JP4814158B2 - Intake manifold device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake manifold device for an internal combustion engine, and more particularly to an intake manifold device for an internal combustion engine having a passage length switching portion capable of switching the length of an intake passage through which intake air flows.

  2. Description of the Related Art Conventionally, in a multi-cylinder engine such as an automobile, an intake manifold is provided between an intake port of a cylinder head and a throttle valve that adjusts an intake air amount, and the intake air sucked into the intake manifold is divided to each intake air. Distribution to ports.

  In recent years, with higher engine output, an internal combustion engine that can change the engine output by shortening the intake passage of the intake manifold at high speed or high load operation and lengthening the intake passage of the intake manifold at low speed or low load operation An intake manifold device for an engine is known. The present applicant has proposed a configuration in which such an intake manifold device has a rotary valve that functions as a passage length switching portion, and switches the intake passage length in the intake manifold by rotating the rotary valve. (See Patent Document 1).

  There is a demand for further simplifying the structure of such a passage length switching unit and reducing the number of parts and the manufacturing cost. For example, as disclosed in Patent Document 2, the shaft is held on a rotating shaft. It is assumed that the communication state of the intake passage of the intake manifold is switched by using a butterfly valve and rotating the butterfly valve.

JP 2003-83072 A JP 2002-235545 A

  As described above, when the passage length of the intake passage is freely switched by such a butterfly valve, the intake air that circulates along the intake passage circulates along the surface of the butterfly valve. It is necessary to make the shape along the intake passage so as not to disturb the flow of the intake air.

  However, in this case, the cross-sectional shape of the butterfly valve is asymmetric with respect to the rotation axis, and the center of gravity position of the butterfly valve coincides with the center position of the rotation axis serving as the rotation center of the butterfly valve. Without being eccentric. As a result, when the butterfly valve is rotationally displaced, vibration accompanying eccentricity between the center of rotation and the center of gravity is generated, stress is applied to the butterfly valve, resulting in a decrease in durability and smooth rotation. It becomes difficult to displace.

  The present invention has been made in view of the above-described problems, and smoothly switches the length of the intake passage through which intake air flows through the passage length switching section and improves the durability of the passage length switching section. An object of the present invention is to provide an intake manifold device for an internal combustion engine.

In order to achieve the above object, the present invention provides a long-pipe intake passage that is independently connected to each cylinder of a main body constituting an internal combustion engine and communicates with a chamber into which intake air is introduced from a throttle device. An intake manifold having a short pipe intake passage that branches off from the pipe intake passage and communicates with the chamber; and an intake manifold provided inside the intake manifold facing the intake passage, and adapted to the intake passage according to the operating condition of the internal combustion engine In an intake manifold device for an internal combustion engine comprising a passage length switching unit for switching the length,
The passage length switching unit includes a switching valve that is provided between the long pipe intake passage and the short pipe intake passage and is rotatably supported via a rotation shaft supported by the intake manifold,
The switching valve includes a plate-shaped first member connected to the rotating shaft;
A second member surrounding the first member, facing the long pipe intake passage and the short pipe intake passage, and having side surfaces formed respectively along the passage shapes of the long pipe intake passage and the short pipe intake passage; ,
The first member is provided on the first member, and the center of gravity of the first member is decentered from the center based on the amount of eccentricity of the center of gravity of the second member with respect to the center of the rotating shaft, and includes the first and second members. Adjusting means adjustable so that the center of gravity position is on the center;
It is characterized by providing.

  According to the present invention, the switching valve constituting the passage length switching unit is constituted by the first member connected to the rotating shaft supported by the intake manifold and the second member surrounding the first member, A side surface of the second member facing the pipe intake passage and the short pipe intake passage is formed so as to follow the shape of the long pipe intake passage and the short pipe intake passage, and one side surface facing the long pipe intake passage; The shapes of the other side faces facing the short pipe intake passage are different. For this reason, the position of the center of gravity of the second member is eccentric with respect to the center of the rotation shaft that is the rotation center of the switching valve. The center-of-gravity position of the second member that is eccentric with respect to the center of the rotating shaft is determined based on the amount of eccentricity of the center-of-gravity position of the second member with respect to the center of the rotating shaft by the adjusting means provided on the first member. Since the center of gravity of one member can be decentered from the center, the center of gravity of the switching valve including the first and second members can be adjusted to be on the center of the rotating shaft.

