JP2009191746A - Intake air control device for multicylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake control device for a multicylinder internal combustion engine, which is capable of controlling the variation of inertia supercharging effect for every cylinders even when distances from intake air control valves to intake valves for closing and opening independent passages are different from one another. <P>SOLUTION: The distance from intake control valves 13 of independent passages 10 provided to the #1 cylinder and #4 cylinder of an internal combustion engine 1 to intake valves 7 are shorter than the distance from intake control valves 13 of independent passages 10 provided to the #2 cylinder and #3 cylinder, and the intake control valves 13 of the independent passages 10 provided to the #1 cylinder and #4 cylinder, and the intake control valves 13 of the independent passages 10 provided to the #2 cylinder and #3 cylinder are driven by common valve shafts 17 and 18, respectively. The distances L1 and L2 from opened ends 10b of the independent passages 10 with respect to a surge tank 11 to the intake control valves 13 are equal to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intake control device for a multi-cylinder internal combustion engine in which an intake control valve is provided between a surge tank and an intake valve.

  As a method of supplying intake air to the internal combustion engine, with the intake control valve provided between the surge tank and the intake valve closed, the negative pressure in the cylinder is increased using the piston lowering in the intake stroke, Impulse supercharging is known in which the intake control valve is quickly opened before shifting to the compression stroke to generate an intake pressure wave in the intake passage to actively utilize the inertia supercharging effect.

  In general, the internal combustion engine is most efficient when the negative pressure generated in the cylinder at the beginning of the intake stroke is reversed by the inertia effect to become positive pressure and the timing at which the intake valve is closed is synchronized. It is known that an inertial supercharging effect can be obtained. For this reason, the intake system of the internal combustion engine is designed so that a highly efficient inertial supercharging effect can be obtained by synchronizing these timings at the engine speed at which maximum torque is desired. Therefore, if the rotational speed of the internal combustion engine deviates from the rotational speed that is the design standard, the inertial supercharging effect cannot be obtained sufficiently and the output torque is reduced. For example, since the intake valve opening time, i.e., the intake stroke time, becomes longer than the pressure reversal time in the lower rotation range than the reference rotation speed, the intake pressure after the timing when the pressure in the cylinder becomes maximum is passed. The valve will close.

  When impulse supercharging is applied to such an internal combustion engine, an intake stroke is started while the intake control valve is kept closed in a lower rotation range than the design standard described above, and then the intake control valve is opened. Thus, the start time of the intake stroke can be substantially delayed. Thereby, since the intake stroke time extended with respect to the pressure reversal time in the low rotation range is shortened, the inertia supercharging effect can be utilized in a wide range.

  When impulse supercharging is applied to a multi-cylinder internal combustion engine, it is desirable to suppress variation in the inertia supercharging effect for each cylinder and make the intake charge efficiency uniform for each cylinder. For example, as an intake control device capable of performing impulse supercharging, an intake control valve is provided in an independent passage provided for each cylinder of a V-type 6-cylinder internal combustion engine, and an intake control valve is provided on a common valve shaft provided for each bank. Are connected to drive each intake control valve for each bank (Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

JP-A-5-248247 JP 2006-207454 A

  Since the intake device of Patent Document 1 drives the intake control valve for each bank with a common valve shaft, it is easy to align the arrangement of the intake control valve with respect to the independent passage among the cylinders of each bank. However, since there is a limit to the number of intake control valves that can be driven by a single valve shaft, the drive of the intake control valves may have to be shared by a plurality of valve shafts as the number of cylinders increases. In the case of using a plurality of valve shafts, it is difficult to arrange the valve shafts coaxially while avoiding mutual interference. Therefore, it is necessary to dispose the valve shafts in the longitudinal direction of the independent passage. When the valve shafts are arranged in this way, the distance from the intake control valve to the intake valve is different, so the distance from the surge tank to the intake control valve is also different among the cylinders. As a result, variation between cylinders occurs in the inertia supercharging effect using the intake control valve. In order to suppress the variation, it is possible to make the opening / closing timing of the intake control valve different for each cylinder, but in that case, it is difficult to avoid complication of control contents.

