JP2008106628A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device for an engine in which turbulence of intake air is not generated in any of the operating ranges, and its weight is reduced as much as possible. <P>SOLUTION: A partition wall 40 partitioning between a surge tank part 30 and a branched pipe part 60, is provided with an opening 42 for medium speed opened in a medium speed operating range and an opening 43 for high speed opened in a high speed operating range. The opening 42 for medium speed is formed to the longest intake passage at the upstream of the opening 43 for high speed. The opening 42 is provided with single swing flappers 51, and the opening 43 is provided with single swing flappers 53. The flappers 51 for medium speed are rotated all together by a drive shaft 52 for medium speed. The flappers 53 for high speed are rotated all together by a drive shaft 54 for high speed. The drive shaft 52 for medium speed is disposed to the upstream of the opening 42 for medium speed. The drive shaft 54 for high speed is disposed to the downstream of the opening 43 for high speed. When the flappers 51, 53 are opened, the flappers can function as straightening plates. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake device for an engine.

  2. Description of the Related Art There is known a variable intake type engine intake device that changes the length of an intake passage according to the rotational speed of the engine.

  In order to embody such a technique, for example, in Patent Documents 1 to 3, a butterfly type or rotary type valve is provided in a surge tank, and openings constituting a plurality of intake paths are selectively opened and closed. Or the structure which changes the length of an intake passage in three steps is disclosed.

Further, Patent Document 4 discloses a configuration in which the length of the intake path is changed in two stages using a single door type valve.
JP 2006-9779 A JP 2002-317637 A Japanese Patent Laid-Open No. 10-299594 US Pat. No. 5,211,139

  By the way, in the configuration in which the length of the intake path is changed in three stages of the low speed region, the medium speed region, and the high speed region, in the low speed region and the medium speed region, the short intake passage is closed and the long intake passage is opened. At this time, when the valve used for opening and closing the intake path is a butterfly type as disclosed in Patent Documents 1 and 2, the opened valve forms undulations in the surge tank, and the surge tank leads to the intake port. This will cause turbulence in the flow to the route to reach, which is not preferable.

  On the other hand, in the rotary valve disclosed in Patent Document 3, it is possible to adopt a configuration that is relatively less likely to be disturbed, but there is a problem that the weight of the entire valve is increased.

  In addition, the single-opening valve as disclosed in Patent Document 4 is advantageous in terms of weight reduction, but air turbulence occurs depending on the layout as in the case of the butterfly valve. In particular, the problem becomes significant in the type in which the length of the intake path is switched to three stages.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an intake device for an engine in which intake air is not disturbed in any of the operating ranges.

