JP2020002919A - Intake structure of engine - Google Patents

Abstract

To provide an intake structure of an engine capable of substantially increasing a volume in a box-type intake manifold to cope with strengthening of emission control by improving suction efficiency of each cylinder while receiving spacial restriction by further devising the structure.SOLUTION: An intake structure of an engine includes an intake manifold 1 having a manifold main body portion 2 including one opening 4 having a dimension to cover a plurality of intake ports p, and an air suction port 3, partitioning walls 13 are respectively disposed to partition an internal space 7 of the manifold main body portion 2 between the adjacent intake ports p, p, and communication ports 14 are formed on intake port-side end portions of the partitioning walls 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intake structure used for various engines such as an industrial diesel engine and a construction machine engine, that is, an intake structure of an engine.

  An intake manifold, which is a main component forming an intake structure of an engine, has a structure that branches from one passage on the air supply side to each cylinder (each intake port) as disclosed in Patent Document 1, for example. Things are common.

  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 the above, it has been considered that a box-shaped intake manifold has a sufficient volume so that the intake manifold itself serves as a surge tank common to the cylinders, 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, 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.

  The object of the present invention is to further improve the suction efficiency of each cylinder while accepting that the above-mentioned space is restricted by further structural contrivance, and to substantially cope with the strengthening of exhaust gas regulations. It is an object of the present invention to provide an intake structure of an engine capable of increasing the volume of a mold intake manifold.

The present invention relates to an intake structure of an engine,
A cylinder head having a plurality of intake ports formed therein, an intake manifold having a manifold body portion having one opening sized to cover the plurality of intake ports, and an intake portion for air are provided.
A partition wall for partitioning the internal space of the manifold body between the adjacent intake ports is provided, and a communication port is formed at an end of the partition wall on the intake port side.
In addition, it is advantageous to provide a funnel acting on the intake port.

  According to the present invention, the venturi effect is exerted by reducing the cross-sectional area of the suction passage at the partition wall, the intake pulsation due to the suction-back is attenuated, and the pulsation noise can be reduced. As a means for achieving this, it is only necessary to provide a partition wall for partitioning the internal space of the manifold main body. Can be achieved.

  As a result, it is possible to increase the volume of the substantially box-shaped intake manifold so as to improve the intake efficiency of each cylinder and respond to the tightening of exhaust gas regulations while accepting the restriction of space. A possible engine intake structure can be provided.

Side view showing intake manifold including intake port FIG. 1 is a sectional view taken along line ZZ of FIG. Side view showing intake port and air funnel 3A and 3B show a shape of an air funnel, FIG. 3A is a sectional view taken along line YY in FIG. 3, and FIG. 3B is a sectional view taken along line XX in FIG.

  Hereinafter, an embodiment of an intake structure of an engine according to the present invention will be described with reference to the drawings when applied to a vertical three-cylinder industrial diesel engine.

  1 and 2 show an intake manifold 1. The intake manifold 1 includes a manifold body 2 having an opening 4 corresponding to an intake port p of a cylinder head 12, and an air inlet 3 having an inlet 5. A plurality of (five) bolting portions 6 are formed in the manifold main body 2 to abut the opening end surface 2a of the manifold main body 2 on the intake side surface 12a of the cylinder head 12 and to bolt the same.

  The manifold main body 2 has one horizontally elongated opening 4 having a size to cover the three intake ports p, p, p arranged in series formed in the cylinder head 12, and an outer peripheral flange wall surrounding the opening 4. 2A. The box-shaped intake manifold 1 is attached to the cylinder head 12 by bolts 11 passed through bolting portions 6 with the opening end surface 2a of the outer peripheral flange wall 2A abutting on the intake side surface 12a of the cylinder head 12. Can be mounted.

  The suction section 3 is provided at a position largely deviated in the longitudinal direction (longitudinal direction of the opening 4) with respect to the manifold body 2, and the suction port 5 and the opening 4 are opened in opposite directions. The inside of the manifold body 2 is formed as a suction passage 7 which is one internal space that connects one cylindrical suction port 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 suction passage 7 is formed as a place surrounded by the back surface 8s of the upper wall 8, the back surface 9s of the lower wall 9, the back surface 10s of the back wall 10, and the like. As shown in FIG. 2, a seal material accommodating groove 17 that opens on the opening end face 2a is provided around the outer peripheral flange wall 2A.

