JP5177543B2 - Intake device for internal combustion engine - Google Patents

Description

  The present invention includes a casing in which a plurality of intake passages are connected, a shaft member that is rotatably supported by the casing, a plurality of valve bodies that are locked to the shaft member and disposed in each intake passage, The present invention relates to an intake device for an internal combustion engine including an actuator that rotates the valve body via the shaft member.

  As prior art document information related to this type of intake device, there is Patent Document 1 shown below. In the intake device described in Patent Document 1, a fitting portion with a shaft member is provided at the center of the valve body, and bearing portions that are fitted into the bearings of the casing are formed on the left and right sides of the fitting portion. . The shape of one shaft member inserted through the valve elements arranged in a quadruple form is such that only the valve element locking part that locks the fitting part of the valve element in a relatively non-rotatable manner has a large diameter part, and the rest The portion has a small diameter in order to provide a clearance between the bearing portion and the shaft member. Even if the casing is a resin molded product and the multiple valve bodies supported by the casing are not lined up accurately in a straight line (hereinafter referred to as “coaxial accuracy failure”), the above-mentioned clearance is the same as the coaxial accuracy. By absorbing this defect, the operability of the actuator that drives the valve body is kept good.

Japanese Unexamined Patent Publication No. 2002-317718 (paragraph numbers 0006 and 0008, FIG. 2)

  However, in the intake device described in Patent Document 1, since the entire length excluding the valve body locking portion that locks the fitting portion of the valve body is made to have a small diameter, the shaft center of the shaft member is the center. The torsional rigidity against the torsional stress may be insufficient. For this reason, there is a concern that the valve body is not swung with a sufficient response to the operation of the actuator. In particular, the response of the valve body provided at the position farthest from the actuator is slow, and there is a possibility that the operations of the plurality of valve bodies are deviated.

  Accordingly, an object of the present invention is to provide an intake device for an internal combustion engine that is relatively easy to swing with a sufficient response to the operation of the actuator in view of the problems of the conventional intake device illustrated above. It is to be provided by means of various structural ideas.

A first characteristic configuration of an intake device for an internal combustion engine according to the present invention is:
A casing in which a plurality of intake passages are formed;
A shaft member rotatably supported by the casing;
A plurality of valve bodies locked to the shaft member and disposed in each intake passage;
An actuator for rotating the plurality of valve bodies via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion ,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The second shaft portion is provided with a tapered connection portion connected to the first shaft portion .

  In the intake device for an internal combustion engine according to the first characteristic configuration of the present invention, the shaft member is configured by a first shaft portion that locks the valve body and a second shaft portion that is easier to bend than the first shaft portion. Therefore, even if the coaxial accuracy of the plurality of valve bodies supported by the casing is poor, the second shaft portion is appropriately elastically bent and deformed to absorb the poor accuracy, thereby smoothing the valve body. Swing operation is realized. Further, since the second shaft portion maintains the torsional rigidity of the shaft member as a whole, it is difficult for the shaft member to be twisted, and the valve body is easily swung with a sufficient response to the operation of the actuator.

Further, the shaft member is supported at a position offset from the axial center of the intake passage toward the inner peripheral surface side of the intake passage,
The plurality of valve bodies include a locked portion at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage,
The plurality of valve bodies include a pressure receiving area in which a fluid passing through the intake passage on one side in a direction perpendicular to the shaft member in the valve body from the locked portion, and a fluid passing through the intake passage on the other side There different pressure receiving area that acts, or Ru receiving area is zero der fluid acts through the intake passage on one side.

In this configuration, the locked portion of the shaft member and the valve body is arranged at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage, so that the flow of gas flowing through the intake passage Hard to influence. Further, in such an offset shape supported valve body, results because torque applied to the shaft member was easily becomes higher, the torsional rigidity to be held in the shaft member works more effectively.

Furthermore, a part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner, and the second shaft portions are adjacent to each other. that provided on how the middle.

With this configuration, the easily bent second shaft portion is disposed at the position farthest from the valve body locking portion, so that it can be bent more freely without being restrained by the locked valve body. It becomes possible.
Further, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body The intake device can be easily assembled because there is little risk of being caught by the locked portion.