  In order to solve the above problems, the present invention includes an intake manifold used for an engine in which a plurality of cylinders are arranged in series, and the intake manifold includes a surge tank portion having a predetermined length along the cylinder row direction. A branch pipe section that extends around the outer periphery of the surge tank section and branches into each cylinder, and distributes air in the surge tank section to a corresponding cylinder; an upstream side of the branch pipe section; and the surge tank section A low-speed opening that is provided at an upstream end of the branch pipe portion and communicates the branch pipe portion and the surge tank portion. And provided on the downstream side of the low-speed opening of the partition wall, provided for the medium-speed opening communicating the branch pipe part and the surge tank part, and provided downstream of the medium-speed opening, A high-speed opening that communicates the branch pipe section and the surge tank section; a medium-speed flapper that opens and closes the medium-speed opening; a high-speed flapper that opens and closes the high-speed opening; and the medium-speed flapper A medium-speed drive shaft that supports each medium-speed flapper in a cantilever manner to drive, a high-speed drive shaft that supports each high-speed flapper in a cantilever manner to drive the high-speed flapper, and Drive means for driving each drive shaft so that the flapper opens and closes the corresponding opening, and the medium speed drive shaft is an upstream edge in the air flow direction of the longest intake path in the branch pipe portion of the medium speed opening Further, the high-speed drive shaft is disposed on the downstream edge side of the air flow in the longest intake path direction in the branch pipe portion of the high-speed opening, and the drive means drives the engine operating region at low speed and medium speed. , When divided with high speed The flapper corresponding to the medium-speed and high-speed openings is closed in the high-speed operation region, and the flapper corresponding to the high-speed opening is closed and the flapper corresponding to the medium-speed opening is opened in the medium-speed operation region. In the region, the engine intake device is characterized in that each drive shaft is driven so that a flapper corresponding to at least the high-speed opening is opened. In this aspect, when the engine operating region is the low-speed operating region, the flappers corresponding to the medium-speed and high-speed openings are closed, so that each flapper functions as a passage wall continuous with the partition wall. For this reason, since the air introduced into the surge tank portion is guided to the cylinder via the low speed opening, the path length becomes the longest. Next, in the medium speed operation region, the flapper corresponding to the opening for high speed is closed and the flapper corresponding to the opening for medium speed is opened, so that the main flow of intake air is introduced into each cylinder from the opening for medium speed The path length is shorter than that in the low-speed driving range. Further, since the flapper corresponding to at least the high-speed opening opens in the high-speed operation region, the main flow of intake air is introduced into each cylinder from the high-speed opening, so that the path length is the shortest. Here, in this aspect, each of the medium-speed and high-speed flappers is cantilevered with the corresponding medium-speed and high-speed drive shafts, respectively, and the medium-speed drive shaft is The high-speed drive shaft is arranged at the upstream edge of the longest intake path in the air flow direction in the branch pipe portion of the speed opening, and the downstream edge of the air flow in the longest intake path direction in the branch pipe portion of the high-speed opening, respectively. Therefore, when each flapper is opened, the free end of the flapper is brought as close as possible to the inner surface side of the surge tank portion of the partition wall, and the opened flapper can function as a rectifying plate. As a result, in the medium-speed operation region and the high-speed operation region, the intake flow is less likely to be disturbed, the intake resistance can be reduced, and the volumetric efficiency (and thus the charging efficiency) can be increased.

  In a preferred embodiment, each flapper has a guide surface that guides the main flow of intake air of the surge tank portion to the opened opening when the corresponding opening is opened. In this aspect, the main flow of the intake air is guided to the opening by the guide surface of the flapper, so that the disturbance of the intake air flow is less likely to occur in the medium speed operation region and the high speed operation region, the intake resistance is reduced, and the volume efficiency ( As a result, the filling efficiency) can be increased.

  In a preferred aspect, the intake manifold is an assembly in which a plurality of resin molded bodies are combined, and the resin molded body includes a surge tank section divided body that forms at least a part of the surge tank section, and a surge tank section. A branch pipe divided body that forms the branch pipe portion by being joined to the divided body, and a drive shaft that is provided for each of the medium speed and high speed drive shafts and that cooperates with the surge tank portion divided body. And at least medium-speed and high-speed frame bodies having openings that allow opening and closing operations of the flappers. In this aspect, when the intake manifold is configured by combining a plurality of resin moldings, the surge tank section divided body with a drive shaft integrated with each flapper and a frame body supporting the drive shaft as a subassembly. Since it can be assembled, the assembly process is simplified.

  In a preferred embodiment, the surge tank part divided body is constituted by a divided body divided into two parts in the vertical direction, the medium speed frame body is attached to the lower divided body, and the high speed frame body is It is attached to the upper divided body. In this aspect, since the surge tank portion divided body is divided into two, the attachment process of each frame body is further facilitated.

  As described above, according to the present invention, when each flapper is opened, the free end of the flapper is brought as close as possible to the inner surface side of the surge tank portion of the partition wall, and the opened flapper can function as a rectifying plate. become. As a result, disturbances in the flow of intake air are less likely to occur in the medium-speed operation range and the high-speed operation region, so the intake resistance is reduced and the volumetric efficiency (and thus the charging efficiency) in each of the operation regions. ) Can be enhanced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view of an engine employing the engine intake device of the present invention, FIG. 2 is a front view of the engine intake device, and FIG. 3 is a view showing the opening of the intake device in the low speed operation region of the engine. 4 is a cross-sectional view showing the valve state, FIG. 4 is a cross-sectional view showing the valve opening state of the intake device in the medium speed operation region of the engine, and FIG. 5 is a valve opening state of the intake device in the high speed operation region of the engine. FIG. 6 is a perspective view of the intake device of the engine, and FIG. 7 is an exploded perspective view of the intake device of the engine.

