JP2007270619A - Intake air cooling system and intake air cooling method of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake air cooling system and an intake air cooling method capable of cooling intake air of an internal combustion engine, without requiring a complicated constitution. <P>SOLUTION: This intake air cooling system has a stack 22 having a large number of fine parallel passages for flowing air and generating a temperature gradient on the inside when propagating acoustic energy, an angular velocity control means 70 controlling angular velocity of the acoustic energy propagating to the stack 22 from the internal combustion engine 1, and a cooling means 23 cooling the acoustic energy propagation side of the stack 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for cooling intake air taken into an internal combustion engine.

A technique for increasing the intake air amount by cooling the intake air to increase the intake air density is disclosed (see Patent Document 1).
JP 2005-69178 A

  However, the above-described conventional technology has a complicated structure and a high manufacturing cost.

  The present invention has been made paying attention to such conventional problems, and provides an intake air cooling device and an intake air cooling method that can cool intake air of an internal combustion engine without requiring a complicated configuration. It is aimed.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention has a plurality of fine parallel passages through which air flows, a stack (22) in which a temperature gradient is generated when acoustic energy propagates, and acoustic energy propagated from the internal combustion engine (1) to the stack (22). The stack (22) has an angular velocity control means (70) for controlling the angular velocity of the stack and a cooling means (23) for cooling the acoustic energy propagation side of the stack (22), and is cooled by the cooling means (23). The intake air is cooled by the portion (22a) on the opposite side to the acoustic energy propagation side.

  According to the present invention, there are a large number of fine parallel passages through which air flows, and when the acoustic energy propagates, the angular velocity of the acoustic energy propagating to the stack, in which the temperature gradient is generated, is controlled, and the acoustic energy propagation side of the stack is controlled. Since the cooling is performed, the temperature on the side opposite to the acoustic energy propagation side of the stack becomes a low temperature. Therefore, the intake air taken into the internal combustion engine can be cooled without requiring a special mechanism.

  Hereinafter, the best mode for carrying out the present invention will be described in more detail with reference to the drawings.

(First embodiment)
The point of the present invention is that the intake air temperature can be lowered. First, in order to facilitate understanding of the invention, the reason why the intake air temperature can be reduced by the present invention will be described.

  As shown in FIG. 1, when a temperature gradient is generated by adding a temperature difference (TH1> TC1) before and after a stack having a large number of fine parallel passages, self-oscillation occurs in the stack under specific conditions. It is known that a traveling wave of acoustic intensity I is generated from the high temperature side.

  On the other hand, as shown in FIG. 2, when a traveling wave of acoustic intensity I propagates through a stack having a large number of fine parallel passages, heat moves in the opposite direction to the traveling wave under specific conditions. It is known that a temperature gradient (TH2> TC2) occurs in the stack, the propagation side becomes high temperature TH2, and the opposite side becomes low temperature TC2.

  The present invention intends to reduce the intake air temperature by utilizing such characteristics. This characteristic will be described in more detail.

  When a fluid (gas) having a thermal diffusion coefficient α is present in the channel having the channel radius r, the thermal diffusion relaxation time τ is expressed by the following equation (1).

  The thermal diffusion coefficient α is determined by the gas state.

  Consider ωτ, which is obtained by multiplying the thermal diffusion relaxation time τ defined by Equation (1) by the angular velocity ω of sound (wave) as a parameter. The thermal boundary layer generated in the vicinity of the wall surface is denoted by δ.

  When the parameter ωτ is sufficiently large (that is, when the channel radius r is sufficiently large with respect to the thermal boundary layer δ, conversely, when the thermal boundary layer δ is sufficiently small with respect to the channel radius r), the stack Changes isothermally.

  On the other hand, when the parameter ωτ is sufficiently small (that is, when the channel radius r is sufficiently small with respect to the thermal boundary layer δ, conversely, when the thermal boundary layer δ is sufficiently large with respect to the channel radius r). In the case, the heat insulation change occurs in the stack, and heat is transferred inside the stack. When acoustic energy propagates to a stack with a sufficiently small parameter ωτ, the acoustic energy is attenuated as it goes downstream of the stack. At this time, the stack has a high temperature on the propagation side and a low temperature as it goes downstream of the stack. A temperature gradient occurs. Thus, the stack in which the parameter ωτ is sufficiently small converts the propagated acoustic energy into the stack temperature, that is, collects the acoustic energy in the stack and converts it into thermal energy.

