JP2008163747A - Intake manifold of multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a vibration suppression effect for a throttle device attached to an intake collecting part of an intake manifold with a distinctive structure of a reinforcement rib provided on the intake manifold of a multi-cylinder internal combustion engine. <P>SOLUTION: The intake manifold M comprises a head side flange 10 coupled to a cylinder head 2, four intake pipes 21 to 24, the intake collecting part 25, a throttle side flange 26 provided at an end 25a of the intake collecting part 25 for attachment of the throttle device 5 and a first rib 51 serving as the reinforcement rib. The first rib 51 is provided integrally with the intake collecting part 25, the two intake pipes 21, 22 inclusive of the first intake pipe 21 closest to the throttle side flange 26 in a cylinder array direction and the head side flange 10 and extends in a straight line saddling the firs and second pipes 21, 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake manifold attached to a cylinder head of a multi-cylinder internal combustion engine, and more particularly, to a reinforcement structure of an intake manifold including an intake manifold portion to which a throttle device is attached.

In order to increase the rigidity of the intake manifold of the multi-cylinder internal combustion engine, a reinforcing rib extending along the central axis of each of the plurality of intake pipes is provided (for example, see Patent Document 1) or connected to a flange. There is a known pipe having a larger thickness at the end of the intake pipe than the central part of the intake pipe (see, for example, Patent Document 2).
Utility Model Registration No. 2539636 Japanese Patent Laid-Open No. 2001-20816

In an intake manifold having an intake manifold portion connected to a plurality of intake pipes, a throttle device having a throttle valve is attached to the intake manifold portion with respect to an intake pipe connected to a head side flange coupled to a cylinder head. . And, the reinforcement ribs provided in each intake pipe and the partial thickening of the intake pipe are mainly aimed at increasing the rigidity of each intake pipe itself, and the effect of suppressing the vibration of the throttle device attached to the intake manifold is limited. It is a thing.
Further, among the plurality of intake pipes, it is the recent intake pipe that is closest to the throttle apparatus in the cylinder arrangement direction that greatly affects vibration suppression of the throttle apparatus due to its rigidity, and then in the cylinder arrangement direction. It is an adjacent intake pipe adjacent to the intake pipe recently. However, in the intake manifold in which the intake pipe and the adjacent intake pipe are simply arranged recently, the contribution degree of the adjacent intake pipe is not so large in terms of the vibration suppressing effect on the throttle device. When the reinforcing rib provided on the intake pipe extends along the central axis, the rigidity of the intake pipe itself has recently been responsible for the vibration suppression of the throttle device. The degree is small.
Furthermore, when the reinforcing rib has a bent portion in plan view, the rigidity of the reinforcing rib decreases due to the presence of the bent portion with respect to the load in the direction passing through both ends of the reinforcing rib in plan view. , The reinforcing function is reduced.
In particular, when the throttle device includes an electric throttle valve that is driven to open and close by an electric motor, since the electric motor is provided, the weight of the throttle device is larger than that of a manual throttle valve. In order to suppress the vibration of the throttle device, it is necessary to further increase the rigidity of the intake manifold.
Further, even in an internal combustion engine that is not equipped with a balancer based on a design concept that emphasizes high output, it is necessary to further increase the rigidity of the intake manifold in order to suppress vibration of the intake manifold.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 to 10 is characterized in that the intake manifold of the intake manifold is formed by the characteristic structure of the reinforcing rib provided in the intake manifold of the multi-cylinder internal combustion engine. It aims at improving the vibration suppression effect with respect to the throttle device attached to a part.

