JP2008008164A - Intake device for internal combustion engine - Google Patents

Abstract

An object of the present invention is to effectively suppress generation of radiated sound by reducing vertical vibration of an intake manifold integrated with a surge tank.
An ACIS actuator 2 attached to a surge tank integrated intake manifold 1 is a mass, and a connecting portion (for example, a mounting member 20) of the ACIS actuator 2 to the surge tank integrated intake manifold 1 is a spring. The rigidity (spring constant) of the actuator connection is adjusted in consideration of the mass of the ACIS actuator 2 so that the resonance frequency of the vibration system (dynamic damper) configured by To do. By making the ACIS actuator 2 a dynamic damper in this way, the resonance vibration level of the surge tank-integrated intake manifold 1 can be reduced without providing a separate single-function dynamic damper.
[Selection] Figure 1

Description

  The present invention relates to an intake device for an internal combustion engine, and more particularly, to an intake device for an internal combustion engine having a surge tank integrated intake manifold.

  An internal combustion engine (hereinafter also referred to as an engine) mounted on a vehicle or the like includes an intake manifold having a plurality of independent intake passages for supplying air into each cylinder (combustion chamber) of the engine and a surge for reducing intake pulsation. An air intake device including a tank or the like is provided.

  As the intake manifold, a resin intake manifold using synthetic resin is used for the purpose of reducing the weight and improving the productivity. As the resin intake manifold, there is a surge tank integrated intake manifold in which a surge tank is integrated.

  In the surge tank integrated intake manifold, as shown in FIG. 9, a throttle body 204 that is controlled to open and close in accordance with the operation of an accelerator pedal is attached. In addition, a surge tank integrated intake manifold 201 includes a variable intake device (ACIS) that makes the intake pipe length variable for the purpose of improving engine output, ecology, emissions, and the like, and a tumble that controls the tumble flow in the combustion chamber of the engine. A control device (TCV) or the like is attached. A structure in which the ACIS actuator 202 and the TCV actuator 203 for driving the ACIS and TCV, respectively, are also attached to the surge tank integrated intake manifold 201 has been studied. Note that the ACIS actuator 202 shown in FIG. 9 is a motor-type actuator.

  By the way, as shown in FIGS. 10A and 10B, the surge tank integrated intake manifold 201 is attached to the cylinder block 101 of the engine 100 in a cantilevered manner. The coupling surface (mounting surface) F to the block 101 and the position of the center of gravity G of the surge tank integrated intake manifold 201 are offset. Therefore, the entire surge tank integrated intake manifold 201 vibrates in the vertical direction due to vibration of the engine 100 and the like, and radiated sound (for example, noise in the 350 to 400 Hz band) is generated by the vertical vibration.

Here, as a technique for suppressing generation of radiated sound accompanying vibration in an engine intake device, there is Patent Document 1 below. In the technique disclosed in Patent Document 1, in an intake structure of an engine provided with a surge tank formed in an intake passage and an independent intake passage having one end opened in the surge tank and the other end communicated with a combustion chamber. , The thickness of the surge tank wall (wall body where the pressure wave propagated from the independent intake passage collides) with the opening to the surge tank of the independent intake passage is larger than the wall thickness of other surge tank walls By increasing the thickness, the vibration of the surge tank is reduced, and the generation of radiated sound due to the vibration is prevented.
Japanese Utility Model Publication No. 2-028585 Japanese Utility Model Publication No. 3-0661150

  By the way, the technique described in Patent Document 1 described above is a technique for preventing membrane vibration due to internal resonance of the surge tank. The mounting structure as shown in FIG. 10, that is, a surge tank integrated intake manifold is cantilevered to the cylinder block. The level of vibration (vertical vibration of the surge tank integrated intake manifold) generated in the structure mounted in the state cannot be reduced.

  The present invention has been made in consideration of such circumstances, and can reduce the vertical vibration of the intake manifold integrated with the surge tank, and can effectively suppress the generation of radiated sound. An object is to provide an apparatus.