  In another feature of the present invention, the second shaft portion connects the straight portion having an outer peripheral surface extending linearly along the shaft center of the shaft member, and the straight portion and the first shaft portion. And a tapered connecting portion.

  With this configuration, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is unlikely to be damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body. The intake device can be easily assembled because there is little risk of being caught by the locked portion.

  Another characteristic configuration of the present invention is that the tapered connecting portion is configured to exhibit a curved tapered shape having a gradually decreasing diameter toward a central portion along the axis of the shaft member.

  According to this configuration, stress can be prevented from concentrating on the easily bendable portion even when a large bending moment is applied to the shaft member, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body. The intake device can be easily assembled because there is little risk of being caught by the locked portion.

The 4th characteristic structure of the intake device of the internal combustion engine by this invention is the following.
A casing in which a plurality of intake passages are formed;
A shaft member rotatably supported by the casing;
A plurality of valve bodies locked to the shaft member and disposed in each intake passage;
An actuator for rotating the plurality of valve bodies via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The second shaft portion is provided with a tapered connection portion connected to the first shaft portion .

  In the intake device for an internal combustion engine according to the fourth characteristic configuration of the present invention, the shaft member is composed of a first shaft portion that locks the valve body and a second shaft portion that is easier to bend than the first shaft portion. Therefore, even if the coaxial accuracy of the plurality of valve bodies supported by the casing is poor, the second shaft portion is appropriately elastically bent and deformed to absorb the poor accuracy, thereby smoothing the valve body. Swing operation is realized. Further, since the second shaft portion maintains the torsional rigidity of the shaft member as a whole, it is difficult for the shaft member to be twisted, and the valve body is easily swung with a sufficient response to the operation of the actuator.
  Further, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body. The intake device can be easily assembled because there is little risk of being caught by the locked portion.

  In another characteristic configuration of the present invention, the shaft member is supported at a position offset from the axial center of the intake passage toward the inner peripheral surface of the intake passage,
  The plurality of valve bodies include a locked portion at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage,
  The plurality of valve bodies include a pressure receiving area in which a fluid passing through the intake passage on one side in a direction perpendicular to the shaft member in the valve body from the locked portion, and a fluid passing through the intake passage on the other side The pressure receiving area on which the fluid acts is different, or the pressure receiving area on which the fluid passing through the intake passage on one side acts is zero.

  In this configuration, the locked portion of the shaft member and the valve body is arranged at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage, so that the flow of gas flowing through the intake passage Hard to influence. Further, in the valve body supported in such an offset shape, the torque acting on the shaft member is likely to be higher, so that the torsional rigidity possessed by the shaft member works more effectively.

  In another characteristic configuration of the present invention, a part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner, and the second shaft portion Is provided in the middle of the valve bodies adjacent to each other.

  With this configuration, the easily bent second shaft portion is disposed at the position farthest from the valve body locking portion, so that it can be bent more freely without being restrained by the locked valve body. It becomes possible.

  In another characteristic configuration of the present invention, a part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner. Is provided with locked portions juxtaposed along the axial center of the shaft member, and the second shaft portion is provided in the middle of the adjacent locked portions.

  If this configuration is adopted, the two first shaft portions positioned so as to sandwich the second shaft portion behave more integrally based on the locking by the locked portions juxtaposed with the valve body, and as a result, the shaft The apparent torsional rigidity of the entire member can be maintained higher.

  In another characteristic configuration of the present invention, the plurality of valve bodies include two locked portions juxtaposed along the axis of the shaft member, and the two second shaft portions are adjacent to each other. It exists in the point provided in the middle of the to-be-latched part.

  With this configuration, the two first shaft portions positioned so as to sandwich the second shaft portion behave more integrally based on the locking by the two locked portions provided on the valve body. The apparent torsional rigidity of the shaft member as a whole can be kept higher.

  In another feature of the present invention, the second shaft portion connects the straight portion having an outer peripheral surface extending linearly along the shaft center of the shaft member, and the straight portion and the first shaft portion. And a tapered connecting portion.

  With this configuration, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is unlikely to be damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body. The intake device can be easily assembled because there is little risk of being caught by the locked portion.

  Another characteristic configuration of the present invention is that the tapered connecting portion is configured to exhibit a curved tapered shape having a gradually decreasing diameter toward a central portion along the axis of the shaft member.

