JPH0740659Y2 - Intake passage structure for variable intake control of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the structure of an intake system in an internal combustion engine (hereinafter, "internal combustion engine" is referred to as "engine" as necessary),
In particular, the present invention relates to an intake passage structure for variable intake control of an internal combustion engine, which is installed in a variable intake control system that changes a passage length to obtain a sufficient intake amount in a wide engine speed range.

[Prior Art] Conventionally, in an engine having a variable passage length intake system, that is, in an engine having an intake system in which a pair of intake passage portions having different passage lengths are arranged in parallel, one of these intake passage portions is used. By providing a variable intake control valve that can change the effective intake passage length by selecting, when the engine speed is relatively low, the control valve is switched so that the effective intake passage length becomes longer, while the engine speed When is relatively high, a variable intake control system has been proposed in which the control valve is switched so that the effective intake passage length is shortened to obtain a high output over a wide engine speed range.

As a structure of the intake passage in such a variable intake control system, a structure shown in FIGS. 7 and 8 is considered.

In FIGS. 7 and 8, 2'is an intake passage, and the intake passage 2 is provided with an intake manifold 11 '. This intake manifold 11 'is composed of an upper intake 11A' on the upstream side and a lower intake 11B on the downstream side, and the upper intake 11A 'is provided with a bypass pipe 11C' constituting a passage length extension. .

Inside the upper intake 11A ′, a surge tank 2a is provided at the inlet portion thereof, and the lower intake 11A is provided at the downstream portion thereof.
A main intake passage 2b 'leading to B is formed. The bypass piping 11C 'is a surge tank for the upper intake 11A'.
It is connected to the portion 2a and has a bypass passage 2c 'formed therein. Further, in the upper intake 11A ', a bypass passage 2d' for connecting the bypass passage 2c 'and the main intake passage 2b' to each other is formed, and a passage length extension portion 14 'is formed from the two bypass passages 2c', 2d '. It is configured.

A variable intake control valve 10 is provided between the surge tank 2a in the upper intake 11A 'and the main intake passage 2b', and when the control valve 10 is switched, it is taken from the air cleaner 6 and passed through the throttle valve 7. The flow path of intake air is a flow path that directly advances from the surge tank 2a into the main intake air passage 2b ', or a flow path that advances from the surge tank 2a into the main intake air passage 2b' via the bypass passages 2c 'and 2d'. Can be selected.

The bypass pipe 11C 'is configured as a member separate from the main body of the upper intake 11A, but this is in consideration of mounting the control valve 10 inside the upper intake 11A. After mounting the control valve 10, ′ is connected to the upper intake 11A so as to have no gap by connection using bolts, welding, or the like.

Further, the bypass pipe 11C 'is formed in a shell type structure in which the bypass passages 2c' are each formed into a substantially arc shape. That is, the bypass passage 2c 'in the pipe 11C' is
As shown in FIGS. 7 and 8, the surge tank 2a is branched into a plurality of pieces (here, six pieces) so that the intake air branches and flows in each cylinder (a six-cylinder engine in this example).
Each of the passages is formed in an arc shape so that the intake air flows in the bypass passage 2c 'relatively smoothly.

In FIGS. 7 and 8, 3 is an exhaust passage, 4 is an intake valve, 5 is an exhaust valve, 8 is an injector, 9 is a catalytic converter, and E is an engine.

With such a structure, if the air from the surge tank 2a is guided to the bypass passage 2c 'side, the effective intake passage length becomes longer by the amount of passing through the bypass passages 2c', 2d ', and the main intake passage 2b'.
If it is guided to the side, the effective intake passage length is shortened, and the variable intake control described above can be performed by the control valve 10.

The control valve 10 is driven by a stepper motor (stepping motor or pulse motor) or a vacuum motor (differential pressure responsive actuator).

[Problems to be solved by the invention] By the way, the intake passage 2 of the intake manifold 11 '
In the conventional intake passage structure for variable intake control of an internal combustion engine, the bypass pipe 11C '
Since the shell type structure is complicated, it is necessary to use a core with a complicated shape (a collapsed core made of sand, etc.) for casting. Casting using such a collapsed core has a problem that the cost is significantly increased.

The present invention is intended to solve such problems, and an object thereof is to provide an intake passage structure for variable intake control of an internal combustion engine, which can be manufactured at low cost.