  The present invention has been made paying attention to such a phenomenon.

  Acoustic energy is generated in an internal combustion engine. The angular velocity of sound (wave) changes according to the angular velocity of pressure waves in the engine cylinder. The acoustic energy propagates through the intake passage from the downstream side to the upstream side. Therefore, the above ω is considered as the angular velocity of the in-cylinder pressure wave. Then, the angular velocity ω of the in-cylinder pressure wave changes according to the rotational speed Ne of the internal combustion engine. That is, if the rotational speed Ne of the internal combustion engine increases, the in-cylinder pressure wave angular velocity ω also increases. Conversely, if the rotational speed Ne of the internal combustion engine decreases, the in-cylinder pressure wave angular velocity ω also decreases. In this way, by changing the rotational speed Ne of the internal combustion engine, the angular velocity of sound (wave) is controlled to generate a temperature gradient in the stack. Then, the intake air is cooled at a portion where the temperature has become low, and is sucked into the internal combustion engine.

  Next, a system for realizing the above concept will be described with reference to FIGS.

  FIG. 3 is a side view for explaining the first embodiment of the intake air cooling device according to the present invention, and FIG. 4 is a plan view for explaining the first embodiment of the intake air cooling device according to the present invention.

  The internal combustion engine 1 sucks air supercharged by the supercharger 50. In the internal combustion engine 1, the intake valve 51 and the exhaust valve 61 open and close in response to the vertical movement of the piston 11.

  A stack 22 is disposed in the intake passage 21. The stack 22 has a number of fine parallel passages. A heat exchanger 23 is disposed around the downstream end of the stack 22. The engine cooling water sent by the pump P circulates in the heat exchanger 23 to cool the stack 22. It is further desirable that the heat exchanger 23 is configured not only around the intake passage 21 but also inside the intake passage 21 and to cool the entire downstream end face of the stack 22.

  The controller 70 calculates the target engine speed and target load of the internal combustion engine based on the accelerator pedal depression amount signal, etc., and the fuel injection timing and fuel injection amount of the fuel injection valve 31, the ignition timing of the spark plug 32, and the throttle valve 33. And the gear ratio of the transmission 34 are controlled. The controller 70 determines that it is possible to change the rotational speed Ne of the internal combustion engine during coasting control or cylinder stop control, and at this time, the acoustic speed is changed by changing the rotational speed Ne of the internal combustion engine. A temperature gradient is generated inside the stack by controlling the angular velocity of (wave). The controller 70 includes a microcomputer that includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The controller 70 may be composed of a plurality of microcomputers.

  In the present embodiment, the stack 22 is provided in the intake passage 21, and the downstream end of the stack 22 is cooled by the engine cooling water. Then, the angular velocity of sound (wave) is controlled by changing the rotational speed Ne of the internal combustion engine to generate a temperature gradient in the stack 22.

  The acoustic energy generated in the internal combustion engine propagates through the intake passage from the downstream side to the upstream side. When acoustic energy propagates to the stack 22 provided in the intake passage 21, a temperature gradient is generated in the stack 22 so that the downstream side has a high temperature and the upstream side has a low temperature. That is, the upstream end 22a of the stack 22 has the lowest temperature. Since the downstream end of the stack 22 is maintained substantially constant by the engine cooling water, the upstream end 22a of the stack 22 has a considerably lower temperature than the engine cooling water. Therefore, the intake air can be cooled. By cooling the intake air in this way, the air charging efficiency can be increased. Moreover, knocking resistance can be improved by lowering the intake air temperature. Therefore, it is possible to advance the ignition timing, and it can be set to the ignition timing at which the torque is most generated, and the fuel consumption is improved.

(Second Embodiment)
FIG. 5 is a plan view for explaining a second embodiment of the intake air cooling device according to the present invention.