  According to this configuration, stress can be prevented from concentrating on the easily bendable portion even when a large bending moment is applied to the shaft member, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of each valve body, one end of the easily bent portion of the shaft member is connected to the valve body. The intake device can be easily assembled because there is little risk of being caught by the locked portion.

An eleventh characteristic configuration of the intake device for an internal combustion engine according to the present invention is:
A casing in which an intake passage is formed;
A shaft member rotatably supported by the casing;
A valve body locked to the shaft member and disposed in the intake passage;
An actuator for rotating the valve body via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The second shaft portion is provided with a tapered connection portion connected to the first shaft portion .

  If it is this structure, since the axial member is comprised by the 1st axial part which latches a valve body, and the 2nd axial part which is easier to bend than a 1st axial part, temporarily severally supported by the casing Even if the coaxial accuracy of the valve bodies is poor, the second shaft portion is appropriately elastically bent and deformed to absorb the poor precision, thereby realizing a smooth swinging operation of the valve bodies. Further, since the second shaft portion maintains the torsional rigidity of the shaft member as a whole, it is difficult for the shaft member to be twisted, and the valve body is easily swung with a sufficient response to the operation of the actuator.
  Further, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of the valve body, one end of the easy-bend portion of the shaft member is connected to the valve body. Since there is little possibility of being caught by a to-be-latched part etc., an assembly of an intake device can be performed easily.
  In addition, it is not always necessary to provide a plurality of valve bodies, and an intake device having a single valve body may be used.

  The twelfth characteristic configuration of the intake device for an internal combustion engine according to the present invention is:
  A casing in which an intake passage is formed;
  A shaft member rotatably supported by the casing;
  A valve body locked to the shaft member and disposed in the intake passage;
  An actuator for rotating the valve body via the shaft member,
  The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion,
  A first direction perpendicular to the central axis of the shaft member; a second direction orthogonal to the first direction and the central axis;
  In the first shaft portion, a first length in the first direction and a second length in the second direction;
  In the second shaft portion, a third length in the first direction and a fourth length in the second direction are set,
  The first length and the third length are equal and the second length and the fourth length are equal; or
  The third length is shorter than the first length, and the fourth length is set shorter than the second length;
  The cross-sectional area in the direction perpendicular to the central axis in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
  The second shaft portion is provided with a tapered connection portion connected to the first shaft portion.

  If it is this structure, when it comprises a shaft member with the 1st axis part which locks the valve body, and the 2nd axis part adjacent to the 1st axis part, the central axis in the 2nd axis part and Since the vertical cross-sectional area is smaller than the cross-sectional area perpendicular to the central axis in the first shaft portion, the cross-sectional area is small even if the coaxial accuracy of the plurality of valve bodies supported by the casing is poor. The second shaft portion is appropriately elastically bent and deformed to absorb the poor accuracy, thereby realizing a smooth swinging operation of the valve body.
  Further, even when a large bending moment is applied to the shaft member, the stress can be prevented from concentrating on the easily bendable portion, so that the shaft member is hardly damaged by mechanical stress. Further, when assembling the intake device, when the valve body is disposed at a predetermined position of the intake passage and the shaft member is inserted into the locked portion of the valve body, one end of the easy-bend portion of the shaft member is connected to the valve body. Since there is little possibility of being caught by a to-be-latched part etc., an assembly of an intake device can be performed easily.
  In addition, it is not always necessary to provide a plurality of valve bodies, and an intake device having a single valve body may be used.

  Another feature of the present invention is that the cross section of the second shaft portion in a direction perpendicular to the central axis is circular.

  With this configuration, since the second shaft portion has a circular cross section, the second shaft portion exhibits a certain degree of ease of bending regardless of the rotation angle of the shaft member with respect to the casing.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows an intake device 50 that supplies combustion air to a cylinder of an internal combustion engine. The intake device 50 includes a casing 1 in which an intake passage 2 is formed, and a throttle valve 3 for controlling an inflow amount of air and the like is disposed in the intake passage 2. The casing 1 is formed by resin injection molding, but may be made of a casting.