  The present invention relates to a surge tank integrated with a surge tank connected to an intake passage of an internal combustion engine and an intake manifold formed with an independent intake passage for introducing intake air from the surge tank to a cylinder of the internal combustion engine. An intake device for an internal combustion engine comprising a body-type intake manifold, wherein the surge tank integrated intake manifold is attached to the internal combustion engine in a cantilevered state, and a device including an actuator is attached to the surge tank integrated intake manifold. The rigidity of the connecting portion of the actuator to the surge tank integrated intake manifold is such that it functions as a dynamic damper for a predetermined resonance frequency of the surge tank integrated intake manifold attached to the internal combustion engine. It is characterized in that the mass of the actuator is set in consideration.

  In the present invention, specific examples of devices attached to the surge tank integrated intake manifold include an ACIS actuator, a TCV actuator, and a throttle body.

  In the present invention, an actuator (for example, an ACIS actuator) attached to a surge tank integrated intake manifold is a mass, and a connecting portion of the actuator to the surge tank integrated intake manifold (hereinafter referred to as an actuator connecting portion) is a spring. The rigidity (spring constant) of the actuator connecting portion is set to the mass of the actuator so that the resonance frequency of the vibration system (dynamic damper) configured by the above-mentioned is compatible with the resonance frequency (for example, 350 to 400 Hz band) of the surge tank integrated intake manifold. Adjust considering the above. By making the actuator into a dynamic damper in this way, it becomes possible to reduce the resonance vibration level of the intake manifold with integrated surge tank without newly providing a single dynamic damper, thus generating radiated sound. It can be effectively suppressed. In addition, by using an existing actuator as a dynamic damper, the radiated sound can be improved without causing an increase in cost, mass, space, and the like.

  In the present invention, among the devices attached to the surge tank integrated intake manifold, the actuator having the largest mass (for example, ACIS actuator) functions as a dynamic damper with respect to a predetermined resonance frequency of the surge tank integrated intake manifold. It is preferable to adjust the rigidity of the connecting portion. By making the actuator having the largest mass into a dynamic damper in this way, the vertical vibration of the surge tank integrated intake manifold can be reduced more effectively, and the radiated sound can be more effectively suppressed.

  In the present invention, a plurality of actuators are attached to a surge tank integrated intake manifold, and each of the actuators (for example, ACIS actuator and TCV actuator) functions as a dynamic damper for different resonance frequencies of the surge tank integrated intake manifold. Further, the rigidity of the connecting portion of each actuator may be set. By adopting such a configuration, for example, it is possible to reduce the low-frequency (for example, 350 to 400 Hz band) vibration level of the surge tank integrated intake manifold and the vibration level of a higher frequency band. Thus, the radiated sound can be improved more effectively.

  In the present invention, when the mass of the actuator is uniquely determined, the mass of the actuator is set to a fixed value, and the resonance frequency of the dynamic damper matches the resonance frequency of the surge tank integrated intake manifold. Adjust the stiffness. In addition, when the mass of the actuator can be changed, the resonance frequency of the dynamic damper is adjusted with the surge tank integrated intake while changing the mass of the actuator, for example, using both the mass of the actuator and the rigidity of the actuator connecting portion as parameters. A method of setting the rigidity of the actuator connecting portion in consideration of the mass of the actuator may be adopted so as to match the resonance frequency of the manifold.

  In the present invention, in addition to an actuator such as an ACIS actuator or a TCV actuator, other devices attached to the surge tank-integrated intake manifold, for example, a device such as a throttle body may be made into a dynamic damper.

  According to the present invention, the actuator is attached to the surge tank integrated intake manifold, and the rigidity of the connecting portion of the actuator to the surge tank integrated intake manifold is set in consideration of the mass of the actuator. Since it is configured to function as a dynamic damper, it is possible to reduce the vertical vibration of the surge tank integrated intake manifold, and the generation of radiated sound can be effectively suppressed.

  An example of the intake device of the present invention will be described with reference to FIGS.