  As shown in FIG. 1, the air sucked in from the suction port 5 flows through the suction path 7 as indicated by arrows a, b, and c, and flows from the opening 4 to the three suction ports p (see also FIG. 3). become. In FIG. 1 and the like, the side with the suction unit 3 is the rear, and the opposite side is the front. In FIG. 2 and the like, the opening 4 side is left and the back wall 10 side is right.

[Embodiment 1]
The partition wall 13 will be described.
As shown in FIGS. 1 and 2, a partition wall 13 is provided for partitioning the intake path 7 of the manifold body 2 between adjacent intake ports p, and an end of the partition wall 13 on the intake port side. A communication port 14 is formed in the portion. The communication port 14 is provided at the center in the width direction (vertical direction) of the end (left end) of the partition wall 13 on the side of the intake port p (left end). Therefore, the partition wall 13 is viewed from the side (front and back). Is formed in a U-shape (or U-shape) that is open to the intake port p side (left side).

  The partition walls 13 are provided at two locations between the three intake ports p, that is, between the first intake port p1 and the second intake port p2, and between the second intake port p2 and the third intake port p3. ing. With these two partition walls 13, 13, the suction path 7 is in a state of being divided into a first space 7A, a second space 7B, and a third space 7C. The first space portion 7A and the second space portion 7B are communicated with each other through a communication port 14 of a front partition wall 13, and the second space portion 7B and the third space portion 7C are communicated with each other through a communication port 14 of a rear partition wall 13. Are in communication.

  The partition wall 13 may be formed integrally with the manifold main body 2, or may be formed as another component attached to the manifold main body 2. Further, the position and shape of each partition wall 13 in the direction in which the intake ports are arranged (front-back direction) can be arbitrarily changed and set. Further, the thickness of the partition wall 13 can also be appropriately selected and set.

  The communication port 14 is a notch formed in the partition wall 13 in FIG. 2, but may be formed by one large hole or a plurality or a small number of small holes. Further, the communication port 14 may be formed by both the notch and the hole. The wall surfaces 13a, 13a of the partition wall 13 are preferably parallel to each other or flat surfaces. However, the thickness of the partition wall 13 may be changed so as to have a drum shape or a barrel shape when viewed in the left-right direction.

The function and effect of providing the partition wall 13 will be described.
Since the first to third space portions 7A, 7B, 7C separated by the partition wall 13 are communicated with the communication port 14 having a sufficiently small area (cross-sectional area) as compared with the partition wall 13, the venturi by the communication port 14 is provided. The effect is exhibited, and the air of the volume of the intake port p other than the intake port p of the intake cylinder can be sucked. In other words, by reducing the cross-sectional area of the suction passage 7 by the partition wall 13, the intake pulsation due to the suction-back is attenuated, and the pulsation noise can be reduced.

  The first to third space portions 7A, 7B, 7C partitioned by the partition wall 13 function as a surge tank for the corresponding intake ports p1, p2, p3, and intake interference at the time of intake of each cylinder is reduced. Thus, the amount of intake air can be increased. Therefore, it leads to improvement of output and reduction of exhaust gas, especially PM, and it becomes possible to respond to a higher level by strengthening exhaust gas regulations.

[Embodiment 2]
The air funnel 15 will be described.
As shown in FIGS. 3 and 4, a cylinder head 12 in which three (one example) intake ports p1, p2, and p3 are formed is provided. The cylinder head 12 has five female threads 18 to which bolts 11 can be screwed, and the intake manifold 1 can be bolted using the five bolts 11.

  The intake manifold 1 is a box-shaped intake manifold 1 (see FIG. 1) having a manifold body 2 having one opening 4 sized to cover the three intake ports p1, p2, and p3 and an air intake 3. . The imaginary line e in FIG. 3 shows the outline of the intake manifold 1 attached to the cylinder head 12. The cylinder head 12 is provided with an air funnel (an example of a funnel) 15 acting on each of the intake ports p (p1, p2, p3).

