JP2020045811A - Internal combustion engine - Google Patents

Abstract

To restrain temperature of a fuel pump from excessively increasing.SOLUTION: An internal combustion engine 10 comprises a fuel pump 40 driven by rotation power of a crank shaft 100 and emitting fuel, and a water pump 50 for pressure feeding cooling water flowing from a radiator 58 inside the internal combustion engine body 20. The fuel pump 40 and the water pump 50 are arranged adjacent to each other, and an air gap is provided between the fuel pump 40 and the water pump 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine.

  In the internal combustion engine disclosed in Patent Document 1, a cylinder head on which an intake valve and an exhaust valve are mounted is disposed at an upper end of a cylinder block. A camshaft that drives an intake valve and an exhaust valve is disposed inside the cylinder head. The rotation power (rotation torque) of the crankshaft is transmitted to these camshafts via a timing chain or the like.

  One of the camshafts has a cylindrical shape, and a pump drive shaft is penetrated inside the camshaft. The pump drive shaft is rotatable relative to the camshaft. The driving force of the crankshaft is transmitted to the pump driving shaft via a pump driving chain. One end of the pump drive shaft is connected via a cam mechanism to a fuel pump for supplying fuel to the fuel injection valve.

JP 2010-112256 A

  In general, when the temperature of the fuel pump becomes excessively high, the fuel in the fuel pump is vaporized, bubbles are accumulated in the fuel pump, and a discharge failure may occur in the fuel pump. Therefore, the temperature of the fuel pump needs to be appropriate. In the internal combustion engine of Patent Literature 1, no consideration is given to the temperature management of the fuel pump, and there is room for further improvement.

  An internal combustion engine for solving the above problems includes a cylinder block, a cylinder head fixed to an upper end of the cylinder block, an oil pan fixed to a lower end of the cylinder block, and a crank. An internal combustion engine including a fuel pump driven by the rotational power of a shaft to discharge fuel, and a water pump for pumping cooling water for cooling the internal combustion engine main body, wherein the water pump is provided by a radiator. The cooling water flowing out is pressure-fed into the internal combustion engine main body, and the fuel pump and the water pump are arranged adjacent to each other, and a gap is provided between the fuel pump and the water pump. I have.

  In the above configuration, since the cooling water from the radiator is supplied to the water pump, the temperature of the water pump is relatively low. The fuel pump is adjacent to the relatively low-temperature water pump without any intervening other members. For this reason, the fuel pump is easily cooled by the water pump, and the temperature of the fuel pump can be prevented from rising excessively.

  The internal combustion engine includes a control unit that controls a flow rate of the cooling water pumped from the water pump, and the control unit is configured to control the water pump when the temperature of the fuel discharged from the fuel pump is higher than when the temperature is not so. The flow rate of the cooling water pumped from above may be increased.

  According to the above configuration, when the temperature of the fuel discharged from the fuel pump is high, a large amount of cooled water is supplied from the radiator to the water pump, and the temperature of the water pump is easily maintained at a relatively low temperature. Therefore, even in a situation where the temperature of the fuel pump can be high, the fuel pump can be cooled by the water pump and the temperature of the fuel pump can be easily maintained in an appropriate range.

FIG. 2 is a schematic view of the internal combustion engine viewed from one side in the axial direction of the crankshaft. FIG. 2 is a schematic view of the internal combustion engine viewed from one side in a width direction.

Hereinafter, an embodiment of an internal combustion engine will be described with reference to the drawings.
First, a schematic configuration of the internal combustion engine will be described. As shown in FIG. 1, the internal combustion engine main body 20 of the internal combustion engine 10 includes a substantially rectangular parallelepiped cylinder block 22 as a whole. A plurality of (not shown, four in this embodiment) cylinders are defined inside the cylinder block 22, and fuel is burned inside these cylinders.

  A substantially rectangular box-shaped oil pan 24 is fixed to the lower end surface of the cylinder block 22 as a whole. The oil pan 24 is open upward. At the bottom of the oil pan 24, oil for lubricating various parts of the internal combustion engine body 20 is stored. The oil pan 24 may be divided into a case forming the upper part of the oil pan 24 and a case forming the lower part of the oil pan 24.

