JP4238560B2 - Intake device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device for an internal combustion engine.
[0002]
[Prior art]
Conventionally, the sound resulting from the operation of an internal combustion engine (hereinafter referred to as an engine) mounted on an automobile or the like has been required to have a sound quality that matches the user's preference as a so-called engine sound. In particular, powerful engine sounds are required for SUV (Sport Utility Vehicles) type vehicles. In order to obtain a powerful engine sound, there has been an intake device that controls the generation of even-order component sounds of engine speed, and evenly increases the even-order component sounds of engine sound as the engine speed increases. Here, the even-order component sound is a sound having a frequency component 2n times (n = 1, 2,...) The engine speed (this is referred to as a 2n-order component sound).
[0003]
In order to obtain a powerful engine sound, it is effective to generate a half order component sound as the engine speed increases, and a half order component sound is generated by the unbalanced weights of the intake and exhaust camshafts that rotate in reverse to each other. There was an internal combustion engine. Here, the half order component sound is a sound of a frequency component (n + 1, 2...) Times (n + 1/2) times the engine speed (this is referred to as an (n + 1/2) order component sound). For example, if the engine speed is 3000 rpm (50 Hz), a 75 Hz sound corresponds to a 1.5th order component sound.
[0004]
Patent Document 1 listed below describes an intake device that controls even-order component sounds.
Patent Document 2 listed below describes an internal combustion engine that generates a half-order component sound.
[Patent Document 1]
JP-A-1-190957
[Patent Document 2]
JP 2002-227612 A
[0005]
[Problems to be solved by the invention]
However, since the conventional intake device does not control the generation of the half-order component sound that accompanies the increase in the engine speed, a powerful engine sound cannot be obtained sufficiently.
[0006]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an intake device that can sufficiently obtain a powerful engine sound.
[0007]
[Means for solving the problems and their functions and effects]
  In order to solve the above-described problem, an intake device that introduces air from the outside to an internal combustion engine, and finally communicates an expansion chamber having a predetermined space capacity to the intake path of the internal combustion engine, each having a different resonance frequency. One end of each of the plurality of intake ducts is provided in communication with the expansion chamber, and each of the other end of the plurality of intake ducts is caused by interference of resonance sound emitted from each other, thereby generating a half-order component sound of the engine speed of the internal combustion engine. Is a possible positional relationshipA duct opening / closing means for opening / closing at least one of the plurality of intake ducts, and the duct opening / closing means increases or decreases a space capacity of the expansion chamber when opening / closing the one intake duct.It is characterized by that.
[0008]
  According to such an intake device, resonance pulsations having different resonance frequencies respectively generated from a plurality of intake ducts generate intake pulsations in the vicinity of both ends of these intake ducts due to air pulsations accompanying opening and closing of the intake valves of the internal combustion engine. Interfering with the sound creates a half-order component sound as the engine speed increases. Therefore, a powerful engine sound can be sufficiently obtained by the intake device of the internal combustion engine. The resonance frequency and positional relationship of each of the plurality of intake ducts may be determined by examining various factors such as the characteristics of the internal combustion engine, the installation environment, and the required engine sound characteristics. As an aspect of such an intake duct, for example, the plurality of intake ducts are two intake ducts, the resonance frequency of the two intake ducts is in the range of about 200 Hz to about 500 Hz, and the two intake ducts The resonance frequency ratio may be in the range of about 1: 2 to about 1: 3.When the duct opening / closing means closes one intake duct, there is no interference of the intake pulsation sound due to the resonance sound from the one intake duct, but when the duct opening / closing means opens the intake duct, Interference of intake pulsation due to resonance from the duct occurs. Therefore, when the duct opening / closing means opens and closes the intake duct, it is possible to switch the powerful timbre of the engine sound or switch between the powerful engine sound and the normal engine sound. When the space capacity of the expansion chamber is increased by the duct opening / closing means, the sound pressure level of the suction sound released from the intake port is decreased. When the space capacity of the expansion chamber is decreased, the sound pressure level of the suction sound is increased. Therefore, the sound volume of the engine sound can be increased / decreased together with the change of the timbre of the engine sound, which is more effective in obtaining a powerful engine sound.