  As shown in FIGS. 3 and 4A and 4B, the air funnel 15 includes a funnel action portion 15A having an inner guide surface 19 extending on the wrapper, and a fitting base for attaching to the cylinder head 12. 15B having a rectangular annular shape when viewed in the left-right direction. The funnel 15 is provided such that the funnel action portion 15A protrudes from the intake side surface 12a of the cylinder head 12 to the intake manifold 1 side (right side), that is, into the intake passage 7 of the intake manifold 1.

  The guide inner peripheral surface 19 is provided with a flowering curve R that opens more toward the distal end side (right side), and can exhibit a smooth air introduction action. In addition, in FIG. 4, although the front-end | tip part (right end) of 15 A of funnel action parts is drawn as being angular, it is preferable that it is rounded. Since the outer surface 20 of the funnel action portion 15A protrudes forward and backward and up and down from the outer surface 21 of the fitting base 15B, a step surface 16 is formed between these two 20 and 21.

  The cylinder head 12 is formed with a mounting recess 22 in which the inner circumference of the inlet side end (the end on the intake side surface 12a side) of the intake port p is increased by one step. Therefore, the air funnel 15 is supported by fitting the fitting base 15B into the mounting recess 22 by press fitting or the like. It should be noted that the cylinder head 12 may be attached to the cylinder head 12 by means other than press fitting, such as cold fitting or bolting. As shown in FIG. 4, the guide inner peripheral surface 19 of the fitting base 15B and the inner peripheral surface 23 of the intake port p are flush with each other, but need not be so.

The function and effect of providing the air funnel 15 will be described.
Each of the intake ports p1, p2, and p3 employs an air funnel 15 to enhance the shape of the air introduction, thereby promoting the intake of air, and increasing the amount of intake to the intake port p without increasing the volume of the intake manifold 1. Becomes possible.

  Therefore, not only can the intake air amount be increased, but also the ease of air flow by the air funnel 15 is improved, so that the intake interference at the time of intake of each cylinder is reduced, leading to an improvement in output and a reduction in exhaust gas, especially PM. In addition, it is possible to respond at a high level by strengthening exhaust gas regulations.

  If the air funnel 15 and the partition wall 13 of the first embodiment are used together, the synergistic effect of the two 15 and 13 further enhances the suction efficiency of each cylinder, making it impossible to tighten exhaust gas regulations. It is possible to correspond without.

[Another embodiment]
(1) The number of partition walls 13 may differ depending on the number of cylinders, or two or more partition walls 13 may be provided between adjacent intake ports p.
(2) The wall surface 13a of the partition wall 13 may have irregularities, undulations, or corrugations.
(3) An intake structure provided with both the partition wall 13 and the air funnel 15 may be used.

(4) In the air funnel 15, as shown in FIGS. 4A and 4B, the curvature of the guide inner peripheral surface 19 is different between the cross section and the vertical section, but may be the same.
(5) The protrusion amount of the funnel action portion 15A can be set arbitrarily in relation to the intake manifold 1.
(6) The air funnel 15 can be attached to or supported by the intake manifold 1 by bolting or the like.

DESCRIPTION OF SYMBOLS 1 Intake manifold 2 Manifold main body part 3 Suction part 4 Opening 7 Internal space (suction path)
12 Cylinder head 12a End face 13 Partition wall 14 Communication port 15 Funnel p Intake port

Claims (6)

An intake manifold having a manifold body having one opening sized to cover the plurality of intake ports and an air intake is provided.
An intake structure for an engine, comprising: a partition wall that partitions an internal space of the manifold body between adjacent intake ports; and a communication port formed at an end of the partition wall on an intake port side.   The communication port is provided at a central portion in the width direction of the end portion of the partition wall at the intake port side, and the partition wall has a U-shape or a U-shape whose side view is open to the intake port side. The intake structure for an engine according to claim 1, wherein the intake structure is formed in a shape. A cylinder head having a plurality of intake ports formed therein, an intake manifold having a manifold main body having one opening sized to cover the plurality of intake ports, and an air intake section are provided.
An intake structure of an engine provided with a funnel acting on the intake port.   The intake structure for an engine according to claim 3, wherein the funnel is provided so as to protrude from an end surface of the cylinder head on the intake manifold side toward the intake manifold.   5. The intake structure for an engine according to claim 3, wherein the funnel is supported by a cylinder head.   The intake structure of an engine according to any one of claims 1 to 5, wherein the intake structure is applied to an in-line three-cylinder engine in which three intake ports are arranged.

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