  As shown in FIG. 2, a crankshaft 100 extending in one direction as a whole is disposed between a lower end surface of the cylinder block 22 and an upper end surface of the oil pan 24. The shaft main body 100a of the crankshaft 100 includes a crank journal that forms the axis of the shaft main body 100a, a crankpin that is connected to a piston (connecting rod), and a crank arm that connects these. And extends in one direction. In FIG. 2, only a part of one side in the axial direction of the shaft main body 100a is shown, and most of the other side in the axial direction is omitted. The shaft body 100a is rotatably supported between a lower end surface of the cylinder block 22 and a crank cap attached to the cylinder block 22. The shaft main body 100a penetrates the cylinder block 22 and the oil pan 24. Therefore, a part of the shaft main body 100 a on one side in the axial direction projects outside the cylinder block 22 and the oil pan 24.

  As shown in FIG. 1, a substantially rectangular parallelepiped cylinder head 26 is fixed to the upper end surface of the cylinder block 22. As shown in FIG. 2, inside the cylinder head 26, an intake port 26a for introducing intake air to each cylinder is defined for each cylinder. When the direction perpendicular to both the vertical direction of the internal combustion engine 10 and the axial direction of the crankshaft 100 is defined as the width direction, each intake port 26a is open on one side surface of the cylinder head 26 in the width direction. Further, inside the cylinder head 26, an exhaust port for discharging exhaust gas from each cylinder to the outside is defined for each cylinder. Although not shown, the cylinder head 26 is provided with an intake valve for opening and closing each intake port 26a and an exhaust valve for opening and closing each exhaust port for each cylinder.

  On the side surface on one side in the width direction of the cylinder head 26, a first mounting hole 26b for each cylinder is opened. Each first mounting hole 26b is open above each intake port 26a. Each first mounting hole 26b communicates with each intake port 26a inside the cylinder head 26. A port injection valve (not shown) for each cylinder that injects fuel into each intake port 26a is inserted into each first mounting hole 26b. A second mounting hole 26c for each cylinder is opened on one side surface in the width direction of the cylinder head 26. Each second mounting hole 26c is open below each intake port 26a. Each second mounting hole 26 c communicates with each cylinder of the cylinder block 22 inside the cylinder head 26. In-cylinder injection valves (not shown) for each cylinder that injects fuel into each cylinder are inserted into each second mounting hole 26c.

  Although not shown in detail, the port injection valve for each cylinder is connected to a low-pressure delivery pipe that stores a fixed amount of fuel. Further, as shown in FIG. 1, the in-cylinder injection valve for each cylinder is connected to a high pressure delivery pipe 33 for storing a fixed amount of fuel. The high-pressure delivery pipe 33 is provided with a temperature sensor 34 for detecting the temperature of the fuel in the high-pressure delivery pipe 33. 2, illustration of the high-pressure delivery pipe 33 and the temperature sensor 34 is omitted.

  As shown in FIG. 1, a substantially rectangular box-shaped cylinder head cover 28 is fixed to the upper end surface of the cylinder head 26 as a whole. The cylinder head cover 28 is open downward, and covers the cylinder head 26 from above.

  A side surface of the oil pan 24, the cylinder block 22, the cylinder head 26, and the cylinder head cover 28 on one side in the axial direction of the crankshaft 100 is covered with a vertically long chain case 29. The chain case 29 covers most of the side surfaces of the oil pan 24, the cylinder block 22, the cylinder head 26, and the cylinder head cover 28. Between the chain case 29, the oil pan 24, the cylinder block 22, the cylinder head 26, and the cylinder head cover 28, a chain chamber R for accommodating a camshaft drive chain 81 and a fuel pump drive chain 83 described later is defined. Have been.