[0009]
The intake device of the present invention having the above-described configuration can also take the following aspects. The plurality of intake ducts may be formed with different pipe lengths. Since the resonance frequency of the intake duct can be changed by changing the pipe length of the intake duct, the engine sound can be tuned without changing the design of the communication part with the expansion chamber.
[0010]
The other end of at least one of the plurality of intake ducts may be communicated with another intake duct. When the installation space of the intake port that is open to the outside and takes in air is limited, by reducing the other end of the intake duct that becomes the intake port, even if the installation space of the limited intake port is limited, it is a powerful engine You can get enough sound.
[0011]
The other end of at least one of the plurality of intake ducts may be disposed in the vicinity of the other end of the other intake duct. The intake efficiency of the internal combustion engine can be increased by using the other ends of the plurality of intake ducts as intake ports and taking in more air from the outside.
[0012]
The expansion chamber may be provided in an air cleaner that removes dust from the intake air. By making the space inside the air cleaner an expansion chamber, it is possible to improve the space efficiency of the intake device.
[0014]
The duct opening / closing means may be provided in an air cleaner that removes dust from intake air. By providing the duct opening / closing means in the space inside the air cleaner, it is possible to improve the mounting space efficiency of the intake device.
[0016]
As such a duct opening / closing means, for example, the duct opening / closing means includes a valve body formed in a substantially semi-cylindrical shape composed of a narrow part and a wide part, a valve body into which the valve body is fitted, and a rotating valve body. A rotary valve or the like provided with a driving means for performing the above is conceivable. In this rotary valve, the narrow portion is fitted into the valve body to open and close the intake duct, and at the same time, the wide portion enters and exits from the valve body to the expansion chamber to increase or decrease the space capacity of the expansion chamber. Accordingly, the engine sound volume can be changed and the volume of the engine sound can be increased or decreased by one operation.
[0017]
In addition to the duct opening / closing means, capacity increasing / decreasing means for increasing / decreasing the space capacity of the expansion chamber may be provided. Therefore, the volume of the engine sound can be increased or decreased separately from the generation of a powerful engine sound. Furthermore, the duct opening / closing means may be provided with a capacity increasing / decreasing means for increasing / decreasing the space capacity of the expansion chamber when opening / closing the one intake duct. Therefore, the timbre and volume of the engine sound can be tuned in detail.
[0018]
Further, the state detecting means for detecting the operating state of the internal combustion engine, and the intake duct is opened and closed by the duct opening and closing means based on the operating state detected by the state detecting means, resulting from the plurality of intake ducts And an open / close control means for controlling the generation of the half order component sound. Therefore, since the half order component sound is generated according to the operating state of the internal combustion engine, it is possible to improve the sense of unity between the operating state of the internal combustion engine and the engine sound. As the operating state of such an internal combustion engine, for example, at least the engine speed or the engine load of the internal combustion engine can be considered. In the case of an internal combustion engine mounted on an automobile, the generation of half-order component sounds can be controlled by determining whether the automobile is in an accelerated state based on the engine speed and engine load, and more powerful engine sound can be achieved more effectively. Can be generated.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
In order to further clarify the configuration and operation of the present invention described below, an embodiment of an intake device for an internal combustion engine to which the present invention is applied will be described below.
[0020]
FIG. 1 is an overall configuration diagram of an intake device for an internal combustion engine according to a first embodiment of the present invention. The internal combustion engine (hereinafter referred to as an engine) 10 and its intake device 15 are mounted on an automobile. The engine 10 includes a piston 110 that conveys an explosive force when a mixture of fuel and air explodes and burns in a cylinder, an intake port 120 that takes in intake air, an intake valve 130 that opens and closes the intake port 120, and an exhaust that discharges exhaust gas. A port 140, an exhaust valve 150 for opening and closing the exhaust port 140, a crank position sensor 160 for detecting the engine speed N, and the like are provided.
