Internal combustion engine

Abstract

To provide an intake air temperature control device capable of increasing and decreasing a temperature of intake air with a single device, and having excellent temperature adjustment efficiency.SOLUTION: An intake air temperature control device 33 has a sprinkling nozzle 34 and a water receiver 35 arranged on a branch pipe 27 of an intake manifold 28, etc., and hot or cold water is selectively supplied to the sprinkling nozzle 34 via a water pump 37. During cold start, a temperature of intake air is increased with hot water to improve combustibility (ignitability), and when the temperature of the intake air becomes excessively high, the temperature is decreased with cold water to ensure high charging efficiency. Since the device uses a direct heat exchange system that exposes the intake air to water, it is compact yet can sufficiently increase and decrease the temperature of the intake air, and is highly responsive.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an internal combustion engine equipped with an intake air temperature control device.

Background Art

[0002] In an internal combustion engine, in order to improve the output, it is advantageous to increase the air density of the intake air flowing into the cylinder bore (combustion chamber) (that is, to increase the charging efficiency). For this purpose, it is preferable that the temperature of the intake air is as low as possible. However, especially when a supercharger is provided, the temperature of the intake air tends to increase. Therefore, it is widely practiced to arrange an air-cooled or water-cooled intercooler on the downstream side of the supercharger.

[0003] On the other hand, in the case of cold start in a cold environment, if the temperature of the intake air is low, the ignitability of the fuel may decrease, resulting in starting failure or engine stall after starting. Therefore, it has also been proposed to interpose an intake heater in the intake passage and heat the intake air with the intake heater during cold start (warm-up operation).

[0004] In addition, abnormal combustion (detonation) may occur during operation in a high-temperature environment or high-load operation. Therefore, water atomized for the purpose of cooling the combustion chamber is also injected into the combustion chamber. Injecting water into the combustion chamber may also be performed for the purpose of preventing deterioration of the exhaust gas components. As an example, Patent Document 1 discloses that a wet tower is interposed upstream of a fuel injection injector in the intake passage, and steam is mixed into the intake air in the wet tower.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As described above, in order to improve the output, it is preferable to lower the intake air temperature to increase the charging efficiency. Therefore, the intercooler is beneficial for improving the charging efficiency. However, since the intercooler cannot raise the temperature of the intake air, it is not a measure for improving the combustibility during cold start. Moreover, if an intercooler and an intake heater are installed together, there are problems such as an increase in cost and a large space requirement, which makes the overall structure bulky.

[0007] Furthermore, as a more fundamental problem, since both the intercooler and the intake heater indirectly exchange heat with the intake air through an element, there is a problem that the temperature reduction efficiency and the temperature increase efficiency per unit volume are poor. That is, there is a problem that the temperature increase and decrease efficiency is poor considering the bulkiness.

[0008] On the other hand, Patent Document 1 aims to suppress the generation of nitrogen dioxide under supercharging by mixing steam into the intake air, and since it does not have a function of changing the temperature of the intake air, it can be said that the effects of improving the charging efficiency and the combustibility (ignitability improvement) during cold start cannot be expected.

[0009] The present invention has been made to improve such a current situation.

Means for Solving the Problems

[0010] The internal combustion engine of the present invention "is provided with an intake air temperature control device that exposes the intake air to water in the intake passage to change the temperature of the intake air, The intake air temperature control device has a water spraying means for passing water in a direction intersecting the flow direction of the intake air in the intake passage, and by varying the temperature of the water, it is possible to selectively raise and lower the temperature of the intake air." It has such a configuration.

[0011] The present invention can be developed in various ways. As an example, in Claim 2, "The intake air temperature control device includes a hot water tank and a cold water tank, and based on the engine temperature or an alternative temperature, the water supply from the hot water tank to the water spraying means and the water supply from the cold water tank to the water spraying means are switched." It adopts the following configuration. As a means for detecting the engine temperature, it is possible to directly detect the temperature of the cylinder block, cylinder head, etc., or it is also possible to use the cooling water temperature as an alternative.

[0012] Note that the "cold water" in the cold water tank specified in the claims means water at a temperature lower than the intake air temperature, and does not mean water at a temperature cooled by a refrigerator, for example. Generally, it is often water at the unheated ambient temperature, but in the case of operation in a high-temperature environment, it is possible to cool it with a radiator or the like.