The invention according to claim 1 is a head-side flange coupled to a cylinder head of a multi-cylinder internal combustion engine, a predetermined number of intake pipes connected to the head-side flange at a downstream end, and the predetermined number In the intake manifold, the intake manifold includes: an intake manifold connected to an upstream portion of the intake pipe; a throttle-side flange provided at a predetermined portion of the intake manifold to which a throttle device including a throttle valve is attached; and a reinforcing rib. The rib extends across the intake manifold, two or more intake pipes including the nearest intake pipe closest to the throttle side flange in the cylinder arrangement direction among the predetermined number of intake pipes, and the head side flange. The intake rib includes a first rib provided integrally, and the first rib extends over the two or more intake pipes.
The invention according to claim 2 is the intake manifold according to claim 1, wherein the two or more intake pipes include the nearest intake pipe and an adjacent intake pipe adjacent to the nearest intake pipe in a cylinder arrangement direction, The first rib is connected to the intake manifold portion closer to the throttle side flange than the adjacent intake pipe in the cylinder arrangement direction.
According to a third aspect of the present invention, there is provided the intake manifold according to the first or second aspect, wherein the reinforcing rib is integrally provided across the intake air collecting portion, the nearest intake pipe, and the head side flange. Including a rib, the second rib straddling the central axis of the latest intake pipe.
According to a fourth aspect of the present invention, in the intake manifold according to the third aspect, the reinforcing rib includes a third rib that is integrally provided across the second rib, the nearest intake pipe, and the head side flange. The third rib extends substantially along the central axis of the latest intake pipe.
According to a fifth aspect of the present invention, in the intake manifold according to any one of the first to fourth aspects, the ribs included in the reinforcing rib are straight.
According to a sixth aspect of the present invention, in the intake manifold according to any one of the first to fifth aspects, an attachment portion to which a stay coupled to the engine main body is attached to the intake manifold portion close to the throttle side flange. The first rib or the second rib is connected to the mounting portion.
A seventh aspect of the present invention is the intake manifold according to any one of the first to sixth aspects, wherein the head side flange includes a plurality of fastenings into which bolts for coupling the head side flange to the cylinder head are inserted. A portion is provided, and the first rib or the second rib is connected to the head-side flange near the fastening portion between the fastening portions adjacent in the cylinder arrangement direction.
According to an eighth aspect of the present invention, in the intake manifold according to any one of the first to seventh aspects, the wall thickness of the most recent intake pipe is the throttle side flange in the cylinder arrangement direction of the predetermined number of intake pipes. It is larger than the farthest intake pipe farthest from
According to a ninth aspect of the present invention, in the intake manifold according to any one of the first to eighth aspects, the predetermined portion is a portion on one side in the cylinder arrangement direction in the intake manifold portion, and the nearest intake pipe Is an end intake pipe located at the one end of the predetermined number of intake pipes.
According to a tenth aspect of the present invention, in the intake manifold according to the ninth aspect, the reinforcing rib is a fourth rib and a fifth rib that is provided integrally with the intake manifold and extends in a straight line in the cylinder arrangement direction. The fourth rib includes the intake manifold portion, an end portion intake pipe farthest from the throttle side flange at the other end in the cylinder arrangement direction among the predetermined number of intake pipes, and the head The first rib and the head-side flange, the fourth rib, and the fifth rib are integrally provided over the side flange and extend in a straight line. Is connected to.

According to the first aspect of the present invention, the two or more intake pipes including the latest intake pipe are connected by the first rib provided across the two or more intake pipes between the intake air collecting portion and the head side flange. As a result, the rigidity of the intake pipe disposed closer to the throttle side flange in the cylinder arrangement direction is increased, so that the vibration suppressing effect on the throttle device attached to the throttle side flange is improved.
According to the second aspect of the present invention, since the first rib is connected to the intake manifold portion closer to the throttle side flange than the adjacent intake pipe in the cylinder arrangement direction, the adjacent intake pipe is recently used in addition to the intake pipe. Since the rigidity of the vicinity of the throttle side flange is enhanced by the integrated first rib, the vibration suppressing effect on the throttle device is improved.
According to the third aspect of the present invention, since the rigidity of the intake pipe is recently increased by the second rib in addition to the first rib, the rigidity of the two or more intake pipes can be further increased, and the throttle device The vibration suppression effect with respect to is improved.
According to the fourth aspect of the present invention, the rigidity of the intake pipe is recently increased by the third rib in addition to the first and second ribs. The vibration suppression effect is improved.
According to the fifth aspect of the present invention, since the first to third ribs are straight ribs, there is no decrease in rigidity due to the ribs having a bent portion, so the first ribs are provided straddling. The rigidity of the two or more intake pipes is improved, and the vibration suppressing effect on the throttle device is improved.
According to the sixth aspect of the present invention, since the rigidity of the mounting portion is increased because it is connected to the engine body via the stay, the rigidity in the vicinity of the throttle side flange is further enhanced by the mounting portion. Further, the rigidity of the two or more intake pipes is increased by the ribs connected to the mounting portion, thereby improving the vibration suppressing effect on the throttle device.
According to the seventh aspect of the present invention, since the rib is connected in the vicinity of the fastening portion having high rigidity because it is fastened to the cylinder head, the rigidity of the two or more intake pipes can be increased and The vibration suppression effect is improved.
According to the eighth aspect, since the rigidity of the intake pipe is recently increased due to the large thickness of the intake pipe, the vibration suppressing effect on the throttle device is improved.
According to the ninth aspect of the present invention, in the intake manifold in which the throttle device is attached to the end portion, an excellent vibration suppressing effect on the throttle device is exhibited.
According to the tenth aspect of the present invention, the rigidity of the intake manifold is enhanced by the rectangular frame-shaped rib formed by the first, fourth, and fifth ribs and the head side flange, thereby suppressing vibrations to the throttle device. The effect is improved.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIG. 1, a multi-cylinder internal combustion engine E having an intake manifold M to which the present invention is applied is an in-line four-cylinder internal combustion engine mounted on a vehicle, and a predetermined number of cylinders, here four cylinders. An engine body comprising a cylinder block 1 that is arranged in series and integrally formed, a cylinder head 2 coupled to the end of the cylinder block 1, and a head cover 3 coupled to the end of the cylinder head 2. Prepare.