  As shown in FIG. 2, the intake device 50 is configured for a four-cylinder internal combustion engine, and four intake passages 2 communicating with the cylinders are connected to the casing 1. The throttle valves 3 arranged in each intake passage 2 are arranged in a substantially straight line. Each throttle valve 3 is made of resin or metal, and is swing-operated by a single control shaft 6 (an example of a shaft member) arranged so as to cross the casing 1. The opening is adjusted at the same time.

  The vicinity of both ends of the control shaft 6 is rotatably supported by a bearing 9 a provided outside the casing 1. One end of the control shaft 6 is attached with a gear 10 for inputting the rotational force of an electric motor M (an example of an actuator) driven based on an electric signal from an ECU (not shown) to the control shaft 6. .

  As shown in FIG. 2, each throttle valve 3 includes a generally plate-shaped valve body 3a (an example of a valve body). A pair of generally cylindrical supported portions 4 and a locked portion 5 positioned between the pair of supported portions 4 are integrally formed on one surface of the valve body 3a. On the other hand, a pair of bearings 2a are formed in the intake passage 2 of the casing 1 with respect to the individual valve bodies 3a. The supported portion 4 and the locked portion 5 are formed with through holes 4 a and 5 a for receiving the control shaft 6. Each of the through holes 4a and 5a has a square cross section.

  As shown in FIG. 3 (b), the valve body 3a is supported so as to be swingable with respect to the casing 1 by each pair of supported portions 4 being fitted into each pair of bearings 2a. It is locked to a part of the control shaft 6 through the locked portion 5 near the center so as not to be relatively rotatable.

  The bearing 9 a and the control shaft 6 of the casing 1 are provided not in the vicinity of the center of the cross section of the intake passage 2 but in a location offset to a part of the inner wall surface. The valve body 3a is also locked by the control shaft 6 so as not to rotate relative to the geometric center position of the valve body 3a along the surface of the valve body 3a (in FIG. 1, the inner wall from above). ing. In other words, of the entire pressure receiving surface that the valve body 3a receives pressure from the fluid passing through the intake passage 2, the area of the pressure receiving surface extending from the locked portion 5 to one side perpendicular to the axis X of the control shaft 6 is on the other side. It is set to be smaller than the area of the extended pressure receiving surface. The area of the pressure receiving surface extending from the locked portion 5 to one side perpendicular to the axis X of the control shaft 6 may be zero.

  The control shaft 6 is a metal bar member extending linearly. As shown in FIG. 3, except for a local exceptional part to be described later, the substantially entire length of the control shaft 6 is an angular cross-sectional region 6S (an example of a first shaft portion) having a square cross-sectional shape. On the other hand, three portions corresponding to the middle of the two valve bodies 3a adjacent to each other in the control shaft 6 are the above-described exceptional portions, have a circular cross section, and can be easily bent with a smaller diameter than the angular cross section region 6S. This is a portion 6R (an example of the second shaft portion).

  The outer diameter of the easily bendable part 6R corresponds to 90 to 110% of one side of the square constituting the cross section of the angular cross section region 6S. That is, the outer diameter of the easy-to-bend portion 6R needs to be 90% or more of one side of the square constituting the cross section of the angular cross section region 6S in order to ensure the strength of the entire control shaft 6. Even if it is 110% of one side of the square, the cross-sectional area of the bendable part 6R is still smaller than the cross-sectional area of the angular cross-sectional area 6S, so the bendability of the easy-bend part 6R is maintained.

  Each of the square cross-sectional areas 6S has the same cross-sectional shape and size over the entire length, and substantially coincides with the through hole 5a of the locked portion 5 of the valve body 3a. When assembling the intake device 50, the four valve bodies 3 a are fitted into the bearings 2 a inside the casing 1, the control shaft 6 is inserted into the locked portion 5 of each valve body 3 a, and the outside of the casing 1 is inserted. It is fitted inside the bearing 9a. Thereby, the location located in the center along the axis X of the square cross-sectional area 6S plays the role of the valve body locking portion 6E engaged with the locked portion 5 of the valve body 3a. At this time, the small-diameter easy-to-bend portion 6R is disposed between two adjacent valve bodies 3a.

