JPH0322546Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an improvement of an intake manifold having a plurality of independent intake passages connected to each intake port of a multi-cylinder engine.

(Prior Art) An engine intake manifold generally includes a plurality of independent intake passages connected to each cylinder of the engine (see Japanese Utility Model Application Publication No. 171955/1983).

(Problems to be Solved by the Invention) Nowadays, in order to obtain a dynamic effect of intake air, such as an intake inertia effect, an extremely long independent intake passage is required. In this way, as the independent intake passage becomes longer, its rigidity decreases,
Problems arise such as vibration and mutual torsional deformation after assembly into the engine. For this reason, it is conceivable to connect the independent intake passages with each other with a reinforcing member, but simply connecting them with a reinforcing member would only increase the weight of the intake manifold.

On the other hand, in recent engines, negative pressure actuators that use negative pressure as a driving source are increasingly being used for various controls. For this reason, a negative pressure tank is often provided to store the negative pressure generated during engine operation, but this negative pressure tank has a fairly large capacity, and the problem is how to secure the space for its installation.

The present invention was developed in consideration of the above circumstances, and provides an engine intake manifold structure that can improve the rigidity of the intake manifold and solve the problems of installing a negative pressure tank all at once. The purpose is to

(Structure, operation, and effect of the invention) In order to achieve the above-mentioned purpose, the invention has the following structure. That is, in an intake manifold of an engine including a plurality of independent intake passages each extending from a surge tank and independently connected to the intake port of each cylinder, a reinforcing member is provided that interconnects each of the independent intake passages, The reinforcing member has a closed cross-section structure, and its internal space is connected to the surge tank via piping, thereby forming a negative pressure storage chamber that is connected to each independent intake passage only through the surge tank, and The configuration is such that a negative pressure storage chamber is attached to the independent intake passage and serves as a negative pressure supply source to a negative pressure operated actuator for switching the flow path of the intake passage.

In this way, since the independent intake passages are interconnected by the reinforcing member, their rigidity can be improved.

Moreover, since this reinforcing member also functions as a negative pressure tank, weight reduction and installation space can be reduced compared to the case where the reinforcing member and the negative pressure tank are separately provided.

Furthermore, the negative pressure storage chamber within the reinforcing member is supplied with negative pressure from the surge tank and is not directly supplied with negative pressure from the independent intake passage, so it is not affected by intake pulsation. This is preferable for ensuring reliable operation of the negative pressure actuator. In particular, negative pressure actuators are mounted in independent intake passages and located close to the negative pressure reservoir, meaning they cannot be spaced far enough from the negative pressure reservoir to sufficiently absorb intake pulsations. It is particularly advantageous that the pressure reservoir itself is not affected by inspiratory pulsations.

Furthermore, since the reinforcing member does not have a communication port for the independent intake passage, sufficient strength can be ensured accordingly, which is preferable in terms of further weight reduction.

(Example) An example of the present invention will be described below based on the attached drawings.

In FIG. 1, reference numeral 1 indicates an in-line four-cylinder engine body. This engine body 1 has intake ports 2 that open independently to each cylinder (not shown).
1a is opened on one side of the engine body 1, and an exhaust port (not shown) is opened on the other side of the engine body 1, which is a so-called cross-flow type.

A surge tank 3 is disposed on one side 1a of the engine body 1. This surge tank 3
extends in the cylinder arrangement direction (direction perpendicular to the plane of the paper) as a whole, and is an integrally molded product of the first surge tank 4 and the second surge tank 5. That is, the surge tank 3 made of this integrally molded product is divided into a first chamber 4A for the first surge tank 4 and a second chamber for the second surge tank 5 by the partition wall 3a extending in the cylinder arrangement direction. 5A. The second surge tank 5 is arranged at a position slightly lower than the first surge tank 4 and slightly offset in a direction away from the engine main body 1.

The first surge tank 4 is individually connected to each intake port 2 via long first intake passages 6 that are independent from each other. Further, the second surge tank 5 is connected to each intake port 2 via mutually independent second intake passages 7. 1st above
The intake passage 6 includes a passage portion 3b integrally formed with the surge tank 3, and an intake pipe 8 connecting the passage portion 3b and the intake port 2. The first intake passage 6 generally extends from the first surge tank 4 in a direction away from one side 1a of the engine body 1, and then curves downward for approximately 180 degrees.
It is shaped so that it is inverted once and passes below the surge tank 3 to reach the intake port 2, thereby ensuring a sufficient length.

