JP5048475B2 - 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, the intake manifold on-off valve is opened during high-speed or high-load operation to increase the flow rate of intake air supplied to the engine, and the intake manifold is opened and closed during low-speed or low-load operation. Variable intake devices that close valves are known.

  In this variable intake device, an openable / closable valve is provided in a collector to which intake air is supplied from the outside via a valve shaft, and the communication state of two volume chambers separated in the collector is switched by the open / close valve. It is possible. That is, the on-off valve closes the partition wall provided between the one volume chamber and the other volume chamber, so that the communication between the volume chambers is cut off, and the flow rate of the intake air supplied to the engine is reduced. On the other hand, when the on-off valve rotates via the valve shaft and is separated from the partition wall, the flow rate of the intake air supplied to the engine is increased through communication between the volume chambers (for example, Patent Documents). 1).

Japanese Patent Laid-Open No. 11-294172

  By the way, in the prior art according to Patent Document 1, when the on-off valve is opened and closed, the on-off valve is displaced so as to oppose the flow of the intake air, so that it is pressed by the intake air, and the on-off valve is driven to rotate. There is a problem in that the load on the driving unit being increased increases. For this reason, it is necessary to increase the output performance of the drive unit, which leads to an increase in the size of the drive unit.

  In addition, the power consumption increases with the increase in the size of the drive unit, and when the passage length is switched by the opening / closing valve, the energized state is maintained in order to stop and hold the rotation displacement of the opening / closing valve. Therefore, the power consumption is further increased.

  The present invention has been made in consideration of the above-described problems, and is an internal combustion engine that can reliably maintain the path length switching state by the path length switching unit and can reduce the size and power consumption of the drive unit. An object of the present invention is to provide an intake manifold device for an 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 a pipe intake passage and communicates with the chamber; and an intake manifold that is provided inside the intake manifold facing the intake passage, and that corresponds to an 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 portion is provided between the long pipe intake passage and the short pipe intake passage, and is provided so as to be rotatable with respect to the intake manifold;
A holding mechanism capable of restricting and holding the rotational displacement of the switching valve when the passage length of the intake passage is switched to the long pipe intake passage or the short pipe intake passage;
With
The holding mechanism is connected to a drive shaft connected to a drive unit, and a first rotation member that is rotatable about the drive shaft;
A valve shaft that supports the switching valve at one end and a roller at the other end, and a second rotating member that is rotatable about the valve shaft;
An engagement groove that extends along a longitudinal direction of the first rotation member, and that has the holding portion that holds the roller at at least one end thereof, and the roller is engaged;
It is characterized by comprising.

  According to the present invention, there is provided the holding mechanism capable of restricting and holding the rotational displacement of the switching valve when the passage length of the intake passage is switched to the long pipe intake passage or the short pipe intake passage by the passage length switching portion. The holding mechanism includes a first rotating member connected to the drive shaft and a second rotating member connected to the valve shaft that supports the switching valve, and the other end of the second rotating member. The roller provided in is engaged with an engaging groove formed along the longitudinal direction of the first rotating member. Then, when the first rotating member rotates under the rotating action of the driving unit, the second rotating member rotates about the valve shaft via the roller engaged with the engaging groove, and the valve When the switching valve supported by the shaft is rotated and displaced by a predetermined angle, and when the intake passage is switched to the long pipe intake passage or the short pipe intake passage by the switch valve, the roller is held in the engagement groove. Is engaged and held.

  Accordingly, the rotational displacement of the switching valve can be reliably controlled, and can be reliably held in a state where the passage length of the intake passage is switched by the passage length switching portion including the switching valve.

  Further, since the rotational displacement of the switching valve can be mechanically held in a state where the energization to the drive unit is stopped, the amount of current consumption used in the drive unit can be reduced to save power. In addition, since the driving load on the driving unit can be reduced, the driving unit can be reduced in size.

Furthermore, the engagement groove is provided on one end portion side of the first rotating member, and when the switching valve is switched to the short pipe intake passage, the first holding portion to which the roller is engaged,
A second holding portion that is provided on the other end side of the first rotating member, and is engaged with the roller when switched to the long pipe intake passage by the switching valve;
With
The first and second holding portions are moved under the pressing action of the intake air when the short valve intake passage or the long pipe intake passage where the switching valve is in contact with the inner wall surface of the intake passage is switched. The acting direction of the acting force applied from the rotating member toward the first rotating member is in line with the line segment connecting the roller engaged with the first and second holding portions and the drive shaft. It is good to form so that it becomes.