  Accordingly, the center of the rotation shaft that is the rotation center of the switching valve can be suitably matched with the center of gravity position of the switching valve, and the center of the rotation shaft and the center of gravity position can be adjusted when the switching valve rotates. Generation of vibration based on eccentricity is prevented, and stress applied to the switching valve and the rotating shaft by the vibration can be reduced. As a result, the load on the passage length switching unit including the switching valve is reduced, and the durability thereof can be improved. The switching valve is smoothly rotated and displaced, and the passage length of the intake passage is passed through the passage switching unit. Can be switched smoothly.

  Further, the adjusting means is provided at a position decentered in the direction opposite to the center of gravity of the second member around the rotation axis, and has a predetermined weight, whereby the second member decentered with respect to the center of the rotation axis. The center-of-gravity position of the entire switching valve including the first member can be suitably moved on the center according to the center-of-gravity position.

  Furthermore, the thickness of the second member is such that the one end side that is the chamber side is formed thin and the other end side that is the main body side is formed thick, so that the center of gravity of the second member that is eccentric to the other end side is formed. Accordingly, the adjusting means may be provided on the first member so as to be on the one end side of the second member.

Furthermore, the first member, formed of a metal timber charges, the second member, by forming an elastic material, conveniently a center of gravity of the first member by providing the adjusting means relative to said first member And it becomes possible to adjust to a desired position suitably.

  According to the present invention, the following effects can be obtained.

  That is, the first member is provided with adjusting means, and based on the position of the center of gravity of the second member eccentric with respect to the center of the rotating shaft, the adjusting means causes the center of gravity of the first member to be eccentric from the center, and the first member And the gravity center position of the switching valve including the second member can be adjusted to be on the center of the rotating shaft. As a result, the center of the rotation shaft that is the rotation center of the switching valve and the center of gravity of the switching valve can be reliably and preferably matched, so that vibration based on the eccentricity between the center of the rotation shaft and the center of gravity is achieved. Can be prevented, the durability of the passage length switching unit including the switching valve can be improved, and the passage length can be switched by smoothly operating the passage switching unit including the switching valve.

  A preferred embodiment of an intake manifold device for an internal combustion engine according to the present invention will be described in detail below with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates an intake manifold device for an internal combustion engine according to an embodiment of the present invention.

  An intake manifold device 10 for an internal combustion engine (hereinafter referred to as an intake manifold device 10) is provided in, for example, a four-cylinder engine 22 having four cylinder chambers mounted on a vehicle or the like.

  1 to 6, the intake manifold device 10 includes an intake manifold 14 having a plurality of branch pipes 12, and an intake passage 16 that is inserted into the branch pipe 12 of the intake manifold 14 and through which intake air flows. A path length switching unit 18 for switching the path length of the motor, and a drive unit (not shown) for rotationally displacing the path length switching unit 18.

  The intake manifold 14 is integrally formed, for example, by welding or bonding a plurality of divided bodies obtained by injection molding of a resin material. The intake manifold 14 has a chamber 20 in which air sucked through a throttle valve of a throttle device (not shown) is temporarily stored, and an intake passage connecting the chamber 20 and a cylinder head (main body portion) 24 of the engine 22. 16 and the like.

  The intake passage 16 includes a short pipe intake passage 26 that sucks intake air from the chamber 20 and supplies the intake air to the engine 22 during high-speed or high-load operation of the engine 22, and low-speed or low-load operation of the engine 22. A long-pipe intake passage 28 that sucks the intake air from the chamber 20 and supplies the intake air to the engine 22, and a connection passage that extends from the joint portion of the short-pipe intake passage 26 and the long-pipe intake passage 28 to the engine 22. 30.

  The intake manifold 14 includes a mounting flange 32 connected to the cylinder head 24 of the engine 22, and the mounting flange 32 is coupled to the cylinder head 24 via a flat mounting surface. As a result, the intake passage 16 of the intake manifold 14 and the cylinder head 24 are connected and communicated with each other through the connection passage 30 penetrating through the mounting flange 32.

