Engine

Abstract

To operate a vortex tube at appropriate timing.SOLUTION: An engine has an engine body comprising: a first cylinder; and a second cylinder. The engine has an intake manifold comprising: a first intake pipe connected to the first cylinder; and a second intake pipe connected to the second cylinder. The engine has an exhaust manifold comprising: a first exhaust pipe connected to the first cylinder; and a second exhaust pipe connected to the second cylinder. The engine has a temperature control system comprising: an air tank connected to the first exhaust pipe via an input piping; and a vortex tube connected to an intake duct via an output pipe.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an engine.

Background Art

[0002] As a device for generating low-temperature air and high-temperature air from compressed air, a vortex tube that swirls compressed air inside a tube has been developed. Engine technologies have been proposed in which the temperature of intake air is adjusted using the low-temperature air or high-temperature air generated by this vortex tube (see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the timing at which adjustment of the temperature of intake air is required, that is, the timing at which the vortex tube is operated, varies according to the operating state of the engine. For this reason, it is required to secure compressed air so as not to miss the opportunity to adjust the intake air temperature, and to operate the vortex tube at an appropriate timing.

Means for Solving the Problems

[0005] According to the present disclosure, an engine has an engine body including a first cylinder and a second cylinder. The engine has an intake manifold including a first intake pipe connected to an intake port of the first cylinder, a second intake pipe connected to an intake port of the second cylinder, and a surge tank to which the first intake pipe and the second intake pipe are connected. The engine has an exhaust manifold including a first exhaust pipe connected to an exhaust port of the first cylinder, a second exhaust pipe connected to an exhaust port of the second cylinder, and a collecting portion to which the first exhaust pipe and the second exhaust pipe are connected. The engine has an intake duct connected to the surge tank of the intake manifold and guiding intake air to the surge tank. The engine has a temperature adjustment system including an air tank connected to the first exhaust pipe via an input pipe, and a vortex tube connected to the intake duct via an output pipe. The temperature adjustment system has a first on-off valve attached to the first exhaust pipe and located downstream of a connection portion between the first exhaust pipe and the input pipe. The temperature adjustment system has a second on-off valve attached to the input pipe connecting the first exhaust pipe and the air tank. The temperature adjustment system has a third on-off valve attached to a connection pipe connecting the air tank and the vortex tube. The temperature adjustment system has a fourth on-off valve attached to the output pipe connecting the vortex tube and the intake duct.

Advantages of the Invention

[0006] According to the present disclosure, the vortex tube can be operated at an appropriate timing.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or substantially the same configurations and elements are denoted by the same reference numerals, and repeated descriptions thereof are omitted.

[0009] <First Embodiment> <Vehicle> FIG. 1 is a diagram showing an example of a vehicle 11 equipped with an engine 10. As shown in FIG. 1, the vehicle 11 has a power unit 13 including an engine 10 and a transmission 12. The output shaft 14 of the power unit 13 is connected to the wheels 17 via a propeller shaft 15 and a differential mechanism 16. Note that the illustrated power unit 13 is a power unit for rear-wheel drive, but is not limited thereto, and may be a power unit for front-wheel drive or all-wheel drive.

[0010] <Engine> FIG. 2 is a diagram showing an engine 10 according to an embodiment of the present disclosure, and FIG. 3 is a diagram showing an example of an engine body 20. As shown in FIG. 2, the engine 10 has an engine body 20 including four cylinders 31 to 34. As shown in FIG. 3, the engine body 20 has a cylinder block 21 to which pistons 31p to 34p are assembled, and a cylinder head 22 to which an intake camshaft 23 and an exhaust camshaft 24 are assembled. In the cylinder block 21, pistons 31p to 34p of the respective cylinders 31 to 34 are assembled so as to be reciprocable, and a crankshaft 25 connected to the pistons 31p to 34p is rotatably supported.