  Thus, even when a pressing force is applied to the switching valve by the intake air flowing into the long pipe intake passage or the short pipe intake passage, the second rotating member connected to the switching valve via the valve shaft is rotated. No action force is applied in the direction of movement, and the rotation of the second rotation member is securely held in a locked state under engagement with the engagement groove of the first rotation member. can do. As a result, the switching state of the short pipe intake passage or the long pipe intake passage in which the switching valve is in contact with the inner wall surface of the intake passage can be reliably maintained.

  Furthermore, the engaging groove is formed with a connecting portion that extends along the longitudinal direction of the first rotating member and connects the first and second holding portions to each other, and the first holding portion and the second holding portion. Are preferably bent in opposite directions with respect to the connecting portion.

  Still further, the intake manifold is provided so as to be able to contact the first rotating member and includes a stopper that restricts the rotational displacement of the first rotating member, so that even when the switching valve is pressed by the intake air. Since the acting force applied from the second rotating member toward the first rotating member can be restricted by the stopper, the switching valve rotates through the first and second rotating members. Displacement can be prevented.

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

  That is, when the first rotating member of the holding mechanism is rotated under the rotating action of the driving unit, the second rotating member is rotated about the valve shaft via the roller engaged with the engaging groove. When the switching valve supported by the valve shaft is rotated and displaced by a predetermined angle, and when the intake passage is switched to the long pipe intake passage or the short pipe intake passage by the switch valve, the roller is moved to the engagement groove. Is engaged and held by the holding portion. As a result, the rotational displacement of the switching valve is reliably regulated and can be reliably held in a state in which the passage length of the intake passage is switched by the passage length switching portion including the switching valve. In addition, since the rotational displacement of the switching valve can be held in a state where the energization to the drive unit is stopped, it is possible to save power of the drive unit and to reduce the size of the drive unit. be able to.

  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 24 having four cylinder chambers mounted on a vehicle or the like.

  As shown in FIGS. 1 and 2, 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, a driving unit (not shown) for rotationally displacing the path length switching unit 18, and a driving force from a driving unit (not shown) to the path length switching unit 18. And a cam mechanism (holding mechanism) 20 that rotates and displaces.

  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 includes a chamber 22 in which air sucked through a throttle valve (not shown) is temporarily stored, and an intake passage that connects the chamber 22 and a cylinder head (main body) 26 of the engine 24. 16 and the like.

  The intake passage 16 is formed to have a substantially rectangular cross section, and a short pipe intake passage 28 that sucks intake air from the chamber 22 and supplies the intake air to the engine 24 when the engine 24 is operated at high speed or high load. During the low-speed or low-load operation, the long-pipe intake passage 30 that sucks the intake air from the chamber 22 and supplies the intake air to the engine 24, and the joint portion between the short-pipe intake passage 28 and the long-pipe intake passage 30 And a connecting passage 32 extending to the engine 24.

  The intake manifold 14 includes a mounting flange 34 connected to the cylinder head 26 of the engine 24, and the mounting flange 34 is coupled to the cylinder head 26 via a flat mounting surface. As a result, the intake passage 16 of the intake manifold 14 and the cylinder head 26 are connected and communicated with each other through the connection passage 32 penetrating through the mounting flange 34.

  The short pipe intake passage 28 is provided above the chamber 22, extends while curving toward the mounting flange 34, and a lower end portion thereof opens toward the chamber 22 side. On the other hand, the long pipe intake passage 30 opens at one end connected to the lower side of the chamber 22 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 30 extends to above the short pipe intake passage 28, and the other end is connected to the short pipe intake passage 28. Thereby, the short pipe intake passage 28 and the long pipe intake passage 30 communicate with each other.

  The short pipe intake passage 28 is provided on the inner side with respect to the long pipe intake passage 30 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 24 is operating at a high speed or a high load, intake air is supplied to the cylinder head 26 constituting the engine 24 through a short pipe intake passage 28 having a short passage length. The intake air is supplied to the cylinder head 26 through the long long pipe intake passage 30.