  With reference to the drawings, the engine 1 according to the present embodiment is a four-cylinder in-line system, and an intake device 10 is fixed to a side portion of a cylinder block 2 constituting each cylinder.

  The intake device 10 includes a throttle body 11 that adjusts the flow rate of air supplied from an air cleaner (not shown), and an intake manifold 20 that is disposed on the downstream side of the throttle body 11.

  As shown in FIG. 7, the intake manifold 20 is an assembly in which a plurality of resin injection-molded products are molded and integrated by vibration welding.

  The intake manifold 20 as an assembly has a surge tank portion 30 fixed to the cylinder block 2 of the engine 1 and a branch pipe portion 60 that is continuous with the surge tank portion 30 and branches for each intake port 3 of the engine 1. is doing.

  Referring to FIG. 2, the surge tank portion 30 integrally includes an introduction pipe 31 to which the throttle body 11 of the engine 1 is attached and a plenum portion 32.

  A flange 31a is formed at the upstream end of the introduction pipe 31, and the throttle body 11 is attached via the flange 31a.

  The plenum portion 32 is formed in a substantially rectangular shape in front view extending long along the cylinder row direction (direction along the crankshaft 4). On the other hand, as shown in FIG. 3, the cross section of the plenum portion 32 has an arc shape that is curved with the introduction pipe 31 approximately at the center so that the side opposite to the engine 1 bulges outward. In the illustrated embodiment, an oil separator 33 is formed at the center of the plenum portion 32, and a blow-by gas control valve (PCV) 34 for controlling the flow of blow-by gas at a negative pressure is provided therein. ing.

  With reference to FIGS. 3-5, between the plenum part 32 and the branch pipe part 60, the substantially circular-arc-shaped partition 40 which partitions both is formed. The partition wall 40 forms a longest intake path PH that guides air introduced from the introduction pipe 31 to the plenum section 32 to each branch pipe section 60, and forms a low-speed opening 41 at the upstream end of the longest intake path PH. ing. In the following description, “upstream side” and “downstream side” will be described based on the direction of intake air flowing along the longest intake path PH.

  An intermediate speed opening 42 that bypasses the low speed opening 41 and communicates the introduction pipe 31 and the branch pipe section 60 is formed in the middle of the partition wall 40 for each branch pipe section 60 (see FIG. 4). Further, on the downstream side of the longest intake path PH from the medium speed opening 42 of the partition wall 40, a high speed opening 43 that communicates the introduction pipe 31 and the branch pipe part 60 is formed for each branch pipe part 60 ( (See FIG. 5).

  A medium speed flapper 51 is disposed in each medium speed opening 42. Each medium speed flapper 51 is a cantilevered resin molded product integrally formed with a medium speed drive shaft 52 extending along the crankshaft 4. On the other hand, a high-speed flapper 53 is disposed in each high-speed opening 43. Each high-speed flapper 53 is a cantilever-shaped resin molded product integrally formed with a high-speed drive shaft 54 extending along the crankshaft 4. The medium-speed and high-speed drive shafts 52 and 54 are rotatably supported by frame bodies 55 and 56 and inner walls of the partition 40 provided respectively. Each flapper 51, 53 forms a guide surface 51a, 53a that curves smoothly along the peripheral surface of the branch pipe section 60 defined by the partition wall 40 when the corresponding opening 42, 43 is closed. Yes.