[0013] In the present invention, the state of the liquid passing through the intake passage can be arbitrarily set. One embodiment is to spray from a nozzle. By atomizing, the total surface area of the water can be increased and the heat exchange efficiency with the intake air can be improved. In this case, by adjusting the particle size and spraying speed, it is possible to set so that the water particles do not ride on the intake air and flow into the cylinder bore.

[0014] Alternatively, when the combustion chamber and the piston are abnormally heated due to overload operation or high EGR operation, etc., it is also possible to send a part of the water into the combustion chamber for cooling. However, by using a nozzle, it is possible to realize sending a part of the water into the combustion chamber by adjusting the injection pressure (injection speed). It is also possible to provide a plurality of types of water spraying means with different functions in the intake passage and use them properly according to the situation.

[0015] As a means for passing water through the intake passage without letting it ride on the intake air, it is also possible to arrange a water flow guide body such as a reticular body or a cotton-like body with high air permeability in the intake passage and let the water flow along the water flow guide body. Alternatively, without using a water flow guide body, it is also possible to make the water large-grained so that it does not ride on the intake air and flow in a dripping state. Needless to say, the water that has passed through the intake passage is recovered (preferably circulated).

Advantages of the Invention

[0016] In the present invention, since intake air can be heated or cooled by one device, intake air can be cooled during supercharging or when overheating is suspected to improve the filling efficiency. On the other hand, during cold start, intake air can be heated to improve combustibility and startability. And since the intake air is brought into direct contact with a liquid (water) for heat exchange, high heat exchange efficiency can be achieved while the device is made compact. As a result, it can contribute to an improvement in output and fuel efficiency. Compared with the case of having both an intercooler and an intake heater, it can also contribute to cost reduction.

[0017] As described above, it is also possible to send a part of water into the combustion chamber, thereby achieving effects such as further improvement in filling efficiency, suppression of abnormal combustion (knocking), and prevention of deterioration of exhaust gas components.

[0018] In the present invention, when raising the temperature of the intake air, it is possible to heat (heat) the water stored in the tank in the middle of the flow path and supply it to the intake passage. However, in this case, there is a concern that responsiveness and temperature stability may become problems.

[0019] On the other hand, if a hot water tank and a cold water tank are provided as in claim 2, it is possible to immediately respond to heating and cooling of the intake air and stabilize the temperature, which is suitable. In particular, if the cooling water after passing through the cylinder head is used as the hot water, it is particularly suitable because a heating means can be made unnecessary (it is possible to use an electric heater in combination, such as heating with a heater only during cranking).

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0021] Next, embodiments of the present invention will be described with reference to the drawings. This embodiment is applied to an internal combustion engine (gasoline engine) for an automobile, and cooling water heated around the engine is used as a heat source for heating inside the vehicle. That is, it is configured such that cooling water flows through the heater core. Hereinafter, the words "front" and "rear" are used to specify directions, and the front-rear direction is the crankshaft axis direction. The side where the timing chain is arranged is the front, and the side where the transmission case is arranged is the rear.

[0022] (1). Basic Structure of Internal Combustion Engine FIG. 1 shows the first embodiment. In FIG. 1(A), in part a, a schematic side view of the internal combustion engine is shown, and in part b, a cross-sectional view of the main part of the present invention as seen from the crankshaft axis direction is shown.

[0023] The basic structure of the internal combustion engine is the same as that of the prior art. The internal combustion engine includes a cylinder block 3 in which a plurality of cylinder bores 2 into which pistons 1 are inserted are arranged in the crankshaft axis direction, and a cylinder head 4 fixed to the upper surface of the cylinder block 3 via a gasket. A head cover 5 is fixed to the upper surface of the cylinder head 4, and an oil pan 6 is fixed to the lower surface of the cylinder block 3. A chain cover (front cover) 7 that covers the timing chain is fixed to the front surfaces of the cylinder head 4, the cylinder block 3, and the oil pan 6, and a transmission case 8 is fixed to the rear surfaces of the cylinder head 4 and the oil pan 6.