  In the second embodiment, a cold heat storage mechanism 40 that can store cold heat at the upstream end of the stack 22 is provided.

  The cold heat storage mechanism 40 includes a reserve tank 41, a pump 42, a heat exchanger 43, a flow path switching valve 44, and a radiator 45.

  The reserve tank 41 stores the refrigerant flowing through the refrigerant passage 46. The pump 42 circulates the refrigerant. The heat exchanger 43 is provided upstream of the stack 22. The heat exchanger 43 conducts the cold heat of the stack 22 to the cold heat storage mechanism 40. The radiator 34 cools the refrigerant. The flow path switching valve 35 switches the flow direction of the refrigerant. The flow path switching valve 35 normally allows the refrigerant to bypass the radiator 34 as shown in FIG. In this state, the pump 42 is driven, and the cold heat of the stack 22 is stored in the reserve tank 33. When the temperature gradient cannot be generated in the stack 22 due to the operating state of the internal combustion engine, the pump 42 is driven to cool the intake air with the cold stored in the reserve tank 33. When the high load state continues and the refrigerant temperature becomes high, the flow path switching valve 35 is switched to allow the refrigerant to flow through the radiator 34 and cool the refrigerant.

  According to this embodiment, since the cold heat storage mechanism 40 is provided, intake air can be cooled more efficiently.

(Third embodiment)
FIG. 6 is a plan view for explaining a third embodiment of the intake air cooling device according to the present invention.

  In the first embodiment, the stack 22 is disposed in the entire intake passage 21. However, in such a configuration, the stack 22 becomes an intake resistance and may cause a pressure loss in the intake passage.

  Therefore, in the third embodiment, the intake passage 21 is made into two passages 21a and 21b corresponding to the intake valves, the stack 22 is arranged in one intake passage 21a, and the stack 22 is not arranged in the other intake passage 21b. I made it. The opening / closing of the intake valve 51a corresponding to the intake passage 21a is controlled according to the required load.

  Here, in order to control the opening / closing of the intake valve 51a according to the required load, for example, a variable valve mechanism disclosed in Japanese Patent Application Laid-Open No. 11-107725 may be used. Here, the variable valve mechanism will be briefly described with reference to FIG.

  The variable valve mechanism 200 includes a cam shaft 210, a link arm 220, a valve lift control shaft 230, a rocker arm 240, a link member 250, and a swing cam 260. The valve 51a is opened and closed.

  The camshaft 210 is rotatably supported on the cylinder head along the engine longitudinal direction. One end of the camshaft 210 is inserted into the cam sprocket 270. The cam sprocket 270 rotates with torque transmitted from the crankshaft of the engine. The camshaft 210 rotates with the cam sprocket 270. The camshaft 210 rotates relative to the cam sprocket 270 by hydraulic pressure, and can change the phase with respect to the cam sprocket 270. With such a structure, the rotational phase of the camshaft 210 relative to the crankshaft can be changed. A cam 211 is fixed to the camshaft 210. The cam 211 rotates integrally with the cam shaft 210. A cam 261 is fixed to the camshaft 210. The cam 261 rotates integrally with the cam shaft 210. The cam 261 opens and closes the intake valve 51b.

  The link arm 220 is supported through the cam 211.

  The valve lift control shaft 230 is disposed in parallel with the camshaft 210. A cam 231 is integrally formed on the valve lift control shaft 230. The valve lift control shaft 230 is controlled by an actuator 280 so as to rotate within a predetermined rotation angle range.

  The rocker arm 240 is supported through the cam 231 and is connected to the link arm 220.

  The link member 250 is connected to the rocker arm 240.

  The swing cam 260 is inserted through the cam shaft 210 and can swing about the cam shaft 210. The swing cam 260 is connected to the link member 250. The swing cam 260 moves up and down to push down the intake valve 51 a through the tappet 53.

  Next, the operation of the variable valve mechanism 200 will be described with reference to FIG.

  FIGS. 8A-1 and 8A-2 are views showing how the lift amount of the intake valve 51a is maximized. FIG. 8A-1 shows a state where the intake valve 51a is closed and the swing direction of the swing cam 260 is reversed. That is, at this time, the cam nose 260b is at the highest position. FIG. 8A-2 shows a state where the intake valve 51a is in the open state and the swing direction of the swing cam 260 is reversed. That is, at this time, the cam nose 260b is at the lowest position.