  As shown in FIG. 1, medium-speed and high-speed negative pressure actuators 57 and 58 are arranged on one side wall of the plenum portion 32, and the medium-speed and high-speed drive shafts 52 and 54 respectively correspond to them. It is configured to rotate. That is, when the engine rotation speed is divided into low speed, medium speed, and high speed, the medium speed negative pressure actuator 57 rotates the medium speed drive shaft 52 in the medium speed operation region by the intake pressure, The flapper 51 is configured to open the corresponding medium speed opening 42 (see FIG. 4). Further, the high-speed negative pressure actuator 58 is configured to rotate the high-speed drive shaft 54 in the high-speed operation region by the intake pressure to open the high-speed opening 43 corresponding to each flapper 53 (FIG. 5). reference). In the present embodiment, in the operation region where the high-speed opening 43 is opened, the medium-speed opening 42 is also opened. However, when the high-speed opening 43 is opened, the main flow of the intake air passes through the high-speed opening 43. Therefore, the charging efficiency during high-speed operation is not impaired. The respective flappers 51 and 53 are rotated by the respective negative pressure actuators 57 and 58 to a range of about 90 ° from the position where the corresponding openings 42 and 43 are blocked. Note that the flappers 51 and 53 are normally biased in the direction of closing the corresponding openings 42 and 43 by the biasing force of the springs built in the negative pressure actuators 57 and 58.

  Furthermore, in the present embodiment, the medium speed drive shaft 52 is upstream of the longest intake path PH of the medium speed opening 42, and the high speed drive shaft 54 is downstream of the high speed opening 43 in the longest intake path direction. Are arranged respectively. As a result, in the state where the openings 42 and 43 corresponding to the flappers 51 and 53 are open, the medium speed flapper 51 covers the upstream inner peripheral surface of the longest intake path PH of the partition wall 40, and the high speed flapper 53. About, it is comprised so that the upper wall part of the plenum part 32 may be covered (refer FIG. 4, FIG. 5).

  The branch pipe part 60 is spirally curved so as to surround the outer periphery of the plenum part 32, and the downstream end is connected to the intake port 3 of the engine 1. A flange 61 for fixing the branch pipe portion 60 to the cylinder block 2 of the engine 1 is formed at the downstream end of the branch pipe portion 60.

  Next, each divided body constituting the intake device 10 as described above will be described.

  Referring to FIG. 7, intake device 10 includes a pair of inner circumferential divided bodies 100A and 100B that are divided into two parts in the vertical direction, and a pair of outer circumferential divided bodies 200A that are disposed outside both inner circumferential divided bodies 100A and 100B. 200B and sub-assemblies 300A and 300B built in the inner circumferential divided bodies 100A and 100B.

  The upper inner circumferential divided body 100 </ b> A is a resin injection-molded product that integrally includes the upper part of the surge tank part 30 (plenum part 32), the introduction pipe 31, and the downstream end of the branch pipe part 60. A groove portion 101A that defines the downstream inner peripheral portion of the branch pipe portion 60 is formed on the outer peripheral portion of the inner peripheral divided body 100A, and the upper outer peripheral divided body 200A is joined to the outer side of the groove portion 101A. A joining surface 102A to be formed is formed. In addition, the inner peripheral divided body 100A also integrally forms the downstream end portion of the branch pipe portion 60, and the flange 61 is integrally formed with the inner peripheral divided body 100A.

  The lower inner circumferential divided body 100 </ b> B is a resin injection molded product integrally having a lower portion of the surge tank portion 30 (plenum portion 32) and an upstream end of the branch pipe portion 60. A groove portion 101B that partitions the upstream inner peripheral portion of the branch pipe portion 60 is formed on the outer peripheral portion of the inner peripheral divided body 100B, as in the upper inner peripheral divided body 100A. Is formed with a bonding surface 102B to be bonded to the lower outer circumferential divided body 200B.

  The upper outer circumferential divided body 200A constitutes a downstream portion of the branch pipe portion 60, and the inner surface is joined to the groove forming each branch pipe portion 60 and the upper inner circumferential divided body 100A. And has a surface.

  The lower outer circumferential divided body 200B constitutes an upstream portion of the branch pipe portion 60, and the inner surface thereof is joined to the groove 201B forming each branch pipe portion 60 and the lower inner circumferential divided body 100B. And a joining surface 202B.

  FIG. 8 is an exploded perspective view of the sub-assembly, FIG. 9 is an enlarged cross-sectional view showing an essential part of FIG. 3, and FIG. 10 is a cross-sectional view showing an assembled state of the frame body.