  Accordingly, the present invention provides an intake control device for a multi-cylinder internal combustion engine that can suppress variations in the inertia boost effect for each cylinder even when the distance from the intake control valve to the intake valve that opens and closes the independent passage is different. The purpose is to do.

  The first intake control device of the present invention includes an independent passage provided for each cylinder of a multi-cylinder internal combustion engine and opened and closed by an intake valve, and an intake passage having a surge tank connected to each of the independent passages, An intake control valve provided for each independent passage, and the intake control valve provided for each independent passage includes at least two intake control valves having different distances to the intake valve, and An intake control device for a multi-cylinder internal combustion engine in which intake control valves having the same distance are driven by a common valve shaft, wherein the intake control is performed from an open end of the independent passage provided for each cylinder with respect to the surge tank. By configuring the distances to the valves to be equal to each other, the above-described problem is solved (claim 1).

  According to the first intake control device, at least two valve shafts are required to drive each intake control valve, but all intake control valves can be driven by providing one actuator for each valve shaft. . Therefore, the number of actuators can be reduced as compared with an aspect in which one valve shaft is provided for each intake control valve. In addition, since the distance from the open end to the intake tank of the independent tank provided for each cylinder to the intake control valve is equal to each other, it is possible to suppress variations among the cylinders of the inertia supercharging effect using the intake control valve.

  Various modes can be adopted to equalize the distance from the open end of the independent passage to the intake control valve. For example, the shape of the surge tank may be set so that the distance from the open end to the intake control valve is equal to each other (Claim 2). In addition, one end of the independent passage having a long distance from the intake control valve to the intake valve may protrude into the surge tank so that the distance from the open end to the intake control valve is equal to each other. (Claim 3). When one end of the independent passage is protruded into the surge tank, the open end is positioned inside the surge tank. Therefore, the distance from the open end to the intake control valve can be made equal between the independent passage having a long distance from the intake control valve to the intake valve and the independent passage having a short distance.

  The second intake control device of the present invention includes an independent passage provided for each cylinder of a multi-cylinder internal combustion engine and opened and closed by an intake valve, and an intake passage having a surge tank connected to each of the independent passages, An intake control valve provided for each independent passage, and the intake control valve provided for each independent passage includes at least two intake control valves having different distances to the intake valve, and An intake control device for a multi-cylinder internal combustion engine in which an intake control valve having the same distance to the intake valve is driven by a common valve shaft, the open end of the independent passage provided for each cylinder with respect to the surge tank The distance from the open end to the intake control valve is different from each other, and the distance from the open end to the intake control valve is short. The cross-sectional area of the independent path is long from the open end to the intake control valve. By being configured to be smaller than the cross-sectional area, to solve the problems described above (Claim 4).

  According to the second intake control device, at least two valve shafts are required to drive each intake control valve, but all intake control valves can be driven by providing one actuator for each valve shaft. . Therefore, the number of actuators can be reduced as compared with an aspect in which one valve shaft is provided for each intake control valve.

According to the Helmholtz resonance principle, which is well known as the principle of inertial supercharging, the resonance frequency f of a system in which a tube with a length L and a passage cross-sectional area A is connected to a volume part with a capacity V is the speed of sound C Then, the formula: f∝C × [(A / (L × V)] ^0.5 Therefore, the inertial supercharging effect is made uniform for each cylinder by making the resonance frequency f uniform for each cylinder. In the second intake control device, although the distance from the open end of the independent passage to the intake control valve is different from each other, the sectional area of the independent passage having a short distance is an independent passage having a long distance. Therefore, the difference between the cylinders having the resonance frequency f can be eliminated or reduced, and the distance from the open end of the independent passage to the intake control valve can be made uniform. At least between the cylinders of the inertia supercharging effect using the intake control valve Variability can be suppressed.

  In the second intake control device, the passage cross-sectional area does not have to be different over the entire length of the independent passage, and it is sufficient if the passage cross-sectional area is different in a part thereof. Further, the passage cross-sectional area of the independent passage may be constant in the longitudinal direction or may vary. For example, in one aspect of the second intake control device, the independent passage having a short distance from the open end to the intake control valve is configured such that the passage cross-sectional area gradually decreases toward the surge tank. (Claim 5). According to this aspect, since a sudden change in the cross-sectional area of the independent passage can be prevented, a difference in passage resistance between the independent passages can be reduced.