  As described above, in the present embodiment, the oil pan 24, the cylinder block 22, the cylinder head 26, the cylinder head cover 28, and the chain case 29 constitute the internal combustion engine body 20. The direction in which the oil pan 24, the cylinder block 22, the cylinder head 26, and the cylinder head cover 28 are stacked corresponds to the vertical direction of the internal combustion engine 10.

  In a space defined by the cylinder head 26 and the cylinder head cover 28, an intake camshaft 30 for driving an intake valve is arranged. As shown in FIG. 2, the intake camshaft 30 includes a shaft main body 30a extending in the axial direction of the crankshaft 100. The shaft main body 30a is rotatably supported between the cylinder head 26 and a cam cap (not shown) attached to the cylinder head 26. A cam mechanism (not shown) for driving the intake valve is mounted in the shaft main body 30a in the extending direction thereof. The shaft main body 30a penetrates the cylinder head 26. Therefore, a part of the shaft main body 30 a on one side in the axial direction of the crankshaft 100 protrudes outside the cylinder head 26. In FIG. 2, only a part of the shaft body 30a on one side in the axial direction is shown, and most of the other side in the axial direction is not shown.

  As shown in FIG. 1, an exhaust camshaft 31 for driving an exhaust valve is disposed at a position adjacent to the intake camshaft 30 in a space defined by the cylinder head 26 and the cylinder head cover 28. The exhaust camshaft 31 includes a shaft main body 31 a extending in the axial direction of the crankshaft 100. The shaft main body 31a is rotatably supported between the cylinder head 26 and a cam cap (not shown) attached to the cylinder head 26. A cam mechanism (not shown) for driving the exhaust valve is mounted in the shaft main body 31a in the extending direction thereof. The shaft main body 31a penetrates the cylinder head 26. Therefore, a part of the shaft main body 31 a on one side in the axial direction of the crankshaft 100 projects outside the cylinder head 26.

  As shown in FIG. 2, in the internal combustion engine 10, a first crank sprocket 100 b which is a gear is attached to a portion of the shaft main body 100 a of the crankshaft 100 which protrudes outside the cylinder block 22 and the oil pan 24. ing. A second crank sprocket 100c, which is a gear, is attached to a portion of the shaft main body 100a on the other axial side of the crankshaft 100 than the first crank sprocket 100b. The first crank sprocket 100b and the second crank sprocket 100c are located in the chain chamber R. The diameter of the first crank sprocket 100b and the diameter of the second crank sprocket 100c are the same. The first crank sprocket 100b and the second crank sprocket 100c rotate integrally with the shaft main body 100a. In this embodiment, the first crank sprocket 100b and the second crank sprocket 100c constitute a part of the crankshaft 100. 1 and 2, the teeth of the first crank sprocket 100b and the second crank sprocket 100c are omitted, and these are shown in a disk shape.

  As shown in FIG. 2, in the internal combustion engine 10, at one end of the shaft main body 30 a of the intake camshaft 30 in the axial direction of the crankshaft 100, that is, at a portion protruding from the cylinder head 26 of the shaft main body 30 a, An intake cam sprocket 30b, which is a gear, is attached. The intake cam sprocket 30b is located in the chain chamber R. The diameter of the intake cam sprocket 30b is larger than the diameter of the second crank sprocket 100c of the crankshaft 100. The intake cam sprocket 30b rotates integrally with the shaft body 30a.

  In the internal combustion engine 10, an end portion of the shaft body 31a of the exhaust camshaft 31 on one axial side of the crankshaft 100, that is, a portion of the shaft body 31a protruding from the cylinder head 26 is provided with an exhaust cam sprocket 31b as a gear. Is attached. The exhaust cam sprocket 31b is located in the chain chamber R. The diameter of the exhaust cam sprocket 31b is the same as the diameter of the intake cam sprocket 30b. The exhaust cam sprocket 31b rotates integrally with the shaft body 31a. 1 and 2, the teeth of the intake cam sprocket 30b and the exhaust cam sprocket 31b are omitted, and these are shown in a disk shape.