[0011] As shown in FIG. 2, an intake port 31i communicating with the combustion chamber 31c of the cylinder (first cylinder) 31 and an exhaust port 31e communicating with the combustion chamber 31c are formed in the cylinder head 22. Further, an intake port 32i communicating with the combustion chamber 32c of the cylinder (second cylinder) 32 and an exhaust port 32e communicating with the combustion chamber 32c are formed in the cylinder head 22. Further, an intake port 33i communicating with the combustion chamber 33c of the cylinder 33 and an exhaust port 33e communicating with the combustion chamber 33c are formed in the cylinder head 22. Further, an intake port 34i communicating with the combustion chamber 34c of the cylinder 34 and an exhaust port 34e communicating with the combustion chamber 34c are formed in the cylinder head 22.

[0012] As shown in FIG. 3, intake valves 41i to 44i for opening and closing the intake ports 31i to 34i and an intake camshaft 23 for driving the intake valves 41i to 44i are attached to the cylinder head 22. Further, exhaust valves 41e to 44e for opening and closing the exhaust ports 31e to 34e and an exhaust camshaft 24 for driving the exhaust valves 41e to 44e are attached to the cylinder head 22. Further, fuel injectors 51a to 54a for injecting fuel into the combustion chambers 31c to 34c and spark plugs 51b to 54b for igniting the air-fuel mixture in the combustion chambers 31c to 34c are attached to the cylinder head 22.

[0013] That is, an intake valve 41i, an exhaust valve 41e, an injector 51a, and a spark plug 51b are attached to the cylinder 31, and an intake valve 42i, an exhaust valve 42e, an injector 52a, and a spark plug 52b are attached to the cylinder 32. Further, an intake valve 43i, an exhaust valve 43e, an injector 53a, and a spark plug 53b are attached to the cylinder 33, and an intake valve 44i, an exhaust valve 44e, an injector 54a, and a spark plug 54b are attached to the cylinder 34.

[0014] As shown in FIG. 2, an intake system 50 for guiding intake air and an exhaust system 70 for guiding exhaust gas are connected to the cylinder head 22. The intake system 50 for guiding intake air includes an intake duct 51, an air cleaner box 52, an intake duct 53, a throttle valve 54, an intake manifold 60, and the like. The intake manifold 60 has an intake pipe (first intake pipe) 61 connected to the intake port 31i, an intake pipe (second intake pipe) 62 connected to the intake port 32i, an intake pipe 63 connected to the intake port 33i, and an intake pipe 64 connected to the intake port 34i. Further, the intake manifold 60 has a surge tank 65 to which the intake pipes 61 to 64 are connected. The intake ducts 51, 53 and the air cleaner box 52 are connected to the surge tank 65 via the throttle valve 54.

[0015] The exhaust system 70 for guiding exhaust gas includes an exhaust manifold 80, a catalytic converter 71, an exhaust pipe 72, a muffler 73, and the like. The exhaust manifold 80 has an exhaust pipe (first exhaust pipe) 81 connected to the exhaust port 31e, an exhaust pipe (second exhaust pipe) 82 connected to the exhaust port 32e, an exhaust pipe 83 connected to the exhaust port 33e, and an exhaust pipe 84 connected to the exhaust port 34e. Further, the exhaust manifold 80 has a collecting portion 85 to which the exhaust pipes 81 to 84 are connected. The exhaust pipe 72 and the muffler 73 are connected to the collecting portion 85 via the catalytic converter 71.

[0016] <Temperature adjustment system> Engine 10 has a temperature adjustment system 90 for adjusting the temperature of the intake air. As shown in FIG. 2, the temperature adjustment system 90 includes an air tank 92 connected to the exhaust pipe 81 via an input pipe 91, and a vortex tube 94 connected to the intake duct 51 via an output pipe 93. The air tank 92 is formed with an input port 92a for connecting the input pipe 91 and an output port 92b for connecting the connecting pipe 95.