[0024] The internal combustion engine of this embodiment is horizontally placed with the crankshaft in a posture that is long in the vehicle width direction and is arranged in the engine room. As shown by the dashed line in part a, a radiator 9 is arranged in front of the rear part of the internal combustion engine. In part a, reference numeral 10 indicates a crank pulley, and reference numeral 11 indicates a water pump. At the rear end of the cylinder head 4, a radiator feed port 12, a heater feed port 13, and a heater return port 14 are arranged.

[0025] The radiator feed port 12 is connected to the upper tank 16 of the radiator 9 by a radiator feed pipe 15, and the lower tank 17 of the radiator 9 is connected to the water pump 11 by a radiator return pipe 18. However, a part of the radiator return pipe 18 is often built into the cylinder block 3.

[0026] In the cylinder head 4, a downward-opening recess (combustion chamber) 20 corresponding to the cylinder bore 2, a group of intake ports 21 opening to the recess 20 and the intake side surface 4a, and a group of exhaust ports 22 opening to the recess 20 and the exhaust side surface (not shown) are formed. Two intake ports 21 are formed in front and rear for each cylinder bore 2, and each intake port 21 is opened and closed by an intake valve 23 respectively. The intake port 21 is inclined with respect to the cylinder bore axis so as to be lower toward the downstream side (so as to approach the cylinder block 3).

[0027] Two exhaust ports 22 are also formed in front and rear for each cylinder bore 2, and each exhaust port 22 is opened and closed by an exhaust valve 24 respectively. The intake valve 23 and the exhaust valve 24 are biased in the closing direction by a spring 25.

[0028] The intake valve 23 and the exhaust valve 24 are inclined with respect to the cylinder bore axis so that their intervals are separated upward when viewed in the crankshaft axis direction. Injectors 26 for injecting atomized fuel toward the intake ports 21 are respectively attached to the upper parts of the respective intake ports 21 in the cylinder head 4. Therefore, the internal combustion engine of the embodiment is of the dual-port dual-injector type, but the dual-port single-injector type can also be adopted. An intake manifold 28 having a branch pipe 27 communicating with the intake port 21 is fixed to the intake side surface 4a of the cylinder head 4.

[0029] What is indicated by reference numeral 29 in part b is a cooling water jacket provided in the cylinder head 4. At the time of cold start, while the temperature of the cooling water rises to a predetermined temperature, all or most of the cooling water flows from the front to the rear through the cooling water jacket 29 of the cylinder head 4, and a part of the cooling water discharged from the cylinder head 4 flows through the heater feed pipe line 30 to the heater core 31 for vehicle heating, and the rest returns to the water pump 11 via a return passage (not shown). When the temperature of the cooling water reaches the predetermined temperature, the thermostat valve opens and the cooling water begins to flow to the radiator 9, and at the same time, the cooling water jacket of the cylinder block 3 is also passed through.

[0030] (2). Intake air temperature control device of the first embodiment As shown in part b, the branch pipe 27 of the intake manifold 28 is fixed to the intake side surface 4a of the cylinder head 4. There are two types of the branch pipes 27 of the intake manifold 28, one in which they are separated for each cylinder corresponding to the two intake ports 21, and the other in which one branch pipe 27 communicates with the two intake ports 21, and this embodiment includes both (for simplification of the structure, it is preferable to branch from one branch pipe 27 to the two intake ports 21).

[0031] Although not shown, the intake manifold 28 is provided with a surge tank, and a throttle body (throttle valve) is fixed to the intake port of the surge tank. In the case of a naturally aspirated internal combustion engine, an air cleaner and a throttle body are connected by an intake duct. In the case of a supercharged internal combustion engine, the intake air exiting the air cleaner is sent to the throttle body via the compressor of the supercharger. This embodiment includes both methods.

[0032] And the internal combustion engine of this embodiment includes an intake air temperature control device 33 that controls the temperature of the intake air passing through the branch pipes 27 of the intake manifold 28. The intake air temperature control device 33 includes a water spray nozzle (spray nozzle) 34 disposed in each branch pipe 27 of the intake manifold 28, a water receiving portion 35 that receives the water (control liquid) sprayed from the water spray nozzle 34, a cold water tank 36 connected to the water receiving portion 35, and an electric water pump 37 that circulates the water. A water level sensor 38 is provided in the cold water tank 36. The water spray nozzle 34 is an example of a water spraying means.