  Each of the short pipe intake passage 28 and the long pipe intake passage 30 is provided in accordance with the number of cylinders (for example, four) of the engine 24, and the short pipe intake passage 28 and the long pipe intake passage 30 are respectively provided. Independently formed in parallel.

  On the other hand, a connecting portion 36 where the inner surfaces of the short pipe intake passage 28 and the long pipe intake passage 30 that are adjacent to each other are joined is provided at a joint portion between the short pipe intake passage 28 and the long pipe intake passage 30. A valve shaft 38 constituting the passage length switching unit 18 is rotatably supported by the connection unit 36.

  The passage length switching unit 18 is provided at a joint portion between the short pipe intake passage 28 and the long pipe intake passage 30, is a long valve shaft 38 supported by the intake manifold 14, and is held by the valve shaft 38. It consists of a plurality of valves (switching valves) 40 that switch the flow state of the intake air in the intake passage 16.

  The valve shaft 38 is formed in an axial shape having a constant diameter and is rotatably supported with respect to the connection portion 36 of the intake manifold 14. Then, the end of the valve shaft 38 is provided so as to protrude to the outside of the intake manifold 14, and the driven cam 42 constituting the cam mechanism 20 is connected (see FIG. 3).

  The drive unit is, for example, a stepping motor that is provided on the side of the intake manifold 14 and is driven to rotate under energization. The rotation angle of the drive unit is input to the drive unit from a controller (not shown). The desired angle is controlled based on the control signal. A drive shaft 44 that is rotatably supported by the intake manifold 14 is connected to the drive unit, and the drive shaft 44 rotates under the rotational action of the drive unit.

  The drive shaft 44 is disposed substantially parallel to the valve shaft 38 at a predetermined interval in the intake manifold 14, and one end thereof is provided so as to protrude outside the intake manifold 14. A drive unit (not shown) is connected to one end of the drive shaft 44, and a drive cam (first rotating member) constituting the cam mechanism 20 is provided between the intake manifold 14 and the drive unit. 46) are connected.

  The valve 40 is made of, for example, a plate body formed in a substantially rectangular shape, and includes a base body 48 made of a metal material and a seal member 50 attached to an end portion of the base body 48. The valve 40 is provided inside the connection passage 32 constituting the intake passage 16, and one end thereof is fixed to the valve shaft 38 with a bolt 52, and the other end faces the connection passage 32. Be placed. That is, the valve 40 is rotatably provided by a predetermined angle with the valve shaft 38 connected to one end as a fulcrum.

  The seal member 50 is provided with a predetermined thickness so as to cover the other end portion of the valve 40, and the seal member 50 abuts against the inner wall surface 32 a of the connection passage 32, whereby the valve 40 and the inner wall surface 32 a The leakage of the intake air through the gap is prevented, and switching between the short pipe intake passage 28 and the long pipe intake passage 30 is performed reliably.

  1 to 3, the cam mechanism 20 is provided on the side of the intake manifold 14 so as to be on the side of the long pipe intake passage 30, and is provided on the other end of the drive shaft 44. A drive cam 46 provided rotatably with the drive shaft 44, and a driven cam (second turning member) 42 provided at an end of the valve shaft 38 and engaged with the drive cam 46 via a roller 54. And a stopper 56 for restricting the rotational displacement of the drive cam 46.

  The drive cam 46 is formed in a plate shape having a predetermined width, and a drive shaft 44 is connected to a corner portion of one end portion thereof, and a cam groove (engagement groove) from the one end portion toward the other end portion. 58 is extended.

  The cam groove 58 is connected to the linear portion (connecting portion) 60 formed at a substantially central portion of the driving cam 46 and the linear holding portion 60 and extends toward one end of the driving cam 46. A second holding portion 64 connected to the linear portion 60 and extending toward the other end portion of the drive cam 46, and a roller 54 held by the driven cam 42 inside thereof. Is inserted.

  The straight portion 60 extends linearly from one end to the other end along the longitudinal direction of the drive cam 46, and is formed with a constant width corresponding to the diameter of the roller 54.

  The first holding portion 62 is inclined at a predetermined angle in a direction away from the drive shaft 44 with respect to the linear portion 60 on one end portion side of the drive cam 46.