  As shown in FIG. 1, a camshaft drive chain 81 is wound around a second crank sprocket 100c of the crankshaft 100, an intake cam sprocket 30b of the intake camshaft 30, and an exhaust cam sprocket 31b of the exhaust camshaft 31. Have been. The camshaft drive chain 81 transmits the rotational power (rotational torque) of the crankshaft 100 to the intake camshaft 30 and the exhaust camshaft 31. That is, when the crankshaft 100 rotates, the intake camshaft 30 and the exhaust camshaft 31 rotate via the intake cam sprocket 30b and the exhaust cam sprocket 31b. Since the second crank sprocket 100c, the intake cam sprocket 30b, and the exhaust cam sprocket 31b are located in the chain chamber R, the camshaft drive chain 81 is located in the chain chamber R. In FIG. 2, illustration of the camshaft drive chain 81 is omitted.

  As shown in FIG. 1, a water pump 50 for pumping cooling water to a water jacket defined in the cylinder block 22 or the cylinder head 26 is fixed to one side surface in the width direction of the internal combustion engine body 20. The water pump 50 is an electric pump. As shown in FIG. 2, the water pump 50 is generally located at a position lower than the center of the cylinder block 22 in the vertical direction. The water pump 50 is located on one side of the center of the crankshaft 100 in the cylinder block 22 in the axial direction.

  The water pump 50 has a substantially rectangular parallelepiped main body 51 as a whole. The main body 51 is arranged so that its axial direction substantially coincides with the axial direction of the crankshaft 100. A part of the main body 51 on one side in the axial direction of the crankshaft 100 protrudes to one side in the axial direction from a side surface of the cylinder block 22 on one side in the axial direction of the crankshaft 100. An electric motor is housed inside the main body 51.

  A flow path forming portion 52 extends upward from a portion of the main body portion 51 on the other side in the axial direction of the crankshaft 100. The flow path of the cooling water is defined inside the flow path forming section 52. A lower part of the flow path forming part 52 houses an impeller that rotates integrally with the electric motor across the main body part 51. In the water pump 50, when the electric motor rotates, the impeller rotates and the cooling water flows upward in the flow path forming portion 52.

  A cooling water passage 55 for supplying cooling water to a flow channel inside the flow channel forming portion 52 is connected to the flow channel forming portion 52 of the water pump 50. An end of the cooling water passage 55 opposite to the water pump 50 is connected to a radiator 58. The radiator 58 is supplied with cooling water heated by the water jacket of the cylinder block 22 and the cylinder head 26. The radiator 58 cools the cooling water by heat exchange with the outside air. The radiator 58 is located in an engine room of a vehicle in which the internal combustion engine 10 is mounted. In FIG. 1, illustration of the radiator 58 is omitted.

  As shown in FIG. 1, a fuel pump 40 that supplies fuel to the in-cylinder injection valve is attached to the cylinder block 22. The fuel pump 40 is located above the crankshaft 100. The housing 41 of the fuel pump 40 has a columnar shape as a whole. The housing 41 is fixed to a portion of the cylinder block 22 on one side in the axial direction of the crankshaft 100 exposed from the chain case 29 via a bracket (not shown). The housing 41 is arranged obliquely so that its central axis intersects both the vertical direction and the width direction. Further, the housing 41 is arranged so that the lower end faces the crankshaft 100 side. Most of the housing 41 projects to one side in the width direction from a side surface of the cylinder block 22 on one side in the width direction.

  A cylindrical inflow port 41 a protrudes from the outer peripheral surface of the housing 41. The inside of the inflow port 41a communicates with the inside of the housing 41. Although not shown in detail, a fuel supply passage extending from the inside of the fuel tank is connected to the inflow port 41a. A cylindrical outflow port 41b protrudes from the outer peripheral surface of the housing 41. The inside of the outflow port 41b communicates with the inside of the housing 41. Although not shown in detail, a fuel supply passage connected to the high-pressure delivery pipe 33 is connected to the outflow port 41b.