  The intake device of this example includes a resin-made surge tank integrated intake manifold 1, and the surge tank integrated intake manifold 1 (hereinafter also referred to as surge tank integrated intake manifold 1) includes an ACIS actuator 2 and a TCV actuator described later. 3 and devices such as the throttle body 4 are attached.

  The surge tank-integrated intake manifold 1 reduces intake air pulsation, and an intake manifold 11 in which a plurality of (four) independent intake passages 11a for supplying air into each cylinder (combustion chamber) of an in-line four-cylinder engine 100 are formed. The surge tank 12 is integrated.

  An engine-side flange 14 for connecting each independent intake passage 11a to each cylinder (combustion chamber) of the engine 100 is provided at the tip of the independent intake passage 11a of the surge tank-integrated intake manifold 1. A fixing member 17 is provided at the lower portion of the surge tank integrated intake manifold 1. The fixing member 17 is attached to the cylinder block 101 of the engine 100.

  The surge tank integrated intake manifold 1 is provided with an intake air introduction passage 15 that protrudes from the outer wall thereof. The intake air introduction passage 15 opens into the surge tank 12. An intake side flange 16 is provided at the tip of the intake air introduction passage 15, and the throttle body 4 is attached to the intake side flange 16. Air that has been filtered by an air cleaner is supplied to the throttle body 4 through an intake passage or the like, and the air that has passed through the throttle body 4 is introduced into the surge tank 12 through the intake introduction passage 15.

  The intake manifold 11 is provided with a tumble control device (TCV) for controlling the tumble flow in the combustion chamber of the engine 100, and a TCV actuator 3 for driving the tumble control device is attached to the surge tank integrated intake manifold 1. It has been.

  Inside the surge tank 12, a variable intake device (ACIS) that makes the intake pipe length variable is provided. This variable intake device is driven by the ACIS actuator 2. An actuator support member 13 for supporting the ACIS actuator 2 is provided at the center of the surge tank integrated intake manifold 1. The actuator support member 13 is a cylindrical member and is opened inside the surge tank 12.

  The ACIS actuator 2 is a diaphragm type actuator, and the mounting member 20 is integrally formed. The attachment member 20 is integrally formed with a fixing portion 21 formed with a boss portion 21 a fitted into the actuator support member 13 of the surge tank integrated intake manifold 1 and a holding portion 22 that holds the ACIS actuator 2.

  The attachment member 20 is fixed to the actuator support member 13 by performing laser welding or the like in a state where the boss portion 21a of the fixed portion 21 is fitted into the actuator support member 13 of the surge tank integrated intake manifold 1. By fixing the attachment member 20 to the actuator support member 13 in this way, the ACIS actuator 2 can be attached to the surge tank integrated intake manifold 1 via the attachment member 20.

  Note that the operating rod 23 (see FIG. 6) of the ACIS actuator 2 protrudes toward the mounting member 20 through the rectangular through hole 2a. A control shaft 24 (see FIG. 6) of the ACIS device inside the surge tank 12 protrudes outside through the circular through hole 21b of the mounting member 20, and the control rod 23 of this ACIS device and the control shaft of the ACIS actuator 2 are projected. 24 is connected in the vicinity of the through hole 21b (see FIG. 6).

  The surge tank-integrated intake manifold 1 having the above-described structure is formed by fastening the engine-side flange 14 and the fixing member 17 to the cylinder block 101 of the engine 100 by bolting, as shown in the schematic diagram of FIG. It is attached to 101 in a cantilever state. In such a structure in which the surge tank integrated intake manifold 1 is mounted in a cantilever state, the coupling surface (attachment surface) of the surge tank integrated intake manifold 1 to the cylinder block 101 and the gravity center position of the surge tank integrated intake manifold 1 are offset. Therefore, the entire surge tank-integrated intake manifold 1 vibrates in the vertical direction due to vibration of the engine 100 (see FIG. 10), and radiated sound (for example, noise in the 350 Hz band) is generated due to the vertical vibration.

