JP2020002921A - Intake manifold - Google Patents

Abstract

To provide an intake manifold capable of substantially enlarging a volume to cope with strengthening of emission control by improving suction efficiency of each cylinder while receiving restriction on a space of an installation place by further devising a structure.SOLUTION: An intake manifold 1 includes a manifold main body portion 2 including one opening 4 formed with a dimension to cover all of a plurality of intake ports p, and an air suction portion 3, and wall surfaces 8s, 9s, 10s and/or inner surface 5A of the intake portion 3 forming an internal space 7 of the manifold main body portion 2 are mirror-finished.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an improvement of an intake manifold used for various engines such as an industrial diesel engine and a construction machine engine.

  As disclosed in Patent Document 1, for example, an intake manifold of an engine generally has a structure that branches from one passage on an air supply side to each cylinder (each intake port).

  In the case of an industrial engine, for example, a small diesel engine for developing countries or low-priced models, in order to save cost and space, one large opening (intake air) covering each intake port without being separated for each cylinder. An intake manifold having an outlet, that is, a so-called box-shaped intake manifold is also frequently used (see Patent Document 2).

JP-A-2007-321641 JP 2001-329923 A

  The box-shaped intake manifold has an intake passage formed by one internal space without branching for each intake port, and thus has a surface that is easily affected by a pulsating wave flowing backward from another intake port. If this effect is large, the amount of air suctioned into the intake port will be smaller than the expected amount, and the combustion state will deteriorate, leading to the inconvenience of increasing black smoke and PM in diesel engines.

  In view of this, it has been considered that a box-shaped intake manifold is provided with a sufficient volume so that the intake manifold itself serves as a surge tank common to each cylinder, thereby reducing intake interference and increasing the intake amount. When the suction amount increases, not only the output can be improved, but also the exhaust gas such as PM can be reduced, and the advantage that the exhaust gas regulation can be strengthened can be obtained.

  However, in the small diesel engine, the injection pump is provided near the intake port at the end of the plurality of cylinders, and the space around the intake port is limited due to the layout of the fuel injection pipe. Therefore, regardless of the branch shape or the box shape, the shape of the intake manifold must be adapted to the limited space, and there is a problem that it is difficult to take a sufficient volume. This problem is more pronounced when the intake manifold is box-shaped.

  It is an object of the present invention to further improve the suction efficiency of each cylinder and to cope with the strengthening of exhaust gas regulations while accepting that the above-mentioned space is limited by a further structural contrivance. The point is to provide an intake manifold that can achieve an expansion of the intake manifold.

The present invention relates to an intake manifold,
A manifold body having one opening sized to cover all of the plurality of intake ports; and an air suction unit, and a wall surface forming an internal space of the manifold body and / or an inner surface of the suction unit. Is mirror-finished.

  It is advantageous if a large number of the fin-shaped projections are formed side by side around the opening side end of the manifold body.

  According to the present invention, since the inner surface of the intake manifold is mirror-finished, the air flow is smooth, and the suction efficiency is improved. Further, since a large number of fin-like projections improve the heat radiation of the opening end of the manifold body, the cooling of the air flowing through the intake port is improved, and the air density can be increased. In other words, this corresponds to substantially increasing the volume of the intake manifold without changing the size.

  As a result, an intake manifold that can substantially increase the volume to improve intake efficiency of each cylinder and respond to stricter exhaust gas regulations while accepting that there are restrictions on the space of the installation location. Can be provided.

Side view from opposite side of opening showing box-shaped intake manifold FIG. 1 is a cross-sectional view taken along line ZZ of FIG. 1 showing a manifold main body. The branched intake manifold is shown, (A) is a partially cutaway plan view, and (B) is a partially cutaway front view of a branch pipe portion.

  Hereinafter, an embodiment of an intake manifold according to the present invention will be described with reference to the drawings, in a case where it is applied to a vertical industrial diesel engine. The present invention can be applied to intake manifolds corresponding to various numbers of cylinders such as two to four cylinders.

  As shown in FIGS. 1 and 2, the intake manifold 1 includes a manifold body 2 having an opening 4 corresponding to an intake port p of a cylinder head 6, and an intake unit 3 having an air intake pipe 5. ing. The manifold main body 2 includes one opening 4 having a horizontally long shape having a size to cover three intake ports p arranged in series formed in the cylinder head 6, and an outer peripheral flange wall 2A surrounding the opening 4. ing.

The suction part 3 is provided at a position largely deviated in the longitudinal direction (longitudinal direction of the opening 4) with respect to the manifold main body part 2, and the intake pipe part 5 and the opening 4 are opened in opposite directions. The inside of the manifold main body 2 is formed as a suction passage 7 which is one internal space that connects one cylindrical intake pipe 5 and the horizontally long opening 4.
The manifold body 2 includes an upper wall 8, a lower wall 9, and a back wall 10, and the opening-side ends of the upper wall 8 and the lower wall 9 are formed on the outer peripheral flange wall 2A.

  The intake manifold 1 can be attached to the cylinder head 6 with five bolts 11 by contacting the outer peripheral flange wall 2A of the manifold body 2 with the intake side surface 6a of the cylinder head 6. The suction section 3 is generally connected to an air cleaner (not shown). The air taken in from the intake pipe part 5 is sucked into the three intake ports p while flowing from the rear to the front in the suction path 7.