  On the other hand, the cross-section of the through hole 4a formed in the supported portion 4 of the valve body 3a is a square whose one side is longer than one side of the square constituting the through hole 5a of the locked portion 5. Therefore, after assembling the intake device 51, the inner surface of the through hole 4 a of the supported portion 4 is basically not in contact with the outer peripheral surface of the control shaft 6. Note that the cross-sections of the through holes 4a and 5a only need to be larger than the control shaft 6, and the cross-sectional shape may be circular or polygonal.

  As shown in FIG. 4, the easily bendable part 6R connects the straight part 6Ra having an outer peripheral surface extending linearly along the axis X, and the straight part 6Ra and the angular cross-sectional area 6S extending on both sides thereof. It consists of a connecting part 6Rb. The connecting portion 6Rb is formed in an arcuate round shape having a center on the outside, and in particular, the extension line on the small diameter side of the rounded portion extends so as to coincide with the straight portion 6Ra. Stress concentration is suppressed when bending stress is applied.

  Along the axis X of the straight portion 6Ra in order to satisfy the two mutually contradicting elements of making the bendable portion 6R sufficiently bendable and maintaining the torsional rigidity of the control shaft 6 as a whole. The length and the diameter of the straight portion 6Ra are substantially equal. With respect to the ratio between the easily bendable portion 6R and the angular cross-sectional area 6S, as shown in FIG. 3B, the control shaft 6 extends from the left end of one bendable portion 6R to the left end of the bendable portion 6R adjacent to the right side. Assuming that the unit length is L, the length L1 along the axis X of the easily bendable part 6R including the connecting part 6Rb is limited to less than 15% of the unit length L.

[Another embodiment]
<1> As illustrated in FIG. 5, a control similar to the above-described embodiment is performed using a valve body 13 a in which a pair of cylindrical supported portions 14 and a pair of left and right locked portions 15 are formed. You may implement by the structure which inserted the shaft 6. FIG.

<2> When the valve main body 13a shown in FIG. 5 is used and the control shaft is inserted and installed instead of the control shaft 6 as shown in FIG. 6, the bendable portion 16R has two valve main bodies adjacent to each other. The control shaft 16 disposed in the middle of the pair of locked portions 15 of each valve body 13a may be used instead of the middle of the 13a. Regarding the ratio between the easily bendable portion 16R and the angular cross-sectional area 16S, the length L1 along the axis X of the easily bendable portion 16R including the connecting portion 16Rb is 15% of the unit length L in the example of FIG. Limited to less than.

<3> A valve body 13a having a single locked portion 5 similar to that shown in FIG. 3 is used, and a control shaft is inserted and installed in place of the control shaft 6 as shown in FIG. At this time, the pair of easy bending portions 26R may use the control shafts 26 disposed on the inner sides of the pair of supported portions 4 on the left and right sides of the locked portion 15 of the valve body 13a. Regarding the ratio between the easily bendable portion 26R and the square cross-sectional area 26S, the left bendable portion 26R corresponding to the valve body 13a adjacent to the right side from the left end of the left bendable portion 26R corresponding to one valve body 13a When the unit length L of the control shaft 26 extends to the left end, the total length L1 along the axis X of one bendable portion 26R is limited to less than 15% of the unit length L.

<4> The bendable portion (second shaft portion) does not necessarily need to be provided with a straight portion having an outer peripheral surface extending linearly along the axis X as illustrated in FIG. As illustrated in FIG. 8, a shape that exhibits a curved taper shape that gradually becomes smaller in diameter toward the central portion along the axis X may be employed as the easily bendable portion. Here, the cross-sectional shape of the easy-to-bend portion 36R cut along a plane orthogonal to the axis X is a circle, but the outer shape of the easy-to-bend portion 36R viewed from the direction orthogonal to the axis X is that of the easy-to-bend portion 36R. It consists of a circular arc consisting of a part of a circle centered on the outside. However, a curved surface shape other than an arc may be used. The outer diameter of the smallest diameter portion of the easily bendable part 36R corresponds to 90 to 110% of one side of the square constituting the cross section of the angular cross section region 6S.

<5> The easy bending portions of the control shaft described in each of the above embodiments have a circular cross section, but the easy bending portion does not necessarily have a circular cross section, and at least the corners of the polygon cross section are lost. As a result, the shape may be any shape as long as it is rounder than the angular cross-sectional area and consequently the cross-sectional area is reduced. However, a circular cross section is considered to be the best in that the bending rigidity of the shaft member is maintained at a constant low value regardless of the operated angle.