[0021]
The intake device 15 for supplying air to the engine 10 includes an intake duct 20a for taking in air from the upstream side of the air flow, an intake sub-duct 20b branched from the intake duct 20a, an air cleaner 50 for cleaning the intake air, and a clean air. An intake path 60 that guides air to the intake port 120 of the engine 10 is arranged in this order. In addition, the intake device 15 also includes a rotary valve 40 as duct opening / closing means for opening and closing the intake sub-duct 20b, and a controller 70 as opening / closing control means for controlling the rotary valve 40.
[0022]
The intake duct 20a is a duct having a predetermined resonance frequency, and one end thereof is provided in communication with the air cleaner 50, and the other end is opened to the outside to serve as an intake port for taking in air. The intake sub duct 20b is a duct having a predetermined resonance frequency different from that of the intake duct 20a. One end of the intake sub duct 20b communicates with the air cleaner 50, and the other end communicates with the intake duct 20a. The positional relationship between the intake duct 20a and the intake sub-duct 20b is a positional relationship that can generate a half-order component sound of the engine speed of the engine 10 due to interference of resonance sounds that are generated when the intake duct 20a and the intake sub-duct 20b are opened. .
[0023]
Here, the relationship between the resonance frequencies of the intake duct 20a and the intake sub duct 20b is determined by examining various factors such as the characteristics of the engine 10, the installation environment, and the required engine sound characteristics. For example, the resonance frequency of the intake duct 20a and the intake sub duct 20b is in the range of about 200 Hz to about 500 Hz, and the ratio of the resonance frequency between the intake duct 20a and the intake sub duct 20b is about 1: 2 to about 1: 3. It can be considered as a range. In this embodiment, the resonance frequency of the intake duct 20a is about 200 Hz, and the resonance frequency of the intake sub duct 20b is about 400 Hz. In the present embodiment, the intake duct 20a and the intake subduct 20b have substantially the same diameter, and the pipe length of the intake duct 20a is approximately twice the pipe length of the intake subduct 20b, that is, the intake duct 20a and the intake subduct 20b. By forming the tube lengths to be different from each other, the respective resonance frequencies are made different. Of course, the resonance frequency may be adjusted by the tube diameter, the cross-sectional shape, and the like.
[0024]
The air cleaner 50 is formed in a substantially box shape having a space inside, and includes an air filter 510 that filters the taken-in air in the middle of the space inside the air cleaner 50. The first expansion chamber 30 having a predetermined space capacity is provided on the upstream side of the air filter 510. A second expansion chamber 520 having a predetermined space capacity is provided on the downstream side of the air filter 510. The first expansion chamber 30 is provided with one end of an intake duct 20a and an intake sub duct 20b communicating with each other. The first expansion chamber 30 houses a rotary valve 40 that opens and closes the intake sub duct 20b. The second expansion chamber 520 communicates with the intake path 60 and finally guides air to the engine 10.
[0025]
The intake path 60 communicates with the second expansion chamber 520 of the air cleaner 50 and the intake port 120 of the engine 10, and an air flow meter 610 that detects an intake air amount Q taken in by the engine 10 from the upstream side of the air flow. A throttle valve 620 for adjusting the amount of intake air taken in by the engine 10 and a fuel injector 640 for injecting fuel into the air flow and supplying the fuel to the engine 10 are arranged in this order. The throttle valve 620 includes a throttle position sensor 630 that detects the throttle opening θ of the throttle valve 620.
[0026]
The controller 70 is connected to a crank position sensor 160, an air flow meter 610, and a throttle position sensor 630, which are state detection means for detecting the operating state of the engine 10, and inputs detection signals from these sensors. The controller 70 is connected to the rotary valve 40, determines the operating state of the engine 10 based on the input detection signal, outputs a control signal to the rotary valve 40, and opens and closes the intake sub duct 20b.
