figure explaining the operation | movement which supplies a cooling water to a water channel from a water supply nozzle. It is a figure explaining the operation | movement which supplies a cooling water to a water channel from a water supply nozzle. It is a figure which shows the example of arrangement | positioning of a push rod and a water supply nozzle. It is a figure which shows the structural example for detecting the presence or absence of the boiling of the cooling water in a water channel. It is a figure which shows the other schematic structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the internal combustion engine which concerns on embodiment of this invention.

Explanation of symbols

  9 Cylinder block, 10 Cylinder head, 11 Cylinder, 12 Piston, 12a Top surface, 12b Recessed part, 13 Combustion chamber, 14 Fuel injection valve, 16 Water film, 17 Water vapor layer, 18 Flame, 19 Combustion gas, 22 Water channel, 24 Cooling water delivery port, 26 Delivery adjustment valve, 32 Push rod, 34 Plunger, 37, 67 Oil chamber, 38, 68 Actuator, 41, 71 Rocker arm, 42, 72 Arm shaft, 43, 73 Roller, 44 Delivery cam , 46, 76 Check valve, 48 Control valve, 54 Cooling water inlet, 56 Receipt adjustment valve, 62 Water supply nozzle, 74 Supply cam, 78, 88 Open / close control valve, 79 Pressure control valve, 83 Pressure chamber, 86 Discharge adjustment valve, 94 water supply flow path, 96 water pressure sensor.

Claims (18)

An internal combustion engine that injects fuel into a cylinder in which a piston reciprocates,
Inside the piston, there are a coolant channel to which coolant is supplied, a coolant outlet for sending the coolant in the coolant channel to the top surface of the piston, a coolant channel and a coolant outlet. A delivery regulating valve that allows or blocks communication, and
A coolant supply means for supplying the coolant to the coolant flow path;
When the fuel is burned in the cylinder, the coolant is driven from the coolant outlet to the top surface of the piston by driving the delivery adjusting valve to connect the coolant passage and the coolant outlet. A delivery adjusting valve driving means for feeding to
An internal combustion engine comprising: The internal combustion engine according to claim 1,
The delivery adjustment valve is a valve that allows communication between the coolant flow path and the coolant delivery port according to an increase in the pressure of the coolant in the coolant flow path.
The delivery adjusting valve driving means is
A movable member disposed on the cylinder head facing the piston in the cylinder axial direction and capable of moving along the cylinder axial direction;
A pressurizing member disposed on the piston facing the movable member in the cylinder axis direction, and pressurizing the coolant in the coolant flow path by being pressed by the movable member;
A movable member driving means that moves the movable member to the pressure member side and presses the pressure member by the movable member, thereby driving the delivery adjustment valve to connect the coolant flow path and the coolant delivery port;
Including an internal combustion engine. An internal combustion engine according to claim 2,
The movable member driving means adjusts at least one of the period during which the movable member is moved to the pressure member side and the amount of movement of the movable member to the pressure member side, so that the coolant from the coolant delivery port is adjusted. An internal combustion engine that adjusts at least one of a delivery period and a delivery amount of the engine. The internal combustion engine according to claim 2 or 3,
The movable member driving means is an internal combustion engine that moves the movable member toward the pressure member so that the movable member presses the pressure member when the piston is positioned near the compression top dead center. The internal combustion engine according to any one of claims 2 to 4,
The movable member drive means is an internal combustion engine including a delivery cam mechanism for converting a rotational motion accompanying the rotation of the crankshaft into a motion of the movable member in the cylinder axial direction. The internal combustion engine according to any one of claims 2 to 5,
The internal combustion engine, wherein the movable member is disposed at a position closer to the exhaust valve than to the intake valve. The internal combustion engine according to any one of claims 1 to 6,
The piston is provided with a coolant inlet that receives the coolant supplied to the coolant channel, and a receiving adjustment valve that opens and closes the coolant inlet, facing the cylinder head in the cylinder axial direction.
The coolant supply means is an internal combustion engine that is a means for driving the reception adjusting valve from the cylinder head side to open the coolant reception inlet and supplying the coolant to the coolant flow path. The internal combustion engine according to claim 7,
The coolant supply means
A coolant supply nozzle disposed in the cylinder head facing the piston in the cylinder axial direction, the coolant discharge port for discharging the coolant, and the receiving adjustment valve side facing the receiving adjustment valve in the cylinder axial direction A discharge adjusting valve that opens the coolant discharge port by moving to, a coolant supply nozzle provided with,
Nozzle driving means for moving the coolant supply nozzle to the piston side and contacting the piston;
While the coolant supply nozzle is in contact with the piston, move the discharge adjustment valve to the acceptance adjustment valve side, drive the acceptance adjustment valve with the discharge adjustment valve, and open the coolant acceptance port. A discharge regulating valve driving means for supplying the coolant to the coolant channel from the outlet through the coolant inlet;
Including an internal combustion engine. An internal combustion engine according to claim 8,
The nozzle drive means is an internal combustion engine that moves the coolant supply nozzle to the piston side so that the coolant supply nozzle contacts the piston when the piston is located near the intake top dead center. An internal combustion engine according to claim 8 or 9, wherein
The nozzle driving means is an internal combustion engine including a supply cam mechanism for converting a rotational movement accompanying the rotation of the crankshaft into a movement of the coolant supply nozzle in the cylinder axial direction. The internal combustion engine according to any one of claims 8 to 10,
The internal combustion engine, wherein the coolant supply nozzle is disposed at a position closer to the intake valve than to the exhaust valve. The internal combustion engine according to any one of claims 1 to 11,
A hollow is formed in the center of the piston top surface,
An internal combustion engine in which the coolant flow path is provided around the recess. An internal combustion engine according to claim 12,
The coolant delivery port is an internal combustion engine that delivers coolant to the edge of the recess on the top surface of the piston. An internal combustion engine according to claim 12 or 13,
The cooling liquid delivery port is an internal combustion engine that sends out the cooling liquid to the outside of the recess in the piston top surface. The internal combustion engine according to any one of claims 1 to 14,
An internal combustion engine comprising boiling determination means for determining whether or not the coolant in the coolant flow path is boiling. The internal combustion engine according to claim 15,
An internal combustion engine that reduces the fuel injection amount into the cylinder or stops the fuel injection into the cylinder when it is determined by the boiling determination means that the coolant in the coolant channel is boiling. The internal combustion engine according to claim 15 or 16,
An internal combustion engine that increases the amount of coolant delivered from the coolant outlet when it is judged by the boiling judgment means that the coolant in the coolant channel is boiling. The internal combustion engine according to any one of claims 15 to 17,
When the cooling liquid is supplied from the cooling liquid supply means to the cooling liquid flow path, the boiling determination means causes the cooling liquid in the cooling liquid flow path to boil based on the change in pressure of the cooling liquid in the cooling liquid supply means. An internal combustion engine that determines whether or not.

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