  The short pipe intake passage 26 is provided above the chamber 20, extends while curving toward the mounting flange 32, and has a lower end opened toward the chamber 20 side. The long pipe intake passage 28 opens at one end connected to the lower side of the chamber 20 and extends while curving along the outer wall surface of the intake manifold 14 from the one end toward the other end. The other end of the long-pipe intake passage 28 extends to above the short-pipe intake passage 26, and the other end is connected to the short-pipe intake passage 26 so as to cross obliquely at a predetermined angle. . Thereby, the short pipe intake passage 26 and the long pipe intake passage 28 communicate with each other.

  The short pipe intake passage 26 is provided on the inner side with respect to the long pipe intake passage 28 formed in a curved shape along the outer wall surface of the intake manifold 14. It is set to be shorter than the passage length. That is, when the engine 22 is operating at high speed or high load, intake air is supplied to the cylinder head 24 constituting the engine 22 through the short pipe intake passage 26 having a short passage length, and when the engine 22 is operating at low speed or low load, The intake air is supplied to the cylinder head 24 through a long long pipe intake passage 28.

  Each of the short pipe intake passage 26 and the long pipe intake passage 28 is provided in accordance with the number of cylinders (for example, four) of the engine 22 (not shown), and the short pipe intake passage 26 and the long pipe intake passage 28 are provided. Are formed independently in parallel.

  On the other hand, a connecting wall 34 that joins the inner surfaces of the short pipe intake passage 26 and the long pipe intake passage 28 adjacent to each other is provided at a joint portion between the short pipe intake passage 26 and the long pipe intake passage 28. The connection wall 34 is joined so as to be substantially orthogonal to the short pipe intake passage 26 and the long pipe intake passage 28, and is provided at the end of the connection wall 34 on the short pipe intake passage 26 side, A first sheet portion 36 protruding from the inner wall surface of the connection wall 34 is provided, and a second sheet portion 38 provided on the long pipe intake passage 28 side and protruding from the inner wall surface of the connection wall 34 is provided.

  The passage length switching unit 18 is provided at a joint portion between the short pipe intake passage 26 and the long pipe intake passage 28, and as shown in FIGS. 2 and 3, a long shaft (supported by the intake manifold 14). (Rotary shaft) 40 and a plurality of valves (switching valves) 42 that are held by the shaft 40 and switch the flow state of the intake air in the intake passage 16.

  The shaft 40 is formed in a shaft shape having a constant diameter, and is provided with a plurality of shaft portions 44 supported by the intake manifold 14 and a plurality of mounting portions 46 provided between the shaft portions 44 to which the valves 42 are mounted. Consists of. The shaft portion 44 is rotatably held at portions between the plurality of intake passages 16 in the intake manifold 14, and a driving portion (not shown) is connected to the end portion thereof.

  The attachment portions 46 are formed in a rectangular cross section, and are provided in a number corresponding to the number of the valves 42 (for example, four locations).

  The mounting portion 46 has a pair of plane portions 48 that are spaced apart from each other by a predetermined distance about the axis of the shaft 40, and the valve 42 is fixed to one of the plane portions 48 that are formed in parallel to each other. The portion 48 is formed with a set of screw holes 50 spaced apart by a predetermined distance along the axial direction of the shaft 40, and the screw holes 50 penetrate in a direction substantially orthogonal to the axis.

  The drive unit includes, for example, a stepping motor that is driven to rotate under energization. The rotation angle of the drive unit is a desired angle based on a control signal input from a controller (not shown) to the drive unit. Controlled. The shaft 40 including the shaft portion 44 and the mounting portion 46 is rotationally displaced by a predetermined angle under the driving action of a driving portion (not shown).

  The valve 42 is formed in a plate shape whose thickness varies along the longitudinal direction, and a base body (first member) 52 made of a metal material and a mold part (second member) that covers the outside of the base body 52. 54.

  As shown in FIG. 4, the base body 52 includes a plate portion 56 made of a plate material having a substantially constant thickness, a bulge portion 58 formed on one end side of the base body 52 and having an increased plate thickness, and a longitudinal direction. And a pair of hole portions 60 provided in a substantially central portion along the line. The hole 60 is provided at a predetermined interval in the width direction like the screw hole 50 formed in the shaft 40, and after the mounting portion 46 of the shaft 40 is disposed so as to face the hole 60, The shaft 40 is fixed by the bolt 62 inserted through the hole 60 being screwed into the screw hole 50.