[0027]
Next, the structure of the rotary valve 40 will be described. FIG. 2 is a perspective view showing the structure of the rotary valve 40 of the intake device 15 according to the first embodiment of the present invention. FIG. 3 is shown to assist in understanding the structure of the rotary valve 40 shown in FIG. FIG. 3 is an assembled perspective view showing the structure of the rotary valve 40 of the intake device 15 according to the first embodiment of the present invention. The rotary valve 40 is a valve body 410 that opens and closes a communication portion between the intake sub-duct 20b and the first expansion chamber 30, a valve body 420 into which the valve body 410 is fitted, a drive that is provided outside the valve body 420 and rotates the valve body 410. Servo motor 440 as a means, and a shaft 430 that transmits the rotational driving force of servo motor 440 to valve body 410 are provided. The servo motor 440 serving as a driving unit rotates the valve body 410 based on the control signal input from the controller 70 described above.
[0028]
The valve body 410 is formed in a substantially semi-cylindrical shape composed of a narrow width portion 411 and a wide width portion 412, and is provided in the valve body 420 so as to be rotatable around a shaft 430 that is also the center of the circle of the substantially semi-cylindrical shape. is there. The valve body 410 is in contact with the first expansion chamber 30 at a surface that cuts the cylinder into a substantially semi-cylinder. The narrow width portion 411 occupies approximately a quarter cylindrical portion of the substantially semi-cylindrical valve element 410, and the wide width portion 412 occupies the remaining approximately quarter cylindrical portion. The wide portion 412 has a width in the direction of the shaft 430 that is approximately the same as the width of the first expansion chamber 30. The narrow width portion 411 has a width in the direction of the shaft 430 that is equal to or larger than the diameter of the intake sub duct 20 b and is narrower than the wide width portion 412.
[0029]
The valve body 420 is formed so that the valve body 410 is fitted so as to cover a surface other than the surface of the valve body 410 that is cut into a substantially semi-cylindrical shape, and a part of the first expansion chamber 30 of the air cleaner 50 is formed. Form. The valve body 420 includes a narrow-width fitting portion 421 into which the narrow-width portion 411 of the valve body 410 is fitted, and a duct communication portion 422 in which the intake sub-duct 20b and the first expansion chamber 30 communicate with each other. The narrow-width fitting portion 421 is formed so as to sandwich the narrow-width portion 411 so as to fill a space formed by narrowing the width of the narrow-width portion 411 of the valve body 410 in the axis 430 direction compared to the wide-width portion 412. The duct communication portion 422 is formed at a position where the circumferential surface of the narrow width portion 411 of the valve body 410 is in contact with the intake sub duct 20b by the rotation of the valve body 410.
[0030]
Next, the operation of the rotary valve 40 will be described. A state in which the rotary valve 40 closes the intake sub duct 20b (hereinafter referred to as a closed state) will be described. FIG. 4 is an enlarged cross-sectional view of the vicinity of the intake duct in the closed state of the intake device 15 according to the first embodiment of the present invention. In the closed state, the narrow width portion 411 of the valve body 410 is fitted into the narrow width fitting portion 421 of the valve body 420 in contact with the duct communication portion 422 of the valve body 420 at the circumferential surface thereof. Therefore, the intake sub duct 20 b does not communicate with the first expansion chamber 30. On the other hand, the entire wide portion 412 of the valve body 410 is fitted into the valve body 420.
[0031]
Therefore, the air introduced into the engine 10 from the outside does not pass through the intake sub duct 20b, passes through the intake duct 20a, enters the first expansion chamber 30, and is finally introduced into the intake port of the engine 10. At this time, a main sound generated from the intake device 15 is an intake pulsation sound generated by air pulsation accompanying opening and closing of the intake valve 130. This intake pulsation sound is a periodic sound related to the engine speed and the number of cylinders of the engine 10, and is mainly composed of a primary component sound and a secondary component sound of the engine speed. Therefore, the intake device 15 in the closed state generates a sound mainly composed of a primary component sound and a secondary component sound.