[0033] A check valve 40 for preventing backflow is interposed in the first pipeline 39 connecting the water pump 37 and the water spray nozzle 34. The cold water tank 36 and the water pump 37 are connected by a second pipeline 41, and the third pipeline 42a connected to the warm water tank 44 and the aforementioned second pipeline 41 are connected via a first three-way valve 43. An electric heater 44a is provided in the warm water tank 44 as an example of a heating means.

[0034] The entire warm water tank 44 is wrapped by a heating tank 45, and the heating tank 45 is interposed in a heating pipeline 42b that connects the heater supply pipeline 30 and the heater return pipeline 53. Therefore, the warm water in the warm water tank 44 can be heated by the electric heater 44a and also by the cooling water that has passed through the cylinder head 4 and has been heated.

[0035] In this case, an ON / OFF type switching valve is arranged at a portion of the heating pipeline 42b upstream of the heating tank 45. When the engine stops, the switching valve is opened and held in the open state for a predetermined time to empty the heating tank 45. Then, the switching valve is closed to maintain the state where the heating tank is empty. When the engine is started and the cooling water is heated to a preset predetermined temperature, the switching valve is opened to receive the heated cooling water from the heater feed pipeline 30 into the heating tank 45 to heat the hot water tank 44. Such control is possible.

[0036] Furthermore, the intake air temperature control device 33 includes a hot water return pipeline 51 for discharging hot water from the water receiving portion 35 to the hot water tank 44. The hot water return pipeline 51 and the cold water tank 36 are connected via a second three-way valve 52. Therefore, the water collected in the water receiving portion 35 can take two modes: a mode of circulating via the hot water tank 44 and a mode of circulating via the cold water tank 36. Of course, a mode in which neither cold water nor hot water circulates can also be selected. It is also possible to directly return the hot water that has passed through the heating tank 45 to the water distribution portion of the cylinder head 4.

[0037] Also, a branched cold water supply pipeline 46 is connected to a portion of the second pipeline 41 downstream of the first three-way valve 43. The cold water supply pipeline 46 is connected to a condensate water tank 49 provided at a portion of the exhaust pipe 47 upstream of the muffler 48. An ON / OFF type switching valve 50 is provided in the cold water supply pipeline 46. The condensate water tank 49 condenses and collects the moisture contained in the exhaust gas, and the exhaust gas is cooled by air.

[0038] A water splash prevention device 54 for preventing the water sprayed from the water spray nozzle 34 from scattering is arranged at the water receiving portion 35. A honeycomb structure is adopted as the water splash prevention device 54, but a metal non-woven fabric or resin non-woven fabric with a coarse mesh, a three-dimensional network body formed by intertwining wire or resin fibers, or a laminate of wire meshes can also be adopted. A sword mountain-like body provided with a large number of upward protrusions can also be adopted.

[0039] The internal combustion engine is equipped with an EGR function, and the EGR gas is refluxed to a portion upstream of the water spray nozzle 34 in the intake passage (for example, the surge tank).

[0040] The cross-sectional shape of the branch pipe 27 in the intake manifold 28 is elliptical or circular, and water flows from top to bottom intersecting the intake flow. And although the water spray nozzle 34 can also spray water in a circular spread, from the viewpoint of the efficiency of the intake temperature increase and high-temperature action, it is preferable that the water spreads evenly over the entire branch pipe 27. In this regard, as shown by the dashed line in (B), it is suitable to form the water spray nozzle 34 in a shape long in the direction intersecting the axis of the branch pipe 27. Even if a plurality of water spray nozzles 34 that spray in a circular shape are arranged in the width direction of the intake port 21, the same effect can be enjoyed.

[0041] (3). Summary The internal combustion engine is equipped with an ECU (Engine Control Unit), and the water pump 37, the water level sensor 38, the three-way valves 43, 52, the switching valve 50, the electric heater 44a, etc. are electrically connected to the ECU. Also, the internal combustion engine is equipped with a rotation sensor, a load sensor, a cooling water temperature sensor, an intake air temperature sensor, an intake air pressure sensor, a throttle opening sensor, an EGR valve, a wastegate valve in the case of being equipped with an exhaust gas turbocharger, a knock sensor, etc. as basic control elements, and these control elements are also electrically connected to the ECU.