<6> Although the angular cross-sectional area 26S (first shaft portion) of the control shaft described in each of the above embodiments has a rectangular cross section, the lengths are different in order to lock the valve body so as not to be relatively rotatable. Any cross-sectional shape having a plurality of diameters may be used, and examples thereof include various regular polygons other than rectangles, polygons other than regular polygons, and ellipses. In this case, a through hole having the same shape may be provided in the locked portion of the valve body.

<7> In the control shaft described in the above embodiment, the cross-sectional shape of the second shaft portion as the bendable portion is sufficiently larger than one side of the square constituting the cross section of the first shaft portion that locks the valve body. However, the dimensional relationship between the cross section of the first shaft portion and the outer diameter of the second shaft portion is not limited to these illustrated forms.
When a first direction perpendicular to the axis X of the control shaft and a second direction perpendicular to the first direction and the axis X are defined, the cross section perpendicular to the axis X in the first shaft portion is the first direction. And a cross section perpendicular to the axis X of the second shaft portion has a third length along the first direction. And a fourth length along the second direction. At this time, the dimensional relationship between the cross section of the first shaft portion and the outer diameter of the second shaft portion may satisfy the following relationship.
That is, the length of the first length is equal to the length of the third length, and the length of the second length is equal to the length of the fourth length, or the length of the first length The third length is shorter than the length, and the fourth length is shorter than the second length. However, it is a condition that the cross-sectional area perpendicular to the axis X in the second shaft portion is smaller than the cross-sectional area perpendicular to the axis X in the first shaft portion. As an example of configuring such a control shaft, the control shaft includes the first shaft portion having a square cross section and the second shaft portion having a circular cross section.
Even if the outer diameter of the second shaft portion is slightly beyond the length of one side of the square constituting the cross section of the first shaft portion, the first length and the second length of the first shaft portion Is equal to or less than 110% of one side of the square, the first length is equal to the third length, and the second length is equal to the second length. The relationship that the length of the length is equal to the length of the fourth length is established.

<8> The first shaft portion may be made of metal, and the easily bent second shaft portion may be made of an elastic member such as rubber. In this case, the cross-sectional shape and dimensions may be the same between the first shaft portion and the second shaft portion.

<9> It is not always necessary to include a plurality of valve bodies, and an intake device including a single valve body may be used.

Schematic showing part of the intake system and cylinder Schematic front view showing the intake system Explanatory drawing showing the relationship between the valve body and the shaft member Partial enlarged view of easy-bend part Explanatory drawing which shows the relationship between the valve main body and shaft member by 2nd Embodiment. Explanatory drawing which shows the relationship between the valve main body and shaft member by 3rd Embodiment. Explanatory drawing which shows the relationship between the valve main body and shaft member by 4th Embodiment. The elements on larger scale which show another embodiment of an easily bendable part

1 Casing 2 Intake Passage 2a Throttle Valve Bearing 3 Throttle Valve 3a Valve Body (Valve)
4 Supported portion 5 Locked portion 6 Control shaft (shaft member)
6E Valve body locking part 6S Square cross-sectional area (first shaft part)
6R Easy bending part (second shaft part)
6Ra Straight portion 6Rb Connection portion 9a Control shaft bearing 50 Intake device M Electric motor (actuator)

Claims (13)