  The internal combustion engine E is further fitted to each cylinder so as to be able to reciprocate and is driven by the pressure of combustion gas generated in a combustion chamber, which will be described later, to rotate the crankshaft, and to the cylinder axis of the cylinder An intake device that guides intake air to a combustion chamber formed between the piston and the cylinder head 2 in a parallel direction and an exhaust device that guides combustion gas as exhaust gas from the combustion chamber to the outside of the internal combustion engine E are provided. Note that the internal combustion engine E does not include a balancer from the viewpoint of emphasizing output. Both the intake device and the exhaust device are attached to the cylinder head 2.

Referring also to FIG. 2, the intake device is connected to the throttle device 5 by a throttle device 5 having a throttle valve for controlling an intake amount of intake air including air sucked through an air cleaner, and a throttle side flange 26 which is an upstream end portion. And an intake manifold M connected to the cylinder head 2 at a head-side flange 10 which is a downstream end. Then, the intake air flows through the intake passage formed by the intake device, and then is sucked into the combustion chamber through an intake port provided in the cylinder head 2. Here, the intake air includes a mixture of the fuel and air when the fuel is supplied in the intake device, and also includes air when the fuel is supplied directly into the combustion chamber.
Note that the terms upstream and downstream relate to the flow of intake air.

  The throttle device 5 includes a throttle body 5a as a body forming an intake passage which is a passage portion of the intake passage in the throttle device 5, the throttle valve supported by the throttle body 5a so that the intake passage can be opened and closed, And an electric motor as an actuator attached to the body 5a for driving the throttle valve to open and close.

  Referring to FIGS. 1 to 4, the intake manifold M is connected to the head-side flange 10 and one head-side flange 10 coupled to the intake-side side wall 2 a where the inlet of the intake port opens in the cylinder head 2. A plurality of predetermined number of intake pipes, here, four first to fourth intake pipes 21 to 24 equal to the number of cylinders, and one intake manifold portion 25 connected to each of the intake pipes 21 to 24, Reinforcement comprising a throttle side flange 26 provided at an end portion 25a as a predetermined portion of the intake air collecting portion 25 to which the throttle body 5a is attached, and a plurality of ribs 51 to 57 to be described later for increasing the rigidity of the intake manifold M. Ribs (hereinafter referred to as “reinforcing ribs”), and these head side flanges 10, the intake pipes 21 to 24, the intake air collecting portions 25, the throttle side flanges 26, and the reinforcing ribs are integrated into a single unit. Is a member .

  The end portion 25a is obtained when the intake air collecting portion 25 is divided into approximately two equal parts in the cylinder arrangement direction, which is the cylinder arrangement direction, into one side portion and the other side portion in the cylinder arrangement direction. Included in the one side portion. The cylinder arrangement direction is parallel to the rotation center line of the crankshaft.

  The intake manifold M is preferably integrally formed by casting from a light metal, for example, an aluminum alloy, as a single member, but may be integrally formed from a forming material other than metal, for example, a synthetic resin.

  A passage portion formed by the intake manifold M in the intake passage is constituted by a collecting passage 35 formed by the intake collecting portion 25 and four branch passages 31-34 formed by the intake pipes 21-24. . The first to fourth branch passages 31 to 34 have first to fourth central axes L1 to L4 and outlets 31o to 34o that open to the head side flange 10, respectively.

  The intake manifold M is attached to the cylinder head 2 by connecting a flat head-side flange 10 linearly extending in the cylinder arrangement direction to the cylinder head 2 via a gasket by a plurality of bolts 13 (see FIG. 1). It is done. Therefore, the head side flange 10 is provided with a plurality of fastening portions 11 provided with through holes 12 as a plurality of bolt holes into which the respective bolts 13 are inserted. The fastening portions 11 fastened to the cylinder head 2 by bolts 13 passing through the through holes 12 or nuts screwed to the bolts 13 are provided at intervals in the circumferential direction at the outer peripheral edge portion 14 of the head side flange 10. It is done. The outer peripheral edge portion 14 has a pair of edge portions 14a and 14b extending along the cylinder arrangement direction, and one of the edge portions 14a has first, fourth, sixth and seventh reinforcing ribs. The ribs 51 to 54, 56, 57 are connected. Each fastening portion 11 is constituted by a bulging portion that is a thick portion at the outer peripheral edge portion 14 and is a portion that bulges outward. The bolt 13 or a nut screwed to the bolt 13 is a fastener for fastening the head side flange 10 to the cylinder head 2.