[0032]
A state in which the rotary valve 40 opens the intake sub duct 20b (hereinafter referred to as an open state) will be described. FIG. 5 is an enlarged cross-sectional view of the vicinity of the intake duct in the open state of the intake device 15 according to the first embodiment of the present invention. In the state shown in FIG. 5, the valve body 410 in the closed state shown in FIG. 4 moves the shaft 430 until the circumferential surface of the narrow portion 411 of the valve body 410 does not contact the duct communication portion 422 of the valve body 420. It is in a state of rotating counterclockwise on the page as the center. In this open state, the narrow width portion 411 of the valve body 410 is further fitted in the back of the narrow width insertion portion 421 of the valve body 420, and the region A1 occupied by the narrow width portion 411 in the closed state of FIG. It becomes a part of the space of the 1 expansion chamber 30, and the 1st expansion chamber 30 contacts the duct communication part 422 through the space which was area | region A1. Therefore, the intake sub duct 20 b communicates with the first expansion chamber 30.
[0033]
Furthermore, the wide portion 412 of the valve body 410 protrudes from the valve body 420 to the first expansion chamber 30 by the amount of rotation of the valve body 410, and the region A2 occupied by the protruding portion of the wide portion 412 is not a space. Since the width of the wide portion 412 is wider than the width of the narrow portion 411, the volume of the region A2 is larger than the volume of the region A1. Accordingly, the space capacity of the first expansion chamber 30 in the open state decreases compared to the closed state because the capacity that decreases in the area A2 is larger than the capacity that increases in the area A1. From this action, the rotary valve 40 also functions as a capacity increasing / decreasing means that increases or decreases the space capacity of the first expansion chamber 30.
[0034]
Therefore, the air introduced into the engine 10 from the outside enters the first expansion chamber 30 through a path that passes through the intake duct 20a and a path that branches from the middle of the intake duct 20a and passes through the intake subduct 20b. Thus, it is introduced into the intake port 120 of the engine 10. At this time, main sounds generated from the intake device 15 are intake pulsation sound and pulsation interference sound generated by air pulsation accompanying opening and closing of the intake valve 130. The pulsation interference sound is generated when resonance sounds having different frequencies generated by opening the intake duct 20a and the intake sub duct 20b interfere with the intake pulsation sound in the vicinity of both ends of the intake duct 20a and the intake sub duct 20b. This pulsation interference sound is a sound mainly composed of a 1.5th order component sound that is a half order component sound of the engine speed. Therefore, the intake device 15 in the open state generates a sound mainly composed of a 1.5th order component sound in addition to the primary component sound and the secondary component sound.
[0035]
Furthermore, the sound pressure level of the sound generated in the intake device 15 increases as the space capacity of the first expansion chamber 30 decreases compared to the closed state. In general, an expansion silencer is known that reduces the sound pressure level by reflecting and interfering with sound generated by expanding and reducing the sound path. In the expansion silencer, the sound pressure level of the sound decreases as the space capacity increases, and conversely, the sound pressure level of the sound increases as the space capacity decreases.
[0036]
Next, a process for controlling the opening / closing of the intake sub duct 20b by the rotary valve 40 based on the operating state of the engine 10 (hereinafter referred to as an opening / closing control process) will be described. FIG. 6 is a flowchart of the controller 70 showing the opening / closing control process. This opening / closing control process is a process repeatedly performed at a predetermined timing while the engine 10 is operating. In an initial state when the engine 10 is activated, the rotary valve 40 is in a closed state.
[0037]
When the process shown in FIG. 6 is started, a detection signal from the air flow meter 610 is input, and the intake air amount Q of the engine 10 is read (step S701). Next, the detection signal from the throttle position sensor 630 is input, and the throttle opening θ is read (step S702). A detection signal from the crank position sensor 160 is input, and the engine speed N of the engine 10 is read (step S703). Thereafter, a process of calculating an estimated value of the engine load F of the engine 10 from the intake air amount Q and the throttle opening θ read in steps S701 and S702 is executed (step S704).
[0038]
After the above processing, based on the current operation state of the engine 10, that is, the engine speed N and the engine load F, an operation information map stored in advance in a storage circuit (not shown) built in the controller 70 is stored. Referring to this, it is determined whether or not the engine 10 is in a predetermined operating state. The operation information map is data in which a predetermined operation state in which the rotary valve 40 is opened is set in advance in accordance with the relationship between the engine speed N and the engine load F. As the predetermined operation state, for example, a state where the engine is high and the engine speed is high assuming that the automobile is accelerated can be considered.