[0042] At cold start, it is preferable to warm the air-fuel mixture to enhance its combustibility. Therefore, during the warm-up operation from cold start until the cooling water temperature rises to a predetermined temperature, as shown by the dotted arrow in (A), the first three-way valve 43 controls the third pipeline 42a and the second pipeline 41 to communicate, and the second three-way valve 52 controls the water receiving part 35 and the warm water return pipeline 51 to communicate, thereby circulating the warm water in the warm water tank 44 and warming the intake air with the warm water sprayed from the water spray nozzle 34.

[0043] In this case, it is preferable to energize the electric heater 44a of the hot water tank 44 simultaneously with cranking so that hot water can be injected into the branch pipe 27 in as short a time as possible after starting. As for the control of the electric heater 44a, it is preferable to cut off the power supply when the temperature of the hot water tank 44 has risen to a predetermined temperature and switch to heating and keeping warm with the cooling water. Therefore, it is preferable to provide a water temperature sensor in the hot water tank 44. It is also possible to heat up the water in the hot water tank 44 at an early stage by energizing the electric heater 44a simultaneously with the opening of the driver's side door of the automobile.

[0044] Also, the water in the hot water tank 44 can be heated up (and kept warm) by the cooling water that has passed through the cylinder head 4. However, as described above, if a switching valve is interposed in the heating pipeline 42b and the heating tank 45 is kept empty until the cooling water has risen to a predetermined temperature, it is preferable because the intake air can be heated up at an early stage. Also, from the viewpoint of responsiveness, it is preferable to make the lengths of the pipelines 39 and 41 as short as possible and set the capacity of the hot water tank 44 to the minimum necessary.

[0045] In the embodiment, the hot water pipeline forms a closed circuit. However, the cooling water in the heater feed pipeline 30 can be led to the hot water tank 44, and the water that has returned to the water receiving part 35 can also be returned from the hot water return pipeline 51 to the heater return pipeline 53 or the water distribution part of the cylinder head 4. (In this case, when the internal combustion engine has stopped in a low-temperature environment, the water in the pipeline is cooled, so cold water will pass through the branch pipe 27 immediately after cold start. Regarding this point, the end part of the first pipeline 39 and the water distribution part of the heater return pipeline 53 or the cylinder head 4 are connected by a bypass passage, and the bypass passage is opened only for a predetermined time immediately after cranking, so that only hot water can flow through the branch pipe 27 to deal with this situation.)

[0046] When the internal combustion engine is getting overheated, as shown by the solid-line arrow in (A), the first three-way valve 43 is switched so that the cooling water flows only through the second pipe 41, and the second three-way valve 52 is switched to a state where the water receiving section 35 and the cold water tank 36 are in communication, thereby injecting cold water into the branch pipe 27. As a result, the intake air can be cooled down to improve the filling efficiency. Consequently, the output can be improved even in a high-load state or a high-temperature state. Also, it can contribute to the improvement of exhaust gas components due to a high EGR rate. When the capacity of the cold water tank 36 drops to the reference level, the switching valve 50 is opened to supply condensed water. Thereby, cold water can be self-supplied without external replenishment.

[0047] And in this embodiment, since the intake air is directly exposed to warm water or cold water, it has excellent heat exchange efficiency and can efficiently and responsively raise the temperature of the intake air or heat it up to a high temperature. Providing the cold water tank 36 and the warm water tank 44 as in the embodiment has the advantage that warm water or cold water can be accurately supplied quickly and in the required amount. It is also possible to control the injection amount of water according to the intake air volume. In this case, the opening degree of the throttle valve and the water supply amount of the water supply pump 37 may be linked.

[0048] Also, in order to prevent the water sprayed from the watering nozzle 34 from riding on the intake air and flowing into the cylinder bore 2, either one or both of the water droplet size and the injection speed may be controlled. The water droplet size and the injection speed may be preset to design the watering nozzle 34, or the watering nozzle 34 may be a variable type controlled by a solenoid or a motor, and it is also possible to adjust it to an optimal mode according to the flow velocity and air volume of the intake air.

[0049] When it is expected that abnormal combustion (detonation) will occur due to a supercharged state or an overload, it is also possible to atomize a part of the cold water and send it to the cylinder bore. This can be addressed by making the watering nozzle 34 variable or by installing a dedicated nozzle. Sending atomized water to the cylinder bore 2 is also suitable from the perspective of suppressing nitrogen oxide generation. Note that since the intake manifold 28 of the embodiment is made of synthetic resin, there is no problem of rust.