  Each of the intake pipes 21 to 24 extending between the head-side flange 10 and the intake manifold portion 25 having the cylinder arrangement direction as the longitudinal direction is curved so that the upper surface of the intake manifold M is convex (FIG. 1). reference). On the other hand, the reinforcing ribs provided integrally with the head side flange 10, the intake pipes 21 to 24, and the intake air collecting portion 25 are provided on the concave lower surface of the intake manifold M (see FIG. 1).

  Here, when one of the upper surface and the lower surface of the intake manifold M is one of the first outer surface and the second outer surface of the intake manifold M, the other of the upper surface and the lower surface is the other of the first outer surface and the second outer surface. In the first outer surface and the second outer surface, a plane including the outlets 31o to 34o and the collecting passage 35 is a specific plane among planes parallel to the cylinder arrangement direction, and a direction orthogonal to the specific plane is a specific direction. In this case, among the outer surfaces of the intake manifold M, the outer surface portion that can be seen from one direction of the specific direction and the outer surface portion that can be seen from the other direction of the specific direction are meant. In this embodiment, an example of the specific plane is a horizontal plane H as shown in FIG. 1, and the specific direction is the vertical direction.

Referring to FIGS. 1 and 2, among the first to fourth intake pipes 21 to 24 that are sequentially arranged side by side in the cylinder arrangement direction, the first intake pipe 21 is closest to the throttle side flange 26 in the cylinder arrangement direction. It is a near recent intake pipe and moves away from the throttle side flange 26 in order of the second, third and fourth intake pipes 21 to 24. For this reason, the fourth intake pipe 24 is the farthest intake pipe farthest from the throttle side flange 26 in the cylinder arrangement direction.
Of the first to fourth intake pipes 21 to 24, the first and fourth intake pipes 21 and 24 are end intake pipes disposed at both ends in the cylinder arrangement direction, The third intake pipes 22 and 23 are intermediate intake pipes disposed between the intake pipes at both ends in the cylinder arrangement direction.

  In the intake manifold portion 25, the upstream end portion of the upstream portion of the first to fourth intake pipes 21 to 24 in the cylinder arrangement direction from the throttle side flange 26 or one end portion 25a toward the other end portion 25b. 21a to 24a are connected side by side, and in the head side flange 10, the downstream end of the first to fourth intake pipes 21 to 24 is directed from one end 10a to the other end 10b in the cylinder arrangement direction. The parts 21b to 24b are connected in sequence.

In all the intake pipes 21 to 24, the entire intake pipes 21 and 22 are constituted by thick pipes whose wall thickness t1 is larger than the wall thickness t2 of at least a part of the intake pipes 23 and 24. On the other hand, the intake pipes 23 and 24 are located near the head side flange 10, that is, near the downstream ends 23 b and 24 b of the intake pipes 23 and 24, and in the range over approximately ¼ of the respective pipe lengths. Thick portions 23t and 24t whose thickness gradually increases toward the side flange 10 are provided. The thick portions 23t and 24t have a maximum thickness equal to the thickness t1. Therefore, the thickness of the intake pipes 21 and 22 is larger than the thickness of the intake pipes 23 and 24.
Further, in each of the intake pipes 21 to 24, as representatively shown in the intake pipe 22 shown in FIG. 5, the four corner portions 22e of the tube wall are formed on the side portions 22s between the pair of corner portions 22e. It is considered to be a thick part with a larger wall thickness.

  Referring to FIG. 2 and FIG. 6 to FIG. 8, there are three membranes made of thin walls connecting the intake pipes 21, 22; 22, 23; 23, 24 adjacent to each other in the cylinder arrangement direction. The ribs 41 to 43 are integrally formed with the intake pipes 21 to 24, respectively. The two film-like ribs 41 and 43 are also connected to the head side flange 10 and the intake air collecting portion 25. The film-shaped rib 41 is integrally formed with a first rib 51 which will be described later. The film-like rib 42 is connected to a part of the intake air collecting portion 25 and the intake pipes 22 and 23, and a hole 44 is formed between the film-like rib 42 and the head side flange 10. The rigidity of the intake manifold M is increased by the film-like ribs 41 to 43.

  In the tank-like or tubular intake gathering portion 25, a throttle-side flange 26 is provided at the end portion 25a, and the end portion 25b is a through-hole closed by a plug, and the sand core sand used during casting is removed. A sand removal hole 27 is provided.

  Referring to FIG. 2, the reinforcing rib is an assembly of at least one of the first to fourth intake pipes 21 to 24 and the first to seventh ribs 51 to 57 rising from the intake assembly portion 25. When viewed from below, which is one of the direction facing the lower surface or the specific direction (hereinafter referred to as “specific direction view”, in this embodiment, the plan view), the first to fifth ribs 51 to 55. Are straight ribs extending in a straight line, and the sixth and seventh ribs 56 and 57 are curved ribs extending in a curved manner.