  The second holding portion 64 is bent and extended substantially perpendicular to the linear portion 60 in the direction opposite to the inclination direction of the first holding portion 62. Moreover, the connection site | part of the 1st holding | maintenance part 62 and the linear part 60 and the connection site | part of the 2nd holding | maintenance part 64 and the linear part 60 are smoothly formed in circular arc shape. In addition, the linear part 60, the 1st and 2nd holding | maintenance parts 62 and 64 are formed with the fixed width | variety corresponding to the diameter of the roller 54 along the extension direction.

  The driven cam 42 is formed in a substantially oval cross section, and the valve shaft 38 is connected to one end portion thereof, and the roller 54 is rotatably supported on the other end portion via a pin portion 66. The roller 54 is provided on the other side surface opposite to the one side surface of the driven cam 42 to which the valve shaft 38 is connected. The driven cam 42 is disposed so as to be substantially orthogonal to the base body 48 constituting the valve 40.

  The stopper 56 is provided adjacent to the lower side of the drive cam 46, and is arranged at an angle capable of contacting the side surface of the drive cam 46 in a state where the valve 40 is rotated and switched to the short pipe intake passage 28. The

  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. As shown in FIGS. 1 and 2, in the low load operation state of the engine 24, the valve 40 rotates counterclockwise (arrow A direction), and the intake passage 16 is switched to the long pipe intake passage 30. The described state will be described as an initial state.

  In this initial state, a control signal is output from a controller (not shown) to the drive unit, and the drive shaft 44 is urged counterclockwise (in the direction of arrow A) under the drive action of the drive unit, whereby the drive shaft Under the rotating action of 44, the driving cam 46 rotates counterclockwise (arrow A direction) about the driving shaft 44 by a predetermined angle. 2 is engaged with the holding portion 64. That is, the driven cam 42 rotates counterclockwise (arrow A direction) around the valve shaft 38 under the moving action of the roller 54 along the cam groove 58. Along with this, the valve 40 rotates and displaces by a predetermined angle counterclockwise (in the direction of arrow A) via the valve shaft 38 that rotates together with the driven cam 42, and comes into contact with the inner wall surface 32a of the connection passage 32. The long pipe intake passage 30 in which the intake passage 28 is closed is brought into a communication state.

  In this case, as shown in FIG. 2, a pressing force P is applied to the valve 40 in the direction of separating the valve 40 from the inner wall surface 32a by the intake air flowing into the closed short pipe intake passage 28. . Specifically, the pressing force P1 is applied in a direction in which the valve 40 is rotated clockwise (arrow B direction) around the valve shaft 38.

  At this time, the acting force F1 acting from the driven cam 42 to the drive cam 46 is on the same straight line as a line segment L connecting the center C1 of the drive shaft 44 and the center C2 of the roller 54, and from the roller 54 to the drive shaft 44. Acting towards the side. In other words, the second holding portion 64 of the cam groove 58 is engaged with the second holding portion 64 in a state where the valve 40 contacts the inner wall surface 32 a of the connection passage 32 and is switched to the long pipe intake passage 30. A line segment L connecting the center C2 of the combined roller 54 and the center C1 of the drive shaft 44 is set in advance so as to be on the same straight line as the acting direction of the acting force F1 acting from the driven cam 42 to the driving cam 46. Has been.

  Thereby, even when the pressing force P1 due to the intake air flowing into the short pipe intake passage 28 is applied to the valve 40, the acting force is applied in the direction in which the driven cam 42 is rotated (direction of arrow B). Therefore, the rotation of the driven cam 42 is locked under the engaging action of the drive cam 46 with the cam groove 58. As a result, even when the energization to the drive unit is stopped, the valve 40 is in contact with the inner wall surface 32a of the connection passage 32 and is maintained in the state where it is switched to the long pipe intake passage 30. In other words, it is possible to maintain the switching state to the long pipe intake passage 30 by the valve 40 in a non-energized state with respect to the drive unit.

  In this case, since the intake air is supplied from the chamber 22 through the long pipe intake passage 30 to the engine 24, the intake air per unit time taken into the engine 24 through the long pipe intake passage 30 having a long passage length is supplied. The flow rate is reduced.