[0017] The vortex tube 94 includes a tube body 96 formed in a cylindrical shape and a conical flow rate adjustment valve 97 attached to the tube body 96. Further, the tube body 96 of the vortex tube 94 is formed with an input port 94a for connecting the connecting pipe 95, a low-temperature output port 94b for discharging low-temperature air, and a high-temperature output port 94c for discharging high-temperature air. By swirling the compressed air at high speed along the inner wall surface of the tube body 96, the vortex tube 94 can generate high-temperature air that is hotter than the compressed air by adiabatic compression, and can generate low-temperature air that is colder than the compressed air by adiabatic expansion.

[0018] The temperature adjustment system 90 has an exhaust shut-off valve (first on-off valve) 101 attached to the exhaust pipe 81. The exhaust shut-off valve 101 is located downstream of the connection part 105 between the exhaust pipe 81 and the input pipe 91. The exhaust shut-off valve 101 controlled by the electric actuator 101a is operable in a communicating state that allows the exhaust pipe 81 to communicate and a shut-off state that shuts off the exhaust pipe 81. Further, the temperature adjustment system 90 has an air filling valve (second on-off valve) 102 and a check valve 106 attached to the input pipe 91. The air filling valve 102 controlled by the electric actuator 102a is operable in a communicating state that allows the input pipe 91 to communicate and a shut-off state that shuts off the input pipe 91. The check valve 106 is attached in a direction that allows the air flow from the exhaust pipe 81 toward the air tank 92. Furthermore, the temperature adjustment system 90 has an air release valve (third on-off valve) 103 attached to the connection pipe 95 that connects the air tank 92 and the vortex tube 94. The air release valve 103 controlled by the electric actuator 103a is operable in a communicating state that allows the connection pipe 95 to communicate and a shut-off state that shuts off the connection pipe 95.

[0019] The output pipe 93 that connects the vortex tube 94 and the intake duct 51 has an output pipe (first pipe section) 93a connected to the intake duct 51, an output pipe (second pipe section) 93b connected to the low-temperature output port 94b of the vortex tube 94, and an output pipe (third pipe section) 93c connected to the high-temperature output port 94c of the vortex tube 94. These output pipes 93a to 93c are connected to each other via a temperature adjustment valve (fourth on-off valve) 104. That is, a temperature adjustment valve 104 is attached to the output pipe 93 that connects the intake duct 51 and the vortex tube 94.

[0020] The temperature control valve 104 that operates in 3 positions has two solenoids 104a and 104b. By cutting off the power supply to both solenoids 104a and 104b, the temperature control valve 104 operates in a shut-off state that shuts off the output pipes 93a to 93c. Also, by energizing the solenoid 104a and cutting off the power supply to the solenoid 104b, the temperature control valve 104 operates in a first communication state (communication state) that allows the output pipes 93a and 93b to communicate with each other. Further, by energizing the solenoid 104b and cutting off the power supply to the solenoid 104a, the temperature control valve 104 operates in a second communication state (communication state) that allows the output pipes 93a and 93c to communicate with each other.

[0021] <Control system> As shown in FIG. 2, the engine 10 has a control system 110 consisting of an electronic control unit 111 to control the engine body 20, the throttle valve 54, the exhaust shut-off valve 101, the air filling valve 102, the air release valve 103, and the temperature control valve 104. As sensors connected to the electronic control unit 111, there are an accelerator sensor 112 that detects the operation amount of the accelerator pedal, a brake sensor 113 that detects the operation amount of the brake pedal, and a vehicle speed sensor 114 that detects the traveling speed of the vehicle 11.

[0022] Also, as sensors connected to the electronic control unit 111, there are an engine rotation sensor 115 that detects the rotational speed of the crankshaft 25, and a throttle opening sensor 116 that detects the opening degree of the throttle valve 54. Further, as sensors connected to the electronic control unit 111, there are an air flow sensor 117 attached to the intake duct 53 to detect the intake air flow rate, an intake air temperature sensor 118 attached to the intake duct 53 to detect the intake air temperature, and a pressure sensor 119 attached to the air tank 92 to detect the pressure inside the air tank 92. Further, a start switch 120 that is operated by the driver at the start of the control system 110 is connected to the electronic control unit 111.