  The first rib 51 extends across the intake air collecting portion 25, the first and second air intake pipes 21, 22, and the head side flange 10, and the intake air collecting portion 25, the intake pipes 21, 22, and the head side flange 10. The first and second intake pipes 21 and 22 and the film-like ribs 41 are formed between the intake air collecting portion 25 and the head side flange 10, that is, on the first and second intake pipes 21 and 22 and the film-like rib 41 in this embodiment. , Extending over the second intake pipes 21 and 22. Therefore, in this embodiment, two or more intake pipes provided across the first rib 51 are the first intake pipe 21 as the latest intake pipe and the adjacent intake pipe adjacent to the intake pipe 21 in the cylinder arrangement direction. The intake pipe 22.

  Of the both end portions 51a and 51b of the first rib 51, the upstream end portion 51a is connected to the intake air collecting portion 25 by being connected to the boss portion 61 formed integrally with the intake air collecting portion 25, and the downstream end portion 51b is the head. It is connected to the side flange 10. The first rib 51 extending from the upstream end 51a toward the downstream end 51b extends in a straight line between the both ends 51a and 51b. Further, the first rib 51 is provided across the central axis L1 of the intake pipe 21 and the central axis L2 of the intake pipe 22 in the specific direction view. Specifically, in the separation direction that is a direction orthogonal to the cylinder arrangement direction when viewed in the specific direction, it straddles the central axis L1 near the intake manifold 25 and straddles the central axis L2 near the head side flange 10. Therefore, the downstream end 51b is on the far side from the central axis L2.

  A position near the head side flange 10 in the cylinder arrangement direction is referred to as a “close side” with respect to a certain member or part, or in the member or the part, and a position far from the head side flange 10 in the cylinder arrangement direction. It is called “far side”.

  A boss portion 61 as an attachment portion to which a stay attached to the cylinder block 1 is attached is located closer to the one side or the one side portion than the center portion of the intake air collecting portion 25, and further from the intake pipe 22 and the central axis L1. Is also located on the near side. The stay, which is a support member for supporting the intake manifold M, is fixed to the boss portion 61 by a bolt as a fixture screwed into two screw holes 61a provided in the boss portion 61 that is long in the cylinder arrangement direction.

The second rib 52 is formed integrally with the intake air collecting portion 25, the intake pipe 21, and the head side flange 10 over the intake air collecting portion 25, the intake pipe 21, and the head side flange 10. The second rib 52 is disposed between the intake air collecting portion 25 and the head-side flange 10, that is, on the intake pipe 21, so that the entirety thereof is closer to the first rib 51. It straddles the head side flange 10 closer than the first rib 51 in the separation direction.
Of the both end portions 52a and 52b of the second rib 52, the upstream end portion 52a is connected to the intake assembly portion 25 by being connected to the boss portion 61 closer to the upstream end portion 51a of the first rib 51, and downstream. The end 52b is connected to the head side flange 10. The second rib 52 extending from the upstream end portion 52a toward the downstream end portion 52b extends in a straight line between the both end portions 52a and 52b. The upstream end 52a is located on the proximity side of the upstream end 21a of the intake pipe 21, and the downstream end 52b is located on the far side of the downstream end 21b.

  Referring also to FIG. 4, the downstream end portions 51b and 52b of the first and second ribs 51 and 52 are located between a pair of adjacent fastening portions 11a and 11b at a predetermined interval d in the cylinder arrangement direction. The connecting portions 11a and 11b are connected in the cylinder arrangement direction. More specifically, the downstream end portion 51b is located in the vicinity of one of the fastening portions 11b on the far side of the pair of fastening portions 11a and 11b, that is, the center of the insertion hole 12 that is the center of the fastening portions 11a and 11b. To the position closer to the fastening portion 11b within a range of 1/3 of the interval d in the cylinder arrangement direction. On the other hand, the downstream end 52b is connected to the vicinity of the fastening portion 11a in the vicinity of the fastening portion 11a on the close side, that is, within a range of 1/3 of the interval d.

  Referring to FIG. 2, the third rib 53 is formed integrally with the intake pipe 21 and the head side flange 10 over the second rib 52, the intake pipe 21 and the head side flange 10. The entire third rib 53 extending from the upstream end 53a toward the downstream end 53b is closer to the center axis L1 between the intake manifold 25 and the head side flange 10, that is, on the intake pipe 21. On the side, it extends substantially in a straight line substantially along or substantially parallel to the central axis L1.

  Of the both end portions 53 a and 53 b of the third rib 53, the upstream end portion 53 a is connected in the middle of the second rib 53, and the downstream end portion 53 b is connected to the head side flange 10. The first rib 51 extends in a straight line between both end portions 53a and 53b. The upstream end is located at the same position as the boss 61 in the cylinder arrangement direction in the second rib 52, and between the upstream end 21a and the portion where the second rib 52 straddles the central axis L1 in the separation direction. To position.