  With reference to FIGS. 8 to 10, the sub-assembly 300 </ b> A is obtained by assembling the medium-speed drive shaft 52 and the medium-speed frame body 55 described above. The sub-assembly 300B is obtained by assembling the high-speed drive shaft 54 of the high-speed flapper 53 and the high-speed frame body 56 described above. The medium speed opening 42 is formed in the lower inner circumferential divided body 100B, and the high speed opening 43 is formed in the upper inner circumferential divided body 100A. Therefore, the sub-assembly 300A is assembled to the lower inner circumferential division body 100B, and the sub-assembly 300B is assembled to the upper inner circumferential division body 100A.

  The medium-speed and high-speed frame bodies 55 and 56 for the sub-assemblies 300A and 300B are used for pivotally supporting the openings 55a and 56a for rotating the corresponding flappers 51 and 53 and the drive shafts 52 and 54, respectively. Recesses 55b and 56b are provided. The medium-speed and high-speed frame bodies 55 and 56 are curved along the portions constituting the partition 40 of the corresponding divided bodies 100A and 100B. At the time of assembly, as shown in FIG. 8, the drive shafts 52 and 54 are assembled to the corresponding frame bodies 55 and 56 to form sub-assemblies 300A and 300B. The sub-assemblies 300A and 300B are divided into the divided bodies. The sub-assemblies 300A and 300B are integrated with the corresponding divided bodies 100A and 100B by being assembled to the inner peripheral surfaces of 100A and 100B and screwed from the joint surfaces of the divided bodies 100A and 100B. The shafts 52 and 54 are supported. Here, as shown in FIG. 10, by screwing the screws 59 from the joint surfaces (outer peripheral side) of the respective divided bodies 100A and 100B, the heads of the screws 59 are brought into contact with the corresponding outer peripheral divided bodies 200A and 200B. Will be covered. As a result, it is possible to prevent such a problem that the screw 59 comes off and enters the branch pipe portion 60.

  In the above-described configuration, the flappers 51 and 53 close the corresponding openings 42 and 43 in the low-speed operation region of the engine 1 by the action of the medium-speed and high-speed negative pressure actuators 57 and 58 shown in FIG. As shown in FIG. 3, fresh air introduced from the introduction pipe 31 into the plenum portion 32 of the surge tank portion 30 follows the longest long intake path PH from the low speed opening 41 and enters the intake port of the engine 1. Will be introduced.

  Further, in the medium speed operation region of the engine 1, the medium speed flapper 51 opens the medium speed opening 42, so that the fresh air introduced into the plenum portion 32 of the surge tank portion 30 is medium as shown in FIG. The air is introduced into the branch pipe portion 60 through the speed opening 42 and then introduced into the respective intake ports 3. Here, as described above, the medium speed drive shaft 52 is disposed on the upstream side of the longest intake path PH of the medium speed opening 42. As a result, the medium-speed flapper 51 covers the upstream inner peripheral surface of the longest intake path PH of the partition wall 40, so that the medium-speed opening 42 is opened. Therefore, the main stream of fresh air introduced into the plenum portion 32 is The air is smoothly guided to the medium speed opening 42 and introduced into the intake port 3 from the branch pipe portion 60. Accordingly, it is possible to prevent the flow of fresh air from being disturbed in the plenum portion 32 as much as possible in the medium speed operation region, and to maintain high filling efficiency.

  Further, since the high-speed flapper 53 opens the high-speed opening 43 in the high-speed operation region of the engine 1, as shown in FIG. 5, fresh air introduced into the plenum portion 32 of the surge tank unit 30 is transferred to the high-speed opening 43. Then, it is introduced into the branch pipe part 60 and introduced into the respective intake ports 3. Here, as described above, the high-speed drive shaft 54 is disposed on the downstream side of the longest intake path PH of the high-speed opening 43. As a result, since the high-speed flapper 53 covers the upper wall portion of the plenum portion 32 and the high-speed opening 43 is opened, the mainstream of fresh air introduced into the plenum portion 32 of the surge tank portion 30 is smoothly high-speed. It is led to the opening 43 for introduction and introduced into the intake port 3 from the branch pipe part 60. Therefore, even in the high-speed operation region, it is possible to prevent the flow of fresh air from being disturbed in the plenum part 32 as much as possible, and to maintain high filling efficiency.