[0023] FIG. 4 is a diagram showing an example of the basic structure of the electronic control unit 111. As shown in FIG. 4, the electronic control unit 111 has a microcontroller 132 in which a processor 130, a main memory (memory) 131, and the like are incorporated. A predetermined program is stored in the main memory 131, and the program is executed by the processor 130. The processor 130 and the main memory 131 are communicably connected to each other. Note that a plurality of processors 130 may be incorporated in the microcontroller 132, or a plurality of main memories 131 may be incorporated in the microcontroller 132.

[0024] Further, the electronic control unit 111 has an input circuit 133, a drive circuit 134, a communication circuit 135, an external memory 136, and a power supply circuit 137. The input circuit 133 converts a signal input from various sensors into a signal that can be input to the microcontroller 132. The drive circuit 134 generates a drive signal for devices such as the electric actuators 101a to 103a described above based on a signal output from the microcontroller 132. The communication circuit 135 converts a signal output from the microcontroller 132 into a communication signal directed to other electronic control units or the like. Further, the communication circuit 135 converts a communication signal received from other electronic control units or the like into a signal that can be input to the microcontroller 132. Furthermore, the power supply circuit 137 supplies a stable power supply voltage to the microcontroller 132, the input circuit 133, the drive circuit 134, the communication circuit 135, the external memory 136, and the like. Also, programs and various data are stored in the external memory 136 composed of a non-volatile memory or the like.

[0025] <Adjustment Control of Intake Air Temperature> Next, the intake air temperature adjustment control executed by the control system 110 will be described. The intake air temperature adjustment control is composed of each control mode of a tank filling mode, an intake air cooling mode, and an intake air heating mode. Here, FIG. 5 is a diagram showing an example of the execution status of the tank filling mode, FIG. 6 is a diagram showing an example of the execution status of the intake air cooling mode, and FIG. 7 is a diagram showing an example of the execution status of the intake air heating mode. Hereinafter, the intake air temperature adjustment control will be described in the order of the tank filling mode, the intake air cooling mode, and the intake air heating mode. As shown in FIG. 2, during normal times when the tank filling mode, the intake air cooling mode, and the intake air heating mode are not being executed, the exhaust shut-off valve 101 is controlled to be in a communicating state, and the air filling valve 102, the air release valve 103, and the temperature adjustment valve 104 are controlled to be in a shut-off state.

[0026] <Tank filling mode> As shown in FIG. 5, in the tank filling mode of filling the air tank 92 with compressed air, the control system 110 controls the injectors 52a to 54a to continue fuel injection into the cylinders 32 to 34, and controls the injector 51a to stop fuel injection into the cylinder 31. Thereafter, the control system 110 controls the exhaust shut-off valve 101 from a communicating state to a shut-off state while keeping the air release valve 103 and the temperature adjustment valve 104 in a shut-off state, and controls the air filling valve 102 from a shut-off state to a communicating state. Thereby, compressed air can be generated by the cylinder 31, and as shown by the arrow a1, the compressed air can be supplied from the exhaust pipe 81 to the air tank 92 through the input pipe 91.

[0027] In this way, in the tank filling mode, the cylinder 31 can be made to function as a compressor while maintaining the engine operating state, and the compressed air discharged from the cylinder 31 can be filled into the air tank 92. Thereby, compressed air can be stored in preparation for the intake air cooling mode and the intake air heating mode described later, so that the vortex tube 94 can be operated at an appropriate timing.

[0028] In the tank filling mode, since the exhaust shut-off valve 101 is controlled to the shut-off state, the exhaust gas from the cylinders 32 to 34 does not flow into the air tank 92. Further, in order to prevent the inflow of exhaust gas into the air tank 92, it is desirable to control the air filling valve 102 to the communicating state after controlling the exhaust shut-off valve 101 to the shut-off state. Also, the tank filling mode in which the cylinder 31 functions as a compressor is a control mode in which the engine torque is more likely to decrease than during normal operation. For this reason, when steady running or coasting running is executed in which the pressure in the air tank 92 falls below a predetermined value and the required driving force falls below a predetermined value, the control system 110 executes the tank filling mode.