  Further, in one aspect of the second intake control device, the size of the intake control valve provided in the independent passage having a short distance from the open end to the intake control valve is determined from the open end to the intake control valve. The distance may be smaller than the size of the intake control valve provided in the independent passage. That is, the size of the intake control valve may be made different according to the difference in the passage sectional area of the independent passage. In this case, since the intake control valve having a small size is reduced in weight and inertia, the response speed of the intake control valve is improved and energy consumption required for driving the intake control valve can be suppressed.

  In the present invention, the open end is set at a position where the increase rate reaches a predetermined rate in the process of increasing the cross-sectional area of the independent passage toward the inside of the surge tank.

  As described above, according to the first intake control device, since the distance from the open end to the surge tank of the independent passage provided for each cylinder is equal to the intake control valve, the inertia excess using the intake control valve is equal. Variations in the supply effect between cylinders can be suppressed. Further, according to the second intake control device, since the passage sectional area of the independent passage with a short distance from the open end to the intake control valve is smaller than the passage sectional area of the independent passage with a long distance, the independent passage Even if the distance from the open end of the engine to the intake control valve is not uniform, it is possible to suppress the variation between cylinders of the inertia supercharging effect using the intake control valve.

(First form)
FIG. 1 is a diagram schematically showing a main part of an internal combustion engine to which an intake control device according to one embodiment of the present invention is applied. The internal combustion engine 1 is configured as an in-line four-cylinder multi-cylinder internal combustion engine having four cylinders 2 arranged in one direction. In the following description, when it is necessary to distinguish the cylinders 2 from each other, cylinder numbers # 1 to # 4 corresponding to the direction in which the cylinders 2 are arranged may be assigned and described.

  Each cylinder 2 is connected to an intake passage 5 and an exhaust passage 6. The intake passage 5 is opened and closed by two intake valves 7 provided in each cylinder 2, and the exhaust passage 6 is connected to each cylinder 2. They are opened and closed by two exhaust valves (not shown). These valves are driven to open and close at a predetermined timing by a valve operating mechanism (not shown). The order of combustion for each cylinder 2 is set in the order of # 1, # 3, # 4, and # 2.

  The intake passage 5 has an independent passage 10 provided for each cylinder 2 and opened and closed by an intake valve 7 and a surge tank 11 to which each independent passage 10 is connected. Each independent passage 10 includes an intake port 10 a that opens to each cylinder 2. The surge tank 11 has a predetermined volume that can alleviate intake air interference for each cylinder 2. An intake throttle valve 12 is provided on the upstream side of the surge tank 11.

  Each independent passage 10 is provided with one intake control valve 13. Each intake control valve 13 is driven to open and close by two valve drive devices 15 and 16. The first valve drive unit 15 is responsible for opening and closing the two intake control valves 13 provided for the # 1 and # 4 cylinders, and the second valve drive unit 16 is provided for the # 2 and # 3 cylinders. It is responsible for opening and closing the two intake control valves 13.

  The first valve drive device 15 has a valve shaft 17 extending in the direction in which the cylinders 2 are arranged, and two intake control valves 13 provided for the # 1 and # 4 cylinders can be integrally rotated on the valve shaft 17. Installed. The second valve drive device 16 has a valve shaft 18 that extends in the direction in which the cylinders 2 are arranged and is displaced in the longitudinal direction of the independent passage 10 with respect to the valve shaft 17. The two intake control valves 13 provided for the # 2 and # 3 cylinders are attached so as to be integrally rotatable. Each of the valve shafts 17 and 18 penetrates the independent passage 10, and one actuator 20 is attached to one end thereof. The actuator 20 is configured as an electric actuator. By sending a control signal to the actuator 20 at a predetermined timing, each intake control valve 13 is rotationally driven from the fully closed position to the fully open position.