  In the outer peripheral flange wall 2A, a seal material accommodating groove 13 opened toward the cylinder head 6 is provided. A bolt stopper 14 having an insertion hole 15 through which the bolt 11 passes is formed as a thick wall along the outer peripheral flange wall 2A. In FIG. 1 and the like, the side with the suction unit 3 is the rear, and the opposite side is the front.

[Embodiment 1]
As shown in FIG. 2, the suction passage 7 is formed by a back surface 8s of the upper wall 8, a back surface 9s of the lower wall 9, a back surface 10s of the back wall 10, and the like. These back surfaces (wall surfaces) 8s, 9s, and 10s are subjected to precision processing and mirror-finished. As an example, the surface roughness Ra is finished to 15 nm or less by grinding. Buffing may be added. Further, the inner peripheral surface (wall surface) 5A of the intake pipe portion 5 may be mirror-finished.

  As shown in FIGS. 1 and 2, a large number of fin-like protrusions 12 are formed around the opening side end of the manifold body 2. Specifically, a large number of thin cooling fin-like protrusions 12 are formed in the outer surfaces of the upper wall 8 and the lower wall 9 near the outer peripheral flange wall 2A. The fin-shaped protrusions 12 are integrally formed with the intake manifold 1, but may be attached as separate components.

  Since the inner surface of the intake manifold 1 is mirror-finished, the air flow is smooth and the intake efficiency is improved. The heat radiation of the end of the manifold body 2 on the opening 4 side is improved by the large number of fin-shaped projections 12, so that the cooling of the air flowing through the intake port p is improved and the air density can be increased. In other words, this corresponds to substantially increasing the volume of the intake manifold 1 without changing its size.

  Since the suction efficiency is improved while being cooled in this way, a large amount of air can be sent to the intake port p as a result. In addition, since the intake efficiency is improved, the intake passage 7 can function as a common surge tank for each intake port p, and in that respect, intake interference during intake of each cylinder can be reduced.

  Therefore, it is possible to increase the amount of suction into the intake port p without changing the size (volume) of the intake manifold 1, and to improve output and reduce exhaust gas, particularly PM, while being an inexpensive means. It is possible to cope with a higher dimension by strengthening exhaust gas regulations.

As a result, the following effects (1) to (8) can be obtained.
(1) Combustion is activated, and the amount of black smoke and PM generated can be reduced.
(2) The combustion is activated, and the fuel consumption rate can be improved.
(3) Combustion is activated, and blue-white smoke in cold weather caused by unburned fuel is suppressed.
(4) The combustion is activated, and the startability in cold weather is improved.
(5) The combustion is activated, the ignition delay period is shortened, the premixed combustion area is reduced, and noise and vibration can be reduced.

(6) Since the air density can be increased, the output can be increased without increasing the displacement.
(7) Since the air density can be increased, the emission of black smoke at high altitudes can be reduced.
(8) Since the intake air temperature can be lowered, the emission amount of NOx is reduced.

[Embodiment 2]
As shown in FIGS. 3A and 3B, the present invention may be applied to a branched intake manifold 1. The intake manifold 1 is for an in-line four-cylinder engine, and has four branch pipes 22 branched from a main pipe (an example of the manifold body 2) 21. Each branch pipe 22 has an opening 4 corresponding to the intake port p.

  An intake inlet pipe 23 is provided from the central portion of the main pipe 21 to the front end of the main pipe 21 along the main pipe 21 with one end of the main pipe 21 as a front and the other end as a rear. (Example of the suction section 3) 27 is provided, and a reverse port 24 is provided at the front end of the intake pipe 23, and the reverse port 24 connects the intake pipe 23 and the main pipe 21 in an inverted manner. 26 is a partition wall.

  The ends on the opening 4 side of each branch pipe 22 are connected and integrated with each other, and a plurality of round holes 25 for bolting to the cylinder head 6 (see FIG. 3B) are formed. A number of fin-like projections 12 are formed around the end of the branch pipe 22 on the opening 4 side. The inner surface 22A of each branch pipe 22 and / or the inner surface 21A of the main pipe 21 are mirror-finished.

  The operation and effect of the branched intake manifold 1 having the mirror-finished suction passage 7 and the like and a large number of fin-shaped protrusions 12 provided around the opening 4 are the same as the operation and effect of the box-shaped intake manifold 1 according to the first embodiment. Are equivalent.

[Another embodiment]
The present invention may be applied to a box-shaped intake manifold used for a two-cylinder diesel engine. In addition, the degree of mirror finish can be arbitrarily selected and set.
The fin-shaped protrusions 12 are regularly formed at regular intervals in FIGS. 1 and 3, but may be irregularly or irregularly spaced, or may be enlarged.

2 Manifold body 3 Suction unit 4 Opening 5A Wall 7 Internal space (suction path)
8 s wall 9 s wall 10 s wall 12 fin-shaped protrusion p intake port

Claims (5)

  An intake manifold comprising: a manifold body having an opening corresponding to an intake port; and an air intake section, wherein a wall surface forming an internal space of the manifold body and / or an inner surface of the intake section are mirror-finished.   The intake manifold according to claim 1, wherein a fin-like projection is formed around an opening-side end of the manifold body.   The intake manifold according to claim 2, wherein a large number of the fin-shaped protrusions are arranged around an opening-side end of the manifold body.   4. The intake manifold according to claim 1, wherein the opening is set to one opening formed to have a size that covers all of the plurality of intake ports. 5.   The intake manifold according to any one of claims 1 to 4, further comprising a manifold body for a two-cylinder or three-cylinder engine in which two intake ports are arranged in series.

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