  The plate portion 56 includes a curved end 64 that is gradually curved with a predetermined radius from the central portion along the longitudinal direction toward one end portion, and the end portion of the curved end 64 becomes gradually thinner toward the tip. It is formed in a tapered shape.

  Further, the curved end 64 is provided with a bulging portion 58 on a side surface that is opposite to the curved direction of the curved end 64. The bulging portion 58 bulges with respect to the side surface of the curved end 64 by a thickness substantially equal to the plate thickness of the plate portion 56, and the plate thickness is the thickest at the central portion side of the base body 52. It is set so as to become gradually thinner toward the one end side. Note that the bulging portion 58 is formed slightly narrower than the plate portion 56 and the curved end 64.

  That is, the base body 52 is formed such that the one end side having the bulging portion 58 with respect to the plate portion 56 having a constant thickness is heavier than the other end side, and the center of gravity of the base body 52 is G1 is offset to one end side with respect to the central portion where the shaft 40 is mounted. That is, the bulging portion 58 functions as an adjusting means that can adjust the position of the center of gravity of the base body 52 by freely changing the arrangement and shape of the base body 52 with respect to the plate portion 56.

  The mold part 54 is made of an elastic material such as rubber, and is formed by molding so as to cover the plate part 56 and the bulging part 58.

  The mold portion 54 is formed so that one end portion side of the plate portion 56 constituting the base body 52 is thinnest and is gradually thickened toward the other end portion side of the plate portion 56. That is, the valve 42 including the mold portion 54 is formed so that the one end side of the base body 52 having the curved end 64 is the thinnest and the other end side of the base body 52 is the thickest. The mold portion 54 is formed so as to slightly protrude in the longitudinal direction of the base body 52 with respect to one end and the other end of the base body 52.

  The shape of the mold portion 54 on the upper surface side of the base body 52 to which the shaft 40 is attached is formed according to the cross-sectional shape of the plate portion 56 constituting the base body 52, and the thickness thereof is larger than that of the upper surface. The thickness is set to be approximately constant. That is, the upper surface side of the mold part 54 is formed in substantially the same shape as the cross-sectional shape of the plate part 56. In other words, the mold part 54 is formed in a curved shape on one end side in the same manner as the curved end 64 part, and is formed in a planar shape on the other end side in the same manner as the plate part 56.

  On the other hand, the mold part 54 is formed in a substantially circular arc shape in which the lower surface side opposite to the upper surface side on which the shaft 40 is mounted is curved from one end portion to the other end portion of the base body 52.

  Thus, since the mold part 54 is formed so that the other end part side is thicker than the one end part side covering the curved end 64 of the base body 52, the weight of the other end part side is one end part. Accordingly, the center of gravity G2 of the mold portion 54 is offset from the center portion where the shaft 40 is mounted to the other end portion side.

  That is, the center of gravity G1 of the base body 52 constituting the valve 42 is offset toward one end with respect to the central part of the valve 42 by providing the bulging portion 58, and the center of gravity of the mold part 54 constituting the valve 42 is provided. G2 is offset toward the other end with respect to the central portion of the valve. Therefore, the center of gravity G3 of the valve 42 including the base body 52 and the mold part 54 is balanced by the base body 52 and the mold part 54 to become the central part of the valve 42, and the center of gravity G3 of the valve 42 is changed to the center of the valve 42. The center of rotation of the shaft 40 can coincide with the center C of the shaft 40.

  In other words, by setting the position and thickness of the bulging portion 58 in the base body 52 based on the gravity center position G2 of the mold portion 54 having different cross-sectional shapes on the upper surface and the lower surface, the gravity center position of the mold portion 54 is set. The state where G2 and the center of gravity position G1 of the base body 52 are decentered can be suitably canceled, and the center of gravity G3 of the valve 42 can be moved onto the center C of the shaft 40 which is the center of rotation of the valve 42.