  Since each of the valve drive devices 15 and 16 is configured as shown in the drawing, the intake control valve 13 having a short distance to the intake valve 7 and the intake control having a long distance to the intake valve 7 among the four intake control valves 13. Two valves 13 are included. In this embodiment, the intake control valve 13 driven by the first valve drive device 15 corresponds to a short distance to the intake valve 7, and the intake control valve 13 driven by the second valve drive device 16 is the intake air. This corresponds to a long distance to the valve 7.

  In this embodiment, regardless of the distance from the intake control valve 13 to the intake valve 7, the surge tank 11 is set such that the distances L1, L2 from the open end 10b of the independent passage 10 to the surge tank 11 to the intake control valve 13 are equal to each other. The shape is set. That is, both end portions 11 a of the surge tank 11 connected to the independent passages 10 provided in the # 1 and # 4 cylinders bulge outward from the independent passages 10. Therefore, the open ends 10b of the independent passages 10 provided in the # 1 and # 4 cylinders are located closer to the cylinder 2 than the open ends 10b of the other independent passages 10. As a result, the distances L1 and L2 from the open end 10b of the independent passage 10 to the intake control valve 13 are equal to each other. Therefore, the resonance frequency according to the Helmholtz resonance principle can be made uniform for each cylinder 2. Thereby, the dispersion | variation between the cylinders of the inertia supercharging effect using the intake control valve 13 can be suppressed.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows an example of an intake air control apparatus according to the second embodiment of the present invention. In the second embodiment, the same members as those in the first embodiment are denoted by the same reference numerals in FIG. As shown in FIG. 2, in this embodiment, the arrangement order of the first valve drive device 15 and the second valve drive device 16, in other words, the arrangement of the intake control valves 13 provided for each cylinder 2 is shown in FIG. 1. Compared to the form shown. That is, in this embodiment, the intake control valve 13 driven by the first valve drive device 15 corresponds to a long distance to the intake valve 7, and the intake control valve 13 driven by the second valve drive device 16 is This corresponds to a short distance to the intake valve 7. Also in this embodiment, a surge tank 21 having a shape set so that the distances L1 and L2 from the open end 10b of the independent passage 10 to the intake control valve 13 are equal to each other is provided as in the embodiment of FIG. The surge tank 21 has a central portion 21a connected to the independent passage 10 provided in the # 2 and # 3 cylinders and bulges toward the side close to the cylinder 2. Therefore, the open ends 10b of the independent passages 10 provided in the # 2 and # 3 cylinders are positioned closer to the cylinder 2 than the open ends 10b of the other independent passages 10. As a result, the distances L1 and L2 from the open end 10b of the independent passage 10 to the intake control valve 13 are equal to each other, and an effect equivalent to that of the embodiment shown in FIG.

(Third form)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 shows an example of an intake air control apparatus according to the third embodiment of the present invention. In the third embodiment, members that are the same as those in the first embodiment are given the same reference numerals in FIG. As shown in FIG. 3, in this embodiment, the first valve driving device 15 and the second valve driving device 16 are arranged in the same manner as in the embodiment shown in FIG. In this embodiment, a surge tank 31 to which each independent passage 10 is connected is provided. The open end 10 b of the independent passage 10 provided in the # 2 and # 3 cylinders is located inside the surge tank 31. In other words, one end of the independent passage 10 provided in the # 2 and # 3 cylinders protrudes into the surge tank 31. The distances L1 and L2 from the open end 10b to the intake control valve 13 are made equal between the independent passage 10 provided in the # 2 and # 3 cylinders and the independent passage 10 provided in the # 1 and # 4 cylinders. be able to. Thereby, this embodiment can also exhibit the same effect as the embodiment shown in FIG.

  The shape of the protruding portion of the independent passage 10 protruding into the surge tank 31 is arbitrary, and the protruding portion may be integrated with the independent passage 10 or separate. FIG. 4 is an enlarged view showing a modification of the embodiment of FIG. As shown in this figure, this modification is provided with a funnel 33 that functions as a protruding portion of the independent passage 10, and the funnel 33 is attached to and detached from the inside of the surge tank 31 using a fastening member 34 such as a bolt. It is attached as possible. The funnel 33 is configured such that the passage cross-sectional area gradually increases toward the open end 10b so that air can be efficiently taken into the cylinder 2 from the surge tank 31. Also in this modified example, an effect equivalent to that of the embodiment of FIG. 3 can be exhibited.

