JPH0649863Y2 - Engine intake passage structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an intake passage structure of an engine in which the charging efficiency of intake air is enhanced by the dynamic effect of intake air.

[Conventional technology]

2. Description of the Related Art Conventionally, various engine intake devices have been known in which the charging efficiency is increased by the dynamic effect of intake air. For example, in the device disclosed in Japanese Examined Patent Publication No. 60-14169, in a multi-cylinder engine, the intake passages of a plurality of groups respectively connected to each cylinder group composed of cylinders whose intake orders are not continuous are provided with independent intake for each cylinder. A large-volume collecting portion to which the upstream end of the passage (intake manifold branch) is connected, and a resonance passage extending upstream from the collecting portion are provided, and the intake passages of each group are connected to each other in the collecting portion. A switching device capable of interrupting communication is provided, and the upstream ends of the resonance passages are connected to the upstream side collection chamber. Then, when the switching device is in a state of shutting off the respective groups from each other, the upstream side collection chamber is provided so that the supercharging action is obtained in the low speed region of the engine by the intake pressure wave reflected in the upstream side collection chamber. The natural frequency of the intake system between the intake port and each intake port is set, and when the switching device is in the state of communicating the intake passages, the inertia by the independent intake passage is relatively high speed. The length of the independent intake passage is set so that the supercharging effect can be obtained.

[Problems to be solved by the device]

According to the conventional intake device as described above, each independent intake passage for each cylinder is formed to be long to a certain extent so that the inertial supercharging effect can be obtained by the independent intake passage in the specific engine speed range, and Since the independent intake passage is connected to the large-capacity collecting chamber, the intake manifold including these parts has a considerable size, and it is difficult to make the intake system sufficiently compact.

Therefore, while reducing the size of the independent intake passage and the collecting portion, a pressure wave is propagated in the range extending over the collecting portion and the passage leading to the independent intake passage so as to have a supercharging action in the rotational speed range where output improvement is required by the pressure vibration. However, also in this case, the intake manifold including the collecting portion and the passage leading to the collecting portion can be made compact, the assembling property with respect to the cylinder head, and the pressure propagation path for providing the supercharging effect in the required operating range. There was a problem to be solved in terms of securing the length of the.

In view of the above circumstances, the present invention can make the intake system a very compact structure while ensuring a sufficient length of the pressure propagation path so that a supercharging effect can be obtained in a desired rotation speed range. In addition, the present invention provides an intake passage structure for an engine that can improve the assemblability to the cylinder head.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides an intake manifold, which is bolted to a cylinder head, extends in the longitudinal direction of the engine close to the wall surface of the cylinder head, and has an intake inlet at one end thereof. Section, which is located on the side opposite to the cylinder head with respect to this collecting pipe section, extends substantially in the same direction as the collecting pipe section, and has one end connected to the inlet side portion of the collecting pipe section and the other end. Is a structure provided with a communication passage connected to a portion of the collecting pipe portion on the side opposite to the inlet side.

[Action]

According to the above configuration, the collecting pipe section and the communication passage form a loop-shaped path for propagating a pressure wave, and the loop-shaped path provides a supercharging action by pressure vibration in a specific rotation speed range. Further, by disposing the collecting pipe portion and the communication passage as in the above configuration, the loop path has a sufficient length, is flat and not bulky, and the upper and lower side portions of the intake manifold are used as the cylinder head. The shape does not interfere with the fastening work when fastening the bolts.

〔Example〕

1 to 3 show an embodiment of the present invention. In these figures, 1 is an engine including a cylinder head 2 and a cylinder block 3, and 10 is the cylinder head 2
It is an intake manifold that is bolted to. The engine 1 shown in the drawing is an in-line four-cylinder engine, and an intake port 5 and an exhaust port (not shown) are arranged in each cylinder 4, and these ports are provided by an intake valve and an exhaust valve (not shown), respectively. It is opened and closed at a predetermined timing. The intake port 5 and the exhaust port are formed in the cylinder head 2.

The intake manifold 10 includes a collecting pipe portion 11 and a communication passage 12. The collecting pipe portion 11 extends in the longitudinal direction of the engine close to the wall surface of the cylinder head 2 and has an intake port 13 at one end portion located laterally of the cylinder head 2. On the side of the collecting pipe portion 11 facing the cylinder head 2, intake outlets 14 communicating with the intake ports 5 of the cylinders 4 are provided at regular intervals, and flanges 15 for attachment to the cylinder head 2 are also provided. The fastening bolt holes 16 are provided on both the upper and lower sides of the flange 15, and the mounting holes 18 for the injectors 17 are provided above the intake ports 14.

A bifurcated tubular connecting member 19 for connecting one end side of the communication passage 12 is coupled to the inlet 13 portion, and an upstream end of the connecting member 19 includes an upstream end including a throttle valve accommodating portion 21 and the like. It is connected to the side intake pipe 20. An opening 22 to which the other end of the communication passage 12 is connected is formed near the end of the collecting pipe 11 on the side opposite to the inlet, facing the side opposite to the cylinder head 2. Further, an opening / closing valve 23 is provided at the inlet 13 portion of the collecting pipe portion 11, and the opening / closing valve 23 is closed in the low speed region of the engine and opened in the high speed region by an operating means (not shown).