[0050] (4). Other Embodiments FIG. 2 shows a second embodiment. The difference from the first embodiment is that it does not include the hot water tank 44. The hot water is supplied from the heater supply pipe 30 to the water spray nozzle 34 and returns from the hot water return pipe 51 to the heater return pipe 53 and the like. Therefore, in this embodiment, the structure is simpler than that of the first embodiment. In this embodiment, a tank with a heater can be interposed at the downstream end of the first pipe 39, and it is possible to energize and heat the heater from the start of cold operation until the cooling water is heated to a predetermined temperature.

[0051] FIG. 3 shows another example of the water spray means. In the third embodiment shown in (A) among them, as the water spray means, a flowing water guide body 55 through which water flows is arranged in the branch pipe 27. As the flowing water guide body 55, a non-woven fabric body with a coarse mesh, a laminate of wire meshes, a three-dimensional network body formed by entangling and joining a large number of bent resin fibers, a bamboo blind-shaped member, etc. can be used. In any case, the flowing water guide body 55 has a porosity such that the intake air can pass through with almost no resistance.

[0052] Since the water flowing through the flowing water guide body 55 is not atomized, a part of it does not flow into the cylinder bore 2 along with the intake air flow. Therefore, problems caused by water entering the cylinder bore 2 can be prevented.

[0053] In the fourth embodiment shown in FIG. 3(B), as the water spray means, a first water spray nozzle 56 for ejecting water droplets and a second water spray nozzle 57 for ejecting mist water are arranged side by side in the longitudinal direction of the branch pipe 27.

[0054] In this embodiment, only the first water spray nozzle 56 is used in the state of heating the intake air or in the normal temperature drop state, and when the combustion chamber becomes abnormally high temperature or an abnormally high temperature is expected, atomized water is also ejected from the second water spray nozzle 57 and a part of it can be controlled to be sent to the cylinder bore 2. Thereby, while maintaining the filling efficiency, the temperature of the combustion chamber can be lowered to prevent abnormal combustion.

[0055] The embodiments of the present invention have been described above, but the present invention can be embodied in various other ways. For example, rust prevention treatment such as resin coating can be applied to the inner surface of the intake port. When a water sprinkling nozzle is provided as the water sprinkling means, considering that the atomized water flows to the downstream side, it is also possible to form the water receiving part so as to extend longer on the downstream side than the rear end of the water sprinkling nozzle. In the case of a direct injection type gasoline engine or diesel engine, the water sprinkling means can also be arranged in the intake port.

Industrial Applicability

[0056] The present invention can be embodied in an internal combustion engine. Therefore, it can be used industrially.

Explanation of Reference Numerals

[0057] 1 Piston 2 Cylinder Bore 3 Cylinder Block 4 Cylinder Head 9 Radiator 21 Intake Port 26 Injector 27 Branch Pipe of Intake Manifold Constituting Intake Passage 28 Intake Manifold 29 Cooling Water Jacket of Cylinder Head 31 Heater Core 33 Intake Air Temperature Control Device 34, 56, 57 Water Sprinkling Nozzle as an Example of Water Sprinkling Means 35 Water Receiving Part 36 Cold Water Tank 37 Water Supply Pump 38 Water Level Sensor 39 First Pipeline 41 Second Pipeline 42a Third Pipeline 43 First Three-Way Valve 44 Hot Water Tank 44a Electric Heater 45 Heating Tank 46 Cold Water Supply Pipeline 49 Condensate Tank 50 Switching Valve 51 Hot Water Return Pipeline 52 Third-party valve 53 Heater return pipeline 54 Splash guard 55 Flowing water guide body

Claims

1. An intake air temperature control device that exposes intake air to water in an intake passage to change the temperature of the intake air, wherein the intake air temperature control device has a water spraying means for passing water in a direction intersecting the flow direction of the intake air in the intake passage, and by varying the temperature of the water, it is possible to selectively increase or decrease the temperature of the intake air. An internal combustion engine.

2. The intake air temperature control device includes a hot water tank and a cold water tank, and based on the engine temperature or an alternative temperature, the supply of water from the hot water tank to the water spraying means and the supply of water from the cold water tank to the water spraying means are switched. The internal combustion engine according to Claim 1.

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