(4th form)
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 shows an example of an intake air control apparatus according to the fourth embodiment of the present invention. In the fourth embodiment, members that are the same as those in the first embodiment are given the same reference numerals in FIG. In this embodiment, the first valve driving device 15 and the second valve driving device 16 are arranged in the same manner as the embodiment shown in FIG. Further, this embodiment has an independent passage 40 provided with an intake control valve 13 having a long distance to the intake valve 7. The independent passage 40 includes an intake port 40a that opens to the cylinder 2, and is connected to the # 2 and # 3 cylinders. The position of the open end 40b of the independent passage 40 with respect to the surge tank 41 is aligned with the open end 10b of the independent passage 10 of the # 1 and # 4 cylinders. Accordingly, the distance L1 from the open end 10b of the independent passage 10 to the intake control valve 13 is longer than the distance L2 from the open end 40b of the independent passage 40 to the intake control valve 13. According to the Helmholtz resonance principle described above, the square root of the passage cross-sectional area is proportional to the resonance frequency, and the square root of the passage length is inversely proportional to the resonance frequency. Therefore, in the present embodiment, the cross-sectional area of the independent passage 40 is made smaller than the cross-sectional area of the independent passage 10 in order to equalize the resonance frequency for each of the independent passages 10 and 40. In the illustrated example, the passage sectional area of the upstream portion 40c of the independent passage 40 located upstream of the intake control valve 13 is made smaller than the passage sectional area of the independent passage 10, and the passage sectional area of the upstream portion 40c is made smaller. It is almost constant. As a result, the resonance frequency can be made uniform for each cylinder 2 or the difference between the cylinders can be reduced. For this reason, even if the distances L1 and L2 from the open ends 10b and 40b of the independent passages 10 and 40 to the intake control valve 13 are not aligned, the variation in the inertia supercharging effect using the intake control valve 13 among cylinders is suppressed. Can do.

(5th form)
Next, a fifth embodiment of the present invention will be described with reference to FIG. This form corresponds to a modification of the form of FIG. The independent passage 50 of this embodiment includes an intake port 50a that opens to the # 2 and # 3 cylinders. The independent passage 50 is configured such that its upstream portion 50 c gradually decreases toward the open end 50 b and is connected to the surge tank 51. The degree of reduction is set so that the resonance frequency can be made uniform for each cylinder 2 or the difference between the cylinders can be reduced. Therefore, according to this embodiment, the variation between the cylinders of the inertia supercharging effect using the intake control valve 13 can be suppressed, and a sudden change in the sectional area of the independent passage 40 can be prevented. The difference in resistance can be reduced.

(Sixth form)
Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 shows an example of an intake air control apparatus according to the sixth embodiment of the present invention. In the sixth embodiment, members that are the same as those in the first embodiment are given the same reference numerals in FIG. As shown in FIG. 7, the 1st valve drive device 15 and the 2nd valve drive device 16 are arrange | positioned similarly to the form shown in FIG. The independent passages 60 of the # 2 and # 3 cylinders include an intake port 60a that opens to the cylinder 2. The position of the open end 60b of the independent passage 60 with respect to the surge tank 61 is the independent passage 10 of the # 1 and # 4 cylinders. Are arranged at the same level as the open end 10b. Accordingly, as in the fourth and fifth embodiments, the distance L1 from the open end 10b of the independent passage 10 to the intake control valve 13 is longer than the distance L2 from the open end 60b of the independent passage 60 to the intake control valve 63. . In this embodiment, in order to equalize the resonance frequency for each of the independent passages 10 and 60, the passage cross-sectional area of the independent passage 60 is smaller than the passage cross-sectional area of the independent passage 10 over its entire length. The intake control valve 63 of the independent passage 60 is downsized relative to the intake control valve 13 of the independent passage 10 so as to correspond to the cross-sectional area of the independent passage 60. According to this embodiment, since the resonance frequency according to the principle of Helmholtz resonance can be made uniform with respect to each cylinder 2 or the difference between the cylinders can be reduced, the intake control valves 13 and 63 can be controlled without the distances L1 and L2. It is possible to suppress the variation between the cylinders of the used inertial supercharging effect. In addition, since the reduced intake control valve 63 is smaller in weight and inertia than the other intake control valves 13, the response speed of the intake control valve 63 is improved and the energy consumption required for driving the intake control valve 63 can be suppressed. it can.