On the other hand, the communication passage 12 is located on the opposite side of the collecting pipe portion 11 from the cylinder head 2 and extends substantially in the same direction as the collecting pipe portion 11. One end of this communication passage 12 is an inlet of the collecting pipe portion 11.
It is connected to the portion on the 13 side through the connecting member 19,
The other end of the communication path 12 is bent toward the collecting pipe portion 11, and the tip of the bent portion 12a is connected to the opening 22 on the side opposite to the inlet side of the collecting pipe portion 11. The connecting portion between the tip of the bent portion 12a and the opening 22 has a curved inner surface so that the air passing through the communication passage 12 smoothly flows toward the central portion of the collecting pipe portion 11. .

According to such an intake passage structure of the present embodiment, in the high speed region of the engine, the opening / closing valve 23 is opened, so that the collecting pipe portion 11 and the communication passage 12 whose both ends are connected to form a loop shape. A path is formed, and a pressure wave propagates through this loop-shaped path, and the pressure vibration provides a supercharging action in a high speed range. Then, the intake air is supplied to the collecting pipe portion 11 from the inlet 13 portion on one end side of the collecting pipe portion 11 (arrow A in FIG. 1), and also passes through the communication passage 12 from the opposite inlet side to the collecting pipe portion 11 as well. (Arrow B) and is distributed well to each cylinder. In this case, if the inner surface of the connecting portion between the tip of the bent portion 12a of the communication passage 12 and the opening 22 on the side opposite to the inlet side of the collecting pipe 11 is curved as described above, the distributability of intake air can be enhanced.

On the other hand, in the low speed range where the supercharging action by the loop-shaped path is not sufficiently obtained, the on-off valve 23 is closed, so that the intake air is supplied to the collecting pipe portion 11 through the communication passage 12 and the pressure transmission state. Is changed to adjust the dynamic effect to adapt to the low speed range.

In particular, with respect to the collecting pipe portion 11 that extends in the longitudinal direction of the engine 1 close to the cylinder head 2, both ends of the communication passage 12 that extends in substantially the same direction as this are connected to the inlet 13 side and the counter inlet side. As a result, while the intake manifold 10 has a compact structure, the length of the communication passage 12 that serves as a passage for low speed and the length of the loop-shaped passage that serves as a pressure propagation passage in the high speed region are sufficient. Can be long.

Further, since the communication passage 12 is located on the side opposite to the cylinder head 2 with respect to the collecting pipe portion 11 and these are arranged so as not to be bulky in the vertical direction, when the intake manifold 10 is attached to the cylinder head 1. This simplifies the work of bolting the upper and lower sides of the flange 15 in which the bolt holes 16 are arranged.

4 and 5 show another embodiment of the present invention. Also in this embodiment, the intake manifold 30, which is bolted to the cylinder head 2, extends in the longitudinal direction of the engine 1 close to the wall surface of the cylinder head 2 and has an intake port 33 at one end thereof.
And a communication passage 32, which is located on the side opposite to the cylinder head with respect to the collecting pipe portion 31 and has both ends connected to the inlet 33 side and the opposite inlet side of the collecting pipe portion 11. An on-off valve 43 which is opened and closed according to the engine speed is provided in the communication passage 32 although the structure is provided. According to this structure, the communication passage 32 is closed by the on-off valve 43 at low speed, and the passage from the inlet 33 portion to the collecting pipe portion 31 becomes a low speed passage, which is more than the embodiment shown in FIGS. 1 to 3. Since the low speed passage is shortened, such a structure may be used when it is desired to bring the dynamic effect of the low speed passage to the high speed side to some extent. Further, when it is desired to further increase the length of the loop-shaped path formed by the communication passage 32 and the collecting pipe portion 31 when the opening / closing valve 43 is opened, as shown in FIG. 4 and FIG. The one end side portion 32a of the passage 32 may be bent laterally of the cylinder head 2 so as to be along the end surface of the cylinder head 2.

[Effect of device]

As described above, according to the present invention, the collecting pipe portion, which extends in the longitudinal direction of the engine in the vicinity of the wall surface of the cylinder head and has the intake inlet at one end thereof, is provided on the opposite side of the collecting pipe portion from the cylinder head. A communication path that is positioned and extends substantially in the same direction as the collecting pipe portion and both ends thereof are connected to the inlet side portion and the non-inlet side portion of the collecting pipe portion forms a loop-shaped path for propagating a pressure wave. As a result, the dynamic effect of this loop-shaped path provides a supercharging effect, and in particular,
While having a very compact structure, it is possible to secure a sufficient length of the loop-shaped path so that a dynamic effect can be obtained in a desired rotational speed range. Moreover, since the collecting pipe portion and the communication passage are arranged so as not to be bulged in the vertical direction, the effect of improving the assembling property of the intake manifold including the collecting pipe portion and the communication passage to the cylinder head, etc. Will bring about.

[Brief description of drawings]

1 is a plan view of an intake passage structure according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a schematic front view thereof, and FIG. 4 is an intake passage structure according to another embodiment. A schematic plan view and FIG. 5 are schematic front views. 1 ... Engine, 2 ... Cylinder head, 10,30 ... Intake manifold, 11,31 ... Collecting pipe part, 12,32 ... Communication passage, 13,33 ... Inlet of collecting pipe part.

Claims (1)

[Scope of utility model registration request] 1. A collecting pipe part having an intake manifold which is bolted to a cylinder head, extends in the longitudinal direction of the engine close to the wall surface of the cylinder head, and has an intake inlet at one end thereof, and to this collecting pipe part. On the other hand, it is located on the opposite side of the cylinder head and extends substantially in the same direction as the collecting pipe section, and
An intake passage for an engine, characterized in that it has a structure in which one end is connected to the inlet side portion of the collecting pipe portion and the other end is connected to the opposite inlet side portion of the collecting pipe portion. Construction.