[0029] Also, the tank filling mode continues until the pressure in the air tank 92 reaches a predetermined value. That is, the control system 110 continues to stop the fuel injection to the cylinder 31 and keep the air filling valve 102 in the communicating state until the pressure in the air tank 92 reaches a predetermined value. Then, when the pressure in the air tank 92 reaches a predetermined value, the control system 110 controls the air filling valve 102 from the communicating state to the shut-off state, controls the exhaust shut-off valve 101 from the shut-off state to the communicating state, and then controls the injector 51a to resume the fuel injection to the cylinder 31. Note that, in order to prevent the inflow of exhaust gas into the air tank 92, it is desirable to control the exhaust shut-off valve 101 to the communicating state after controlling the air filling valve 102 to the shut-off state.

[0030] <Intake air cooling mode> As shown in FIG. 6, in the intake air cooling mode for reducing the temperature of the intake air, the control system 110 controls the injectors 51a to 54a and continues fuel injection into the cylinders 31 to 34. Further, the control system 110 holds the exhaust cutoff valve 101 in a communicating state, and while holding the air filling valve 102 in a cutoff state, controls the air release valve 103 from a cutoff state to a communicating state and controls the temperature adjustment valve 104 from a cutoff state to a first communicating state. Thereby, as shown by the arrow b1, compressed air can be supplied from the air tank 92 to the vortex tube 94, and the compressed air can be separated into low-temperature air and high-temperature air in the vortex tube 94. Then, as shown by the arrow c1, the low-temperature air is supplied from the low-temperature output port 94b to the output pipe 93b, and as shown by the arrow d1, the high-temperature air is supplied from the high-temperature output port 94c to the output pipe 93c.

[0031] In this intake air cooling mode, since the temperature adjustment valve 104 is controlled to the first communicating state, the low-temperature output port 94b communicates with the intake duct 51, and low-temperature air is supplied from the vortex tube 94 to the intake duct 51. Thereby, since low-temperature air can be mixed into the intake air, the intake air can be actively cooled. For example, by executing the intake air cooling mode in the high-load operation region of the engine 10, the temperature of the intake air can be reduced to prevent abnormal combustion such as knocking. Since the output pipe 93 is connected upstream of the air flow sensor 117, even when low-temperature air from the vortex tube 94 is mixed into the intake air, the control system 110 can appropriately grasp the flow rate of the intake air toward the intake manifold 60. In the intake air cooling mode, the high-temperature air discharged from the high-temperature output port 94c is discharged to the outside.

[0032] <Intake Air Heating Mode> As shown in FIG. 7, in the intake air heating mode for raising the temperature of the intake air, the control system 110 controls the injectors 51a to 54a and continues fuel injection into the cylinders 31 to 34. Further, the control system 110 holds the exhaust shut-off valve 101 in the communicating state, and controls the air release valve 103 from the shut-off state to the communicating state and the temperature adjustment valve 104 from the shut-off state to the second communicating state while holding the air filling valve 102 in the shut-off state. Thereby, as indicated by arrow b2, compressed air can be supplied from the air tank 92 to the vortex tube 94, and the compressed air can be separated into low-temperature air and high-temperature air in the vortex tube 94. Then, as indicated by arrow c2, the low-temperature air is supplied from the low-temperature output port 94b to the output pipe 93b, and as indicated by arrow d2, the high-temperature air is supplied from the high-temperature output port 94c to the output pipe 93c.

[0033] In this intake air heating mode, since the temperature adjustment valve 104 is controlled to the second communicating state, the high-temperature output port 94c communicates with the intake duct 51, and high-temperature air is supplied from the vortex tube 94 to the intake duct 51. Thereby, since high-temperature air can be mixed into the intake air, the intake air can be actively heated. For example, by executing the intake air heating mode immediately after engine startup, the temperature of the intake air can be raised to promote fuel vaporization and catalyst temperature rise, and the exhaust gas can be properly purified. Note that in the intake air heating mode, the low-temperature air discharged from the low-temperature output port 94b is discharged to the outside.