[0039]
If it is determined that it is in a predetermined operating state (step S705), an opening signal for opening the rotary valve 40 is output to the rotary valve 40 (step S706). When the valve body 410 closes the intake sub duct 20b, the rotary valve 40 receiving the input of the opening signal rotates the valve body 410 by the servo motor 440 to open the intake sub duct 20b. If the valve body 410 opens the intake sub duct 20b, the opening is maintained. The controller 70 ends the opening / closing control process after performing the process of step S706.
[0040]
On the other hand, if it is determined that the operating state is not the predetermined operating state (step S705), a closing signal for closing the rotary valve 40 is output to the rotary valve 40 (step S707). In response to the input of the closing signal, when the valve body 410 opens the intake sub duct 20b, the rotary valve 40 rotates the valve body 410 by the servo motor 440 to close the intake sub duct 20b. If the valve body 410 closes the intake sub duct 20b, the closing is maintained. The controller 70 ends the opening / closing control process after performing the process of step S707.
[0041]
According to the first embodiment described above, the intake device 15 opens the intake sub-duct 20b closed by the rotary valve 40 when the controller 70 determines that the engine 10 is in a predetermined operating state. As a result, a half-order component sound is generated as the engine speed increases, and in addition, the volume generated by the intake device 15 increases. Therefore, a powerful engine sound can be sufficiently obtained according to the operating state of the engine 10.
[0042]
Next, a second embodiment of the present invention will be described. FIG. 7 is an enlarged cross-sectional view of the vicinity of the intake duct of the intake device 15 according to the second embodiment of the present invention. The overall structure of the intake device 15 is as shown in FIG. 1, and only the structure of the intake duct is different. In the second embodiment shown in FIG. 7, in addition to the intake duct 20a and the intake sub duct 20b of the first embodiment, an intake sub duct 20c having a predetermined resonance frequency different from these intake ducts is provided. One end of the intake sub duct 20c communicates with the air cleaner 50, and the other end thereof is in the middle of the intake duct 20a, and communicates upstream from the position where the intake sub duct 20b communicates with the intake duct 20a. The positional relationship between the intake duct 20a and the intake sub-ducts 20b and 20c is a positional relationship in which a half-order component sound of the engine speed of the engine 10 can be generated due to interference of resonance sounds generated when the intake duct 20a and the intake sub-ducts 20b and 20c are opened. It is said.
[0043]
The rotary valve 40 is provided so as to be able to rotate from the position PA in the open state A where the intake sub duct 20b is opened in the intake air of the first embodiment to the position PB in the open state B where the intake sub duct 20c is opened. The controller 70 controls the rotary valve 40 to a closed state, an open state A, and an open state B according to the operating state of the engine 10.
[0044]
Therefore, in the open state B, in addition to the interference in the open state A, interference with the intake pulsation sound due to the resonance sound of the intake sub-duct 20c occurs, and a half-order component sound having a tone different from that in the open state A is generated. Furthermore, in the open state B, the space capacity of the first expansion chamber 30 is reduced compared to the open state A, so that the sound pressure level of the sound generated in the intake device 15 can be further increased than in the open state A. Therefore, two different types of powerful engine sounds can be obtained according to the operating state of the engine 10.
[0045]
Next, a third embodiment of the present invention will be described. FIG. 8 is an enlarged cross-sectional view of the vicinity of the intake duct of the intake device 15 according to the third embodiment of the present invention. The overall structure of the intake device 15 is as shown in FIG. 1, and only the structure of the intake duct is different. In the third embodiment shown in FIG. 8, an intake sub duct 20d is provided instead of the intake sub duct 20c in the second embodiment. The intake sub duct 20d has one end communicating with the air cleaner 50 and the other end communicating with the intake sub duct 20b. The positional relationship between the intake duct 20a and the intake sub-ducts 20b and 20d is a positional relationship in which a half-order component sound of the engine speed of the engine 10 can be generated due to interference of resonance sounds generated when the intake duct 20a and the intake sub-ducts 20b and 20d are opened. It is said. Therefore, the same effect as in the second embodiment can be obtained.