  Therefore, in this example, among the devices attached to the surge tank integrated intake manifold 1, the ACIS actuator 2 having the largest mass is used, and the attachment member 20 serving as a connecting portion of the ACIS actuator 2 to the surge tank integrated intake manifold 1 is used. It is characterized in that the radiated sound due to the vertical vibration of the surge tank integrated intake manifold 1 is suppressed by adjusting the rigidity and making the ACIS actuator 2 a dynamic damper. This point will be described in detail below.

  First, an element that determines the resonance frequency (fn) of a vibration system (dynamic damper) constituted by the ACIS actuator 2 and the mounting member 20 (actuator connecting portion) is an ACIS actuator as shown in the vibration system model of FIG. 2 (M) and the spring constant (K) of the mounting member 20, and the relational expression between these mass (M), spring constant (K) and resonance frequency (fn) is fn = (1 / 2π) √ (K / M). Therefore, by adjusting the spring constant K, that is, the rigidity of the mounting member 20 of the ACIS actuator 2 using this relational expression, the resonance frequency of the dynamic damper constituted by the ACIS actuator 2 and the mounting member 20 is set to the surge tank level. The body-type intake manifold 1 can be tuned to a resonance frequency (for example, 350 Hz band) of vertical vibration.

  As a specific method for adjusting the rigidity of the mounting member 20 of the ACIS actuator 2, for example, as shown in FIG. 3, the thickness of the holding portion 22 of the mounting member 20 is increased (the mounting member 120 of FIG. And an adjustment method of increasing the rigidity of the mounting member 20 by applying a build-up M to the connecting portion of the holding portion 22 to the ACIS actuator 2. . As another example, as shown in FIG. 4, an adjustment method in which build-up M ′ is applied to a connecting portion of the holding portion 22 ′ of the mounting member 20 ′ with the ACIS actuator 2 can be mentioned.

  In this way, by adjusting the rigidity of the mounting member 20, the resonance frequency of the dynamic damper constituted by the ACIS actuator 2 and the mounting member 20 is changed to the resonance frequency (for example, the vertical vibration of the surge tank integrated intake manifold 1). The rigidity of the mounting member 20 (the rigidity of the actuator connecting portion) can be optimized so as to conform to the 350 Hz band). As a result, the ACIS actuator 2 can exert a dynamic damper effect. For example, as shown in the graph of FIG. 8, the vibration level (vibration level of the intake manifold resonance frequency) of the surge tank-integrated intake manifold 1 can be reduced. . As a result, radiated sound can be effectively suppressed.

-Other embodiments-
In the above example, the ACIS actuator 2 is made a dynamic damper by adjusting the rigidity of the mounting member 20 of the ACIS actuator 2 serving as the actuator connecting portion. However, due to the mass of the ACIS actuator 2, the mounting of the ACIS actuator 2 is performed. If it is difficult to adjust the resonance frequency of the dynamic damper constituted by the ACIS actuator 2 to the resonance frequency of the surge tank integrated intake manifold 1 only by adjusting the rigidity of the member 20, the mounting member 20 of the ACIS actuator 2 In addition to the rigidity, an adjustment method of increasing the rigidity of the actuator connecting portion by increasing the thickness (thickness t shown in FIG. 2) of the actuator support member 13 which is the actuator connecting portion on the surge tank integrated intake manifold 1 side. It may be adopted. In addition, as a method for increasing the rigidity of the actuator support member 13, there are a method of devising the number and arrangement of reinforcing ribs of the actuator support member 13 in addition to a method of increasing the wall thickness t.

  In the above example, the rigidity of the actuator connecting portion (ACIS actuator 2 mounting member 20 and actuator support member 13) is adjusted with the mass of ACIS actuator 2 as a fixed value, but the present invention is not limited to this. If the mass of the ACIS actuator 2 can be changed without being changed, the dynamic damper is used while changing the mass of the ACIS actuator 2 using both the mass of the ACIS actuator 2 and the rigidity of the actuator connecting portion as parameters. The rigidity of the actuator connecting portion may be set in consideration of the mass of the ACIS actuator 2 so that the resonance frequency of the actuator matches the resonance frequency of the surge tank integrated intake manifold 1.