  As described above, in the present embodiment, when the operation region of the engine 1 is the low speed operation region, the flappers 51 and 53 corresponding to the medium speed and high speed openings 42 and 43 are closed. It functions as a passage wall continuous with the partition 40. For this reason, the air introduced into the surge tank section 30 is guided to the cylinder via the low-speed opening 41, so that the path length is the longest. Next, in the medium speed operation region, the flappers 51 and 53 corresponding to the high speed opening 43 close and the medium speed opening 42 opens the medium speed flapper 51. As a result of being introduced into the cylinder, the path length is shorter than in the low-speed operation region. Further, in the high-speed operation region, the high-speed flapper 53 opens at least the high-speed opening 43, and as a result, the main path of intake air is introduced into each cylinder from the high-speed opening 43, so that the path length becomes the shortest. Here, in the present embodiment, each of the medium speed and high speed flappers 51 and 53 is cantilevered with the corresponding medium speed and high speed drive shafts 52 and 54, respectively. The drive shaft 52 is disposed upstream of the medium speed opening 42 in the longest intake path direction, and the high speed drive shaft 54 is disposed downstream of the high speed opening 43 in the longest intake path direction. When 51 and 53 are opened, the free ends of the flappers 51 and 53 are brought as close as possible to the inner surface side of the plenum portion 32 of the surge tank 30 of the partition wall 40 so that the opened flappers 51 and 53 function as a rectifying plate. It becomes possible. As a result, in the medium-speed operation region and the high-speed operation region, the intake flow is less likely to be disturbed, the intake resistance can be reduced, and the volumetric efficiency (and thus the charging efficiency) can be increased.

  In the present embodiment, the flappers 51 and 53 have guide surfaces 51a and 53a for guiding the main flow of the intake air of the surge tank 30 to the opened opening when the corresponding openings 42 and 43 are opened. Yes. For this reason, in the present embodiment, since the main flow of intake air is guided to the corresponding opening 42 (or opening 43) by these guide surfaces 51a and 53a, the flow of intake air is further disturbed in the medium speed operation region and the high speed operation region. It becomes difficult to occur, the intake resistance can be reduced, and the volumetric efficiency (and thus the filling efficiency) can be increased.

  In the present embodiment, the intake manifold 20 is joined to the inner circumferential divided bodies 100A and 100B as surge tank section divided bodies that constitute at least a part of the surge tank section 30, and these inner circumferential divided bodies 100A and 100B. By combining the outer peripheral divided bodies 200A and 200B as the branch pipe divided bodies constituting the branch pipe portion 60 and the plurality of resin molded bodies having the medium speed and high speed frame bodies 55 and 56 as main elements. It is an assembly. Therefore, in the present embodiment, when the intake manifold 20 is configured by combining a plurality of resin molded bodies, the drive shafts 52 and 54 integrated with the flappers 51 and 53 and the drive shafts 52 and 54 are pivotally supported. Since the inner circumferential divided bodies 100A and 100B can be assembled with the frame bodies 55 and 56 as sub-assemblies, the assembly process is simplified.

  Moreover, in this embodiment, the surge tank part division body is comprised by the inner peripheral division bodies 100A and 100B divided into two up and down, and the medium speed frame bodies 55 and 56 are the lower inner peripheral division bodies. The high-speed frame bodies 55 and 56 are attached to the upper inner circumferential divided body 100A. For this reason, in this embodiment, since the surge tank part division body is divided | segmented into two, the attachment process of each frame body 55 and 56 becomes still easier.

  As described above, in the present embodiment, when the flappers 51 and 53 are opened, the free ends of the flappers 51 and 53 are brought as close as possible to the inner surface side of the surge tank 30 of the partition wall 40 to open the flappers 51. , 53 can function as a current plate. As a result, disturbances in the flow of intake air are less likely to occur in the medium-speed operation range and the high-speed operation region, so the intake resistance is reduced and the volumetric efficiency (and thus the charging efficiency) in each of the operation regions. ) Can be enhanced.

  The above-described embodiments are merely preferred specific examples of the present invention, and the present invention is not limited to the above-described embodiments. For example, each of the medium speed flapper and the high speed flapper may be composed of one sheet, and it goes without saying that various modifications are possible within the scope of the claims of the present invention.