[0046]
Next, a fourth embodiment of the present invention will be described. FIG. 9 is an enlarged cross-sectional view of the vicinity of the intake duct of the intake device 15 according to the fourth embodiment of the present invention. The overall structure of the intake device 15 is as shown in FIG. 1, and only the structure of the intake duct is different. In the fourth embodiment shown in FIG. 9, an intake sub duct 20e is provided instead of the intake sub duct 20b in the first embodiment. One end of the intake sub duct 20e communicates with the air cleaner 50, and the other end is disposed in the vicinity of the other end of the intake duct 20a. The positional relationship between the intake duct 20a and the intake sub-duct 20e is a positional relationship in which a half-order component sound of the engine speed of the engine 10 can be generated by interference of resonance sounds generated when the intake duct 20a and the intake sub-duct 20e are opened. Yes.
[0047]
The rotary valve 40 is provided so as to be able to rotate to the position of the open state C where the intake sub duct 20e is opened. The controller 70 controls the rotary valve 40 between a closed state and an open state C according to the operating state of the engine 10.
[0048]
Therefore, in the closed state, air is taken in from the outside only from the intake duct 20a. In the open state C, air is taken in from the outside from the intake sub duct 20e in addition to the intake duct 20a. Therefore, in addition to the same effects as in the first embodiment, the intake efficiency of the engine 10 can be increased.
[0049]
Next, a fifth embodiment of the present invention will be described. FIG. 10 is an enlarged cross-sectional view of the vicinity of the intake duct of the intake device 15 in the fifth embodiment of the present invention. The overall configuration of the intake device 15 is as shown in FIG. 1, and the structures of the intake duct and the duct opening / closing means are different. In the fourth embodiment shown in FIG. 9, the intake duct 20a and the intake sub ducts 20b and 20c are provided as in the second embodiment, and valves 45a, 45b and 45c are provided instead of the rotary valve 40. The valves 45a, 45b, and 45c open and close the intake duct 20a and the intake sub-ducts 20b and 20c, respectively, and move to positions PD, PE, and PF, respectively, to open these ducts. The controller 70 controls the opening and closing of the valves 45a, 45b, and 45c, respectively, according to the operating state of the engine 10. Thus, half order component sounds of various different timbres are generated depending on the combination of the open intake ducts. Therefore, a powerful engine sound with various tones can be obtained.
[0050]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. is there. For example, the number of intake ducts may be three or more. The shape of the intake duct is not limited to a cylindrical shape, and may have various cross-sectional shapes. The first expansion chamber 30 may be provided separately from the air cleaner 50. The duct opening / closing means may be provided not in the first expansion chamber 30 but in the inlet duct or in the middle thereof. The opening / closing control process does not need to be provided with the controller 70 dedicated to the intake device 15, and may be performed by a controller of another device (for example, a fuel injection control device (EFI-ECU)). The opening / closing of the intake duct may be switched by a manual switch, or the duct opening / closing means may be switched directly by hand. The predetermined operating state of the engine 10 may be determined from the speed of the automobile on which the engine 10 is mounted, the gear used for the transmission, the user's operation pattern, and the like. The capacity increasing / decreasing means may be provided separately from the duct opening / closing means instead of the rotary valve 40 also serving as the duct opening / closing means. Moreover, you may apply to the internal combustion engine mounted in a motorcycle, a ship, etc. instead of the internal combustion engine mounted in a motor vehicle.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an intake device 15 for an internal combustion engine according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a structure of a rotary valve 40 of the intake device 15 in the first embodiment of the present invention.
FIG. 3 is an assembled perspective view showing the structure of the rotary valve 40 of the intake device 15 according to the first embodiment of the present invention.
FIG. 4 is an enlarged cross-sectional view of the vicinity of an intake duct in a closed state of the intake device 15 according to the first embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of the vicinity of the intake duct in the open state of the intake device 15 according to the first embodiment of the present invention.