  On the other hand, when the engine 24 is switched from the low load operation to the high load operation, a control signal based on the engine speed or the like is output from a controller (not shown) to the drive unit, and the drive unit The drive shaft 44 connected to is rotated clockwise (in the direction of arrow B). As a result, as shown in FIG. 4, the drive cam 46 is rotated clockwise (in the direction of arrow B) by a predetermined angle about the drive shaft 44, and the second cam groove 58 is rotated along with the rotation operation. The roller 54 engaged with the holding portion 64 moves along the cam groove 58 toward the linear portion 60 side. As the roller 54 moves, the driven cam 42 starts to rotate clockwise (in the direction of arrow B) at the other end side having the roller 54 around the valve shaft 38, and the valve shaft 38 together with the driven cam 42. And the valve 40 is rotated and displaced clockwise (in the direction of arrow B) by a predetermined angle.

  Further, when the driving cam 46 rotates clockwise (in the direction of arrow B), the roller 54 of the driven cam 42 further moves from the straight portion 60 of the cam groove 58 toward the first holding portion 62 side, and the first The long pipe intake passage 30 is closed and the short pipe intake passage 28 is closed when the seal member 50 provided at the tip of the valve 40 abuts against the inner wall surface 32 a of the connection passage 32 while being engaged with the holding portion 62. It will be in the state connected with the connection channel | path 32 (refer FIG. 5).

  In this case, a pressing force P2 is applied to the valve 40 in a direction in which the valve 40 is separated from the inner wall surface 32a by the intake air flowing into the closed long-pipe intake passage 30. Specifically, the pressing force P2 is applied in a direction in which the valve 40 is rotated counterclockwise (arrow A direction) around the valve shaft 38.

  At this time, the acting force F2 acting from the driven cam 42 to the drive cam 46 is on a line segment L connecting the center C1 of the drive shaft 44 and the center C2 of the roller 54, and acts in a direction away from the roller 54. is doing. In other words, the first holding portion 62 of the cam groove 58 is engaged with the first holding portion 62 in a state where the valve 40 contacts the inner wall surface 32 a of the connection passage 32 and is switched to the short pipe intake passage 28. A line segment L connecting the center C2 of the combined roller 54 and the center C1 of the drive shaft 44 is set in advance so as to be on the same straight line as the acting direction of the acting force F2 acting from the driven cam 42 to the driving cam 46. Has been.

  Thus, even when a pressing force P2 due to the intake air flowing into the long pipe intake passage 30 is applied to the valve 40, no acting force is applied in the direction in which the driven cam 42 is rotated, and the drive cam Under the action of engagement with the cam groove 58 of 46, the rotation of the driven cam 42 is locked. As a result, even when the energization of the drive unit is stopped, the valve 40 is in contact with the inner wall surface 32a of the connection passage 32 and is maintained in a state where it is switched to the short pipe intake passage 28. Further, since the side surface of the drive cam 46 is in contact with the stopper 56, the rotational displacement of the drive cam 46 in the clockwise direction (arrow B direction) is also regulated.

  That is, the intake air is directly introduced from the chamber 22 into the short pipe intake passage 28 and supplied to the engine 24 through the short pipe intake passage 28. As a result, the intake air is rapidly supplied from the chamber 22 to the engine 24 in a short time.

  As described above, in the present embodiment, the cam mechanism 20 including the drive cam 46 and the driven cam 42 is provided on the side of the intake manifold 14, and the drive connected to the drive unit is connected to one end of the drive cam 46. A shaft 44 is connected, and a valve shaft 38 holding a valve 40 is connected to one end of the driven cam 42. Further, a roller 54 provided at the other end of the driven cam 42 is engaged with a cam groove 58 formed along the longitudinal direction of the drive cam 46, and the intake passage 16 is made into the short pipe intake passage 28 or the valve 40. The roller 54 is engaged with the first holding portion 62 or the second holding portion 64 in the cam groove 58 in a state where the long pipe intake passage 30 is switched.

  As a result, in a state where the valve 40 is in contact with the inner wall surface 32a of the intake passage 16, a line segment L connecting the center C2 of the roller 54 and the center C1 of the drive shaft 44, and the driven cam 42 to the drive cam 46 is obtained. The acting direction of the acting forces F1 and F2 acting can be on the same straight line. Therefore, even when the pressing forces P1 and P2 by the intake air flowing into the long pipe intake passage 30 or the short pipe intake passage 28 are applied to the valve 40, an acting force is applied in the direction in which the driven cam 42 is rotated. Therefore, the rotation of the driven cam 42 can be reliably held in a locked state under the engaging action of the drive cam 46 with the cam groove 58.