  In the head-side flange 10, the downstream end 52b of the second rib 52 located farther from the downstream end 21b of the intake pipe 21 and the downstream end of the third rib 53 located closer to the downstream end 21b. The part 53b is located at a position sandwiching the downstream end 21b in the cylinder arrangement direction, and is located farther and closer to the downstream end 21b in the cylinder arrangement direction, respectively. For this reason, the second rib 52 and the third rib 53 longer than the second rib 52 constitute a y-shaped rib in the specific direction view.

  The fourth rib 54 is formed integrally with the intake manifold 25, the intake pipe 24, and the head side flange 10 over the intake manifold 25, the intake pipe 24, and the head side flange 10. Of the both end portions 54a and 54b of the fourth rib 54, the upstream end portion 54a is connected to the end portion 55b of the fifth rib 55 in the cylinder arrangement direction, and the downstream end portion 54b is connected to the head side flange 10. The fourth rib 54 extending from the upstream end portion 54a toward the downstream end portion 54b extends in a straight line between the both end portions 54a and 54b across the central axis L4. The upstream end portion 54a is located farther from the central axis L4, and the downstream end portion 54b is located closer to the downstream end portion 24b.

  Referring to FIGS. 2 and 4, the fifth rib 55 is formed integrally with the intake air collecting portion 25. In the fifth rib 55, one end portion 55a in the cylinder arrangement direction, that is, the adjacent end portion is connected to the boss portion 61, and the other end portion, that is, the far end portion 55b is an intake assembly. It is connected to a protrusion 63 provided integrally with the portion 25. A support that supports the intake manifold M by being attached to the cylinder block 1 in the middle of the fifth rib 55 and at a position corresponding to the center of the arrangement of the first to fourth intake pipes 21 to 24 in the cylinder arrangement direction. Another boss portion 62 to which a stay as a member is attached is integrally formed.

  Referring to FIG. 2, the first rib 51 or the second rib 52, the head side flange 10, the fourth rib 54, and the fifth rib 55 are connected to each other so as to form one side of a quadrangle to form a frame-structured rib. To do. The quadrangle is a trapezoid having the head-side flange 10 and the fifth rib 55 as two substantially parallel sides and the first rib 51 or the second rib 52 and the fourth rib 54 as the remaining two sides.

  Referring to FIGS. 2 and 6, the sixth rib 56 is formed integrally with the intake air collecting portion 25, the intake pipe 22, and the head side flange 10 over the intake air collecting portion 25, the intake pipe 22, and the head side flange 10. And are provided integrally. The sixth rib 56 extending from the upstream end portion 56a toward the downstream end portion 56b is located between the intake air collecting portion 25 and the head side flange 10 so that the entirety thereof overlaps the central axis L2 when viewed in a specific direction. It extends slightly curved.

  Referring to FIGS. 2, 6, and 8, the seventh rib 57 spans the intake air collecting portion 25, the intake pipe 23, and the head side flange 10, and the intake air collecting portion 25, the intake pipe 23, and the head side flange 10. Are integrally formed with each other. The seventh rib 57 extending from the upstream end portion 57a toward the downstream end portion 57b is located between the intake air collecting portion 25 and the head side flange 10 so that the entirety thereof overlaps the central axis L3 when viewed in a specific direction. It extends slightly curved.

Referring to FIGS. 1, 2, and 6 to 8, the first and second ribs 51 and 52 have apexes 51c and 52c that connect the apexes of the upstream ends 51a and 52a and the apexes of the downstream ends 51b and 52b. Since the rib has a height substantially located on a straight line and is higher than the sixth and seventh ribs 56 and 57 having the top portions 56c and 57c, the rigidity of the first and second intake pipes 21 and 22 is increased. Contribute.
Referring to FIG. 4, the fifth rib 55 gradually increases from the far end 25b toward the close end 25a, thereby contributing to high rigidity in the vicinity of the throttle flange 26.

Next, operations and effects of the embodiment configured as described above will be described.
According to the structure of the reinforcing rib of this embodiment, the vibration suppressing effect on the throttle device 5 including the throttle body 5a attached to the throttle side flange 26 is improved by the high rigidity by the structure described below.

  The reinforcing ribs are integrally provided across the first and second intake pipes 21 and 22 and the head side flange 10 which are two or more intake pipes including the intake collecting portion 25 and the first intake pipe 21 as the latest intake pipe. The first rib 51 extends across the first and second intake pipes 21 and 22, so that the first and second intake pipes 21 and 22 are connected to the intake assembly portion 25 and the head. By connecting and integrating with the side flange 10 by a first rib 51 provided across the intake pipes 21 and 22, the intake pipe 21 and the intake pipe 21 disposed near the throttle side flange 26 in the cylinder arrangement direction. 22 rigidity is increased.