  In the above example, the ACIS actuator 2 having the largest mass among the devices attached to the surge tank-integrated intake manifold 1 is made a dynamic damper to reduce the vibration level in the low frequency range (for example, 350 Hz band). In addition to this, the rigidity of the actuator connecting portion of another device, for example, the TCV actuator 3, may be adjusted to reduce the vibration level at a frequency higher than the low frequency range (for example, 350 Hz band). Further, a dynamic damper may be configured using the throttle body 4. Furthermore, you may make it comprise a dynamic damper using the other device attached to the surge tank integrated intake manifold 1.

  In the above example, the diaphragm type ACIS actuator is shown as a dynamic damper. However, the present invention is not limited to this, and the motor type ACIS actuator 202 shown in FIG. The vibration level may be reduced. When the motor-type ACIS actuator 202 is attached to the surge tank integrated intake manifold 201 with fastening bolts, a method of adjusting the rigidity of the actuator connecting portion by increasing or decreasing the number of fastening bolts may be adopted. Good.

  In the above example, an example in which the present invention is applied to an intake device of an in-line four-cylinder engine has been shown. It is also applicable to other intake devices.

It is a disassembled perspective view which shows the whole structure of the surge tank integrated intake manifold applied to the intake device of this invention. It is a perspective view which shows the structure only of the surge tank integrated intake manifold of FIG. It is a perspective view which shows an example of an ACIS actuator and an attachment member. It is a perspective view which shows the other example of an ACIS actuator and an attachment member. It is a perspective view which shows another example of an ACIS actuator and an attachment member. It is a figure which shows typically the attachment structure to the engine of the intake tank integrated intake manifold shown in FIG. It is a figure which shows the model of the vibration system comprised by an ACIS actuator and an attachment member. It is a graph which shows the damper effect of the dynamic damper comprised with the ACIS actuator and attachment member of FIG. It is a perspective view which shows the whole structure of the other example of a surge tank integrated intake manifold. It is a schematic diagram which shows the problem of the attachment structure to the engine of a surge tank integrated intake manifold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surge tank integrated intake manifold 11 Intake manifold 11a Independent intake passage 12 Surge tank 13 Actuator support member 14 Engine side flange 17 Fixed member 2 ACIS actuator 20 Mounting member 21 Fixed portion 22 Holding portion 3 TCV actuator 4 Throttle body 100 Engine 101 Cylinder block

Claims (3)

A surge tank integrated intake manifold in which a surge tank connected to an intake passage of an internal combustion engine and an intake manifold formed with an independent intake passage for introducing intake air from the surge tank to a cylinder of the internal combustion engine are integrated. An intake device for an internal combustion engine in which the surge tank integrated intake manifold is attached to the internal combustion engine in a cantilever state,
A device including an actuator is attached to the surge tank integrated intake manifold, and the actuator functions as a dynamic damper with respect to a predetermined resonance frequency of the surge tank integrated intake manifold attached to the internal combustion engine. An intake device for an internal combustion engine, wherein the rigidity of the connecting portion to the surge tank integrated intake manifold is set in consideration of the mass of the actuator. The intake device for an internal combustion engine according to claim 1,
The rigidity of the actuator connecting part is set so that the actuator with the largest mass among the devices attached to the surge tank integrated intake manifold functions as a dynamic damper for the predetermined resonance frequency of the surge tank integrated intake manifold. An intake device for an internal combustion engine, characterized in that The intake device for an internal combustion engine according to claim 1 or 2,
A plurality of actuators are attached to the surge tank integrated intake manifold, and the rigidity of the connecting portion of each actuator is such that each actuator functions as a dynamic damper for different resonance frequencies of the surge tank integrated intake manifold. Is set, an intake device for an internal combustion engine.

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