  FIGS. 8B-1 and 8B-2 are views showing a state when the lift amount of the intake valve 51a is minimized. FIG. 8B-1 shows a state where the cam nose 260b is at the highest position and the swing direction of the swing cam 260 is reversed. FIG. 8B-2 shows a state where the cam nose 260b is at the lowest position and the swing direction of the swing cam 260 is reversed. In the present embodiment, the maximum lift amount of the intake valve 51a is zero. Therefore, in FIGS. 8B-1 and 8B-2, the intake valve 51a is always closed regardless of the operation of the swing cam 260.

  In order to increase the lift amount of the intake valve 51a, as shown in FIGS. 8A-1 and 8A-2, the valve lift control shaft 230 is rotated to lower the position of the cam 231 and the shaft center P1 is pivoted. Set below the heart P2. As a result, the entire rocker arm 240 moves downward.

  When the camshaft 210 is rotationally driven in this state, the driving force is transmitted from the link arm 220 → the rocker arm 240 → the link member 250 → the swing cam 260.

  As shown in FIG. 8A-1, when the cam 211 is on the left side of the camshaft 210, the base circle portion 260a of the swing cam 260 is in contact with the tappet 53. At this time, the intake valve 51a is closed. To do.

  As shown in FIG. 8A-2, when the cam 211 is on the right side of the camshaft 210, the cam nose 260b of the swing cam 260 is in contact with the tappet 53, and at this time, the intake valve 51a is opened.

  In order to reduce the lift amount of the intake valve 51a, as shown in FIGS. 8B-1 and 8B-2, the valve lift control shaft 230 is rotated to raise the position of the cam 231 and the shaft center P1 is pivoted. Set to the upper right of the center P2. As a result, the entire rocker arm 240 moves upward.

  When the camshaft 210 is rotationally driven in this state, the driving force is transmitted from the link arm 220 → the rocker arm 240 → the link member 250 → the swing cam 260.

  As shown in FIG. 8B-1, when the cam 211 is on the left side of the camshaft 210, the base circle portion 260a of the swing cam 260 is in contact with the tappet 53. At this time, the intake valve 51a is closed. To do.

  As shown in FIG. 8B-2, even when the cam 211 is on the right side of the camshaft 210, the base circle portion 260a of the swing cam 260 is in contact with the tappet 53. At this time, the intake valve 51a Closes.

  As described above, when the valve lift control shaft 230 is rotated to raise the position of the cam 231 and the shaft center P1 is set to the upper right of the shaft center P2, the camshaft 210 rotates to swing the swing cam. Even if it moves, the intake valve 51a is always closed.

  FIG. 9 is a diagram showing the lift amount and opening / closing timing of the intake valve 51a by the variable valve mechanism 200. FIG. The solid line shows the lift amount and opening / closing timing of the intake valve 51a when the valve lift control shaft 230 is rotated. The broken line is a diagram showing the opening / closing timing of the intake valve 51a when the phase of the camshaft 210 with respect to the cam sprocket 270 is changed.

  According to the structure of the variable valve mechanism 200 described above, the lift amount and operating angle of the intake valve 51a can be continuously changed. In this way, by changing the angle of the valve lift control shaft 230 and the phase of the camshaft 210 with respect to the cam sprocket 270, the lift amount and operating angle of the intake valve 51a can be changed continuously and freely.

  With the above configuration, the opening and closing of the intake valve 51a is controlled according to the required load. Specifically, when the load is low, the intake valve 51a is closed and the intake valve 51b is opened and closed, thereby sucking air from the intake passage 21b. When the load is high, the intake valve 51a and the intake valve 51b are synchronously opened and closed to suck air from the intake passages 21a and 21b.

  In this way, a necessary amount of air can be secured and the stack 22 can cool the air. If the intake air temperature decreases, the knocking resistance can be improved. Therefore, it is possible to advance the ignition timing even when the compression ratio is increased, and it is possible to set the ignition timing at which the torque is most generated, thereby improving fuel efficiency.