  In the housing 41, a cylindrical lifter 42 is housed. The lifter 42 protrudes from a lower end surface of the housing 41. The lifter 42 is capable of reciprocating within the housing 41 in the direction of its central axis. A portion of the lifter 42 opposite to the housing 41 penetrates the chain case 29. A part of the lifter 42 on the side opposite to the housing 41 is located in the chain chamber R.

  An elliptical cam 43 in plan view is in contact with an end edge of the lifter 42 opposite to the housing 41. The drive shaft 44 penetrates the cam 43 in the axial direction of the crankshaft 100. The cam 43 rotates integrally with the drive shaft 44.

  As shown in FIG. 2, a fuel pump sprocket 45, which is a gear, is attached to one end of the drive shaft 44 in the axial direction of the crankshaft 100. The diameter of the fuel pump sprocket 45 is smaller than the diameter of the first crank sprocket 100b of the crankshaft 100. The fuel pump sprocket 45 is located at the same position as the first crank sprocket 100b in the axial direction of the crankshaft 100. The fuel pump sprocket 45 rotates integrally with the drive shaft 44. 1 and 2, the teeth of the fuel pump sprocket 45 are omitted, and the fuel pump sprocket 45 is illustrated in a disk shape.

  As shown in FIG. 1, a fuel pump drive chain 83 is wound around a first crank sprocket 100b of the crankshaft 100 and a fuel pump sprocket 45 of the fuel pump 40. The fuel pump drive chain 83 transmits the rotational power of the crankshaft 100 to the fuel pump 40. That is, when the crankshaft 100 rotates, the drive shaft 44 of the fuel pump 40 rotates via the fuel pump sprocket 45. When the drive shaft 44 rotates, the cam 43 rotates together with the drive shaft 44. As a result, the lifter 42 reciprocates in the housing 41. Then, fuel is supplied from the housing 41 to the high-pressure delivery pipe 33. As described above, the fuel pump 40 is drivingly connected to the crankshaft 100, and is driven by the rotational power of the crankshaft 100. Since the first crank sprocket 100b and the fuel pump sprocket 45 are located in the chain chamber R, the fuel pump drive chain 83 is located in the chain chamber R. In FIG. 2, illustration of the fuel pump drive chain 83 is omitted.

Next, the mounting position of the fuel pump 40 will be described in detail.
As shown in FIG. 2, the housing 41 of the fuel pump 40 is located at a position overlapping the main body 51 of the water pump 50 in the axial direction of the crankshaft 100. In this embodiment, the housing 41 of the fuel pump 40 is located at a position overlapping with a portion of the main body 51 of the water pump 50 that protrudes from one surface of the cylinder block 22 in the axial direction. As shown in FIG. 1, the housing 41 of the fuel pump 40 is disposed adjacent to the main body 51 of the water pump 50 on the other side and upper side in the width direction of the internal combustion engine 10. A gap is provided between the housing 41 of the fuel pump 40 and the main body 51 of the water pump 50. In other words, no other member is interposed between the housing 41 of the fuel pump 40 and the main body 51 of the water pump 50, and the two are directly adjacent to each other. The inflow port 41 a protruding from the housing 41 of the fuel pump 40 protrudes from the housing 41 toward the main body 51 of the water pump 50.

  A part of the upper side of the housing 41 of the fuel pump 40 is located at a position overlapping the flow path forming portion 52 of the water pump 50 in the vertical direction and the width direction of the internal combustion engine 10. That is, the upper part of the housing 41 of the fuel pump 40 is adjacent to the flow path forming portion 52 of the water pump 50 in the axial direction of the crankshaft 100. A gap is formed between a part of the upper side of the housing 41 of the fuel pump 40 and the flow path forming portion 52 of the water pump 50. In other words, there is no other member between the upper part of the housing 41 of the fuel pump 40 and the flow path forming portion 52 of the water pump 50, and the two are directly adjacent to each other.