[Means for Solving the Problems] Therefore, in the intake passage structure for variable intake control of an internal combustion engine according to the present invention, a pair of intake passage portions having different passage lengths are provided in parallel in an intake system of the internal combustion engine. Intake passage,
A variable intake control valve capable of varying the effective intake passage length by selecting one of the intake passage portions, and the passage length extension portion forming the long passage of the intake passage portion is formed in a shell type structure. Thus, the shell type structure is formed by joining the outer wall portion and the inner wall portion that are manufactured separately from each other, the outer wall portion is formed of a metal material, and the inner wall portion is formed of a resin. It is characterized by being formed of a material.

[Operation] In the above-described intake passage structure for variable intake control of the internal combustion engine of the present invention, the shell type structure portion as the passage length extending portion forming the long passage of the intake passage portion is manufactured separately from each other. Further, since the outer side wall portion and the inner side wall portion are connected to each other, the shape of each side wall portion itself is simplified and the manufacturing of this portion is facilitated. Moreover, since the inner wall portion is made of a resin material, the inner wall portion can be manufactured very easily, and the outer wall portion made of metal can be joined by a simple means such as fitting. .

[Embodiment] Hereinafter, an intake passage structure for variable intake control of an internal combustion engine as an embodiment of the present invention will be described with reference to the drawings.
Fig. 2 is a vertical sectional view thereof, Fig. 2 is a sectional view taken along the line II-II of Fig. 1, Fig. 3 is a sectional view taken along the line III-III of Fig. 1 and 4, and Fig. 4 is a plan view thereof. FIG. 5 is a side view thereof, and FIG. 6 is an overall configuration diagram showing an engine system having the main intake passage.

Now, the gasoline engine system having the main intake passage is configured as shown in FIG. In FIG. 6, the engine (internal combustion engine) E is a V-type 6-cylinder engine.

An intake passage 2 and an exhaust passage 3 are connected to a combustion chamber 1 of each cylinder of the engine E (the ignition portion of a spark plug is exposed in the combustion chamber 1).
The intake passage 2 and each combustion chamber 1 are controlled to communicate with each other by an intake valve 4, and the exhaust passage 3 and each combustion chamber 1 are connected to an exhaust valve 5
The communication is controlled by.

Further, in the intake passage 2, the air cleaner 6,
A throttle valve 7 and an electromagnetic fuel injection valve (electromagnetic valve; injector) 8 are provided, and a catalyst converter (three-way catalyst) 9 for purifying exhaust gas and a muffler (not shown) are arranged in the exhaust passage 3 from the upstream side thereof. Muffler) is provided.

Further, injectors (electromagnetic valves) 8 are provided in the intake manifold portion by the number of cylinders. Since the engine E of this embodiment is a V-type 6-cylinder engine, six electromagnetic valves 8 are provided. That is, it can be said that the engine is a so-called multipoint fuel injection (MPI) type engine.

Further, the throttle valve 7 is connected to an accelerator petal in the vehicle compartment via an accelerator cable, so that the throttle valve 7 can be rotated according to the amount of depression of the accelerator petal.

By the way, in the intake passage 2, as shown in FIGS.
An intake manifold 11 is provided, and this ten manifold 11 is composed of an upper intake 11A on the upstream side and a lower intake 11B on the downstream side.
1A has a bypass pipe 11 that constitutes the passage length extension 14.
C is attached. These are mainly made of an aluminum material.

Inside the upper intake 11A, a surge tank 2a is provided at the inlet portion thereof, and the lower intake 11B is provided at the downstream portion thereof.
A main intake passage 2b leading to is formed. The bypass pipe 11C is connected to the surge tank 2a of the upper intake 11A, and a bypass passage 2c is formed inside. Further, in the upper intake 11A, a bypass passage 2d is formed which connects and connects the bypass passage 2c and the main intake passage 2b. In addition, two bypass passages 2c, 2
A passage length extension 14 is formed from d.

A variable intake control valve 10 is provided between the surge tank 2a in the upper intake 11A and the main intake passage 2b.
By switching the control valve 10, as a flow path of intake air taken from the air cleaner 6 and passing through the throttle valve 7,
A flow path that goes directly from the surge tank 2a into the main intake passage 2b,
Alternatively, it is possible to select a flow path from the surge tank 2a to the main intake passage 2b via the bypass passages 2c and 2d.