  Further, the mold portion 54 is formed so that a portion facing the hole portion 60 of the base body 52 is exposed to the outside, and the upper surface side where the shaft 40 is mounted corresponds to the shape of the mounting portion 46 of the shaft 40. Thus, a concave portion 66 that is recessed in a substantially rectangular shape is formed. On the other hand, the lower surface opposite to the upper surface on which the shaft 40 is mounted is recessed in a circular shape according to the shape of the bolt 62 that fixes the shaft 40 around the hole 60. That is, the mold part 54 is formed such that the part facing the hole 60 of the base body 52 is recessed by a predetermined depth.

  Then, the mounting portion 46 of the shaft 40 is inserted into the concave portion 66 of the mold portion 54, and the bolt 62 inserted through the hole portion 60 is screwed into the screw hole 50 of the shaft 40. In contrast, the valve 42 is fixed. In this case, since the thickness of the attachment portion 46 is set to be smaller than the depth of the recess portion 66, the attachment portion 46 is suitably accommodated without protruding from the recess portion 66.

  Further, as shown in FIGS. 5 and 6, the valve 42 is disposed such that one end portion formed in a tapered shape inside the intake manifold 14 faces the connection wall 34, and is provided at the end portion. The first sheet portion 36 and the second sheet portion 38 are disposed between the first sheet portion 36 and the second sheet portion 38. One end portion of the valve 42 is disposed so as to be slightly separated from the inner wall surface of the connection wall 34 in a state of being fixed to the shaft 40, and when the valve 42 is rotated and displaced, Further, the displacement is regulated by contacting the second sheet portions 36 and 38. That is, the valve 42 is provided to be rotatable within a predetermined angle between the first seat portion 36 and the second seat portion 38 with the shaft 40 as the center.

  Further, the one end of the valve 42 abuts against the first and second seat portions 36 and 38, thereby switching between the short pipe intake passage 26 and the long pipe intake passage 28 constituting the intake passage 16.

  On the other hand, the other end portion of the valve 42 is disposed so as to be on the connection passage 30 side, and when the one end portion of the valve 42 is brought into contact with and locked to the first seat portion 36, the other end portion is It contacts the inner wall surface of the connection passage 30 extending from the short pipe intake passage 26 and is engaged with a first groove 68 formed on the inner wall surface. Further, when one end portion of the valve 42 is brought into contact with and locked to the second seat portion 38, the other end portion comes into contact with the inner wall surface of the connection passage 30 extending from the long pipe intake passage 28, It is engaged with the second groove portion 70 formed on the inner wall surface. The first and second groove portions 68 and 70 are provided at positions facing the first and second sheet portions 36 and 38 with the shaft 40 as the center, and are recessed at a predetermined depth with respect to the inner wall surface of the connection passage 30. Formed.

  That is, the long pipe intake passage 28 and the connection passage 30 communicate with each other in a state in which the valve 42 is rotationally displaced, one end thereof is in contact with the first seat portion 36 and the other end is engaged with the first groove portion 68. In addition, the short pipe intake passage 26 is blocked, and the intake air of the chamber 20 is sucked into the engine 22 through the long pipe intake passage 28. In addition, the short pipe intake passage 26 and the connection passage 30 communicate with each other in a state where one end of the valve 42 is in contact with the second seat portion 38 and the other end is engaged with the second groove portion 70. The intake passage 28 is blocked, and the intake air in the chamber 20 is drawn into the engine 22 through the short pipe intake passage 26.

  In this case, one end portion of the valve 42 is sealed by coming into contact with the first seat portion 36 or the second seat portion 38, and intake air from the long pipe intake passage 28 or between the short pipe intake passage 26 and the valve 42 is sealed. The other end of the valve 42 is sealed by being engaged with the first groove 68 or the second groove 70, and the intake air passing between the connection passage 30 and the valve 42 is sealed. Leakage is prevented. In this case, since the mold part 54 of the valve 42 is formed of an elastic material such as rubber, the airtightness when the valve 42 abuts is suitably maintained.

  The intake manifold device 10 for an internal combustion engine according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.