  The first rib 51 is connected to the intake manifold 25 at the upstream end 51a in the cylinder arrangement direction closer to the throttle side flange 26 than the second intake pipe 22 (that is, closer side), so that the first intake pipe In addition to 21, the first rib 51 integrated with the second intake pipe 22 adjacent to the intake pipe 21 in the cylinder arrangement direction increases the rigidity in the vicinity of the throttle side flange 26. Further, since the upstream end portion 51a is located closer to the center axis L1, the rigidity in the vicinity of the throttle side flange 26 is further enhanced.

  The reinforcing rib includes a second rib 52 provided integrally with the intake air collecting portion 25, the first intake pipe 21, and the head side flange 10, and the second rib 52 straddles the central axis L1 of the intake pipe 21. As a result, the rigidity of the intake pipe 21 is increased by the second rib 52 in addition to the first rib 51, so that the rigidity of the first and second intake pipes 21 and 22 is further increased. The upstream end portion 52a of the second rib 52 is positioned closer to the upstream end portion 51a of the first rib 51, so that the rigidity in the vicinity of the throttle side flange 26 is further increased.

  The reinforcing rib includes a third rib 53 integrally provided across the second rib 52, the intake pipe 21, and the head side flange 10, and the third rib 53 extends substantially along the central axis L1. Since the rigidity of the first intake pipe 21 is increased by the third rib 53 in addition to the first and second ribs 51 and 52, the first and second intake pipes provided across the first rib 51 are provided. The rigidity of 21 and 22 is further increased. The downstream end portion 52b of the second rib 52 and the downstream end portion 53b of the third rib 53 are located farther and closer to the upstream end portion 21b in the cylinder arrangement direction, respectively. By configuring the ribs 52 and 53 as y-shaped ribs when viewed in a specific direction, the rigidity of the first and second intake pipes 21 and 22 provided across the intake pipe 21 and thus the first rib 51 is increased. Increased further.

  Since the first to third ribs 51 to 53 included in the reinforcing rib are straight ribs, there is no decrease in rigidity due to the ribs having a bent portion, so the straight first ribs 51 are provided across the straight ribs. The rigidity of the first and second intake pipes 21 and 22 and the rigidity of the intake pipe 21 provided with the straight second and third ribs 52 and 53 are further enhanced.

  The intake air collecting portion 25 is provided with a boss portion 61 to which a stay coupled to the cylinder block 1 is attached on the close side, and the first rib 51 and the second rib 52 are connected to the boss portion 61, thereby Since the rigidity of the boss portion 61 is increased because it is connected to the block 1 via the stay, the rigidity in the vicinity of the throttle side flange 26 is further increased by the boss portion 61, and further connected to the boss portion 61. The first and second ribs 51 and 52 increase the rigidity of the first and second intake pipes 21 and 22.

  The head side flange 10 is provided with a plurality of fastening portions 11 into which bolts 13 for coupling the head side flange 10 to the cylinder head 2 are inserted, and the first rib 51 and the second rib 52 are adjacent in the cylinder arrangement direction. In the vicinity of the fastening portions 11a and 11b having high rigidity because they are fastened to the cylinder head 2 by being connected to the head side flange 10 between the fastening portions 11a and 11b and close to the fastening portion 11b and the fastening portion 11a, respectively. Since the first and second ribs 51 and 52 are connected to each other, the rigidity of the first and second intake pipes 21 and 22 is increased.

  The thickness t1 of the intake pipes 21 and 22 is larger than the intake pipe 23 and the intake pipe 24 as the farthest intake pipe, so that the rigidity of the intake pipes 21 and 22 is increased.

  The first rib 51 or the second rib 52, the head side flange 10, the fourth rib 54, and the fifth rib 55 are connected so as to form one side of the quadrangle, whereby the first rib 51 or The rigidity of the intake manifold M is increased by the ribs having a rectangular frame structure formed by the second rib 52, the fourth rib 54, the fifth rib 55, and the head side flange 10.