  The operation of the electric motor in the water pump 50 is controlled by the electronic control unit 12 mounted on the internal combustion engine 10. The electronic control unit 12 is a computer including a nonvolatile ROM in which various programs (software) are stored, a volatile RAM in which data is temporarily stored when executing the programs, and the like. A signal from a temperature sensor 34 that detects the temperature FT of the fuel in the high-pressure delivery pipe 33 is input to the electronic control unit 12. The electronic control unit 12 receives a signal from a water temperature sensor 36 that detects a water temperature WT near the outlet of the water jacket (the outlet of the cooling water from the internal combustion engine body 20). Further, a signal from a crank angle sensor 35 for detecting the engine speed NE is input to the electronic control unit 12. Signals from other sensors attached to various parts of the internal combustion engine 10 are also input to the electronic control unit 12.

  The electronic control unit 12 controls the rotation speed of the electric motor by controlling the voltage applied to the electric motor. Then, as the rotation speed of the electric motor changes, the flow rate of the cooling water pumped from the water pump 50 changes. Specifically, as the rotation speed of the electric motor increases, the flow rate of the cooling water pumped from the water pump 50 increases. As described above, the electronic control unit 12 functions as a control unit that controls the flow rate of the cooling water pumped from the water pump.

  The electronic control unit 12 calculates a target rotation speed of the electric motor at predetermined intervals. Then, the electronic control unit 12 controls the electric motor such that the actually measured value of the rotation speed of the electric motor becomes the calculated target rotation speed. When calculating the target rotation speed of the electric motor, the electronic control unit 12 first calculates the basic value of the target rotation speed of the electric motor based on the engine operating state such as the water temperature WT near the outlet of the water jacket and the engine rotation speed NE. Is calculated. Then, the electronic control unit 12 adds a correction value corresponding to the temperature of the fuel discharged from the fuel pump 40 to the basic value. The electronic control unit 12 previously stores a map indicating the relationship between the temperature of the fuel and the correction value. In this map, the correction value increases as the temperature of the fuel increases. Therefore, the electronic control unit 12 corrects the basic value so that the higher the temperature of the fuel, the higher the rotation speed of the electric motor. That is, the electronic control unit 12 controls the water pump 50 so that the flow rate of the cooling water pumped from the water pump 50 is higher when the fuel temperature is higher than when the fuel temperature is not higher than the same basic value. I do. In this embodiment, the electronic control unit 12 treats the temperature FT of the fuel detected by the temperature sensor 34 as the temperature of the fuel discharged by the fuel pump 40.

Next, the operation and effect of the present embodiment will be described.
As shown in FIG. 2, the cooling water circulates inside and outside the internal combustion engine body 20. That is, the cooling water cooled by the radiator 58 flows into the water pump 50 from the radiator 58 and is pressure-fed from the water pump 50 to a water jacket such as the cylinder block 22. Then, the cooling water flows out of the water jacket such as the cylinder block 22 and is returned to the radiator 58.

  As described above, since the cooling water from the radiator 58 is supplied to the water pump 50, the temperature of the water pump 50 is relatively low. The housing 41 of the fuel pump 40 is adjacent to the relatively low-temperature water pump 50 without any intervening members. Specifically, no other member is interposed between the housing 41 of the fuel pump 40 and the main body 51 of the water pump 50, and the two are directly adjacent to each other. Further, no other member is interposed between the upper part of the housing 41 of the fuel pump 40 and the flow path forming portion 52 of the water pump 50, and both are directly adjacent to each other. As described above, since the housing 41 of the fuel pump 40 is disposed near the water pump 50 and no other member is interposed between the housing 41 of the fuel pump 40 and the water pump 50, The housing 41 of the pump 40 is easily cooled by the water pump 50. Therefore, it is possible to suppress the temperature of the housing 41 of the fuel pump 40 from excessively increasing.

  Further, as described above, since the housing 41 of the fuel pump 40 is located at a position where it can be easily cooled by the water pump 50, the inflow port 41a located around the housing 41 and the fuel supply passage connected to the inflow port 41a. Is easily cooled by the water pump 50. Therefore, it is possible to suppress the temperature of the inflow port 41a and the end of the fuel supply passage from excessively rising. Similarly, the outflow port 41b located around the housing 41 and the end of the fuel supply passage connected to the outflow port 41b are also easily cooled by the water pump 50. Therefore, it is possible to prevent the temperature of the outflow port 41b and the end of the fuel supply passage from excessively rising.