[0034] <Second Embodiment> As shown in FIG. 5, in the tank filling mode, by causing the cylinder 31 to function as a compressor, compressed air is supplied from the cylinder 31 to the air tank 92. Here, as shown in FIG. 3, the intake camshaft 23 includes one cam 23a that drives the intake valve 41i of the cylinder 31, and the exhaust camshaft 24 includes one cam 24a that drives the exhaust valve 41e of the cylinder 31. That is, in the tank filling mode, the cylinder 31 sucks air in the intake stroke and then discharges air in the exhaust stroke. In other words, every time the crankshaft 25 rotates twice, an amount of air equal to the stroke volume is supplied from the cylinder 31 to the air tank 92.

[0035] In this tank filling mode, in order to efficiently fill the air tank 92 with compressed air, it is conceivable to add cams to the intake camshaft 23 and the exhaust camshaft 24. Here, FIG. 8 is a diagram showing a part of the intake camshaft 140 and the exhaust camshaft 150 provided in the engine according to another embodiment of the present disclosure. FIG. 8 shows the drive portion of the intake valve 41i on the intake camshaft 140 and the drive portion of the exhaust valve 41e on the exhaust camshaft 150. Further, FIG. 9 is a diagram showing the operating state of the cylinder 31 in the tank filling mode. FIG. 9 shows four operating states with the crank angle advanced by 180° each. The arrows shown in FIG. 9 indicate the rotation direction of the crankshaft 25, the moving direction of the piston 31p, and the flow direction of the intake air.

[0036] As shown in FIG. 8, the intake camshaft (camshaft) 140 includes a first cam 141 used when burning the air-fuel mixture in the cylinder 31, and a second cam 142 used when filling the air tank 92 with compressed air. The first cam 141 is constituted by one cam peak 141a, while the second cam 142 is constituted by two cam peaks 142a and 142b that are 180° out of phase. Similarly, the exhaust camshaft (camshaft) 150 includes a first cam 151 used when burning the air-fuel mixture in the cylinder 31, and a second cam 152 used when filling the air tank 92 with compressed air. The first cam 151 is constituted by one cam peak 151a, while the second cam 152 is constituted by two cam peaks 152a and 152b that are 180° out of phase.

[0037] When executing the tank filling mode, the intake valve 41i is driven by the second cam 142 of the intake camshaft 140, and the exhaust valve 41e is driven by the second cam 152 of the exhaust camshaft 150. Thereby, compressed air can be efficiently filled from the cylinder 31 into the air tank 92. That is, as shown in FIG. 9, the stroke in which the piston 31p moves toward the bottom dead center becomes the intake stroke for sucking air into the cylinder 31, and the stroke in which the piston 31p moves toward the top dead center becomes the exhaust stroke for discharging air from the cylinder 31. In other words, every time the crankshaft 25 makes one revolution, an amount of air corresponding to the stroke volume is supplied from the cylinder 31 to the air tank 92.

[0038] In this way, by using the intake camshaft 140 and the exhaust camshaft 150, compressed air can be efficiently filled into the air tank 92, and the execution time of the tank filling mode accompanied by a decrease in engine torque can be shortened. As a result, it becomes easier to secure the opportunity to execute the tank filling mode, so that depletion of the compressed air stored in the air tank 92 can be prevented, and the vortex tube 94 can be operated at an appropriate timing.

[0039] In addition, as the structure for switching the cams 141 and 142 of the intake camshaft 140 and the structure for switching the cams 151 and 152 of the exhaust camshaft 150, various practical examples of variable valve mechanisms can be applied. For example, it may be a structure that moves the intake camshaft 140 and the exhaust camshaft 150 in the axial direction, or it may be a structure that switches the rocker arm by hydraulic control. Further, the cams 141 of the intake camshaft 140 and the cams 151 of the exhaust camshaft 150 have the same shape as the cams 23a of the intake camshaft 23 and the cams 24a of the exhaust camshaft 24 described above. That is, by using the cams 141 and 151 of the camshafts 140 and 150, it is possible to control the cylinder 31 in the intake stroke, compression stroke, combustion stroke, and exhaust stroke.