(Fourth embodiment)
FIG. 10 is a plan view for explaining a fourth embodiment of the intake air cooling device according to the present invention.

  Also according to the third embodiment, the stack 22 may become an intake resistance and cause a pressure loss in the intake passage. Therefore, in the fourth embodiment, a wave control valve 52 that opens and closes in synchronization with the intake valve 51 is provided, and the stack 22 is disposed in the wave passage 24. A heat exchanger 23 is disposed at the downstream end of the stack 22. A cold heat conduction plate 25 is connected downstream of the stack 22. The cold heat conduction plate 25 conducts the cold heat of the stack 22 to the intake passage 21 and cools the intake air.

  According to the present embodiment, since the stack 22 is disposed in the wave passage 24, it is not disposed in the intake passage 21. Therefore, the stack 22 can be prevented from becoming an intake resistance and causing a pressure loss in the intake passage, and a sufficient output of the internal combustion engine can be secured.

(Fifth embodiment)
As described above, acoustic energy is generated in an internal combustion engine. The angular velocity of sound (wave) changes according to the angular velocity of pressure waves in the engine cylinder. The acoustic energy propagates through the intake passage from the downstream side to the upstream side. Therefore, the above ω is considered as the angular velocity of the in-cylinder pressure wave. The angular velocity ω of the in-cylinder pressure wave changes not only with the rotational speed Ne of the internal combustion engine but also with the opening / closing timing of the intake valve. Therefore, in the present embodiment, a mechanism for changing the opening / closing timing of the intake valve will be described.

  An electromagnetically driven valve can be used to change the opening / closing timing of the intake valve. For the electromagnetically driven valve, for example, a mechanism disclosed in JP 2000-45733 can be used. Here, the electromagnetically driven valve will be briefly described.

  11A and 11B are diagrams for explaining opening / closing timing adjustment of the exhaust valve by the electromagnetic drive mechanism. FIG. 11A shows a state when the valve is opened, and FIG. 11A shows a state when the valve is closed.

  The intake valve 51 opens and closes the intake port 52 by being seated on or separated from the valve seat 53. A mover 55 is fixed to the valve stem 54 of the intake valve 51. The mover 55 is made of a magnetic material. The mover 55 is connected to the upper spring 56 and the lower spring 57. The upper spring 56 and the lower spring 57 loosely insert the valve stem 54. A valve opening electromagnetic coil 58 and a valve closing electromagnetic coil 59 are provided above and below the mover 55. The valve opening electromagnetic coil 58 is loosely inserted into the lower spring 57. The valve closing electromagnetic coil 59 is loosely inserted into the upper spring 56.

  Next, the opening / closing operation of the intake valve 51 will be described. In a state where power supply to both the valve opening electromagnetic coil 58 and the valve closing electromagnetic coil 59 is interrupted, the mover 55 is placed between the electromagnetic coils 58 and 59 by the elastic force of the upper spring 56 and the lower spring 57. Located in. When the valve opening electromagnetic coil 58 is energized, as shown in FIG. 11A, the mover 55 is attracted to the valve opening electromagnetic coil 58 and moves in the direction of arrow C to open the intake port 52. On the other hand, when the valve closing electromagnetic coil 59 is energized, the mover 55 is attracted to the valve closing electromagnetic coil 59 and moves in the direction of arrow D as shown in FIG. 11B, thereby closing the intake port 52.

  The electromagnetic drive mechanism of the present embodiment can control the angular velocity ω of the in-cylinder pressure wave even when the opening / closing timing of the intake valve is changed, can control the temperature gradient inside the stack, and cools the intake air Can do.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

  For example, it is more effective if it is mounted on a series hybrid vehicle that is operated at the rated speed.