It is the schematic of the engine which employ | adopted the engine intake device of this invention. It is a front view of the intake device of the engine. It is sectional drawing which shows the valve opening state of the intake device in the low speed driving | operation area | region of the same engine. It is sectional drawing which shows the valve opening state of the intake device in the medium speed driving | operation area | region of the same engine. It is sectional drawing which shows the valve opening state of the intake device in the high-speed driving | operation area | region of the engine. It is a perspective view of the intake device of the engine. It is a disassembled perspective view of the intake device of the engine. It is a disassembled perspective view of a subassembly. It is an expanded sectional view which expands and shows the principal part of FIG. It is a cross-sectional view which shows the assembly | attachment state of a frame body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Intake port 10 Intake device 11 Throttle body 20 Intake manifold 30 Surge tank part 31 Introducing pipe 31a Flange 36 High speed opening 40 Bulkhead 41 Low speed opening 42 Medium speed opening 43 High speed opening 51 Medium speed flapper 51a Guide surface 52 Medium speed drive shaft 53 High speed flapper 53a Guide surface 54 High speed drive shaft 55 Medium speed frame body 56 High speed frame body 57 Medium speed negative pressure actuator 58 High speed negative pressure actuator 60 Branch pipe section 100A , 100B Inner circumference divided body 200A, 200B Outer circumference divided body 300A, 300B Sub divided body PH Longest intake path

Claims (4)

An intake manifold used for an engine having a plurality of cylinders arranged in series is provided, and the intake manifold surrounds the surge tank portion having a predetermined length along the cylinder row direction and the outer periphery of the surge tank portion. A branch pipe part that extends and branches for each cylinder and circulates air in the surge tank part to a corresponding cylinder; and a partition wall that partitions the upstream side of the branch pipe part and the surge tank part; In the intake system of the engine whose length can be changed,
Provided at an upstream end of the branch pipe part, and an opening for low speed communicating the branch pipe part and the surge tank part;
An opening for medium speed that is provided on the downstream side of the opening for low speed of the partition, and that communicates the branch pipe part and the surge tank part,
A high-speed opening provided downstream of the medium-speed opening and communicating the branch pipe portion and the surge tank portion;
A medium speed flapper for opening and closing the medium speed opening;
A high-speed flapper for opening and closing the high-speed opening;
A medium speed drive shaft for supporting each medium speed flapper in a cantilever manner so as to drive the medium speed flapper;
A high-speed drive shaft for supporting each high-speed flapper in a cantilever manner so as to drive the high-speed flapper;
Drive means for driving each drive shaft so that each flapper opens and closes the corresponding opening,
The medium speed drive shaft is at the upstream edge in the air flow direction of the longest intake path in the branch pipe portion of the medium speed opening, and the high speed drive shaft is the longest intake path direction in the branch pipe portion of the high speed opening. Are arranged on the downstream edge side of the air flow,
When the driving region of the engine is divided into low speed, medium speed, and high speed, the flapper corresponding to the medium speed and high speed openings is closed in the low speed operation area, and the high speed opening is in the medium speed operation area. And the corresponding flapper is opened, and the corresponding flapper is opened, and in the high-speed operation region, each drive shaft is driven so that at least the corresponding flapper opens the high-speed opening. The engine intake system. The engine intake device according to claim 1,
An intake device for an engine, wherein each flapper has a guide surface that guides the main flow of intake air in the surge tank portion to the opened opening when the corresponding opening is opened. The engine intake device according to claim 1 or 2,
The intake manifold is an assembly in which a plurality of resin molded bodies are combined, and the resin molded body is joined to a surge tank section divided body that constitutes at least a part of the surge tank section, and a surge tank section divided body. As a result, the branch pipe divided body constituting the branch pipe section and the medium-speed and high-speed drive shafts are provided for the respective drive shafts in cooperation with the surge tank section divided body. And at least a medium-speed and high-speed frame body having an opening that allows opening and closing operations of each flapper. The engine intake device according to claim 3,
The surge tank section divided body is configured by a vertically divided body, the medium speed frame body is attached to the lower divided body, and the high speed frame body is the upper divided body. An intake system for an engine characterized by being attached to the engine.

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