[0040] <Third Embodiment> In the example shown in FIG. 2, a temperature adjustment valve 104 that operates in three positions is attached to the output pipe 93 that connects the intake duct 51 and the vortex tube 94, but it is not limited to this. FIG. 10 is a diagram showing an engine 160 according to another embodiment of the present disclosure. In FIG. 10, the same parts as those shown in FIG. 2 are denoted by the same reference numerals and their description is omitted.

[0041] As shown in FIG. 10, the output pipe 93 that connects the vortex tube 94 and the intake duct 51 includes an output pipe 93a connected to the intake duct 51 and an output pipe 93b connected to the low-temperature output port 94b of the vortex tube 94. The output pipe 93a and the output pipe 93b are connected to each other via a temperature adjustment valve (fourth on-off valve) 164 that operates in two positions. That is, the temperature adjustment valve 164 is attached to the output pipe 93 that connects the intake duct 51 and the vortex tube 94.

[0042] The temperature adjustment valve 164 has one solenoid 164a. By cutting off the energization to the solenoid 164a, the temperature adjustment valve 164 operates in a cutoff state to cut off the output pipes 93a and 93b. Also, by energizing the solenoid 16a, the temperature adjustment valve 164 operates in a communication state to communicate the output pipes 93a and 93b with each other. In this way, the temperature adjustment valve 164 is an on-off valve that operates in two positions: a cutoff state and a communication state.

[0043] Even when such a temperature adjustment valve 164 is used, by controlling the temperature adjustment valve 164 to be in the communication state, the intake air cooling mode described above can be executed. In the example shown in FIG. 10, by controlling the temperature adjustment valve 164 to be in the communication state, the output pipes 93a and 93b are communicated with each other to supply low-temperature air to the intake duct 51, but it is not limited to this. For example, the output pipe 93a connected to the intake duct 51 and the output pipe 93c connected to the high-temperature output port 94c of the vortex tube 94 may be connected via a temperature adjustment valve 164 that operates in two positions. In this case, by controlling the temperature adjustment valve 164 to be in the communication state, the intake air heating mode described above can be executed.

[0044] <Other Embodiments> The present disclosure is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist thereof. For example, although the illustrated engine body 20 has four cylinders, it is not limited thereto, and it may be an engine body having two or more cylinders, or it may be an engine body having three or more cylinders. Further, in the above description, in the tank filling mode, one cylinder 31 is used as a compressor, but it is not limited thereto, and two or more cylinders may be used as a compressor. The illustrated engines 10 and 160 are gasoline engines using gasoline as fuel, but it is not limited thereto, and it may be a diesel engine using light oil as fuel, or it may be a hydrogen engine using hydrogen as fuel. Further, the illustrated engines 10 and 160 are in-line engines, but it is not limited thereto, and it may be a horizontally opposed engine or a V-type engine.

[0045] In the above description, two camshafts 23 and 24 (140 and 150) are used, but it is not limited thereto, and one camshaft having an intake cam and an exhaust cam may be used. Further, in the above description, the control system 110 is configured by one electronic control unit 111, but it is not limited thereto, and the control system 110 may be configured by two or more electronic control units. Further, as the exhaust shut-off valve 101, the air filling valve 102, the air release valve 103, and the temperature adjustment valves 104 and 164, any valve structure may be adopted as long as it can operate between a communicating state and a shut-off state. For example, as the exhaust shut-off valve 101 or the like, a spool valve may be adopted, a gate valve may be adopted, a ball valve may be adopted, or a butterfly valve may be adopted. Further, in the illustrated example, the output pipe 93 is connected to the intake duct 51, but it is not limited thereto, and the output pipe 93 may be connected to any position of the intake system 50 as long as it is upstream of the air flow sensor 117. For example, in the illustrated intake system 50, the output pipe 93 may be connected to the air cleaner box 52, or the output pipe 93 may be connected to the intake duct 53.