  In addition, as described above, the inflow port 41a protrudes toward the water pump 50. That is, the inflow port 41a faces the water pump 50 side. Therefore, the inflow port 41a is more likely to be cooled by the water pump 50 than when the inflow port 41a faces the opposite side to the water pump 50. Since the inflow port 41a is easily cooled by the water pump 50, the fuel in a stage before flowing into the housing 41 of the fuel pump 40, that is, the fuel before being compressed in the housing 41 of the fuel pump 40 can be cooled. . Therefore, generation of vapor in the housing 41 of the fuel pump 40 can be suppressed.

  Further, in the above configuration, when the temperature of the fuel discharged from the fuel pump 40 is high, the water pump 50 is controlled so that the flow rate of the cooling water pumped from the water pump 50 increases. Therefore, when the temperature of the fuel discharged from the fuel pump 40 is high, the water pump 50 is supplied with a large amount of cooled cooling water from the radiator 58. Therefore, even when the temperature of the fuel discharged from the fuel pump 40 is high, the temperature of the water pump 50 is likely to be maintained at a relatively low temperature. Therefore, even in a situation where the temperature of the housing 41 of the fuel pump 40 can be high, the housing 41 of the fuel pump 40 is cooled by the water pump 50 so that the temperature of the housing 41 of the fuel pump 40 falls within an appropriate range. Can be maintained.

The present embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
The correction value for correcting the basic value of the target rotation speed of the electric motor may be increased stepwise according to the temperature of the fuel discharged from the fuel pump 40. The correction value for correcting the basic value of the target rotation speed of the electric motor is a first correction value when the temperature of the fuel discharged from the fuel pump 40 is lower than a predetermined reference value, and a correction value when the temperature of the fuel is lower than the predetermined reference value. The second correction value may be two values (a two-stage correction value) with the second correction value being higher than the second correction value and being smaller than the first correction value.

  The method of correcting the basic value of the target rotation speed of the electric motor by the electronic control unit 12 is not limited to the example in the above embodiment. For example, the electronic control unit 12 may calculate a final target rotation speed by multiplying a basic value of the target rotation speed of the electric motor by a coefficient. Even in this case, if the coefficient is set to a larger value as the temperature of the fuel discharged from the fuel pump 40 is higher, the pumping from the water pump 50 is higher when the temperature of the fuel discharged from the fuel pump 40 is higher than when it is not. The flow rate of cooling water to be used can be increased.

  The method of controlling the rotation speed of the electric motor by the electronic control unit 12 is not limited to the method of correcting the basic value. For example, a method using a map may be adopted as a method for controlling the rotation speed of the electric motor. Specifically, for example, a map representing the relationship between the water temperature WT near the outlet of the water jacket, the flow rate of the cooling water pumped from the water pump 50, and the temperature of the fuel discharged from the fuel pump 40 is used. Alternatively, the amount of cooling water (the target rotation speed of the electric motor) may be calculated according to the water temperature WT and the temperature of the fuel. Even in this case, in the above map, if the flow rate of the cooling water increases as the temperature of the fuel increases, the temperature of the fuel discharged from the fuel pump 40 is high for the same water temperature WT. The flow rate of the cooling water to be pumped from the water pump 50 can be increased as compared with the case other than that.

  The flow rate of the cooling water pumped from the water pump 50 may be controlled by controlling components other than the electric motor. For example, a valve that can open and close the flow path of the cooling water passage 55 is provided in the middle of the cooling water passage 55, and the opening degree of the valve is adjusted according to the temperature of the fuel discharged from the fuel pump 40. Good.

  The water pump may be of a type that is drivingly connected to the crankshaft 100. Also in this case, for example, as in the above-described modification, if a valve that can open and close the flow path of the cooling water passage 55 is provided and the opening degree of the valve is adjusted, the flow rate of the cooling water can be controlled.