FIG. 6 is a flowchart of the controller 70 showing an opening / closing control process.
FIG. 7 is an enlarged cross-sectional view of the vicinity of an intake duct of an intake device 15 according to a second embodiment of the present invention.
FIG. 8 is an enlarged cross-sectional view of the vicinity of an intake duct of an intake device 15 according to a third embodiment of the present invention.
FIG. 9 is an enlarged cross-sectional view of the vicinity of an intake duct of an intake device 15 according to a fourth embodiment of the present invention.
FIG. 10 is an enlarged sectional view of the vicinity of an intake duct of an intake device 15 according to a fifth embodiment of the present invention.
[Explanation of symbols]
10 ... Engine
15 ... Intake device
20a ... Intake duct
20b, 20c, 20d, 20e ... intake sub duct
30 ... 1st extension room
40 ... Rotary valve
45a, 45b, 45c ... valve
50 ... Air cleaner
60 ... Intake route
70 ... Controller
110 ... Piston
120 ... Intake port
130 ... Intake valve
140 ... exhaust port
150 ... Exhaust valve
160 ... Crank position sensor
410 ... Valve
411 ... narrow portion
412 ... Wide part
420 ... Valve body
421 ... Narrow insertion part
422 ... Duct communication part
430 ... axis
440 ... Servo motor
510 ... Air filter
520 ... Second extension room
610 ... Air flow meter
620 ... Throttle valve
630 ... Throttle position sensor
640 ... Fuel injector
A1 ... Area
A2 ... Area
PA: Position of the rotary valve 40 in the open state A
PB: Position of the rotary valve 40 in the open state B
PC: Position of the rotary valve 40 in the open state C
PD: Position of valve 45a in open state
PE: Valve 45b open position
PF: Position of valve 45c in open state

Claims (11)

An intake device that introduces air into the internal combustion engine from outside,
An expansion chamber having a predetermined space capacity is finally communicated to the intake path of the internal combustion engine;
One end of a plurality of intake ducts each having a different resonance frequency is provided in communication with the expansion chamber,
Each of the other ends of the plurality of intake ducts has a positional relationship capable of generating a half-order component sound of the engine speed of the internal combustion engine due to interference of resonance sound emitted ,
Providing a duct opening and closing means for opening and closing at least one of the plurality of intake ducts;
The duct opening / closing means increases or decreases the space capacity of the expansion chamber when opening and closing the one intake duct .   The intake device according to claim 1, wherein the plurality of intake ducts are formed to have different pipe lengths.   The intake device according to claim 1 or 2, wherein the other end of at least one of the plurality of intake ducts is communicated with another intake duct.   The intake device according to any one of claims 1 to 3, wherein the other end of at least one of the plurality of intake ducts is disposed in the vicinity of the other end of the other intake duct.   The intake device according to any one of claims 1 to 4, wherein the expansion chamber is provided in an air cleaner that removes dust from intake air. 6. The air intake apparatus according to claim 1, wherein the duct opening / closing means is provided in an air cleaner that removes dust from the intake air. The intake device according to any one of claims 1 to 6 ,
The duct opening / closing means is a rotary valve provided with a valve body formed in a substantially semi-cylindrical shape composed of a narrow part and a wide part, a valve body into which the valve body is fitted, and a drive means for rotating the valve body. An intake device. The intake device according to any one of claims 1 to 7 ,
State detecting means for detecting an operating state of the internal combustion engine;
Open / close control means for controlling the generation of the half-order component sound caused by the plurality of intake ducts by opening / closing the intake duct by the duct opening / closing means based on the operating state detected by the state detection means. Inhalation device. The intake device according to claim 8 , wherein the operating state is at least an engine speed or an engine load of the internal combustion engine. The intake device according to any one of claims 1 to 9 , further comprising a capacity increasing / decreasing means for increasing or decreasing the space capacity of the expansion chamber. The intake device according to any one of claims 1 to 9 , wherein the duct opening / closing means includes capacity increasing / decreasing means for increasing / decreasing a space capacity of the expansion chamber when the one intake duct is opened / closed.

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