A casing in which a plurality of intake passages are formed;
A shaft member rotatably supported by the casing;
A plurality of valve bodies locked to the shaft member and disposed in each intake passage;
An actuator for rotating the plurality of valve bodies via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion ,
The shaft member is supported at a position offset from the axial center of the intake passage toward the inner peripheral surface of the intake passage,
The plurality of valve bodies include a locked portion at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage,
The plurality of valve bodies include a pressure receiving area in which a fluid passing through the intake passage on one side in a direction perpendicular to the shaft member in the valve body from the locked portion, and a fluid passing through the intake passage on the other side Is different from the pressure receiving area on which the pressure acts, or the pressure receiving area on which the fluid passing through the intake passage on one side acts is zero,
A part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner, and the second shaft portions are adjacent to each other of the valve bodies. In the middle,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The intake device for an internal combustion engine, wherein the second shaft portion includes a tapered connection portion connected to the first shaft portion . The second shaft portion has a straight portion having an outer peripheral surface extending straight along the axis of the shaft member, and said tapered connecting portion which connects the first shaft portion and the straight portion An intake device for an internal combustion engine according to claim 1, comprising: 2. The intake device for an internal combustion engine according to claim 1, wherein the tapered connection portion is configured to exhibit a curved taper shape that gradually decreases in diameter toward a central portion along the axis of the shaft member. A casing in which a plurality of intake passages are formed;
A shaft member rotatably supported by the casing;
A plurality of valve bodies locked to the shaft member and disposed in each intake passage;
An actuator for rotating the plurality of valve bodies via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion ,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The intake device for an internal combustion engine, wherein the second shaft portion includes a tapered connection portion connected to the first shaft portion . The shaft member is supported at a position offset from the axial center of the intake passage toward the inner peripheral surface of the intake passage,
The plurality of valve bodies include a locked portion at a position offset from the axial center of the intake passage to the inner peripheral surface side of the intake passage,
The plurality of valve bodies include a pressure receiving area in which a fluid passing through the intake passage on one side in a direction perpendicular to the shaft member in the valve body from the locked portion, and a fluid passing through the intake passage on the other side The intake device for an internal combustion engine according to claim 4 , wherein the pressure receiving area on which the fluid acts is different or the pressure receiving area on which the fluid passing through the intake passage on one side acts is zero. A part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner, and the second shaft portions are adjacent to each other of the valve bodies. The intake device for an internal combustion engine according to claim 5 , which is provided in the middle. A part of the first shaft portion is a valve body locking portion that locks the locked portion of the valve body in a relatively non-rotatable manner, and the plurality of valve bodies are arranged at the shaft center of the shaft member The intake device for an internal combustion engine according to claim 5, further comprising a locked portion juxtaposed along the second shaft portion, wherein the second shaft portion is provided in the middle of the adjacent locked portions. The plurality of valve bodies include two locked portions juxtaposed along the shaft center of the shaft member, and the second shaft portion is provided between two adjacent locked portions. The intake device for an internal combustion engine according to claim 7 . The second shaft portion has a straight portion having an outer peripheral surface extending straight along the axis of the shaft member, and said tapered connecting portion which connects the first shaft portion and the straight portion An intake device for an internal combustion engine according to any one of claims 4 to 8 , further comprising: Said tapered connecting portion, according to any one of the shaft member toward a central portion along the axis of claims 4 which is configured to progressively assume a curved tapered to a smaller diameter 8 An intake device for an internal combustion engine. A casing in which an intake passage is formed;
A shaft member rotatably supported by the casing;
A valve body locked to the shaft member and disposed in the intake passage;
An actuator for rotating the valve body via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion ,
The cross-sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is set smaller than the cross-sectional area in the direction perpendicular to the central axis in the first shaft portion,
The intake device for an internal combustion engine, wherein the second shaft portion includes a tapered connection portion connected to the first shaft portion . A casing in which an intake passage is formed;
A shaft member rotatably supported by the casing;
A valve body locked to the shaft member and disposed in the intake passage;
An actuator for rotating the valve body via the shaft member,
The shaft member includes a first shaft portion that locks the valve body, and a second shaft portion that is easier to bend than the first shaft portion ,
A first direction perpendicular to the central axis of the shaft member; a second direction orthogonal to the first direction and the central axis;
In the first shaft portion, a first length in the first direction and a second length in the second direction;
In the second shaft portion, a third length in the first direction and a fourth length in the second direction are set,
The first length and the third length are equal and the second length and the fourth length are equal; or
The third length is shorter than the first length, and the fourth length is set shorter than the second length;
Sectional area in the direction perpendicular to the central axis of the shaft member in the second shaft portion is small rather is set than the cross-sectional area of the central axis perpendicular direction in the first shaft portion,
The intake device for an internal combustion engine, wherein the second shaft portion includes a tapered connection portion connected to the first shaft portion . The intake device for an internal combustion engine according to claim 12 , wherein a cross section of the second shaft portion in a direction perpendicular to the central axis is circular.

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