That is, when the control valve 10 is in the closed position shown by the solid lines in FIGS. 1 and 6, the intake air flows through the long intake passage portion passing through the bypass passages 2c and 2d, and the control valve 10 is shown in FIGS. When in the open position indicated by the chain line in Fig. 1, intake air is not allowed to flow through the bypass passages 2c, 2d.
It is designed to flow through a short intake passage that does not go through. The engine output characteristic when the intake air flows through the long intake passage portion via the bypass passages 2c and 2d is the low torque first type when the peak of the engine output torque is on the low rotation side, and the torque fully closed characteristic As a result, the engine output characteristic when the intake air flows through the short intake passage portion that does not pass through the bypass passages 2c and 2d is a high-torque high-torque type where the peak of the engine output torque is on the high rotation side.

Further, in this embodiment, the upper intake 11A is divided into a surge tank 2a, an upstream portion 11a containing the bypass passage 2d, the control valve 10 and a downstream portion 11b downstream thereof,
The upstream portion 11a and the downstream portion 11b are manufactured separately, the coupling flange portions are abutted, and the upper flange 11A is joined by a connection using bolts, welding, or the like without a gap, to form the upper intake 11A.

Further, the bypass pipe 11C is configured as a separate member from the main body of the upper intake 11A, and the pipe 11C is connected to the control valve 10 after mounting the control valve 10 by bolts or welding so that there is no gap. Combined with intake 11A.

Further, the bypass pipe 11C is formed in a shell type structure in which the bypass passages 2c are each formed into a substantially arc shape. That is, the bypass passage 2c in the pipe 11C is
As shown in the figure, the surge tank 2a is branched into a plurality (here, 6) so that the intake air branches and flows in each cylinder (in this example, a 6-cylinder engine). It is formed in an arc shape and is set so that the intake air flows relatively smoothly in the bypass passage 2c.

The pipe (shell type structure) 11C is formed by connecting the outer wall portion 13 and the inner wall portion 12 which are manufactured separately from each other. The outer wall portion 13 is formed of an aluminum material like the other portions of the intake manifold 11,
The inner wall portion 12 is formed of a relatively heat-resistant resin material such as nylon 66 or a fiber reinforced resin obtained by reinforcing nylon 66 with glass fiber or the like.

That is, as shown in FIGS. 1 to 3, the outer wall portion 13 of the pipe 11C is formed with a plurality of (here, six) curved grooves 13a so as to form the outer wall surface of each bypass passage 2c, The pipe 11C and the upper intake 11A are connected to each other on the outside wall portion.
It is formed between the flange-shaped end surface 13b of 13 and the flange-shaped end surface of the upper intake 11A.

On the other hand, the inner wall 12 made of a resin material or the like is provided with a curved groove 12a so as to form the inner wall surface of each bypass passage 2c, and the surge formed by the outer wall 13 and the upper intake 11A. It is built in the space near the tank 2a. Each bypass passage (port cell) 2c is formed by the curved groove 12a and the curved groove 13a of the outer wall portion 13. On the other hand, a surge tank cell 12c forming a part of the surge tank 2a is formed in the outer peripheral direction of the inner wall portion 12.

In this example, a total of six inner wall portions 12 are formed independently for each curved groove 12a and are respectively coupled to the outer wall portions 13, but the inner wall portions 12 are plural (for example, two or three).
The bypass passage 2c may be common to all passages, or the entire bypass passage 2c may be integrated. In addition, the inner wall 12 and the outer wall 13
The connection is made by fitting the convex portion 12b formed on the inner side wall portion 12 into the concave portion 13c formed on the outer side wall portion 13, and this coupling is also made by caulking or the like. Good.

Since the intake passage structure for variable intake control of the internal combustion engine as one embodiment of the present invention is configured as described above, the variable intake control can be performed using this intake passage. That is, when the engine speed is relatively low by operating the control valve 10, the passage length extension 14 (that is, the inner wall 12
By using the bypass passage 2c formed by the outer wall 13 and the bypass passage 2d in the upper intake 11A) to lengthen the effective intake passage length, when the engine speed is relatively high, the passage length extension portion By shortening the effective intake passage length without using 14, it is possible to obtain high output over a wide engine speed range.