  For example, when the engine 22 is operating at a low speed or under a low load, the valve 42 is urged counterclockwise (in the direction of arrow A) under the urging action of a resilient member such as a spring (not shown), and one end of the valve 42 is connected. The other end of the valve 42 is in contact with the inner wall surface of the connection passage 30 and is engaged with the first groove 68 (see FIG. 5). That is, both end portions of the valve 42 are sealed with respect to the first seat portion 36 serving as the end portion of the long pipe intake passage 28 and the inner wall surface of the connection passage 30.

  That is, the long pipe intake passage 28 and the connection passage 30 constituting the intake passage 16 are connected and communicated by the valve 42 constituting the passage length switching unit 18, and the chamber 20 and the engine 22 are connected via the long pipe intake passage 28. Communicated with each other. In this case, since the end portion of the short pipe intake passage 26 is closed by the valve 42, the flow of intake air through the short pipe intake passage 26 is blocked. As a result, the intake air from the chamber 20 is supplied to the cylinder head 24 of the engine 22 through the long pipe intake passage 28 and the connection passage 30.

  Further, since this intake air flows along the upper surface side of the valve 42 to which the shaft 40 is mounted, the upper surface shape of the mold portion 54 that forms the outer shape of the valve 42 is the inner shape of the long pipe intake passage 28. It is formed in a desired shape in advance so as to follow the wall surface shape.

  At this time, since the intake air is supplied from the chamber 20 to the engine 22 via the long pipe intake passage 28, the flow rate of the intake air sucked into the engine 22 through the long pipe intake passage 28 having a long passage length is reduced. In addition, distribution time will be required.

  On the other hand, when the engine 22 is operating at high speed or high load, a control signal based on the accelerator opening is output from a controller (not shown) to the drive unit, and the drive unit is driven to rotate in the opposite direction. As a result, the valve 42 rotates clockwise (in the direction of arrow B) by a predetermined angle around the shaft 40.

  One end portion of the valve 42 is separated from the first seat portion 36 of the connection wall 34 and comes into contact with the second seat portion 38, and the other end portion of the valve 42 is separated from the first groove portion 68 of the connection passage 30. Thus, the second groove portion 70 is engaged. As a result, both end portions of the valve 42 are sealed with respect to the second seat portion 38 and the connection passage 30 which are end portions of the short pipe intake passage 26.

  That is, the short pipe intake passage 26 constituting the intake passage 16 and the connection passage 30 are connected and communicated by the valve 42 constituting the passage length switching unit 18, and the chamber 20 and the engine 22 are connected via the short pipe intake passage 26. Communicated with each other. In this case, since the end of the long pipe intake passage 28 is closed by the valve 42, the flow of intake air through the long pipe intake passage 28 is blocked. As a result, the intake air from the chamber 20 is supplied to the cylinder head 24 of the engine 22 through the short pipe intake passage 26 and the connection passage 30.

  Further, since this intake air flows along the lower surface side of the valve 42, the lower surface shape of the mold portion 54 forming the outer shape of the valve 42 is formed in a substantially arc shape in cross section so that the short pipe intake passage 26 It is formed in a desired shape in advance so as to follow the inner wall surface shape.

  As a result, the intake air is supplied from the chamber 20 to the engine 22 through the short pipe intake passage 26 and the connection passage 30 of the intake passage 16 in a short time and in a large capacity.

  Thus, the flow rate and the inflow time of the intake air sucked into the engine 22 are suitably controlled under the switching action of the passage length switching unit 18 according to the operating state of the engine 22, and accordingly, the engine 22 The output can be improved.

  As described above, in the present embodiment, the valve 42 constituting the passage length switching unit 18 includes the plate-like base body 52 made of a metal material, and the mold part 54 made of an elastic material that covers the base body 52. The upper surface and the lower surface shape of the mold portion 54 facing the short pipe intake passage 26 and the long pipe intake passage 28 in the intake manifold 14 are along the inner wall surfaces of the short pipe intake passage 26 and the long pipe intake passage 28. Formed respectively. Therefore, the cross-sectional shape of the mold part 54 constituting the valve 42 is different between the upper surface side facing the long pipe intake passage 28 and the lower surface side facing the short pipe intake passage 26, and is along the longitudinal direction of the mold part 54. The weight distribution is different between the one end side and the other end side.