  The temperature of the fuel discharged from the fuel pump 40 is not limited to the temperature of the fuel in the high-pressure delivery pipe 33. The temperature of the fuel discharged from the fuel pump 40 may be, for example, a temperature directly detected by a temperature sensor in the housing 41 of the fuel pump 40. Further, the temperature of the fuel discharged from the fuel pump 40 may be estimated from the calorific value of the internal combustion engine 10 or the outside air temperature around the housing 41. That is, any value may be used as long as the value appropriately reflects the temperature of the fuel discharged from the fuel pump 40.

  It is not essential to control the flow rate of the cooling water pumped from the water pump 50. Even if the flow rate of the cooling water pumped from the water pump 50 is not controlled, if the housing 41 of the fuel pump 40 and the water pump 50 are adjacent to each other without any intervening other members, the water pump 50 allows the housing 41 of the fuel pump 40 to be cooled.

  -The mounting position of the fuel pump 40 is not limited to the example of the above embodiment. If the housing 41 of the fuel pump 40 and the water pump 50 are adjacent to each other without any other members interposed therebetween, the mounting position of the fuel pump 40 can be changed.

  -The position of the inflow port 41a in the fuel pump 40 with respect to the water pump 50 is not limited to the example of the above embodiment. The inflow port 41a may face the opposite side to the water pump 50.

  The structure of the fuel pump 40 is not limited to the structure in which the lifter 42 reciprocates with the cam 43 as in the above embodiment. Any fuel pump may be used as long as the pump can obtain the required fuel pressure using the rotational power of the crankshaft 100 as a drive source. When the structure of the fuel pump 40 is changed, it is only necessary that at least a part of the fuel storage portion of the fuel pump 40 and the water pump 50 are adjacent to each other without any other members interposed therebetween.

  -The shape of the water pump 50 is not limited to the example of the above embodiment. An appropriate water pump 50 may be employed in consideration of the space required for mounting the water pump 50 in the internal combustion engine 10, the performance required for the water pump 50, and the like.

The water pump 50 need not be directly fixed to the internal combustion engine body 20. For example, the water pump 50 may be fixed to a vehicle skeleton or the like.
The manner of driving connection between the crankshaft 100, the intake camshaft 30, and the exhaust camshaft 31 and the manner of driving connection between the crankshaft 100 and the fuel pump 40 are not limited. For example, both the fuel pump sprocket 45 and the first crank sprocket 100b may be changed to a pulley, and the fuel pump drive chain 83 may be changed to a belt.

  Similarly, the intake cam sprocket 30b, the exhaust cam sprocket 31b, and the second crank sprocket 100c may be changed to pulleys, and the camshaft drive chain 81 may be changed to a belt.

  The configuration of the internal combustion engine main body 20 of the above embodiment is only a schematic illustration, and the configuration of the internal combustion engine main body 20 can be appropriately changed.

DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 12 ... Electronic control unit, 20 ... Internal combustion engine main body, 22 ... Cylinder block, 24 ... Oil pan, 26 ... Cylinder head, 40 ... Fuel pump, 50 ... Water pump, 58 ... Radiator, 100 ... Crankshaft .

Claims (2)

A cylinder block, a cylinder head fixed to an upper end of the cylinder block, and an internal combustion engine main body including an oil pan fixed to a lower end of the cylinder block;
A fuel pump driven by the rotational power of the crankshaft to discharge fuel,
An internal combustion engine including a water pump for pumping cooling water for cooling the internal combustion engine body,
The water pump is for pumping cooling water flowing out of a radiator into the internal combustion engine body,
The internal combustion engine, wherein the fuel pump and the water pump are disposed adjacent to each other, and a gap is provided between the fuel pump and the water pump. A control unit that controls a flow rate of cooling water to be pumped from the water pump,
The internal combustion engine according to claim 1, wherein the control unit increases the flow rate of the cooling water pumped from the water pump when the temperature of the fuel discharged from the fuel pump is higher than when the temperature is not high.

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