It is a figure explaining the principle of this invention. It is a figure explaining the principle of this invention. 1 is a side view illustrating a first embodiment of an intake air cooling device according to the present invention. It is a top view explaining 1st Embodiment of the intake-air-cooling apparatus by this invention. It is a top view explaining 2nd Embodiment of the intake air cooling device by this invention. It is a top view explaining 3rd Embodiment of the intake-air-cooling apparatus by this invention. It is a figure explaining a variable valve mechanism. It is a figure explaining operation | movement of a variable valve mechanism. It is a figure which shows the lift amount and opening / closing timing of the intake valve by a variable valve mechanism. It is a top view explaining 4th Embodiment of the intake-air-cooling apparatus by this invention. It is a figure explaining the opening-and-closing timing adjustment of the exhaust valve by an electromagnetic drive mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 11 Piston 21 Intake passage 22 Stack 51 Intake valve 61 Exhaust valve 70 Controller (angular velocity control means)

Claims (13)

A stack having a large number of fine parallel passages through which air flows, and in which a temperature gradient is created when acoustic energy propagates;
Angular velocity control means for controlling the angular velocity of the acoustic energy propagating from the internal combustion engine to the stack;
Cooling means for cooling the acoustic energy propagation side of the stack;
Have
The intake air is cooled by the portion of the stack opposite to the acoustic energy propagation side that is cooled by the cooling means;
An intake air cooling apparatus for an internal combustion engine. The angular velocity control means controls the angular velocity of acoustic energy by changing the angular velocity of pressure waves in the engine cylinder by controlling the engine speed.
The intake air cooling device for an internal combustion engine according to claim 1. The angular velocity control means controls the angular velocity of the acoustic energy by changing the angular velocity of the pressure wave in the engine cylinder by controlling the opening and closing timing of the intake valve.
The intake air cooling device for an internal combustion engine according to claim 1. Controlling the opening and closing timing of the intake valve when the internal combustion engine does not require driving force;
The intake air cooling apparatus for an internal combustion engine according to claim 3. The stack is provided in an intake passage of the internal combustion engine;
The cooling means cools a downstream portion of the stack in the intake direction;
The intake air cooling device for an internal combustion engine according to any one of claims 1 to 4, wherein the intake air cooling device is an internal combustion engine. The intake passage is formed of a plurality of passages for one cylinder,
The stack is disposed in at least one of the plurality of passages,
Energy propagation control means for controlling the propagation of acoustic energy to the stack according to the engine load;
The intake air cooling device for an internal combustion engine according to claim 5. A wave control valve that opens and closes in synchronization with the intake valve;
A wave passage communicating with the wave control valve;
With
The stack is provided in the wave passage;
The cooling means cools the wave control valve side of the stack,
And further comprising a cold heat conduction means for conducting cold heat of the stack to the intake passage.
The intake air cooling device for an internal combustion engine according to any one of claims 1 to 4, wherein the intake air cooling device is an internal combustion engine. The cooling means is a device for circulating cooling water of the internal combustion engine.
The intake air cooling device for an internal combustion engine according to any one of claims 1 to 7, wherein the intake air cooling device is an internal combustion engine. It further has a cold heat storage mechanism that is connected to a portion of the stack opposite to the acoustic energy propagation side and stores cold generated by the stack.
The intake air cooling device for an internal combustion engine according to any one of claims 1 to 8, wherein the intake air cooling device is an internal combustion engine. The cold heat storage mechanism circulates liquid water and stores cold heat using the liquid water.
The intake air cooling device for an internal combustion engine according to claim 9. The cold heat storage mechanism is
A radiator capable of cooling the liquid water;
A liquid water flow switching valve for switching whether the liquid water passes through or bypasses the radiator;
With
After consuming the cold heat stored in the liquid water, the liquid water flow switching valve is switched, and the liquid water is cooled by the radiator.
The intake air cooling apparatus for an internal combustion engine according to claim 10. Cools air that has been supercharged by a turbocharger and has risen in temperature,
The intake air cooling device for an internal combustion engine according to any one of claims 1 to 11, wherein the intake air cooling device is an internal combustion engine. An angular velocity control step for controlling the angular velocity of the acoustic energy propagating to the stack, which has a large number of fine parallel passages through which air flows and a temperature gradient is generated when acoustic energy propagates;
A cooling step for cooling the acoustic energy propagation side of the stack;
Have
The intake air is cooled by a portion of the stack opposite to the acoustic energy propagation side that is cooled by the cooling step;
An intake air cooling method for an internal combustion engine.

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