  Thus, even when the center of gravity G2 of the mold part 54 constituting the valve 42 is eccentric to the other end part side having a larger thickness, the one end part side of the base body 52 covered with the mold part 54 By providing a bulging portion 58 having an increased thickness with respect to the plate portion 56 and intentionally decentering the gravity center position G1 of the base body 52 toward one end, the base body 52 and the mold portion 54 It is possible to move the center of gravity position G3 of the valve 42 combined with to the center.

  Therefore, the center C of the shaft 40, which is the rotation center of the valve 42, and the center of gravity G3 of the valve 42 can be reliably and suitably matched, and the center of gravity G3 of the valve 42 is rotated when the valve 42 rotates. And the rotation center C are prevented from generating vibration, and the stress applied to the valve 42 by the vibration can be reduced.

  As a result, by setting the center of gravity G3 of the valve 42 as the rotation center C, the valve 42 can be smoothly rotated, and the stress applied to the mounting portion of the shaft 40 and the shaft 40 in the valve 42 is applied. Accordingly, the durability of the passage length switching unit 18 including the valve 42 can be improved.

  Further, since the load on the driving unit is reduced, it is possible to drive with a smaller driving torque, and accordingly, the driving unit can be downsized.

  The intake manifold device for an internal combustion engine according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

1 is an overall longitudinal sectional view of an intake manifold device for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is an external perspective view of a passage length switching unit constituting the intake manifold device for an internal combustion engine shown in FIG. 1. It is a disassembled perspective view which shows a part of passage length switching part shown in FIG. It is an external appearance perspective view which shows the base body which comprises the valve | bulb of the channel length switching part of FIG. FIG. 2 is an enlarged cross-sectional view showing the vicinity of a passage length switching portion in the intake manifold device for an internal combustion engine of FIG. 1. 6 is an enlarged cross-sectional view showing a state in which the passage length of the intake passage is switched by a passage length switching portion in the intake manifold device for the internal combustion engine of FIG. 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Intake manifold apparatus 12 ... Branch pipe 14 ... Intake manifold 16 ... Intake passage 18 ... Passage length switching part 20 ... Chamber 22 ... Engine 26 ... Short pipe intake passage 28 ... Long pipe intake passage 30 ... Connection passage 34 ... Connection wall 36 ... first seat part 38 ... second seat part 40 ... shaft 42 ... valve 52 ... base body 54 ... mold part 56 ... plate part 58 ... bulge part 62 ... bolt 68 ... first groove part 70 ... second groove part

Claims (4)

A long pipe intake passage that is independently connected to each cylinder of the main body constituting the internal combustion engine and communicates with a chamber into which intake air is introduced from a throttle device, and a short pipe that branches from the long pipe intake passage and communicates with the chamber. An internal combustion engine comprising: an intake manifold having a pipe intake passage; and a passage length switching portion that is provided inside the intake manifold facing the intake passage and switches a passage length of the intake passage according to an operating state of the internal combustion engine In the intake manifold system,
The passage length switching unit includes a switching valve that is provided between the long pipe intake passage and the short pipe intake passage and is rotatably supported via a rotation shaft supported by the intake manifold,
The switching valve includes a plate-shaped first member connected to the rotating shaft;
A second member surrounding the first member, facing the long pipe intake passage and the short pipe intake passage, and having side surfaces formed respectively along the passage shapes of the long pipe intake passage and the short pipe intake passage; ,
The first member is provided on the first member, and the center of gravity of the first member is decentered from the center based on the amount of eccentricity of the center of gravity of the second member with respect to the center of the rotating shaft, and includes the first and second members. Adjusting means adjustable so that the center of gravity position is on the center;
An intake manifold device for an internal combustion engine. The apparatus of claim 1.
The intake manifold device for an internal combustion engine, wherein the adjusting means is provided at a position decentered in a direction opposite to the center of gravity of the second member around the rotation shaft and has a predetermined weight. The apparatus according to claim 1 or 2,
The intake manifold device for an internal combustion engine, wherein the second member is formed such that one end portion on the chamber side is thin and the other end portion on the main body side is thick. The device according to any one of claims 1 to 3,
Wherein the first member is made whether we form a metallic material, said second member is an internal combustion engine air intake manifold apparatus characterized by being formed from a resilient material.

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