  The present invention is not limited to the above embodiments, and can be implemented in various forms. The intake control device of the present invention is not limited in the number of cylinders of the internal combustion engine that can be applied. Therefore, the intake control device of the present invention can be applied to a multi-cylinder internal combustion engine of 6 cylinders or 8 cylinders in addition to the above-described 4 cylinders. The cross-sectional shape of the independent passage according to the present invention is arbitrary. That is, since the Helmholtz resonance principle described above is one of the parameters of the cross-sectional area of the path, the independent path may be circular, elliptical, or polygonal.

  Further, the mounting position of the intake control valve according to the present invention may be anywhere between the surge tank and the intake valve. For example, the intake control valve can be mounted in the intake port formed in the cylinder head. .

The figure which showed typically the principal part of the internal combustion engine to which the intake control device which concerns on one form of this invention was applied. The figure which showed an example of the intake control device which concerns on the 2nd form of this invention. The figure which showed an example of the intake control device which concerns on the 3rd form of this invention. The enlarged view which showed the modification of the form of FIG. The figure which showed an example of the intake control device which concerns on the 4th form of this invention. The figure which showed an example of the intake control apparatus which concerns on the 5th form of this invention. The figure which showed an example of the intake control apparatus which concerns on the 6th form of this invention.

Explanation of symbols

1 Internal combustion engine 2 Cylinder 5 Intake passage 7 Intake valve 10 Independent passage 10b Open end 11 Surge tank 13 Intake control valves 17, 18 Valve shaft 21 Surge tank 31 Surge tank 40 Independent passage 40b Open end 41 Surge tank 50 Independent passage 50b Open end 60 Independent passage 60b Open end 63 Intake control valve

Claims (6)

An independent passage provided for each cylinder of a multi-cylinder internal combustion engine and opened and closed by an intake valve; an intake passage having a surge tank connected to each of the independent passages; and an intake control valve provided for each independent passage; And the intake control valve provided for each independent passage includes at least two intake control valves having different distances to the intake valve, and the intake control valve has the same distance to the intake valve. Is an intake control device for a multi-cylinder internal combustion engine driven by a common valve shaft,
An intake control device for a multi-cylinder internal combustion engine, characterized in that a distance from an open end of the independent passage provided for each cylinder to the surge tank to the intake control valve is equal to each other.   The intake control device according to claim 1, wherein the shape of the surge tank is set so that distances from the open end to the intake control valve are equal to each other.   The one end of the independent passage having a long distance from the intake control valve to the intake valve is protruded into the surge tank so that the distance from the open end to the intake control valve becomes equal to each other. The intake control device described in 1. An independent passage provided for each cylinder of a multi-cylinder internal combustion engine and opened and closed by an intake valve; an intake passage having a surge tank connected to each of the independent passages; and an intake control valve provided for each independent passage; And the intake control valve provided for each independent passage includes at least two intake control valves having different distances to the intake valve, and the intake control valve has the same distance to the intake valve. Is an intake control device for a multi-cylinder internal combustion engine driven by a common valve shaft,
The cross-sectional area of the independent passage where the distance from the open end to the intake control valve with respect to the surge tank of the independent passage provided for each cylinder is different from each other and the distance from the open end to the intake control valve is short An intake control device for a multi-cylinder internal combustion engine, wherein the distance from the open end to the intake control valve is smaller than the cross-sectional area of the independent passage.   The intake control device according to claim 4, wherein the independent passage having a short distance from the open end to the intake control valve is configured such that a passage cross-sectional area thereof gradually decreases toward the surge tank.   The size of the intake control valve provided in the independent passage where the distance from the open end to the intake control valve is short is the size of the intake control valve provided in the independent passage where the distance from the open end to the intake control valve is long. The intake control device according to claim 4, wherein the intake control valve is smaller than a size of the intake control valve.

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