On the other hand, the second intake passage 7 is substantially constituted by a branch pipe 8a branched from the upstream end of the intake pipe 8, and a second surge tank 5 opens downward.
is connected to the lower end surface of. That is, the second surge tank 5 (second chamber 5A) and the branch pipe 8a are configured by effectively utilizing the dead space formed by the first surge tank 4 and the first intake passage 6.

A shutter valve 9 as a passage switching means is disposed within the branch pipe 8a. The shutter valve 9 is opened and closed by an actuator, which will be described later, depending on the engine speed, and is closed when the engine is running at low speeds and opened when the engine is at high speeds.

Note that 10 is a fuel injection valve, and 11 is a delivery pipe.

Here, in the embodiment, the intake air is supplied only to the first surge tank 4, and therefore, the dual throttle body 12
is connected to the first surge tank 4. Of course, the pair of throttle valves 13 and 14 disposed in the throttle body 12 are one for low load and the other for high load, and when the engine load is low, only one throttle valve opens and the engine load is reduced. When the value exceeds a predetermined value, the other throttle valve also begins to open.

As shown in FIG. 2, the intake pipes 8 constituting the independent intake passage 6 are connected to each other by a reinforcing member 21 extending in the cylinder arrangement direction. This reinforcing member 21 has an internal space having a substantially rectangular cross section, and this internal space is used as a negative pressure storage chamber S.
That is, the negative pressure storage chamber S, via the piping 22,
Although not shown, a check valve connected to the first surge tank 4 (first chamber 4A) and in the middle of this piping prevents the flow of negative pressure from the negative pressure storage chamber S to the first surge tank 4. is connected. As a result, the load in the first surge tank 4 that occurs as the engine operates is stored in the negative pressure storage chamber S. Such a reinforcing member 21 is used for the intake pipe 8
The negative pressure storage chamber S is integrally formed by casting.
The openings at both ends, which are formed to discharge the core for forming the core, are closed by plugs 23 (see FIG. 2). In the embodiment, in order to ensure that the negative pressure storage chamber S is continuous and long in the cylinder arrangement direction, the substantially lower half of the reinforcing member 21 is located below the intake pipe 8, and the substantially upper half thereof is located below the intake pipe 8. It is integrally connected to the side wall of the intake pipe 8. However, the negative pressure storage chamber S is not in direct communication with the independent intake passage 6 (there is no communication port for the independent intake passage 6), and is connected to (the second chamber 4A of) the surge tank 3 via piping 22. The air intake passage 6 is connected to the independent intake passage 6 only through the air intake passage 6.

The shutter valve 9 is driven to open and close by a negative pressure actuator 31. That is, a mounting seat 8b is formed on the side surface of the intake pipe 8 located at one end in the cylinder arrangement direction (see FIG. 2), and the actuator 31 is fixed to this mounting seat 8b via a bracket (not shown). There is. On the other hand, a rotary shaft 32 for attaching a shutter valve 9 is rotatably supported in the intake pipe 8 while extending in the cylinder arrangement direction (this bearing portion is shown as 8c in FIG. 2). And the rotating shaft 32
and the rod 33 of the actuator 31 are connected via a link 34. Of course, the negative pressure chamber of the actuator 31 is connected to the negative pressure storage chamber S via a piping (not shown) as is known, and an electromagnetic switching valve is connected in the middle of this piping to adjust the pressure according to the engine speed. , the negative pressure supply to the actuator 31 is controlled.

In the above configuration, when the engine is running at low speed, the shutter valve 9 is closed and the equivalent intake pipe length is from the intake port 2 to the first intake passage 6.
The long path leading to the surge tank 4 provides an intake inertia effect synchronized with low engine rotation. In addition, when the engine is running at high speed, the shutter valve 9 is opened, and the equivalent intake pipe length is a short path from the intake port 2 to the second surge tank 5 via the second intake passage 7. Effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a side sectional view taken along the line of FIG. FIG. 2 is a plan view of the independent intake passage with the surge tank removed. Figure 3 is a plan view of the surge tank. 1...Engine body, 2...Intake port, 6...
...Independent intake passage, 21...Reinforcement member, 31...Negative pressure actuator.

Claims (1)

[Scope of Claim for Utility Model Registration] In an engine intake manifold, which has a plurality of independent intake passages each extending from a surge tank and independently connected to the intake port of each cylinder, the independent intake passages are interconnected. A double reinforcing member is provided, and the reinforcing member has a closed cross-section structure, and an internal space thereof is communicated with the surge tank via piping, so that a negative air passage connected to each independent intake passage only via the surge tank is provided. A pressure storage chamber, and the negative pressure storage chamber serves as a negative pressure supply source to a negative pressure actuator that is attached to the independent intake passage and switches the flow path of the intake passage. The intake manifold structure of the engine.