Description of Reference Numerals

[0046] 10… Engine, 20… Engine body, 31… Cylinder (first cylinder), 32… Cylinder (second cylinder), 31i, 32i… Intake port, 31e, 32e… Exhaust port, 51… Intake duct, 60… Intake manifold, 61… Intake pipe (first intake pipe), 62… Intake pipe (second intake pipe), 65… Surge tank, 80… Exhaust manifold, 81… Exhaust pipe (first exhaust pipe), 82… Exhaust pipe (second exhaust pipe), 85… Collection part, 90… Temperature adjustment system, 91… Input pipe, 92… Air tank, 93… Output pipe, 93a… Output pipe (first pipe section), 93b… Output pipe (second pipe section), 93c… Output pipe (third pipe section), 94… Vortex tube, 94b… Low-temperature output port, 94c… High-temperature output port, 95… Connecting pipe, 101… Exhaust shut-off valve (first on-off valve), 102… Air filling valve (second on-off valve), 103… Air release valve (third on-off valve), 104… Temperature adjustment valve (fourth on-off valve), 105… Connection part, 110… Control system, 130… Processor, 131… Main memory (memory), 140… Intake camshaft (camshaft), 141… First cam, 142… Second cam, 150… Exhaust camshaft (camshaft), 151… First cam, 152… Second cam, 160… Engine, 164… Temperature adjustment valve (fourth on-off valve)

Claims

1. An engine body including a first cylinder and a second cylinder, an intake manifold including a first intake pipe connected to an intake port of the first cylinder, a second intake pipe connected to an intake port of the second cylinder, and a surge tank to which the first intake pipe and the second intake pipe are connected, an exhaust manifold including a first exhaust pipe connected to an exhaust port of the first cylinder, a second exhaust pipe connected to an exhaust port of the second cylinder, and a collecting portion to which the first exhaust pipe and the second exhaust pipe are connected, an intake duct connected to the surge tank of the intake manifold and guiding intake air to the surge tank, a temperature adjustment system including an air tank connected to the first exhaust pipe via an input pipe and a vortex tube connected to the intake duct via an output pipe, having wherein the temperature adjustment system includes a first on-off valve attached to the first exhaust pipe and located downstream of a connection portion between the first exhaust pipe and the input pipe, a second on-off valve attached to the input pipe connecting the first exhaust pipe and the air tank, a third on-off valve attached to a connection pipe connecting the air tank and the vortex tube, a fourth on-off valve attached to the output pipe connecting the vortex tube and the intake duct, having an engine.

2. The engine according to claim 1, having a control system including a processor and a memory communicably connected to each other, wherein the control system when filling the air tank with compressed air, after stopping fuel injection to the first cylinder while continuing fuel injection to the second cylinder, controls the first on-off valve from a communicating state to a blocking state and controls the second on-off valve from a blocking state to a communicating state while keeping the third on-off valve and the fourth on-off valve in a blocked state, an engine.

3. The engine according to claim 2, wherein the control system when adjusting the temperature of intake air supplied to the intake manifold, while keeping the first on-off valve in a communicating state and the second on-off valve in a blocking state, controls the third on-off valve from a blocking state to a communicating state and controls the fourth on-off valve from a blocking state to a communicating state, an engine.

4. In the engine according to claim 1, the output pipe connecting the intake duct and the vortex tube includes a first pipe portion connected to the intake duct, a second pipe portion connected to the low-temperature output port of the vortex tube, and a third pipe portion connected to the high-temperature output port of the vortex tube, the fourth on-off valve is operable in a blocking state for blocking the first pipe portion, a first communication state for communicating the first pipe portion and the second pipe portion with each other, and a second communication state for communicating the first pipe portion and the third pipe portion with each other, engine.

5. In the engine according to claim 1, the camshaft provided in the first cylinder includes a first cam used when burning an air-fuel mixture in the first cylinder and a second cam used when filling compressed air into the air tank, engine.

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