  In addition, the rotational displacement of the valve 40 can be mechanically held by the cam mechanism 20 in a state where the energization to the drive unit is stopped, so that the amount of current consumption used in the drive unit is reduced and power is saved. Can be achieved.

  Furthermore, since the driving load on the driving unit can be reduced, the driving unit can be reduced in size. In other words, it is possible to switch the passage length of the intake passage 16 by driving the passage length switching portion 18 including the valve 40 using a drive portion with a small output.

  Furthermore, since the drive unit is provided on the side of the intake manifold 14, the overall size of the intake manifold device 10 can be reduced by reducing the size of the drive unit. The space inside the engine room can be used effectively.

  In the above-described cam mechanism 20 of the intake manifold device 10, the case where the plate-like drive cam 46 having the cam groove 58 is provided has been described. However, the present invention is not limited thereto, and is formed in a cylindrical shape, for example. You may make it apply the cylindrical groove cam which has a cam groove along the surrounding surface, the end surface cam which moves the roller 54 using the end surface of a cylindrical body, etc.

  Further, in the above-described intake manifold device 10, the case where the cam mechanism 20 is provided only on one end side of the drive shaft 44 and the valve shaft 38 has been described, but with respect to both ends of the drive shaft 44 and the valve shaft 38. The cam mechanisms having the same configuration may be provided. As a result, the valve 40 can be rotated and held by the valve shaft 38 more reliably.

  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 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. It is a partially omitted external perspective view showing a valve and a cam mechanism constituting a passage length switching unit. It is an expanded sectional view which shows the state which the valve | bulb which comprises the channel length switching part of FIG. 2 rotated only the predetermined angle via the cam mechanism. FIG. 5 is an enlarged cross-sectional view showing a state where a valve constituting the passage length switching unit of FIG. 4 is further rotated by a predetermined angle via a cam mechanism and switched from a long pipe intake passage to a short pipe intake passage.

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 ... Cam mechanism 24 ... Engine 28 ... Short pipe intake passage 30 ... Long pipe intake passage 32 ... Connection passage 38 ... Valve shaft 40 ... valve 42 ... driven cam 44 ... drive shaft 46 ... drive cam 54 ... roller 56 ... stopper 58 ... cam groove 60 ... linear part 62 ... first holding part 64 ... second holding part

Claims (3)

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 portion is provided between the long pipe intake passage and the short pipe intake passage, and is provided so as to be rotatable with respect to the intake manifold;
A holding mechanism capable of restricting and holding the rotational displacement of the switching valve when the passage length of the intake passage is switched to the long pipe intake passage or the short pipe intake passage;
With
The holding mechanism is connected to a drive shaft connected to a drive unit, and a first rotation member that is rotatable about the drive shaft;
A valve shaft that supports the switching valve at one end and a roller at the other end, and a second rotating member that is rotatable about the valve shaft;
An engagement groove that extends along a longitudinal direction of the first rotation member, and that has the holding portion that holds the roller at at least one end thereof, and the roller is engaged;
Tona is, the engagement groove is provided at one end side of the first rotating member, when switched to the short intake duct by said switching valve, a first said roller is engaged A holding portion; and a second holding portion provided on the other end portion side of the first rotating member and engaged with the roller when switched to the long pipe intake passage by the switching valve. The first and second holding portions are configured to perform the first and second holding portions under the pressing action of the intake air when switching the short pipe intake passage or the long pipe intake passage where the switching valve contacts the inner wall surface of the intake passage. The acting direction of the acting force applied from the two rotating members toward the first rotating member is in line with a line segment connecting the roller engaged with the first and second holding portions and the drive shaft. become so formed intake manifold system for an internal combustion engine according to claim Rukoto. Apparatus according to claim 1 Symbol placement,
The engaging groove is formed with a connection portion extending along the longitudinal direction of the first rotating member and connecting the first and second holding portions to each other, and the first holding portion and the second holding portion. An intake manifold device for an internal combustion engine, wherein the portion is bent in a direction opposite to the connection portion. The apparatus according to claim 1 or 2 ,
An intake manifold device for an internal combustion engine, comprising: a stopper provided in the intake manifold so as to be able to contact the first rotating member and restricting the rotational displacement of the first rotating member.

Images