  A throttle-side flange 26 is provided at an end 25a of the intake air collecting portion 25, and is an end intake pipe located at the end on the close side among the four intake pipes 21 to 24 having a predetermined number of the latest intake pipes. With the certain first intake pipe 21, the intake manifold M to which the throttle device 5 is attached to the end portion 25a exhibits an excellent vibration suppressing effect on the throttle device 5.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The first rib 51 may be provided over three or more intake pipes including the most recent intake pipe, such as the first intake pipe 21 and the second and third intake pipes 22 and 23.
The first to fourth ribs 51 to 54 may have bent portions on the corresponding intake pipes 21, 22, 24 between the intake air collecting portion 25 and the head side flange 10 in a specific direction.
Only one of the first and second ribs 51 and 52 may be connected to the boss portion 61. Further, only the first rib 51 may be connected in the vicinity of the tightening portion 11b, or only the second rib 52 may be connected in the vicinity of the tightening portion 11a.
The multi-cylinder internal combustion engine may include a plurality of cylinders other than four, and may be a V-type or a horizontally opposed internal combustion engine in which one bank includes a plurality of cylinders.
The predetermined number is not necessarily the same as the number of cylinders of the internal combustion engine, and may be a number smaller than the number of cylinders.
The intake manifold may be formed by integrating a plurality of separate members by fixing means such as welding.
The predetermined portion where the throttle side flange 26 is provided may be a portion near the end portion 25a which is a portion included in the one side portion together with the end portion 25a, or the center of the intake air collecting portion 25 in the cylinder arrangement direction. Part.
The throttle valve device may be a carburetor that also serves as a fuel supply device.
The internal combustion engine may be provided with a balancer.
The internal combustion engine is used for a vehicle in the above embodiment, but may be used for a ship propulsion device such as an outboard motor having a crankshaft oriented in the vertical direction. You may use for machines other than a ship propulsion apparatus.

It is a side view when the intake manifold to which the present invention is applied is attached to the engine body. FIG. 2 is a view taken in the direction of the arrow II in FIG. 1 and is a view of the intake manifold as viewed from one side in a specific direction. It is a figure of the principal part in the III arrow view of FIG. It is IV arrow line view of FIG. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. It is the VIII-VIII sectional view taken on the line of FIG.

Explanation of symbols

2 ... cylinder head, 5 ... throttle device, 10 ... head side flange, 21-24 ... intake pipe, 25 ... intake manifold, 26 ... throttle side flange, 51-57 ... rib,
E: Internal combustion engine, M: Intake manifold.

Claims (10)

A head-side flange coupled to a cylinder head of a multi-cylinder internal combustion engine, a predetermined number of intake pipes connected to the head-side flange at a downstream end, and an upstream portion of the predetermined number of intake pipes In an intake manifold comprising an intake air collecting portion, a throttle side flange to which a throttle device provided with a throttle valve provided at a predetermined portion of the intake air collecting portion is attached, and a reinforcing rib,
The reinforcing rib includes two or more intake pipes including the latest intake pipe that is closest to the throttle side flange in the cylinder arrangement direction among the predetermined number of intake pipes, and the head side flange. An intake manifold including a first rib provided integrally thereover, wherein the first rib extends across the two or more intake pipes.   The two or more intake pipes include the nearest intake pipe and an adjacent intake pipe adjacent to the nearest intake pipe in the cylinder arrangement direction, and the first rib is more than the adjacent intake pipe in the cylinder arrangement direction. 2. The intake manifold according to claim 1, wherein the intake manifold is connected to the intake air collecting portion near a throttle side flange.   The reinforcing rib includes a second rib provided integrally over the intake air collecting portion, the nearest intake pipe, and the head side flange, and the second rib straddles the central axis of the nearest intake pipe. The intake manifold according to claim 1 or 2, wherein the intake manifold is provided.   The reinforcing rib includes a third rib that is integrally provided across the second rib, the nearest intake pipe, and the head side flange, and the third rib is substantially along a central axis of the nearest intake pipe. The intake manifold according to claim 3, wherein the intake manifold extends.   The intake manifold according to any one of claims 1 to 4, wherein the rib included in the reinforcing rib is straight.   An attachment portion to which a stay coupled to the engine body is attached is provided near the throttle side flange, and the first rib or the second rib is connected to the attachment portion. Item 6. The intake manifold according to any one of Items 1 to 5.   The head side flange is provided with a plurality of fastening portions into which bolts for coupling the head side flange to the cylinder head are inserted, and the first rib or the second rib is adjacent to the fastening direction in the cylinder arrangement direction. The intake manifold according to any one of claims 1 to 6, wherein the intake manifold is connected to the head side flange between the portions near the fastening portion.   8. The wall thickness of the most recent intake pipe is larger than the farthest intake pipe farthest from the throttle-side flange in the cylinder arrangement direction among the predetermined number of intake pipes. The intake manifold according to claim 1.   The predetermined portion is a portion on one side in the cylinder arrangement direction in the intake manifold portion, and the nearest intake pipe is an end intake pipe located at an end on the one side among the predetermined number of intake pipes. The intake manifold according to claim 1, wherein the intake manifold is provided.   The reinforcing rib includes a fourth rib and a fifth rib that is provided integrally with the intake manifold portion and extends in a straight line in the cylinder arrangement direction. The fourth rib includes the intake manifold portion, Of the predetermined number of intake pipes, the other end in the cylinder arrangement direction is provided integrally with the end-side intake pipe farthest from the throttle-side flange and the head-side flange, and extends in a straight line. The intake manifold according to claim 9, wherein the straight first rib, the head side flange, the fourth rib, and the fifth rib are connected to form one side of a quadrangle. .

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