Further, the shell-type structure bypass pipe 11C forming the passage length extension portion 14 is formed by connecting the outer side wall portion 13 and the inner side wall portion 12, so that the outer side wall portion 13 has a simple shape. Even when the outer wall portion 13 is manufactured by aluminum casting, the core is not used, and it is possible to manufacture the outer wall portion 13 at low cost and with high accuracy by using a die casting method or the like. Further, since the inner side wall portion 12 is made of a resin material or the like, it can be manufactured extremely easily by using a general resin molding method or the like in combination with the simplification of its shape. Furthermore, since the resin inner side wall 12 can be connected to the outer side wall 13 very easily, as a result, the productivity of the pipe 11C can be greatly improved, and the manufacturing cost can be significantly reduced. is there.

There is also an advantage that the intake system can be made lighter.

Furthermore, aluminum casting or resin molding by the die-cast manufacturing method allows the passage inner wall surface to be formed more smoothly than in sand casting, which reduces the ventilation resistance in the intake passage and has the advantage of contributing to improved engine performance. is there.

On the other hand, since the upper intake 11A of the intake manifold 11 of the main intake passage 2 is divided into the surge tank 2a, the bypass passage 2d, and the upstream portion 11a and the downstream portion 11b containing the control valve 10, the casting of each portion is performed. This facilitates the installation of the control valve 10 and can contribute to the reduction of the manufacturing cost from this aspect even in consideration of the connecting process of the two parts 11a and 11b.

The upper intake 11A is connected to the upstream part 11a and the downstream part 11a.
A configuration not divided into b and b (see FIG. 7) is also conceivable.

[Advantages of the Invention] As described in detail above, according to the intake passage structure for variable intake control of an internal combustion engine of the present invention, in the intake system of the internal combustion engine,
An intake passage formed by arranging a pair of intake passage portions having different passage lengths in parallel, and a variable intake control valve capable of varying the effective intake passage length by selecting one of the intake passage portions, A passage length extension portion forming a long passage of the intake passage portion is formed in a shell type structure, and the shell type structure connects the outer wall portion and the inner wall portion manufactured separately from each other. The following effects and advantages are obtained by a simple configuration in which the outer side wall is formed of a metal material while the inner side wall is formed of a resin material.

There is an advantage that the productivity of the intake passage structure capable of performing desired variable intake control can be greatly improved and the manufacturing cost can be significantly reduced.

The intake system can be made lighter by using resin materials, etc.
When equipped in a vehicle, it can also contribute to improved running performance.

Aluminum casting and resin molding by die casting can be used for the shell type structure part, and the inner wall surface of the passage can be formed smoothly compared with sand casting, which reduces the ventilation resistance in the intake passage and improves engine performance. Contribute to the improvement of.

[Brief description of drawings]

1 to 6 show a variable intake control device for an internal combustion engine as an embodiment of the present invention. FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is a sectional view taken along the line II-II of FIG. , Fig. 3 is II of Fig. 1, 4
I-III arrow sectional view, FIG. 4 is a plan view thereof, FIG. 5 is a side view thereof, FIG. 6 is an overall configuration diagram showing an engine system having a main intake passage, and FIGS. FIG. 7 shows an intake passage structure for variable intake control of the internal combustion engine, FIG. 7 is an overall configuration diagram showing an engine system having this intake passage, and FIG. 8 is a plan view thereof. 1 ... Combustion chamber, 2 ... Intake passage, 2a ... Surge tank,
2b ... main intake passage, 2c, 2d ... bypass passage, 3 ... exhaust passage, 4 ... intake valve, 5 ... exhaust valve, 6 ... air cleaner, 7 ... throttle valve, 8 ... solenoid valve, 9 ... Catalytic converter, 10 ... Variable intake control valve (control valve), 11 ...
Intake manifold, 11A ... Upper intake, 11B
...... Lower intake, 11C ...... Bypass pipe (shell type structure), 11a ...... Upstream part, 11b ...... Downstream part, 12 ...
… Inner wall, 12a …… curved groove, 12b …… convex, 12c …… surge tank cell, 13 …… outer wall, 13a …… curved groove, 13b
...... Flange-shaped end face, 13c ...... recess, 14 ...... passage length extension, E ...... engine.

Claims (1)

[Scope of utility model registration request] In an intake system of an internal combustion engine, an intake passage having a pair of intake passages having different passage lengths, and an effective intake passage length by selecting one of the intake passages. And a variable intake control valve capable of making variable, and a passage length extension portion forming a long passage of the intake passage portion is formed in a shell type structure, and the shell type structure is manufactured separately from each other. A variable internal combustion engine, characterized in that the outer side wall and the inner side wall are joined together, the outer side wall is formed of a metal material, and the inner side wall is formed of a resin material. Intake passage structure for intake control.